Micro MediaLab

All of the following are common ways that bloodborne pathogens are transmitted, EXCEPT? Please select the single best answer Sexual contact Drug users sharing needles Airborne particles in schools and offices An infant's exposure to its mother's body fluids

Airborne particles in schools and offices

This species of Candida accounts for around 20 percent of urinary yeast isolates. Please select the single best answer Candida albicans Candida glabrata Candida krusei Candida tropicalis

Candida glabrata

The ideal stool sample for parasitic examination is one that is freshly collected and submitted to the laboratory at: Please select the single best answer Refrigerator temperature (2° C) Incubation temperature (37° C) A temperature of -70° C Room temperature (approximately 22° C)

Room temperature (approximately 22° C) liquid stool should be examined w/in 30 minutes and semisolid stools w/in 60 minutes

Schistosoma species can be differentiated by the shape and location of a spine located on the egg. Which species is paired with the correct location and shape of the spine?

S. mansoni - Large lateral spine S. japonicum - S. haematobium -

All of the following may be typically recovered in positive blood cultures, EXCEPT?

Cryptococcus neoformans

Illustrated in the top photograph is a 4-day growth of silky, light gray-white to yellow colonies grown on Sabouraud's dextrose agar incubated at 30° C, recovered from an "athlete's foot" infection (tinea pedis) of a young football player. Note the projection of delicate hyphae to the periphery of the colonies. The identification can be made by observing the conidia formations in the lactophenol blue stained mount prepared from the surface of one of the colonies. With these observations, select the species identification from the multiple choices.

Epidermophyton floccosum

Trichomonas, Giardia, and Chilomastix belong to which of the following parasitic classifications based on the type of motility?

Flagellates

A fungus culture from a toe-nail scraping demonstrates large, club-shaped macroconidia with no microconidia. The most likely identification is: Please select the single best answer Trichophyton mentagrophytes Microsporum canis Epidermophyton floccosum Trichophyton gypseum

Epidermophyton floccosum

What is the methodology used for detecting the presence of bacteria in blood samples that are loaded onto a BACTEC analyzer?

Fluorescent change

Blood specimens are typically sterile; however, if an organism is suspected, a peptide nucleic acid probe (PNA) FISH can be used to identify the organism directly from the specimen. Which of the following microscopes can be used to exam PNA FISH slides?

Fluorescent microscope

Members of the HACEK group:

Haemophilus (Aggregatibacter aphrophilus), Actinobacillus, Cardiobacterium, Eikenella, Kingella

A vaginal swab for anaerobic culture is received in the laboratory. How should this specimen be handled?

This specimen should be rejected

The bacterial species shown on the blood agar plate illustrated in the photograph was recovered from a blood culture of a patient with fever. The most likely source of infection is which of the following? Please select the single best answer Urinary tract Respiratory tract Indwelling catheter Cutaneous wound

Indwelling catheter

The classic TORCH panel of tests includes the following diseases with the exception of: Please select the single best answer Rubella Toxoplasma gondii Infectious mononucleosis Cytomegalovirus

Infectious mononucleosis

Illustrated in the top image are 10 day old rough, buff, gray-white colonies growing on Middlebrook 7H11 agar. These colonies are commonly recovered from expectorated or induced sputum specimens obtained from patients with signs and symptoms of pneumonia. The appearance of these colonies provide for a presumptive identification, supported by the positive yellow-pigmented niacin reaction seen in the reagent tube in the lower photograph. From these observations, select from the multiple choices the presumptive identification of this isolate. Please select the single best answer Mycobacterium fortuitum Mycobacterium kansasii Mycobacterium tuberculosis Mycobacterium gordonae

Mycobacterium tuberculosis

Why is Mycobacterium tuberculosis not seen on gram stained smears? Please select the single best answer Mycobacterium tuberculosis stains gram-positive, just too light to identify. Mycobacterium tuberculosis is too small to visualize in a gram stain. Mycobacterium tuberculosis has a waxy coating on its surface which prevents gram stain penetration. Mycobacterium tuberculosis have an impervious nucleocapsid.

Mycobacterium tuberculosis has a waxy coating on its surface which prevents gram stain penetration

which otf parasites is/are considered to be a free-living and atrial (organisms that settle outside of the intestinal tract) ameba(e)

Naegleria folweri

A joint fluid was received in the microbiology laboratory. The specimen was cloudy and many neutrophils with intracellular and extracellular Gram negative diplococci were seen on the Gram stain. The specimen was inoculated to sheep blood and chocolate agar and grew a small, grayish white colony on chocolate with no growth observed on the sheep blood. Which of the following is most likely the organism?

Neisseria gonorrhoeae

The colonies observed in the upper image on the right are non-pigmented and dry to chalky. They were recovered from an expectorated sputum sample of an immunocompromised 70-year-old man with pneumonia. The Gram stain shown in the lower image to the right depicts delicate, branching bacilli. Based on this information, what is the most likely identification of this pathogen?

Nocardia asteroides

Identify this suspicious form measuring 50 um, shown here under both low and high power, found in a stool sample.

Psuedoparasite

Abiotrophia defectiva (formerly Streptococcus defectivus) and Granulicatella adiacens (formerly S. adjacens, then A. adiacens) are the names currently given to two species of what were previously called nutritionally variant streptococci (NVS). What supplement must be added to blood culture medium to recover these organisms in cases of "culture negative endocarditis?" Thiamine Pyridoxal SPS Synthetic resins

Pyridoxal NVS/nutritionally deficient steptococci are thiol-requiring/pyridoxal-requiring since they need cyseine or the active form of B6(pyridoxal)

Some strains of Group F Strep can carry the group A antigen, potentially leading to a false positive identification of group A, Streptococcus pyogenes. A spot test that is helpful in differentiating these two species and thus preventing a false report is:

Pyrrolidonyl-b-naphthylamide (PYR)

The dermatophytic fungus shown in this photomicrograph, is recovered from a ringworm lesion of the skin of the back of the hand of an 8-year-old boy. What was the most likely source for this fungus?

soil in the back yard

Isolates of nonmotile and nonpigmented enterococci that are resistant to vancomycin can be assumed to have an acquired resistance by the transfer of which of the following genes?

van A and can B genes

All of the following are Lancefield carbohydrate antigens found on beta-hemolytic Streptococcus species. All of the following antigens are found on organisms from the Streptococcus anginosus group EXCEPT? Please select the single best answer A B F G

B

A CSF shunt specimen was sent to the microbiology laboratory for culture. The shunt specimen was inoculated to chocolate agar and a thioglycollate broth. After two days of incubation in CO2 at 37°C, the chocolate agar had no growth and the thioglycollate broth had growth at the bottom of the tube. The microbiology tech then subbed the thioglycollate broth to an anaerobic blood agar plate and incubated the plate in anaerobic conditions at 37C for 48 hours. After the 48 hour incubation, the anaerobic blood agar plate was evaluated: Growth: Small, white colonies were observed Gram Stain: Gram positive, pleomorphic, diphtheroid-like rod Biochemical: Catalase positive; Nitrate Reduction positive, Sensitive to Vancomycin and Kanamycin Which of the following organisms is most likely the cause of the CSF shunt infection?

Cutibacterium (Propionibacterium) acnes

Which of the following microscopic techniques is best suited for direct examination of the infectious agent of syphilis? Please select the single best answer Light microscopy Phase-contrast microscopy Dark-field microscopy Electron microscopy

Dark-field microscopy

The organism pictured below was a Gram-positive rod isolated from a sore on the hand of a fish market employee. It is shown on triple sugar iron agar. What is the most likely identification if it is catalase negative and non-motile?

Erysipelothrix rhuziopathiae

Which of the following microorganisms is LEAST likely to produce a capsule or slime layer? E col K pneumo S. pneuno P. aeruginosa

Escherichia coli

blood cultures are collected from a septic patient with a history of chronic UTIs. The sheep blood agar and the chocolate agar grow a creamy colony that has feet-like or star-like projections from the colony. The Gram stain of the colony demonstrates a budding yeast with pseudohyphae. What would be the next step in identifying the organism?

Germ tube the org is Candida albicans. Colony descr matches and is tube pos in 3hrs

The area of suppressed growth surrounding a disk impregnated with an antimicrobial on a sensitivity plate is referred to as the zone of: Please select the single best answer Resistance Breakpoint MIC Inhibition

Inhibition

A 20 year-old female was admitted into the hospital complaining of 10 to 15 bloody mucous stools per day, fever, gastrointestinal disturbances, abdominal pain, and nausea. The preliminary O & P report went out as "Probable Entamoeba histolytica trophozoites and cysts, confirmation pending." This patient is most likely suffering from: Traveler's diarrhea Extraintestinal amebiasis Intestinal amebiasis Giardiasis

Intestinal amebiasis

This illustration demonstrates a non-pathogenic amoeba that measures 5-20 µm, contains a large glycogen mass, and a single nucleus with a large karyosome and no peripheral chromatin. What is this parasite? Please select the single best answer Entamoeba hartmanni cyst Entamoeba coli cyst Endolimax nana cyst Iodamoeba bütschlii cyst

Iodamoeba bütschlii cyst

Which of the following has been compared to a hockey puck when discussing its morphology on chocolate agar?

