2016.3.Microbiology

Motility is a key initial assessment in the presumptive identification of the nonfermentative gram negative bacilli. Place each of the bacterial species into Bucket A if it is motile and into Bucket B if it is nonmotile.

Motile Burkholderia cepacia Motile Alcaligenes faecalis (odorans) Nonmotile Moraxella osloensis Nonmotile Chryseobacterium meningosepticum

Which of the following microorganisms should be maintained as a stock culture to check for encapsulated unknowns?

b. Klebsiella pneumoniae c. Streptococcus pyogenes b and c only

Match the organisms on the right with the culture media that bests suits their growth/identification.

Neisseria, Haemophilus Chocolate agar Anaerobes Chopped meat broth Gardnerella vaginalis Columbia CNA agar w/blood Salmonella, Shigella Hektoen enteric agar

Match each virus with its appropriate nucleic acid content:

RNA Togavirus RNA Coronavirus DNA Herpesvirus DNA Adenovirus

Surprise! Both a budding yeast with pseudohyphae and clusters of gram positive staphylococci were observed in a Gram stain smear prepared from a positive blood culture. The most likely source of infection is:

An indwelling catheter

Which of the following has a life cycle that most closely resembles that of Plasmodium sp:

Babesia microti

The colonies seen in the upper frame, grown after 48 hours incubation aerobically at 35°C, and the accompanying gram stain in the lower frame are uncommonly associated with human disease, but have been associated with septicemia, bronchopneumonia, osteomyelitis and other infections, particularly in intravenous drug users. The most likely identification is:

Bacillus circulans

Match the name of each savory mouthful of the gourmet food listed with the name of the bacterial species ready to attack.

Feta cheese Listeria monocytogenes Steak tartar Escherichia coli 0157 Egg nog Salmonella enteriditidis Oysters on a half shell Vibrio vulnificus

An 87-year old patient had a foot wound that grew gram-negative rods on McConkey agar as pink to dark pink oxidase-negative colonies along with the following results: TSI: A/A Indole: neg. MR: neg. VP: pos. Citrate: pos. H2S: neg. Urea: pos. Motility: neg. Ornithine: neg. Antibiotic susceptibility: Carboxicillin and ampicillin resistant, all others sensitive. What is the MOST likely organism?

Klebsiella pneumonia

What is the MOST likely identification of a pink yeast isolate, recovered from respiratory secretions of a patient with AIDS, that gave the following results? Germ tube - negative Urease - positive Blastospores - positive Arthrospores - negative

Rhodotorula spp.

The appearance of the bacterial colonies growing on the surface of the Hektoen Enteric agar plate shown in this photograph are consistent with each of the following bacterial species except:

Shigella sonnei

This member of the Enterobacteriaceae is shown on triple sugar iron agar, lysine iron agar, urea agar, citrate agar, phenylanine deaminase agar, and motility indole ornithine agar. The most likely identification would be:

Shigella sonnei

A day-care outbreak of diarrhea revealed an oxidase-negative, non-lactose fermenting, nonmotile, gram-negative rod. These characteristics presumptively indicate:

Shigella species

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. The most likely organism would demonstrate the following biochemical results:

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

The fastidious gram negative bacillus, often producing pitting of the agar around the colonies growing on blood agar, as illustrated in this photograph, producing a bleach-like odor is most commonly associated with one or more of the following conditions:

- "Clenched fist" infection of the hand - "Skin-popping" cellulitis

Which of the following would be the most appropriate temperature for long term storage of viral cultures:

-70° C

Among nonfermenters as a whole, I alone can produce indole.

Chryseobacterium (Flavobacterium) meningosepticum

Upon reviewing a fecal preparation for Ova and Parasites, a technologist thought he/she had just identified the egg of Taenia saginata. After a quick look, the Microbiology supervisor reminded the technologist that T. saginata eggs are indistinguishable from which of the following?