Moraxella catarrhalis large pinkish to brown opaque colonies that can be moved over the agar intact with a loop

Each of the following characteristics is a prerequisite for a bacterial species to be classified within the family Enterobacteriaceae except: Please select the single best answer Gram-negative organism Bacilli shaped Motility via peritrichous flagellae Fermentation of glucose

Motility via peritrichous flagellae

Which Mycobacterium species will have a negative result for niacin, nitrate reduction, Tween hydrolysis (5 days), and iron uptake? Please select the single best answer Mycobacterium tuberculosis Mycobacterium kansasii Mycobacterium bovis Mycobacterium gordonae

Mycobacterium bovis

A three-year-old female was seen by a local ear, nose and throat specialist for chronic ear pain. She had been treated several times for otitis media by her pediatrician with no resolution. Drainage from her ear grew an acid fast bacillus that gave the following biochemical reactions: Iron Uptake- Positive Nitrate reduction- Positive Arylsulfatase - Positive MacConkey agar growth, 5 days- Positive It should be identified as: Mycobacterium avium complex Mycobacterium fortuitum Mycobacterium chelonae Mycobacterium kansasii

Mycobacterium fortuitum

The bacterial species producing the set of reactions seen in the oxidative/fermentative (OF) glucose tubes illustrated in this photograph at the right is a (an): Please select the single best answer Fermenter Aerobe Nonoxidizer

Oxidizer

isolated from nasal secretions and caused atrophic rhinitis, a tissue-destructive disorder in the nose

Kleb phenuoniae subsp. ozaenae causes an offensive smelling, purulent infection of nasal mucous membrane called ozena

Rothia mucilaginosa is a member of the family Micrococcaceae that has been associated with endocarditis in patients after cardiac catherization, as well as intravenous drug users. Which test listed below would be most helpful in making a species identification?

Presence of a capsule

In order to prepare the acridine orange (AO) reagent, what is added to the AO powder?

sodium acetate buffer

When three tubes of cerebrospinal fluid are received in the laboratory they should be distributed to the various laboratory sections as follows:

#1 Chemistry, #2 Microbiology, #3 Hematology

A physician called the microbiology laboratory and asked what he needed to order to quickly diagnose Bordetella pertussis from a child who had what appeared to be having whooping cough. Which of the following should the physician be told to order?

PCR testing

Thick Giemsa-stained blood smears are primarily used to screen for the presence of:

Plasmodium species

Various methods have been employed for the detection of Clostridioides difficile disease, which method is the new gold standard for detection? Please select the single best answer Culture on cycloserine-cefoxitin-fructose agar (CCFA) Cell cytotoxicity neutralization assay (CCNA) Enzyme immunoassays (EIA) detecting toxins Nucleic acid amplification tests (NAATs)

? NAAT

All of the following are Lancefield carbohydrate antigens found on beta-hemolytic Streptococcus species. All of the following antigens are found on organisms from the Streptococcus anginosus group EXCEPT? Please select the single best answer A B F G

B

which otf parasites has a life cycle that most closely resembles that of Plasmodium species

Babesia microti

Which of the following organisms is considered a contaminant when isolated from blood cultures and is part of normal skin flora?

Bacillus subtilis

symptoms consistent with cellulitis - gramstain from pt blood culture revealed gram-positive cocci in pairs and short chains. Bld cx grw orgnism susceptible to a 0.04 unit disk of bacitrctin. Other characteristis one would expect to see with this bacteria isolate include:

Beta hemolysis, negative catalase, negative CAMP, no growth in 6.5% salt suspect Group A Strep (pyogenes)

A D-zone test is performed to determine if Staphylococcus aureus or Streptococcus agalactiae has an inducible resistance to clindamycin. This inducible resistance is due to which of the following mechanisms? Please select the single best answer vanC gene msrA gene erm gene mecA gene

erm gene

Each otf characteristics will diff between Listeria monocytogenes and Erysipelothrix rhusiopathiae except: hydrolysis of esculin motility catalase fermentation of glucose

fermentation of glucose

what is the term for a human infection from a blood and tissue nematode?

filariasis

this term is defined as the presence of arthropods in or upon a human host:

infestation

Blastomyces derm Histoplasma capsu Sporothic schnckii Fusarium sp.

mold descriptions

if a positive result for a rapid HIV test is obtained, all otf are possible next steps EXCEPT:

no additional testing required western blot is the most widely used confirmatory testing but IFA and line immunoassay works too

a tech receives a request for VRE colonization testing on patient in the hospital. Which otf is an appropriate area of the body for culture for screening?

rectal area VRE = vanc-resistant Enterococcus

some fungi discriptions

trichophyton mentagrophytes microsporum gypseum microsporum canis epidermophyton floccosum

Identify the species of dimorphic fungi in its yeast form as observed under the microscope in this image. Please select the single best answer Blastomyces dermatitidis Paracoccidioides brasiliensis Sporothrix schenckii Coccidioides immitis

Blastomyces dermatitidis

This image illustrates a lactophenol blue mount prepared from a mold recovered after 7 days incubation on brain heart infusion broth. The individual microconidia, each borne by a delicate conidiophore, suggests the mold form of the following organism:

Blastomyces dermatitidis

which bacterial species is most likely represented by the spreading, wrinkled, non-hemolytic colony appearance as illustrated in the photograph?

Burkholderia pseudomallei

A 35-year-old man presented to his doctor with fever, diarrhea, abdominal pain, and epigastric discomfort. Upon questioning the patient, it was learned that he travels extensively for business and loves to try new varieties of raw fish. The patient is most likely suffering from: Please select the single best answer Clonorchiasis Sheep liver rot Paragonimiasis Schistosomiasis

Clonorchiasis Clonorchis sinensis, Chinese liver fluke from fish

A 55-year-old male immigrant from Korea presented to the ER with severe jaundice. He experienced intermittent but less severe bouts of jaundice in the past. During surgery, his proximal bile duct appeared to be enlarged with a nodular area of inflammation. A surgical biopsy was done and a parasite was observed residing in the lumen in the stained section. Further examination revealed a collection of ova within the ovary of this fluke as see in this image (arrow). Which of the organisms listed below is most likely? Please select the single best answer Clonorchis sinensis Fasciola hepatica Enterobius vermicularis Paragonimus westermani

Clonorchis sinensis

from the listed below, which organism is classified as a abligate anaerobe? Mycobacteria Staphylococcus aureus Neisseria sp Clostridium novyi

Clostridium novyi one of the most oxygen-susceptible anaerobes with cell being killed within 10 mins of exposure to atmospheric air

Consider the following characteristics of hookworm infection. Each statement is correct EXCEPT: Please select the single best answer Filariform larvae penetrate human skin into the blood. Larvae are carried in the blood to the bronchial tree where they mature in the lungs. Larvae are swallowed and travel to the small intestine where they mature. Gastrointestinal symptoms may include diarrhea, nausea, and hemorrhage.

Larvae are carried in the blood to the bronchial tree where they mature in the lungs.

Which of the following life cycle stages is correctly matched to its location within the host? Please select the single best answer Sporozoites in erythrocytes Merozoites in erythrocytes Gametocytes in liver cells Trophozoite in liver cells

Merozoites in erythrocytes

What causes the hemolysis associated with malarial infections? Please select the single best answer Multiplication of merozoites within erythrocytes Invasion of erythrocytes by sporozoites Host's immunologic response to damaged erythrocytes Toxins produced by the malarial organisms

Multiplication of merozoites within erythrocytes

The reactions observed in this Kligler Iron Agar slant (left) and Christensen's urease slant (right) provide the presumptive identification of: Please select the single best answer Citrobacter freundii Edwardsiella tarda Salmonella typhimurium Proteus mirabilis

Proteus mirabilis

the bacteria producing the swarming on the surface of the 5% sheep BAP shown in the photo was indole negative. The most likely ID is:

Proteus mirabilis

which otf stool pathogens would demonstrate the following reactions: TSI: A/A with H2S production LIA: R/A

Proteus spp.

a day-care outbreak of diarrhea revealed an oxidase-negative, non-lactose fermenting, nonmotile, gram-negative characteristics presumptively indicate which organism?

Shigella species

If septic arthritis is suspected, specimens from which of the following normally sterile sites should be collected to detect the microorganism causing the condition? Please select the single best answer Serous fluid Synovial fluid Cerebrospinal fluid (CSF) Blood

Synovial fluid

The federal government has categorized critical biological agents into three groups: A, B, and C. Why are the agents in category A classified as the highest-priority?