Taenia solium

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

Actinobacillus actinomycetemcomitans

What is the one test result that is the most specific in establishing an identification of Staphylococcus aureus?

A strong positive tube coagulase test

Influenza B or C related illnesses tend to be more severe than those caused by influenza A

False

The carbohydrate utilization reaction seen in the QuadFerm system shown in the image provides a definitive identification of N. gonorrhoeae.

False

A positive RPR test and a negative FTA-ABS test is most likely the result of:

False positive reaction

Which statements concerning vancomycin resistance in Enterococci are true?

- Low level vancomycin resistance is characteristic of E. gallinarum and E. casseliflavus. - Both ampicillin and vancomycin resistance are found more frequently in E. faecium than in E. faecalis.

Beta hemolytic colonies grew from the blood culture bottle after 18 hours incubation (see image). Which of following tests would be helpful in making a preliminary identification? (Choose all that apply)

- PYR - Catalase - Bacitracin susceptibility - SXT susceptibility

Ideally, a molecular section will have designated and separated areas for which of the following groups of activities? (Choose all that apply.)

- Reagent preparation, sample preparation and extraction, amplification and detection/identification - Specimen login, reagent preparation, specimen prep and amplification, detection and identification

Which of the following HPV types are most likely to be associated with cervical cancer?

16 and 18

The photograph illustrates a classic case of scrofula infection, most commonly caused by Mycobacterium scrofulaceum. The age range when this condition is most likely to appear is:

5-10 years

Match the complications that are most likely to be associated with each of the two yeast diseases that are listed in the drop-down box:

Cryptococcosis Meningoencephalitis Candidiasis Esophagogastritis Cryptococcosis Cranial nerve palsy Candidiasis Onychomycosis Candidiasis Renal abscess Candidiasis Thrush

Match each virus with its appropriate nucleic acid content:

DNA Hepatitis B virus RNA Hepatitis C virus RNA Retroviruses DNA Herpesviruses

Illustrated in this photograph is the surface of a MacConkey agar plate on which are growing colonies of a non-fermentative gram negative bacillus recovered from a wound specimen. The iridescent light pink colonies suggest Acinetobacter species. Each of the following characteristics are helpful in supporting this identification except:

Denitrification of nitrates

The laboratory test most commonly used to establish a diagnosis of primary syphilis is:

Direct fluorescent antibody test

A 42 year old chain smoker experienced an increase in cough, sputum production and intermittent shortness of breath for over one week. A diagnosis of chronic bronchitis with acute exacerbation was made. The photomicrograph is a gram stain of an early morning, spontaneously expectorated sputum. Based on the pleomorphic coccobacilli shown in the gram stain, the most likely cause of the exacerbation is:

Haemophilus influenzae

Acute obstructive epiglottitis, both in adults and children, is caused by the bacterial species shown in this split screen photograph. The colonies recovered on chocolate agar (upper frame) required both hematin and NAD, (as shown by colony growth only between the X and V strips in the lower frame). The most likely identification is:

Haemophilus influenzae

Illustrated in this photograph is a sulfide indole motility (SIM) tube (left) and an esculin hydrolysis slant (right) after inoculation with an unknown gram positive bacillus and incubation at 30°C for 24 hours. Based on the reactions observed, the most likely identification is:

Listeria monocytogenes

A process by which bacteria or other biological material are preserved through freeze drying under vacuum is termed:

Lyophilization

Which of the following Mycobacterium species is associated closely with HIV/AIDS patient infections?

M. avium-intracellulare complex

Along with Mycobacterium tuberculosis, which other mycobacterium species can cause tuberculosis of those listed below?