These organisms can be easily disseminated or transmitted person-to-person

All of the following are types of acid-fast stains, EXCEPT: Please select the single best answer Ziehl-Neelsen Fluorochrome Kinyoun Calcofluor white

Calcofluor white

Which of the following HPV types are most likely to be associated with cervical cancer? Please select the single best answer 6 and 11 16 and 18 42 and 43 44 and 54

16 and 18

An Enterobacteriaceae grows as a clear colony on MacConkey but a salmon-colored colony with a black center on Hektoen enteric agar. Which of the following TSI reactions would match these morphologies? Please select the single best answer Alk/A H2S A/A H2S Alk/A no H2S A/A no H2S

A/A H2S

A 40-year-old man with a prosthetic valve developed intermittent bouts of low grade fever. A changing cardiac murmur suggested the possibility of endocarditis; however, repeat blood cultures over a two week period were all negative. Bacteria resembling those seen in the lower image were finally seen in Gram stain of a positive bottle. Colonies were recovered when broth was subcultured to a blood agar plate with a staph streak, as shown in the upper image. What is the most likely bacterial species? Please select the single best answer Streptococcus mitis group Enterococcus faecalis Abiotrophia defectiva Streptococcus bovis

Abiotrophia defectiva

Many organisms have developed resistance to antibiotics. What mode of resistance has MRSA acquired? Please select the single best answer Acquisition of new targets Enzymatic inactivation of antibiotics Efflux Target site modification

Acquisition of new targets

the bacterial species commonly found in association with deep tissue actinomycosis is:

Aggregatibacter actinomycetemconitans part of normal flora in the oral cavity

Which of the following is necessary to test for in order to detect patients in the "window" period of a hepatitis B infection? Please select the single best answer HBsAg Anti-HBs Anti-HBe Anti-HBc

Anti-HBc

This image is of a 60 µm ovum that was observed in a diarrheal stool specimen from a middle-aged male immigrant from Nigeria who had suffered mild eosinophilic pneumonia a month before. What is presumptive identification for the organism? Please select the single best answer Ancylostoma duodenale Enterobius vermicularis Ascaris lumbricoides Trichuris trichiura

Ascaris lumbricoides

Illustrated in the composite image on the left is a 72-hour growth on Sabouraud's dextrose agar of a finely granular, black-pigmented colony obtained from a subcutaneous abscess at the site of an intravenous transfusion. The image to the right illustrates the microscopic appearance of a small inoculum taken from the surface of the center portion of the colony. A small spherical vesicle is surrounded by a row of phialides producing small, black-staining conidia. With these observations, select from the multiple choices the name of the fungus species as presented. Please select the single best answer Aspergillus fumigatus Aspergillus flavus Aspergillus niger Aspergillus terreus

Aspergillus niger

the infection diseases listed below are listed with the most commonly associated bacterium, EXCEPT:

Aspergillus niger - "Black lung"

The colonies seen growing on the surface of the blood agar plate shown in the upper photograph were recovered from a blood culture after 36 hours of aerobic incubation at 35° C. A Gram stain prepared from one of the colonies is shown in the lower photomicrograph. The most likely identification is: Please select the single best answer Clostridium species Listeria monocytogenes Corynebacterium striatum Bacillus circulans

Bacillus circulans

What is the most likely organism, based on the gram stain photomicrograph? Nocardia spp Bacillus spp Corynebacterium spp Lactobacillus spp

Bacillus sp.

This image represents parasites belonging to which of the following groups? Please select the single best answer Blood Nematodes Blood Hemoflagellate Blood Sporozoite Blood Protozoa

Blood Nematodes

What is the nuclear appearance of an Endolimax nana trophozoite? Please select the single best answer Blot-like karyosome, no peripheral chromatin Central karyosome, even peripheral chromatin Large karyosome, no peripheral chromatin Eccentric karyosome, uneven peripheral chromatin

Blot-like karyosome, no peripheral chromatin

The top image is characteristic of the clinical presentation of oropharyngeal thrush that may be observed in patients with AIDS. Specimen samples sent to the mycology laboratory for culture often grow yeast colonies on agar plates within 2 - 3 days of incubation at 30° C. Observed in the bottom photograph is the surface of a niger seed agar plate growing two different yeast species. The one to the left represents the clinical isolate and the one to the right is a control strain. It is important to recognize the colonies of the clinical isolate as it may be potentially resistant to commonly used anti-fungal agents. Select the species of yeast involved in this infection. Please select the single best answer Candida dubliniensis Candida glabrata Candida albicans Candida parasilosis

Candida dubliniensis

Which of the following organisms is gram-positive? Please select the single best answer Neisseria gonorrhoeae Brucella species Clostridioides difficile Pseudomonas aeruginosa

Clostridioides difficile

The flat, spreading gray-white colonies with an outer zone of beta hemolysis as observed on the surface of an anaerobic blood agar plate shown in the upper image were recovered from a blood culture of an elderly man leading to a potential diagnosis of cancer of the colon. Observed in the gram stain are short gram-positive bacilli, some with distinctive central and sub-terminal spores. The organism is a lactose fermenter and produces DNAse. From these observations, select the most likely isolate. Please select the single best answer Cutibacterium (Propionibacterium) acnes Clostridium septicum Actinomyces israeli Clostridioides difficile

Clostridium septicum

A 27-year-old missionary presented to the emergency department complaining of severe watery diarrhea, weight loss, abdominal pain, nausea, vomiting, a low-grade fever, and fatigue. (He noted that he had recently returned from a three-week visit to Panama.) Stool specimens were collected and submitted for ova and parasite examination. These images were taken from a wet mount preparation of the concentrate as well as a dry slide stained by modified acid-fast. The cysts seen in both preparations are spherical and measure 8µm in diameter. What is the most likely identification of this parasite? Images courtesy of CDC DPDx. Please select the single best answer Entamoeba histolytica Cyclospora cayetanensis Cryptosporidium parvum Dientamoeba fragilis

Cyclospora cayetanensis

The addition of Lugol's Iodine to a direct and indirect wet prep is used to detect which of the following protozoan stages? Please select the single best answer Cysts Eggs Larvae Trophozoites

Cysts

All of the following are roles of a sentinel microbiology laboratory, EXCEPT? Please select the single best answer Rule out pathogens. Determine that a bioterrorist event has occurred. Transfer suspicious specimens to reference laboratories. Be familiar with likely agents involved in a bio crime.

Determine that a bioterrorist event has occurred.

Stool is the specimen of choice for the recovery of which one of the following parasites? Please select the single best answer Trichinella spiralis Diphyllobothrium latum Plasmodium falciparum Schistosoma haematobium

Diphyllobothrium latum

This cestode is commonly associated with dogs and cats but may also be transmitted to humans through the ingestion of dog and cat fleas that contain the cysticercoid stage of the parasite. Laboratory diagnosis may be made by observing groups of egg packets, as seen in the diagram, in the stool. Please select the single best answer Dipylidium caninum Hymenolepis nana Taenia saginata Echinococcus granulosus

Dipylidium caninum

Humans serve as accidental (incidental) hosts in the life cycle of which one of these parasites? Please select the single best answer Trichuris trichiura Taenia solium Echinococcus granulosus Clonorchis sinensis

Echinococcus granulosus humans become hosts by ingestion of embryonated eggs present in the vegetation or from soil contaminated with feces of carnivores that serve as definitive hosts (like dogs)

The term "hydatid sand" is used in reference to which of the following tapeworms? Please select the single best answer Taenia saginata Echinococcus species Hymenolepis diminuta Hymenolepis nana

Echinococcus species

Which of the following best describes the organisms seen in the attached image? Please select the single best answer Gram-positive bacilli Gram-negative bacilli Gram-variable bacilli Acid-fast bacilli

Gram-positive bacilli

The 6 µm in diameter trichrome-stained cyst illustrated in this photomicrograph was inadvertently observed in a stool specimen that was being examined for reasons not clinically related to parasitic diseases. Further history revealed that the patient for whom the stool examination was being performed, had only rare bouts of mild diarrhea. Based on the characteristics in the illustration and the patient information, the most likely identification is: Please select the single best answer Entamoeba histolytica Entamoeba coli Entamoeba dispar Entamoeba hartmanni

Entamoeba hartmanni

Illustrated in the top image is a 7-day-old colony with a gray-yellow, velvety mold and a black-staining perimeter extending to the reverse of the colony. Although characteristic of a colony of chomomycosis, what is the identification of fungi that produces the sharply pointed end of the phialide from which clusters of elliptical conidia are formed? Please select the single best answer Cladophialophora carrionii Phialophora richardsiae Exophiala jeanselmei Fonsecaea pedrosoi

Exophiala jeanselmei

What is the common name for the sheep liver fluke? Please select the single best answer Fasciolopsis buski Fasciola hepatica Clonorchis sinensis Paragonimus westermani

Fasciola hepatica

Illustrated in the top image is a slow-growing, 8-day-old colony with velvety brown, deep radial grooves and a black periphery consistent with one of the agents of chromomycosis. In the bottom image, note the conidiophores produced from the sides of the hyphae producing short, branching phialides, giving rise to clusters of elliptical conidia. From the list of choices shown below, select the correct presumptive identification of this isolate. Please select the single best answer Phialophora verrucosa Cladophialophora carrionii Fonsecaea pedrosoi Exophiala species

Fonsecaea pedrosoi

Which term describes the cellular morphology of bacteria with a pointed end? Please select the single best answer Cocci Coccobacilli Fusiform Bacilli

Fusiform

a 35-year-old male presented to the local clinical complaining of abdominal cramps, severe diarrhea, and intestinal gas. A foul-smelling and light-colored stool specimen was collected and sent to the laboratory for parasite examination. This form was recovered from the stool concentrate and measured 10 um by 12 um. The patient is infected with which one otf organisms?

Giardia duodenalis (formerly lamblia) blue arrow - two oval nuclei red arrow - two median bodies green arrow - midline axonemes

Which of the following sugars has been fermented when a gram-negative bacillus produces an alkaline slant and an acid butt on triple sugar iron agar (TSI)? Please select the single best answer Lactose Sucrose Glucose Glucose and sucrose

Glucose

Two sputum specimens were submitted to the Microbiology laboratory for culture. A Gram stained smear was evaluated for each specimen prior to culturing. The fields that are shown in these images are representative of the 20 - 30 low power fields (lpf) that were examined. Which one of the two results represents a sputum specimen that is acceptable for culturing? Gram stain A Gram stain B Both are acceptable for culturing Neither are accepted for culturing

Gram stain A

Current CDC (2014) recommendations for initial HIV screening include FDA-approved immunoassay for detection of: Please select the single best answer HIV-1 p31 antigen HIV-1 and HIV-2 antibody, HIV-1 p24 antigen HIV-1 antibody and HIV-1 gp41 antigen HIV-1 and HIV-2 antibody

HIV-1 and HIV-2 antibody, HIV-1 p24 antigen

This organism has been placed in trypticase soy broth and then streaked on a nutrient agar plate. Strips containing X, V, and XV were placed on the plate and it was incubated 24 hours in CO2 conditions. With this information and the picture to the right, what is the identification of this organism? Please select the single best answer Brucella abortus Haemophilus influenzae Haemophilus parainfluenzae Pasteurella multocida

Haemophilus influenzae

Review each matched pair. Each correctly matches the bacterial species with its Gram staining reaction and morphology EXCEPT: Please select the single best answer Image A = Staphylococcus epidermidis Image B = Moraxella catarrhalis Image C = Streptococcus pneumoniae Image D = Enterococcus faecalis

Image B = Moraxella catarrhalis

The glycoproteins neuraminidase (NA) and hemagglutinin (HA) are used to subtype the following virus: HPV HSV Flu A HBV

Influenza A Virus

Using molecular methods to identify organisms can provide GREATER specificity when compared to phenotypic methods. Which of the following organisms would molecular methods not be beneficial over phenotypic methods in identification? Please select the single best answer Corynebacterium and related genera Klebsiella species Nocardia and related genera Dimorphic mycologic pathogens

Klebsiella species applies to most Enterobacteriaciae

This suspicious form was recovered from a bone marrow biopsy and measures 4 µm in length. What is the MOST likely identification of this organism? Please select the single best answer Trypanosoma epimastigote Trypanosoma trypomastigote Leishmania epimastigote Leishmania amastigote

Leishmania amastigote

Animal inoculation may be used to identify all of the following conditions except: Please select the single best answer Malaria Leishmaniasis Toxoplasmosis Trypanosomiasis

Malaria

Which one of the following parasites, whose common names are listed, is not associated with intestinal infections? Please select the single best answer Whipworm Dwarf tapeworm Malayan filarial worm Pinworm

Malayan filarial worm

Matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) is used for the identification of aerobic bacterial isolates on a urine culture bench. Upon placing the target into the MALDI-TOF instrument, no peaks were found on any target spots, including the quality control. What caused this issue? Please select the single best answer Quality control organism was not added to the target wells Matrix solution was not added to the target wells The target was not cleaned properly Quality control organism has deteriorated

Matrix solution was not added to the target wells

A patient shows signs of conjunctivitis including itching of the eyes, reddening of the conjunctiva, purulent secretion, and lid edema. A culture was taken of the secretion and a Gram-negative coccobacilli was seen on both the Sheep's blood and chocolate agars. There was no growth observed on the MacConkey agar. Additionally, the colonies were oxidase-positive, catalase-positive, reduced nitrate to nitrite, and liquefied gelatin. The identification of this organism is: Please select the single best answer Haemophilus influenzae Moraxella lacunata Neisseria gonorrhoeae Acinetobacter lwoffii

Moraxella lacunata

The Thayer-Martin agar plate seen in this illustration exhibits marked growth. The most likely organism found here would be: Please select the single best answer Staphylococcus aureus Streptococcus pyogenes Neisseria gonorrhoeae Shigella sp.

Neisseria gonorrhoeae

Dracunculus medinensis belongs to which category of parasites? Please select the single best answer Cestode Nematode Filaria Trematode

Nematode

Patterns of hydrolysis of tyrosine, xanthine, and casein are characteristics helpful in making species identifications within which genera?

Norcardia

Which parasite gives birth to live larvae known as microfilariae? Please select the single best answer Strongyloides stercoralis Necator americanus Diphyllobothrium latum Onchocerca volvulus

Onchocerca volvulus

Which one of the following results is typical of Campylobacter jejuni? Please select the single best answer Optimal growth at 42 ºC Oxidase negative Catalase negative Nonmotile

Optimal growth at 42 ºC

MacConkey agar contains all of the following except: Please select the single best answer Penicillin Bile salts Lactose Crystal violet

Penicillin

The trophozoite is the only morphologic form in the life cycle of: Please select the single best answer Trypanosoma cruzi Pentatrichomonas hominis Chilomastix mesnili Retortamonas intestinalis

Pentatrichomonas hominis

Based on the picture and the criteria below, how would the Gram stain be interpreted? Host cells and background material: pink | blue ? Smear thickness: 1 cell thick or > 1 cell thick? Precipitated stain: yes | no? Would this field be appropriate for reading? yes | no? Please select the single best answer Pink, 1 cell thick, No, Yes Pink, >1 cell thick, No, Yes Blue, 1 cell thick, No, Yes Blue, >1 cell thick, Yes, No

Pink, 1 cell thick, No, Yes

All of the following are statements concerning the gram stain. Which of the following is a TRUE statement? Please select the single best answer Can diagnose most parasites. Identification of organisms is definitive. Mycobacteria can be diagnosed. Presumptive evidence is provided.

Presumptive evidence is provided.

Observation of colonies producing brick red fluorescence under long-wave ultraviolet light on KVLB agar allows for presumptive identification of which anaerobic bacterial genus? Please select the single best answer Fusobacterium Peptostreptococcus Bacteroides Prevotella

Prevotella

A patient had a transfusion reaction to red blood cells and the remains from the unit of blood were sent to the microbiology laboratory for culture. The organism that grew was a gram-negative bacilli that was catalase and oxidase positive and was negative for gelatin hydrolysis. The organism was inoculated on a Pseudo F agar slant and incubated for 24 hours. Fluorescence was observed when using a UV light as seen in the image. This organism is most likely: Please select the single best answer Pseudomonas putida Pseudomonas stutzeri Burkholderia cepacia Pseudomonas alcaligenes

Pseudomonas putida

The granular, wrinkled, yellow-pigmented colonies shown in the upper photograph were recovered on chocolate agar after 48 hours of incubation from a respiratory specimen collected from a patient with cystic fibrosis. Note in the lower composite photograph that colonies on the surface of blood agar are flat, granular, and only slightly wrinkled. On MacConkey agar the colonies lack lactose fermentation and lack pyocyanin production. The spot oxidase test is positive, and nitrates are reduced. With these observations, select the presumptive identification of this isolate. Please select the single best answer Pseudomonas stutzeri Burkholderia cepacia Elizabethkingia meningoseptica Acinetobacter baumannii

Pseudomonas stutzeri

Illustrated in this photograph are the biochemical reactions of an unknown bacterial species produced in Kligler Iron Agar, Sulfide Indole Motility agar, indole broth, Voges Proskauer broth, and Simmons citrate. The bacterial species most likely producing the reactions seen here is: Please select the single best answer Salmonella typhimurium Salmonella typhi Proteus mirabilis Citrobacter freundii

Salmonella typhi non-lactose-fermenter (alkaline/acis KIA), pos H2S production

Consumption of undercooked poultry or the handling of reptiles could cause which of the following conditions? Please select the single best answer Pasteurellosis Brucellosis Tularemia Salmonellosis

Salmonellosis

The upper image is a 4 day old colony grown on Sabouraud's Dextrose agar, recovered from a bacterial culture that was considered to be a "contaminant". The lower image is a high power image of a methylene-blue stained mount prepared from the surfaces of the colony. With these observations, select the fungus genus from the multiple choices as listed. Please select the single best answer Sepedonium Scedosporium Beauveria Chrysosporium

Sepedonium

Illustrated in this photograph, reading from left to right, are tubes of Kligler Iron agar (KIA), Sulfide Indole Motility agar, indole broth, Voges Proskauer broth and Simmons citrate. The bacterial species most likely producing the reactions illustrated here is: Please select the single best answer Shigella sonnei Escherichia coli Yersinia frederikensii Providencia stuartii

Shigella sonnei

Often recovered from puncture wounds of the fingers, wrists and arms, illustrated in the top photograph is the 4 day growth on SABHI agar after incubation at 30o C. The colony is circumscribed, yellow, rough and wrinkled centrally, surrounded by narrow smooth, white circular growth with a distinct brown-black outer border. The identification can be made by observing the lactophenol blue stained fruiting heads in the bottom photomicrograph. From these observations, select the name of this fungal isolate. Please select the single best answer Histoplasma capsulatum Sporothrix schenckii Paracoccicioides brasiliensis Blastomyces dermatitidis

Sporothrix schenckii

The class of protozoa with no apparent organelles for locomotion is known as: Please select the single best answer Mastigophora Sporozoa Ciliata Sarcodina

Sporozoa i.e. Plasmodium, Babesia, Cryptosporidium, and Toxoplasma

In a HPV infection, where does the viral DNA replicate? Please select the single best answer Squamous epithelial cells Glandular cells Intraepithelial cells White blood cells

Squamous epithelial cells

The image to the right is a gram stain of a positive blood culture. The bacterial genus most likely to grow out in culture is: Please select the single best answer Staphylococcus Streptococcus Listeria Corynebacterium

Staphylococcus

Whipworm infection is typically diagnosed by the microscopic observation of adult worms or barrel-shaped eggs with polar plugs in stool specimens. What organism is known as the whipworm? Please select the single best answer Trichuris trichiura Ascaris lumbricoides Necator americanus Enterobius vermicularis

Trichuris trichiura

Which of the following statements about hepatitis C virus (HCV) is true? Please select the single best answer There is vaccination against infection with HCV. The primary route of infection with HCV is airborne transmission. Patients infected with HCV will always have observable symptoms. The majority of individuals who are infected with HCV and develop antibodies in their serum (seroconvert) will develop a chronic infection and active liver disease.