M. bovis M. africanum M. microti

The Thayer-Martin agar plate seen in this illustration exhibits marked growth. The most likely organism found here would be:

N. gonorrhoeae

Each of the following properties inherent in a bacterium contribute to the virulence except:

Production of opsonins

The reactions observed in this Kligler Iron Agar slant (left) and Christensen's urease slant (right) provide the presumptive identification of:

Proteus mirabilis

Prior to receiving antibiotic therapy, a patient had a urinary tract infection with gram-negative, motile rods producing the following reactions: Indole: pos. H2S (TSI): pos. MR: pos. VP: neg. Phenylalanine deaminase: pos. Urea: pos. Citrate: pos. Ornithine decarboxylase: neg Gelatin hydrolysis: pos. Based on the reations above, what organism is MOST likely causing the infection?

Proteus vulgaris

The tubes below are the Hugh and Liefson O/F basal medium with glucose and a pH indicator of bromthymol blue. The image below demonstrates a typical reaction for which organism?

Pseudomonas aeruginosa

The pigment produced on the Pseudocel agar plate illustrated in this photograph is:

Pyocyanin

Which of the yeasts listed below is known as brewer's or baker's yeast?

Saccharomyces cerevisiae

Information obtained from culture smears can allow for a more rapid diagnosis.

True

In tissues infected with Histoplasma capsulatum, which of the following is usually true?

fungus is usually intracellular

The Entamoeba histolytica trophozoite is usually characterized by the presence of the following:

small central karyosome in the nucleus, ingested RBC's

Isolation and detection of Gardnerella vaginalis from vaginal secretions is improved by which of the following?

utilization of human blood agar

Match each hyaline mold from the drop-down list to its corresponding colony and microscopic description. The mold colonies are illustrated in the image on the right.

- Fusarium species - Colony in upper left quadrant (orange sphere); micoscopic description: Multi-celled, sickle-form macro - Scedosporium apiospermum - Colony in upper right quadrant (grayish-brown spherical shape); microscopic description: Dark, elliptical conidia each supported by a conidiophore ("lollipops") - Penicillium species - Colony in bottom left quadrant (lilypad-like shape); microscopic description: Chains of spherical conidia produced from branching phialides. - Gliocladium - Colony in bottom right quadrant (green sphere with yellow inner circle); microscopic description: Tight clusters of spherical conidia held by finger-like phialides.

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:

Bacteroides fragilis group

It may come as some surprise that odors emitted by bacterial colonies may be helpful in making a preliminary identification. Match the names of each of the odors listed with its most likely bacterial species association.

Barnyard Clostridium difficile Bleach Eikenella corrodens Burned chocolate Proteus vulgaris Mothballs Pasteurella multocida

A presumptive identification of a bacterial species can often be made by observing the type of hemolysis when grown on blood agar. Match the name of each of the bacterial species listed with either Bucket A (alpha hemolytic) or Bucket B (beta hemolytic) depending on its usual hemolytic activity on 5% sheep blood agar.

Bucket B Streptococcus pyogenes Bucket A Streptococcus pneumoniae Bucket A Streptococcus salivarius Bucket B Streptococcus agalactiae

The stage of viral replication where the envelope is being acquired and the HIV is leaving the host cell is known as:

Budding

The black colonies growing on the surface of this cystine-tellurite agar plate, with black pigment diffusing into the surrounding medium, is one of the characteristics of Corynebacterium diphtheriae. Another closely related Corynebacterium species that may have a similar appearance on tellurite agar is:

C. ulcerans

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 that were examined. Which one of the two results represents a sputum specimen that is acceptable for culturing?

Gram stain A

Spinal fluid cultures on a 3-day-old infant revealed beta-hemolytic, Gram-positive cocci occurring in pairs and chains. The organism was catalase-negative and bile esculin-negative. Resistance to 0.04 U disk of bacitracin was noted. The other test necessary to identify this organism is a positive test by:

CAMP

An unknown isolate has been inoculated to two agar plates on which either a CAMP test (Bucket A) or an optochin disk test (Bucket B) has been performed. Match each of the conditions listed with Bucket A or Bucket B depending upon which positive test the bacterial species recovered would be most likely associated.

CAMP test (Bucket A) Meningitis in the newborn Optochin disk test (Bucket B) Adult meningitis CAMP test (Bucket A) Neonatal sepsis Optochin disk test (Bucket B) Otitis media Optochin disk test (Bucket B) Community acquired pneumonia

Human dog bite infections may be caused by each of the following bacterial species except:

Capnocytophaga ochracea

Different species of Neisseria can be differentiated from each other by:

Carbohydrate utilization

The bacterial species represented by the positive test illustrated in the photograph of a 5% sheep blood agar plate cross streaked with a hemolytic strain of Staphylococcus aureus has been associated with each of the following conditions except:

Carcinoma of the colon

Which of the following is a selective media recommended for the isolation of Clostridium difficile?

Cefoxitin-cycloserine-fructose agar (CCFA)

A 25 year old man was experiencing some difficulty in chewing and swallowing food. He had incurred a deep laceration of the lower leg in a lawn mower incident one week before. The wound was healing but signs of infection persisted. The photomicrograph shown here portrays a gram stain of a spreading, gray colony isolated from an aspirate of the wound, incubated under anaerobic conditions. Three additional bacterial species were recovered on blood agar incubated aerobically. The most likely identification is:

Clostridium tetani

Match the names of each of the yeast species with its most likely colony morphology as seen in the images on the right.

Cryptococcus neoformans Upper left Geotrichum candidum Upper right Candida albicans Lower left Rhodotorula rubra Lower right

The India ink preparation is used as a presumptive test for the presence of which organism?

Cryptococcus neoformans in CSF

Which statement about bacterial culture for Clostridium difficile is TRUE?

Culture on appropriate media provides an effective means of recovering the organism.

This organism has been placed in tryptocase soy broth and then streaked on a nutrient agar plate. Strips contain X, V, and XV were place on the plate and it was incubated 24 hours with CO2. What is the identification of this organism?

Haemophilus influenzae

Match the names of the organisms listed with the appropriate bucket indicating whether each more commonly causes disseminated (septicemic) or localized infections.

Disseminated infection Vibrio vulnificus Localized infection Staphylococcus aureus Localized infection Erysipelothrix rhusiopathiae Disseminated infection Salmonella typhi

Which of the following serological tests would be used for the diagnosis of Q-fever:

EIA or indirect immunoflourescence

The long pencil-shaped, multi-celled, thin, smooth-walled macroconidia illustrated in this photomicrograph are characteristic of:

Exserohilum species

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 delicate cob-web appearance of the colonies on blood agar (upper image) and the production of macroconidia with a conspicuous prickly surface as seen in the lower image are characteristic of:

Histoplasma capsulatum

Based on the results of two in-vitro susceptibility testing, patients with septicemia from each of the bacterial species listed below can potentially be treated with vancomycin except:

Leuconostoc mesenteroides

It may be of surprise that the identification of a gram positive bacillus may be suspected based on the Gram stain morphology. Match each of the names of each the bacterial genera listed with the letter of its most likely photomicrograph.

Nocardia species A Lactobacillus species B Bacillus species C Corynebacterium species D

The microscopic appearance of the multi-celled dictyospores of this dematiaceous mold have been referred to as "bales of cotton" on a stick. This feature is characteristic of:

Stemphylium species

Each of the following bacterial species work synergistically to produce bacterial vaginosis except:

Streptococcus agalactiae

A 67 year-old man was seen in the emergency room complaining of cough, fever, and piercing right posterior chest pain. X-ray of the chest revealed consolidation of the right middle lobe of the lung. A sputum culture grew the bacterial species shown in the upper photograph. The lower photomicrograph illustrates a gram-stain of the sputum specimen. The most likely cause of the pneumonia is:

Streptococcus pneumoniae

The curved, multi-celled, dark brown staining macroconidia divided by transverse septa that can be observed in the photomicrograph on the right is characteristic of which of the following species of dematiaceous fungi?

Curvularia species

Who am I, here in this mush, Looking like a test tube brush?

Erysipelothrix rhusiopathiae

Which of the following dematiaceous fungal species produce conidia in clusters?