The majority of individuals who are infected with HCV and develop antibodies in their serum (seroconvert) will develop a chronic infection and active liver disease.

The diffuse erythroderma and edema of the hand shown in the upper photograph is of a 24-year-old female with fever, headache, and hypotension. The blood agar plate shown in the lower photograph was inoculated with purulent material aspirated from a vertebral disk abscess. The most likely condition is:

Toxic shock syndrome

A pleural fluid specimen is received in the laboratory for aerobic culture. The specimen measures about 0.5 mL. How should the tech process this specimen for culture? Please select the single best answer Use a sterile pipette and add a drop of fluid per agar plate Insert a swab into the specimen container and inoculate all agar plates Add 0.5 mL of saline to the 0.5 mL of fluid, vortex, and inoculate plates Reject the specimen due to insufficient quantity for culture

Use a sterile pipette and add a drop of fluid per agar plate

A patient presents to the emergency room with severe headaches, nausea, and vomiting. CSF chemistry results are as follows: Protein - 74 mg/dL (15-45 mg/dL) Glucose - 53 mg/dL (40-85 mg/dL) Based on the patient's complaints and the above laboratory results what is the most probable condition? Please select the single best answer Fungal Meningitis Bacterial Meningitis Traumatic Tap Viral Meningitis

Viral Meningitis

A woman came to see her physician as she was having vaginal/vulvar itching and some pain upon urination. To obtain a diagnosis of a yeast infection, which of the following is the test of choice? Please select the single best answer Fungal culture Wet preparation Routine vaginal culture Nucleic acid base test

Wet preparation

The portion of a tapeworm used for attachment to the host's intestine is called the:

scolex

Molecular methods can identify the presence of methicillin-resistant staphylococcus aureus (MRSA) in patient specimens by detecting different species-specific genes. All of the following are species-specific genes in detecting MRSA EXCEPT? Please select the single best answer 16S and 23S ribosomal RNA genes and spacer regions DNA gyrase (gyrA) Superoxide dismutase (sodA) van A

van A

All otf organisms have been linked to causing endocaarditis except?

Haemophilus influenzae

Identification of intestinal microsporidial spores is usually done by using which of the listed stains?

Giemsa stain

The antigen marker most closely associated with transmission of HBV infections is: Please select the single best answer HBsAg HBeAg HBcAg HBiAg

HBeAg connotes active replication of Hep B virus HBsAg is first to appear in infection and indicates active infection HBcAg tested to determine the course of HBV infections

Which otf can produce indole?

Chryseobacterium spp.

Common colds are most often associated with which agent?

Rhinovirus

Which otf organisms is Gram-negative?

Vibrio

a single adult worm tht contains both male and female sex organs is known as:

hermaphroditic

The bacterial species growing on the surface of the MacConkey agar plate shown in this photograph, a coccobacillary non-fermenter and a common cause of nosocomial hospital acquired pneumonia, can be presumptively identified as:

Acinetobacter baumannii

What is the phenotypic property of Saccharomyces yeast species that helps establish its species identification? Please select the single best answer Polysaccharide capsule Ascospore production Trehalose assimilation Slow growing yeast

Ascospore production

What is the phenotypic property of Saccharomyces yeast species that helps establish its species identification? Please select the single best answer Polysaccharide capsule Ascospore production Trehalose assimilation Slow growing yeast

Ascospore production

Which Aspergillus species show biseriate with phialides covering the entire surface of a spherical vesicle with black conidia as microscopic morphological features?

Aspergillus niger

A farmer is diagnosed with a fungal respiratory infection. A fungal culture produced a rapidly growing blue-green colony. Microscopically, septate hyphae with long conidiophore ending in a dome-shaped vesicle were observed as well as long chains of conidia protruding from the vesicle as seen in this illustration. The most likely identification is: Please select the single best answer Penicillium species Fusarium species Aspergillus species Geotrichum species

Aspergillus species

which otf morphological structures for Giardia intestinalis trophozoite is pictured in the section labeled B?

Axonemes A- anterior flagella C- nuclei D- median (parabasal) bodies

Enterobius vermicularis (pinworm) is classified as which of the following?

Nematode

which otf is a selective medium for Campylobacter jejuni?

Skirrow agar

When a Specked Nuclear Antibody (ANA) pattern is observed, what follow-up test for antibodies related to Systemic Lupus Erythematosus (SLE) is not beneficial? Please select the single best answer Testing for antibodies to Smith (Sm) Testing for all antibodies to the extractable nuclear antigens (ENA) Testing for antibodies to SS-A/SS-B+ Testing for antibodies to U1RNP+ and dcSSc

Testing for antibodies to U1RNP+ and dcSSc they are speckled patterns but are not associated with SLE

Which statement about assays for the antigenic detection of both Clostridioides difficile toxins A and B is TRUE? Please select the single best answer The antigenic assays give rapid results. The assays can only detect simultaneous production of toxin A and toxin B. The assays provide a high level of sensitivity. Assays that detect toxin A alone will detect all clinically significant strains.

The antigenic assays give rapid results.

A physician calls the lab to order a Hepatitis A IgG test but cannot find the code. What do you tell the physician? Please select the single best answer There are no IgG-only tests for Hepatitis A, only a total with/without reflex to IgM Which IgG test are you looking for: surface antigen, envelope, or core IgG? It depends on where the patient is coming back from with travel history. We only have tests for antigens not antibodies for IgG

There are no IgG-only tests for Hepatitis A, only a total with/without reflex to IgM

Which EBV markers would be MOST likely positive for an individual who had infectious mononucleosis nine years ago? Please select the single best answer All markers will remain positive. Only anti-viral capsid antigen (VCA)-IgM and heterophile are positive. Only anti-VCA (IgG) and anti-Epstein-Barr nuclear antigen (EBNA) are positive. None of the markers would be positive after nine years.

Only anti-VCA (IgG) and anti-Epstein-Barr nuclear antigen (EBNA) are positive.

A 38-year-old male presented to the E.R. complaining of severe cough, chest pain, shortness or breath, and fatigue. Microscopic examination of a bloody sputum specimen revealed this suspicious form. The patient is most likely suffering from: Fasciola Clonorchis Paragonimus Echinococcus

Paragonimus westermani

The cytochrome oxidase-positive bacterial species that is DNAse negative, ornithine decarboxylase positive, and is associated with gastroenteritis in children after the ingestion of contaminated water is most likely: Please select the single best answer Aeromonas hydrophila Salmonella enterica Plesiomonas shigelloides Shigella sonnei

Plesiomonas shigelloides

Which phrase describes enrichment media? Please select the single best answer Contains certain factors that allow colonies of specific organisms to appear different than other colonies. Contains pigments to differentiate lactose fermenters from non-lactose fermenters. Encourages the growth of specific types of organisms. Contains agents that inhibit all but one specific organism.

Encourages the growth of specific types of organisms

There are two patterns present in this microscopic field from an antinuclear antibody ANA test. The test is viewed using fluorescent microscopy. One pattern can be seen in the interphase cells (a) and the area outside of the chromosomal area of the mitotic cells (b). The other pattern is recognizable in the chromosomal area of the metaphase mitotic cells (c). What are these two patterns? Please select the single best answer Homogeneous and nucleolar Speckled and homogeneous Speckled and centromere Centromere and nucleolar

Speckled and homogeneous

A tech is working on a culture from an aspirated lesion. The culture grows non-hemolytic colonies with flattened edges and raised centers, resembling a fried egg on blood agar. Gram stain of the colonies shows plump Gram-negative bacilli with bipolar staining. What is the likely identification of the organism?

Yersinia pestis

An abdominal wound culture grows E. coli on the aerobic culture. The anaerobic culture has growth of two gram negative rods, one of which is aerobic. The other gram negative rod has 2+ growth on BBE plate and is resistant to Kanamycin, Colistin, and Vancomycin disc. This organism can be identified as: Veillonella Prevotella fragilis Bacteroides fragilis group Fusobacterium necrophorum

Bacteroides fragilis group BBE = Bacteroides Bile Esculin Agar

Cyclosporine and tacrolimus (both immunosuppressive drugs) have multiple therapeutic ranges, why? Please select the single best answer There is no therapeutic range established for either. Because of the slow uptake of the medications by tissues. Because both drugs have ranges dependent on the organ transplanted and the time after transplantation. Because of the short half-lives of the drugs.

Because both drugs have ranges dependent on the organ transplanted and the time after transplantation.

Which of the following bioterrorism agent categories is the easiest to spread, has the ability to cause major harm, panic, and death, and carries the highest level of risk with regard to national security? Please select the single best answer Category A Category B Category C Category D

Category A

The selective medium XLD is seen in this illustration. What is the significance of the black colonies observable on this plate?

Hydrogen sulfide production

When performing sequence-based analysis to identify a bacterial isolate, all of the following must occur to ensure accurate results are obtained EXCEPT? Please select the single best answer Pure colony isolate must be provided Organism must be submitted on an agar slant or in bacterial transport media Mixed cultures can be used as specific sequence is being identified Quantity of organism must be enough to create a turbid suspension for DNA extraction

Mixed cultures can be used as specific sequence is being identified

Which of the following is the most likely identification of an acid-fast bacilli recovered from an induced sputum with these culture findings? Slow growth at 37C Niacin test - Pigmented photochromogenic Nitrate test + Catalase + Mycobacterium kansasii Mycobacterium tuberculosis Mycobacterium simiae Mycobacterium chelonei

Mycobacterium kansasii

This Plasmodium species produces severe anemia in its human host, is very common to have CNS involvement, and has a 6-17-month duration for an untreated infection? Please select the single best answer Plasmodium ovale Plasmodium falciparum Plasmodium malariae Plasmodium vivax

Plasmodium falciparum

An uncommon laboratory isolate, the colonies on blood agar, as seen in the top upper frame of the composite image were cultured from the throat swab of a 10 year old girl presenting with a red throat and mucosal pseudomembrane. These tiny gray-white, non hemolytic colonies are non-descriptive. Distinctive are the black pigmented colonies as observed on Tinsdale agar (lower image in the top composite photograph). Illustrated in the lower composite photomicrograph (upper image) are slender gram positive bacilli. Bacilli with meta-chromatic granules are observed in a methylene blue stained microscopic mount (lower image). From these observations, select the presumptive identification of this isolate.

Corynebacterium diphtheriae

what is the infective stage for the intestinal amebae?

cyst

Which phrase describes enrichment media? Please select the single best answer Contains certain factors that allow colonies of specific organisms to appear different than other colonies. Contains pigments to differentiate lactose fermenters from non-lactose fermenters. Encourages the growth of specific types of organisms. Contains agents that inhibit all but one specific organism.

Encourages the growth of specific types of organisms.

In tissues infected with Histoplasma capsulatum, which of the following is usually true? Please select the single best answer Hyphae usually invade blood vessels Encapsulated yeast cells are typical Conidiophores with metulae and phialides are typical Fungus is usually intracellular

Fungus is usually intracellular

Which one of the following adult worms resides in the human intestine? Please select the single best answer Heterophyes heterophyes Paragonimus westermani Clonorchis sinensis Schistosoma haematobium

Heterophyes heterophyes

The mechanism by which certain strains of Enterococcus species have developed resistance to the synergistic combination of an aminoglycoside and beta-lactam antibiotics is considered: Please select the single best answer Alteration of penicillin binding proteins Beta lactamase activity against the beta-lactam moiety High level gentamicin resistance Efflux of antibiotics from the bacterial cell

High level gentamicin resistance

This member of the Enterobacteriaceae gave these reactions: Biochemical Reaction H2S (TSI) Negative Ornithine Negative Lysine Positive Citrate Positive Urea Positive Phenylalanine Negative Motility Negative What is this organism? Please select the single best answer Enterobacter cloacae Klebsiella pneumoniae Escherichia coli Yersinia enterocolitica

Klebsiella pneumoniae

The colonies growing on the surface of a thiosulfate citrate bile sucrose (TCBS) agar plate (the green color indicates lack of sucrose fermentation) were identified as Vibrio vulnificus. The serious complication of infections with this bacterial species is: Please select the single best answer Life-threatening septicemia Cholera-like diarrheal syndrome Severe electrolyte imbalance Progressive cellulitis and gas gangrene

Life-threatening septicemia

what is the first step of the ethyl acetate concentration procedure?

Mix stool with 10% formalin and strain for sediment 2nd add saline, centrifuge, decant 3rd resuspend sediment with 10% formalin and add ethyl acetate to induce spec grav differences 4th centrifuge spec to obtain 4 layers

The tiny colonies growing on chocolate agar after 3 days of incubation, as illustrated in the left plate in the upper photograph, were recovered from a skin abscess at the site of a contaminated needle injection. The colonies growing on Middlebrook 7H10 agar seen to the right in the image were larger, smooth, convex, and gray-white. Acid-fast stains were positive for the appearance of slender bacilli, consistent with one of the rapidly growing Mycobacteria. Reactions for nitrate reduction and iron uptake were negative. A distinctive characteristic was the antibiotic resistance to Ciprofloxacin (left upper strip) and Polymyxin B susceptibility (vertical strip) in the lower photograph. From these observations, select the identification of this isolate. Please select the single best answer Mycobacterium chelonae Mycobacterium fortuitum Mycobacterium gordonae Mycobacterium scrofulaceum

Mycobacterium chelonae

The gram stain image on the right is a vaginal smear obtained from an 11-year-old girl suspected of being the victim of sexual abuse. The appearance of intracellular gram-negative diplococci (GNDC), as seen in the segmented neutrophil at the tip of the arrow, can represent different organisms. Therefore, recovery of the bacterial species in culture and biochemical identifications is needed before the case can be resolved. Each of the following may appear as intracellular GNDC EXCEPT: Please select the single best answer Neisseria gonorrhoeae Moraxella osloensis Acinetobacter baumannii Gardnerella vaginalis

Neisseria gonorrhoeae

Which of the following gastrointestinal pathogens has an incubation period of 1-8 hours? Please select the single best answer Salmonella spp. Listeria monocytogenes Staphylococcus aureus Vibrio spp.

Staphylococcus aureus

A 6-year-old girl was seen in the emergency department with pain and tenderness in her lower right quadrant. A CBC showed a high white blood cell count with increased segmented neutrophils and bands. The child was admitted to surgery with a diagnosis of appendicitis. During surgery, the appendix appeared normal, but an enlarged node was removed and cultured. A diagnosis of mesenteric lymphadenitis was made. Gram-negative rods were isolated. Which of the following biochemical results are most likely produced by the suspect organism? Please select the single best answer Triple sugar iron agar (TSIA) acid over acid, H2S negative, lysine positive, indole positive, urea negative TSIA acid over acid, H2S negative, lysine negative, indole variable, urea positive TSIA alkaline over acid, H2S positive, lysine negative, indole negative, urea variable TSIA acid over acid, H2S positive, lysine positive, indole variable, urea negative

TSIA acid over acid, H2S negative, lysine negative, indole variable, urea positive

Which antinuclear antibody (ANA) pattern is seen in the image on the right, which represents the result of an ANA test viewed using fluorescent microscopy? Note: (a) points to the nuclei of interphase cells, the primary consideration for discerning the ANA pattern and (b) indicates a metaphase mitotic cell. Please select the single best answer There is no discernable pattern Homogeneous Centromere Nucleolar

There is no discernable pattern

From the list of incubation temperatures, select the one that is currently recommended as a routine temperature of incubation for the laboratory recovery of fungi from culture specimens, being both successful and cost-effective. Please select the single best answer 30°C 35°C 30°C and 35°C 45°C

30°C

The spherical, finely-spiked macroconidia of Sepedonium species appear similar to those microscopically seen in the mold form of Histoplasma capsulatum. By what characteristic may Sepedonium be excluded? Please select the single best answer Absence of growth on inhibitory mold agar (IMA) containing cycloheximide and chloramphenicol Ability to produce yeast conversion when colonies are incubated at 35 - 37 degrees C Production of septate hyphae and simple or branched conidiophores No microconidia production

Ability to produce yeast conversion when colonies are incubated at 35 - 37 degrees C

A microbiologist performed a Gram stain procedure on a sputum specimen and was unable to determine if what was seen on the smear were tiny, Gram-negative organisms or stain debris. Which of the following stains would help the microbiologist make a correct determination?

Acridine Orange this stain stains all nucleic acids but not g= stain debris

The growth on a blood agar plate as illustrated in the photograph was prepared from the surface drainage of a subcutaneous abscess of a 50 year old man following a deep penetrating splinter wound. The colonies on this young culture are small, rough, gray-white, and non-hemolytic. Older larger colonies became sunken centrally having a "molar tooth" appearance. The gram stain reveals gram positive branching filaments. Key biochemical reactions include hydrolysis of esculin, nitrate reduction, and negative catalase. From these observations, select from the multiple choices the identifaction of this isolate Bifidobacterium species Propionibacterium species Actinomyces israeli Clostridium septicum

Actinomyces israeli

A clean-catch midstream urine specimen from a woman was sent to the microbiology laboratory for culture. The patient had a history of dysuria, frequent urination, suprapubic pain, no fever, no flank pain, or any urinary symptoms in the last 4 weeks before her current episode. The urine grew out 1,000 cfu/mL of Escherichia coli. Which of the following categories would the patient be classified?

Acute, uncomplicated UTI in women

A beta-hemolytic Streptococcus was isolated from a throat culture. It gave the following biochemical reactions: Bacitracin - Susceptible Bile esculin - Negative 6.5% NaCl - No growth CAMP - Negative SXT - Resistant What is the presumptive identification? Please select the single best answer Beta hemolytic Streptococcus, group B Beta hemolytic Streptococcus, not group A, B, or D Beta hemolytic Streptococcus, Group G Beta hemolytic Streptococcus, Group A

Beta hemolytic Streptococcus, Group A

Illustrated in the top photomicrograph is a 4-day old colony growing on Sabouraud's dextrose agar with a smooth dark gray to black surface surrounded by dark gray and white peripheral bands. The colony morphology is not distinctive. The identification is made by observing the septate hyphae and conidia as microscopically observed in the lactophenol cotton blue-stained mount obtained from the surface of the colony as illustrated in the bottom photomicrograph. From these observations, select the most probable fungi.