Exophiala species

The hyaline mold illustrated in this photomicrograph can be identified as:

Gliocladium species

The term "HACEK" is often associated with infective endocarditis. Which of the following organisms is NOT included in the "HACEK" group?

Hemophilus influenzae

Match the viruses below with their associated diseases.

Hepadnavirus Hepatitis Arbovirus Encephalitis Parvovirus Fifth disease Paramyxovirus Measles-Mumps

Which of the following staining methods would you use to demonstrate the metachromatic granules of Corynebacterium diphtheriae:

Methylene blue

Tiny translucent gray colonies were recovered on blood agar from a patient with purulent conjunctivitis. Gram negative diplococci were seen on Gram stain. The preparation illustrated in this photomicrograph was obtained from colonies growing at the margin of inhibition of a 10ug/ml penicillin disk. The most likely identification is:

Moraxella lacunata

Acinetobacter species are similar to Neisseriaceae with the exception that Acinetobacter species are generally:

Oxidase negative

Match the organism names from the drop down box to the name of the associated condition listed below.

Plasmodium ovale Malaria Trypanosoma cruzi Chagas' Disease Cestodes Tapeworms Trypanosoma rhodesiense Sleeping Sickness

A class II, or higher, biological safety cabinet (BSC) must be used when manipulating potential bioterrorism agents or if aerosols are likely.

True

This parasite resides in human intestine.

Taenia solium scolex

The bacterial species belonging to the HACEK group can be linked to specific clinical conditions. Match the names of the bacterial species with the name of its most likely associated infection.

- Actinobacillus actinomycetemcomitans - Localized juvenile periodontitis - Cardiobacterium hominis - Culture negative endocarditis - Eikenella corrodens - Clenched fist infection - Kingella kingae - Juvenile osteomyelitis

With regards to identifying resistance in enterococci, which general statements are true?

- Both disk diffusion and broth microdilution tests should be incubated a full 24 hours to detect vancomycin resistance. - BHI agar with 6 ug/mL vancomycin can be employed as a screening methodology for vancomycin resistance. - Methodologies employed should also address the detection of high level resistance to gentamicin and streptomycin.

A 70 year old man who had incurred a cerebral vascular accident three days previously was semicomatose and having difficulty breathing. He developed sudden fever overnight and was found to have pneumonia. The gram stain shown in this photomicrograph was obtained from purulent material obtained through the intubation tube. The most likely diagnosis is:

Aspiration pneumonia

The lecithin hydrolysis, indicated by the tips of the arrows in this photograph of an egg yolk agar plate, may be produced by each of the following Bacillus species except:

Bacillus subtilis

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 Blastomyces dermatitidis. However, there is the possibility that this mold represents its saprophytic counterpart, which is called:

Chrysosporium species

A Gram-negative rod from a stool culture produces red colonies with black centers on XLD (Xylose Lysine Decarboxylase) agar. When it is inoculated to triple sugar iron agar and lysine iron agar, it should appear as which of the sets of tubes in the photograph below?

Left

Look, look, can you not see What penicillin has done to me?

Moraxella osloensis

Which of the following media is commonly used when performing the Kirby-Bauer disk diffusion?

Mueller-Hinton agar

The Mycobacterium species capable of growing on modified MacConkey agar (crystal violet removed from the formula), as illustrated in this photograph, is:

Mycobacterium fortuitum

The Mycobacterium species most likely associated with the skin lesions shown in this photograph, representative of "swimming pool granuloma" is:

Mycobacterium marinum

The cytochrome oxidase-positive bacterial species that is DNAse negative, ornithine positive, and is associated with gastroenteritis in children is most likely:

Plesiomonas shigelloides

Clear colonies are growing on Sorbitol MacConkey agar in the clinical laboratory. When viewing the image shown here, WHICH SET of Lysine Iron Agar slants and Kligler's Iron Agar slants would correlate with clear colonies growing on MacConkey agar?

Set three