Bipolaris species

This bacterial species shows good growth in 48 hours of entire, white, smooth, non-hemolytic colonies on blood agar (image to the left in the composite), and lightly pink pigmented, smooth entire colonies on chocolate agar (image to the right in the composite). This species is included in the class of motile, oxidase-positive non-fermenters, indigenous in the respiratory tract of domestic animals, but can cause human sinusitis and pneumonia in animal caretakers. Carbohydrate utilization is asaccharolytic except for oxidative utilization of maltose, as illustrated in the lower composite image -- a key reaction is rapid urease production, and nitrates are reduced as also illustrated in the lower composite photograph. Based on these observations, select from the multiple choices the identification of this isolate.

Bordetella bronchiseptica

Which of the following growth factor(s) is necessart for the proper culture of Haemophilus influenza?

Both X and V factors

Which is the most commonly reported organism in cases of laboratory-acquired bacterial infection?

Brucella species apprx. 2% of all Brucella cases are acq in the lab

Selective media CNA agar Skirrow agar Thayer-Martin media Cystine-tellurite blood agar

CNA = gram-pos cocci Skirrow = C. jejuni T-M = Neisseria gonorrhoeae C-t = Corynebacterium diphtheriae

The growth of yellow-white yeast colonies with a smooth or hair-like surface within 2 - 3 days on non-selective culture media generally requires further procedures to make a presumptive identification. Microscopic observation of the subculture of colonies growing on cornmeal agar is one such approach, as illustrated in the photomicrograph. Note the "logs in stream" arrangement of elongated blastoconidia. From the multiple choices, select the name of the presumptive yeast identification.

Candida kefyr

Which of the following organisms is indole negative? Please select the single best answer Escherichia coli Klebsiella oxytoca Chryseobacterium indologenes Capnocytophaga canimorsus

Capnocytophaga canimorsus

For an isolate of Escherichia coli, Klebsiella, or Proteus species testing positive for ESBL (Extended Spectrum Beta Lactamases), all of the following antibiotics should be reported as resistant except: Please select the single best answer Aztreonam Cefazolin Cefoxitin Ceftriaxone

Cefoxitin

A patient grew out a Staphylococcus lugdunensis and after susceptibility testing, the isolate gave results indicating probable resistance to oxacillin. Which of the following is the best method to detect the mec-A gene to determine if the organism has true oxacillin resistance? Please select the single best answer Oxacillin agar screen Cefoxitin disk diffusion Vancomycin agar screen D-zone test

Cefoxitin disk diffusion

ANA staining pattern demonstated?

Centromere discrete speckels in the nucleaus of the interphase ce;;s. (a) points to nuclei of serveral interphase cells (b) metaphase mitotic cell

This antinuclear antibody (ANA) test pattern is characterized by staining of discrete speckles in the nucleus of the interphase cells (a) and discrete speckling also in the chromosomal area of the metaphase mitotics (b) when viewed using fluorescent microscopy. This image represents which of the following patterns? Please select the single best answer Centromere pattern Peripheral or rim pattern Speckled Multiple nuclear dots

Centromere pattern

A CSF shunt tip specimen was sent to the microbiology laboratory for culture. The shunt specimen was inoculated to sheep blood agar, chocolate agar, and a thioglycollate broth. After 24 hours of CO2 and non-CO2incubation at 37°C, the sheep blood agar, chocolate agar, and the thioglycollate broth had growth. The microbiology tech evaluated the media and observed the following: Growth: Sheep blood grew small, white non-hemolytic colonies. Chocolate grew small, white colonies. Gram Stain: Gram-positive cocci in clusters Biochemical: Catalase positive; coagulase-negative Which of the following organisms is most likely the cause of the CSF shunt tip infection? Please select the single best answer Staphylococcus aureus Cutibacterium (Propionibacterium) acnes Coagulase-negative staphylococci Viridans group streptococci

Cutibacterium (Propionibacterium) acnes

Cytomegalovirus (CMV) appears to suppress cell-mediated immune functions. Which of the following is a characteristic finding in persons infected with CMV? Please select the single best answer Increased CD4+ cells; decreased CD8+ cells Increased CD4+ cells; increased CD8+ cells Decreased CD4+ cells; increased CD8+ cells Decreased CD4+ cells; decreased CD8+ cells

Decreased CD4+ cells; increased CD8+ cells

Members of the HACEK (AACEK) group represent slow-growing gram-negative bacilli associated with what?

Endocarditis

Which of the following parasites is the cause of both intestinal and extraintestinal amebiasis? Please select the single best answer Entamoeba coli Endolimax nana Iodamoeba butschlii Entamoeba histolytica

Entamoeba histolytica

A pathologist my detect the presence of this parasite in an H&E-stained section of the lumen of the appendix, as seen in the upper image. Additional fields of view may locate the ovary and the morphology of the ova contained within it, as observed in the lower image. Based on these observations, select the presumptive identification of this parasite.

Enterobius vermicularis

which classification encompasses a group of organisms that may contain multiple genera and consists of organisms with a common attribute?

Family

This ubiquitous parasite is found primarily in areas where sheep and cattle are raised. The natural hosts for the completion of its life cycle are sheep. Humans often serve as accidental hosts. Which of the following conditions may be associated with the presence of this stool parasite 130-150 µm long by 60-90 µm wide?

Fascioliasis pictured: Fasciola hepatica (id'd by size)

Which of the following best describes the organisms seen in this illustration:

Gram-variable

Which otf instruments is used for continuous monitoring of mycobacterial growth?

MGIT 960 uses modified Middlebrook 7H9 broth

illustrated in this photograph is the surface of a 5% sheep blood agar plate on which are growing colonies of yellow-pigmented Staphylococcus sp. Note the tiny semi-translucent colonies that satellite around some of the colonies. Pleomorphic gram-negative bacilli where seen on gram stain. The most likely identification is:

Haemophilus influenzae Factor X (hemin) from the blood, Factor V (NAD) from the Staph colonies allow H. influ to grow

Illustrated in this photograph is an H & E-stained section of a gastric biopsy obtained from a patient with suspected peptic ulcer disease. Based on the biopsy findings, the bacterial species that would most likely be recovered is:

Helicobacter pylori

Which of the following species of bacteria is positive for rapid urease production, as demonstrated by a color change in urea agar from yellow to pink within two hours? Salmonella enterica Escherichia coli Helicobacter pylori Campylobacter jejuni

Helicobacter pylori

Which of the following is a DNA virus? Hepatitis B virus Hepatitis C virus Rabies virus Influenza A virus

Hepatitis B virus

Illustrated in the top image is the surface of a blood agar culture plate incubated at 35°C for 3 days. Note the growth of tiny smooth, pasty, yellow-white yeast colonies. Although a presumptive identification might be made from the macroscopic morphology, confirmation is made by observing the yeasts forms in the lactophenol stained mount observed in a tease mount prepared from one of the colonies. From these observations, what is the most likely identification?

Histoplasma capsulatum

Of the dimorphic fungal species listed below, which has the slowest rate of growth in primary culture? Please select the single best answer Coccidioides immitis Histoplasma capsulatum Sporothrix schenckii Blastomyces dermatidis

Histoplasma capsulatum avg of 7-15 days, but may take 8 weeks, for colonies to appear Sporo 24-48 hours Cocci 5 days Blasto 5-14 days

The colonies shown in the upper image were obtained on blood agar from a sputum specimen after 10 days incubation at 30°C. The lower image is a photomicrograph of a lactophenol blue mount made from a portion of the colony. The diagnosis is most likely: Coccidioidomyccosis Blastomycosis Histoplasmosis Paracoccidioidomycosis

Histoplasmosis

What is the medium of choice for isolating Gardnerella vaginalis? Please select the single best answer Modified Thayer-Martin (MTM) agar Malonate broth Human blood bilayer Tween (HBT) agar New York City (NYC) medium

Human blood bilayer Tween (HBT) agar

Rocky Mountain spotted fever (RMSF), caused by Rickettsia rickettsii, is MOST reliably diagnosed by which laboratory technique?

IFA testing

A culture from a sputum specimen grew a mucoid, lactose fermenting organism. Biochemical testing on this isolate gave the following key reactions: VP: positive; Indole: negative; Urea: 1+, Motility: nonmotile, Citrate: positive. What is the most likely organism given the site of isolation and biochemical reactions? K. pneumo E. coli K. oxytoca K. aerogenes

Klebsiella pneumoniae

What is the probable identity of an organism isolated from a wound culture that demonstrates the following test results? Phenylalanine Deaminase = negative TSI = A/A gas Citrate = positive Lysine = positive SIM = negative/negative/negative Urea = weakly positive Please select the single best answer Escherichia coli Klebsiella pneumoniae Klebsiella aerogenes Proteus vulgaris

Klebsiella pneumoniae

All of the following Mycobacterium species produce pigments, EXCEPT?

Mycobacterium fortuitum group

The following aerobic, branching, filamentous gram-positive species is weakly acid fast and known to cause mycetomas and lung infections in immunocompromised individuals: Nocardia species Mycobacterium species Streptomyces species Corynebacterium species

Nocardia species

All of the following are characteristic of Burkholderia pseudomallei EXCEPT? Has been reported as the cause of laboratory-acquired infection Oxidase positive Non-motile Catalase positive

Non-motile

The adult flukes related to this 100 µm ovum typically inhabit the lung parenchyma; ova are most commonly found in sputum specimens. Diagnostic features for the ovum include a slightly thickened shell with a prominent shouldered operculum (as seen at the left lower end), a developing larva within the shell that is retracting from the inner margin leaving a clear space. Infections with this fluke are endemic in the orient, West Africa, South and Central America, and may be observed in patients who have traveled to one of these regions. Human infection occurs following ingestion of poorly cooked crab meat or crayfish contaminated with metacercariae. Intermittent chest pain and cough with occasional spitting up of blood (hemoptysis) may be experienced after infection. From the choices below, select the trematode species related to this ovum. Please select the single best answer Clonorchis sinensis Fasciola hepatica Fasciolopsis buski Paragonimus westermani

Paragonimus westermani

Illustrated in the upper photograph is the growth of off-white, convex colonies with internal flecking after anaerobic incubation for 48 hours on anaerobic blood agar. Beta hemolysis is not observed. The colonies were recovered from a uterine cervix specimen obtained from a 30-year-old female with postpartum endometritis. The gram stain reveals small gram-positive cocci arranged in short chains and pairs. A spot indole and catalase test were negative. From these observations, select the presumptive identification of this isolate. Please select the single best answer Porphyromonas asaccharolytica Peptostreptococcus anaerobius Veillonellla parvula Bacteroides fragilis

Peptostreptococcus anaerobius

What type of healthcare occupational exposure has the greatest risk of HIV transmission?

Percutaneous injury

Which site listed below should be accepted for a rapid strep screen? Tongue Cheek Peritonsillar fossae Nares

Peritonsillar fossae

A tech working in microbiology reported the following results throughout their workday. Which of the result would be considered an urgent alert value that must be called to the physician? Please select the single best answer Wound culture report with Staphylococcus aureus Positive acid fast smear Urine culture with >100,000 CFU/mL of E.coli Sputum Gram stain showing Gram positive cocci

Positive acid fast smear

the colonies growing on the BAP, as shown in the upper image, are gray, white, and swarming. Note in the image below, that the colonies growing on XLD agar have black centers with pigmentation that does not extend into the agar. A presumptive ID of Proteus species can be made. Select the biochemical reaction that serves to separate Proteus vulgaris from Proteus mirabilis

Positive indole

On a plate growing Streptococcus pneumoniae, the zone of inhibition around the disk shown in the image has been measured at 23 mm. Based on this result, you should:

Report oxacillin-susceptible

Smooth gray-white, convex, glistening non-hemolytic colonies were observed growing on the surface of anaerobic blood agar after 48 hours. This isolate was obtained from a nasal swab specimen. Short Gram positive bacilli in short chains and in diphtheroidal-like clusters were observed on Gram stain. Spot test results included a positive catalase and a negative indole reaction. This organism was presumptively identified as Cutibacterium (Propionibacterium) acnes. With this presumptive identification, select from the multiple choices what the next step should be.

Report with added comment: "probable contaminant"

lysine iron agar is a less commonly used cx medium that is most helpful in the identification of

Salmonella enteritidis shows the decarboxylation of H2S prod of Salmonella sp.

Serological detection of the Vi antigen aids in identification of:

Salmonella typhi Vi Ag may mask the presence of the somatic (O) Ag produced by Enterobaacteriaceae

Which one of the following parasites migrates through the circulation (blood) before maturing in the portal venous system? Please select the single best answer Schistosoma mansoni Enterobius vermicularis Taenia saginata Trichuris trichiura

Schistosoma mansoni

This antinuclear antibody (ANA) pattern is characterized by granular staining in the nuclei of the interphase cells (a). There is also an absence of staining in the chromosomal area of the metaphase mitotic cells (b). The slide is viewed using fluorescent microscopy. Which pattern is this? Please select the single best answer Homogeneous Speckled Nucleolar Centromere

Speckled

presumptive identification of a bacterial species can often be made by observing the type of hemolysis when grown on 5% sheep blood agar. Which of the following organisms is nearly always alpha-hemolytic?

Streptococcus pneumoniae pyogenes and agalactia is beta, Enterococcus can be all but tyipiclly gamma

which otf organisms is the leading cause of bacterial meningitis in infants, young children, and adults in the US?

Streptococcus pneumoniae N. mening and H. influ are 2nd and 3rd

The ability of streptococci to spread within the tissues and cause rapidly advancing cellulitis is due to the production of several virulence factors. Each of the following correctly describes the effects of the specific virulence factor EXCEPT: Please select the single best answer Streptokinase causes the hydrolysis of fibrin clots. Streptolysin O is toxic to many cell types, including neutrophils and monocytes. Streptolysin S is associated with the rash of scarlet fever and the pathogenesis of the streptococcal toxic shock-like syndrome. Hyaluronidase depolymerizes the ground substance in connective tissue.

Streptolysin S is associated with the rash of scarlet fever and the pathogenesis of the streptococcal toxic shock-like syndrome.

This suspicious form was recovered from a stool specimen. What parasite demonstrates this typical morphology?

Strongyloides rhabditiform larva S. stercoralis - short buccal cavity Ascaris hook worm - long buccal cavity

Illustrated in the upper image is the anterior portion of a nematode filariform larva with a short buccal cavity. The ovum illustrated in the lower image is also part of the life cycle of this nematode. What presumptive identification can be made from the parasite species listed below? Please select the single best answer Ancylostoma duodenale Necator americanus Strongyloides stercoralis Trichostrongylus spp.

Strongyloides stercoralis

Which is successful molecular identification of methicillin-resistant Staphylococcus aureus (MRSA) based upon?

The detection of the S. aureus (orfX, nuc, or coa) gene and the mecA gene

Two techs performed E.coli O157:H7 serotyping on a suspected colony. The serotyping uses the O157 somatic antigen as the target for agglutination. One tech performed quality control and patient samples by using a suspension of the colony and latex reagent. The results reported by the tech were positive. The second tech also did the serotyping using quality control and patient samples by using a suspension of colony, latex reagent, and the isolate suspension with the negative control. The second tech's results were negative. Quality control passed in all testing. Why did the techs obtained different results for the serotyping?

The second tech tested the suspension with negative control

which one otf parasites can cross the placenta and cause serious fetal infection?

Toxoplasma gondii

this suspicious form found in stool and measuring 10um by 5 um, is responsible for which otf diseases? Malaria Traveler's diarrhea None; considered as a non-pathogen Amebiasis

Traveler's diarrhea Pictured: Giardia lamblia

all otf parasites are correctly matched with their primary symptom, EXCEPT:

Trich vaginalis - diarrhea

inflammatory reaction of skin with erythema and micro-pustule formation, most consisitent with a dermatophyte infection. The lactophenol blue mount was prepared from a 4-day old colony. The lactophenol blue microscopic mount illustrates small, spherical conidia arranged in loose clusters along the sides of thin hyaline hyphae. The species identification can be confirmed by the positive urease reaction as shown. What is the appropriate identification?

Trichophyton mentagrophytes

Growing on the surface of the anaerobic blood agar plate illustrated in the upper image are indistinct small, gray, convex, translucent colonies free of beta hemolysis. Gram negative cocci lying singly and in clusters are seen on Gram stain, as illustrated in the lower photomicrograph. Nitrates are reduced, indole is negative, and carbohydrates are not utilized (asaccharolytic). This isolate being part of the microbiota of the mouth, upper respiratory tract and intestine. What is this organism?

Veillonella parvula

Which of the following corresponds to a way to prevent infection with Sporothrix schenckii? Please select the single best answer Avoid caves Avoid areas of roosting birds Wear gloves when gardening Wear shoes when showering in a public shower, such as gyms or dorms

Wear gloves when gardening

A Gram negative rod exhibiting bipolar staining was isolated from sheep blood agar after 24 hours of incubation. Oxidase Negative Urease Negative Catalase Positive Indole Negative Which of the following species is most probable? Please select the single best answer Brucella species Yersinia pestis Bacillus anthracis Francisella tularensis

Yersinia pestis

A respiratory culture is submitted to the microbiology lab for testing. An organism displaying the following characteristics is recovered: Gram stain shows fat, gram-negative rods in single or short chains that may demonstrate bipolar staining Faster growth at 25oC Gray-white, translucent colonies on sheep blood agar (SBA) at 24 hours that turn slightly yellow and opaque at 48 hours Irregular colonies that have a "fried egg" and/or "hammered copper" appearance after 48-72 hours Catalase positive Oxidase negative Urea negative Indole negative What is the most likely organism, based on these resullts?

Yersinia pestis

What is considered to be the technique of choice for isolating the oocysts of Cystoisospora belli and Cryptosporidium parvum? Please select the single best answer Knott technique Giemsa stain Trichrome stain Zinc sulfate flotation

Zinc sulfate flotation

The best clinical specimen for the recovery of Legionella pneumophilia is:

bronchial washings

the following statement regarding automated identification systems are correct except: may misidentify biological threat agents designed to identify rapidly growing microorganisms likely to produce aerosols during setup can reliably identify Francisella tularensis

can reliably identify Francisella tularensis