BOC Microbiology Practice Questions
The fastidious gram negative bacillus, often producing pitting of the agar around the colonies growing on blood agar, producing a bleach-like odor is most commonly associated with one or more of the following conditions: - "Clenched fist" infections of the hand - Juvenile periodontitis - Pneumonia - Dog bite cellulitis
"Clenched fist" infections of the hand
A mid-stream, clean catch urine is submitted for culture on an elderly patient. The media is inoculated using a .001 mL loop and grows 74 dark pink colonies on MAC agar. Consider the following results: TSI = A/A, Oxidase = -, Motility = +, Indole = -, Citrate = +, VP = +, Lysine decarboxylase = -, Ornithine decarboxylase = +, Urea = - How should this organism be reported out? - 74,000 CFU/mL Enterobacter cloacae - 740 CFU/mL Serratia marscecens - 7,400 CFU/mL Providencia stuartii - 74,000 CFU/mL Klebsiella oxytoca
74,000 CFU/mL Enterobacter cloacae
With its ability to grow at 45C, the Aspergillus species most commonly recovered from hospital heat vents and air ducts, serving as the primary environmental source of hospital-acquired respiratory infection, is: - A. flavus - A. fumigatus - A. terreus - A. niger
A. fumigatus
Consider the following results on a nonseptate mold: Colony morph = many gray colonies, cotton-candy appearance, Microscopic = sporangiophores between rhizoids, producing pear-shaped sporangia Which of the following is most likely present? - Aspergillus spp - Penicillium spp - Rhizopus spp - Absidia spp
Absidia spp
Direct Gram stain from a peritoneal fluid specimen appeared as Gram-positive cocci. After 24 hours, clear, convex, entire colonies grew on blood agar and faint lavender colonies were noted on MacConkey, grown aerobically. Gram stain was repeated and appeared as Gram-negative coccobacilli. The isolate was oxidase negative, catalase positive, non-motile, and resistant to penicillin. What is the presumptive identification? - Acinetobacter baumannii - Pseudomonas aeruginosa - Neisseria species - Moraxella catarrhalis
Acinetobacter baumannii
The bacterial species growing on the surface of the MAC plate is a coccobacillary non-fermenter and a common cause of nosocomial hospital-acquired pneumonia and can be presumptively identified as: - Acinetobacter baumannii - Burkholderia cepacia - Moraxella catarrhalis - Neisseria lactamica
Acinetobacter baumannii
Of the following, which genus is catalase-positive, oxidase-negative small, gram-negative coccobacilli that are mostly associated with animals, but may be attributed to wound and dental infections, bacteremia, and endocarditis in humans? - Campylobacter - Acintobacillus - Pseudomonas - Vibrio
Acintobacillus
What are the 4 nitrogenous bases that are found in RNA? - Adenine, guanine, cytosine, thymine - Adenine, guanine, cytosine, uracil - Adenine, guanine, uracil, thymine - Adenine, uracil, cytosine, thymine
Adenine, guanine, cytosine, uracil
Dematiaceous molds can be broadly separated into two major groups: the agents of chromomycosis and clinically insignificant commensals or contaminants. Which of the statements below is true? - Agent of chromomycosis grow more slowly than clinically insignificant commensals or contaminants - Agent of chromomycosis grow more rapidly than clinically insignificant commensals or contaminants - Agent of chromomycosis grow at the same rate as clinically insignificant commensals or contaminants - Agents of chromomycosis don't grow in vitro, where clinically insignificant commensals or contaminants do
Agent of chromomycosis grow more slowly than clinically insignificant commensals or contaminants
The bacterial species commonly found in associated with deep tissue actinomycosis is: - Actinobacillus spp - Streptococcus spp - Aggregatobacter aphrophilus - Aggregatibacter actinomycetemcomitans
Aggregatibacter actinomycetemcomitans
Which class of antibiotics would be most effective in treatment of an infection caused by a gram-negative bacteria or one caused by Mycobacterium tuberculosis? - Tetracyclines - Aminoglycosides - Penicillins - Cephalosporins
Aminoglycosides
The eggs of Necator Americans are basically indistinguishable from the eggs of: - Ancylostoma duodenale - Ascaris lumbricoides - Trichinella spiralis - Trichuris trichura
Ancylostoma duodenale
When is the phenotypic property of Saccharomyces yeast species that is helpful in establishing its species identification? - Polysaccharide capsule - Ascospore production - Trehalose assimilation - Slow growing yeast
Ascospore production
All of the following fungi are appropriately listed with their respective morphology, except? - Syncephalastrum spp produce merosporangia - Fusarium spp produce macroconidia - Coccidioides immitis produces arthroconidia - Aspergillus spp produce ascospores
Aspergillus spp produce ascospores
Which of the following is a presumptive test for the identification of Lancefield group A Streptococcus? - Bacitracin susceptibility - Positive coagulase - Hippurate hydrolysis - Gram stain
Bacitracin susceptibility
The production of polar germ tubes is a characteristic that is associated with which of these dematiaceous fungi? - Alternaria species - Phialophora verrucosa - Bipolaris species - Curvularia species
Bipolaris species
Consider the following results on an isolate from a CSF specimen, growing on cornmeal agar: Blastospores = +, Pseudohyphae = -, Chlamydospores = -, Arthrospores = - Which of the following tests should be performed next? - Birdseed agar and urease - India ink and glucose - India ink and germ tube - Germ tube and glucose
Birdseed agar and urease
Which culture medium is specifically formulated to recover Salmonella type from stool specimens? - Selenite broth - Bismuth sulfite agar - Salmonella/Shigella (SS) agar - Deoxycholate citrate agar
Bismuth sulfite agar
Which of the following would be best for recovering B. pertussis from a nasopharyngeal specimen? - MacConkey agar - Chocolate agar - Blood agar - Bordet-Gengou agar
Bordet-Gengou agar
Bordet-Gengou potato infusion agar is the medium of choice for the recovery of which of the following organisms? - Bordetella pertussis - Corynebacterium diphtheriae - Haemophilus influenzae - Neisseria meningitidis
Bordetella pertussis
The recovery of Mycoplasma hominis from the genital tract of females has been associated with all of the following clinical syndromes except: - Premature rupture of membranes - Delivery of low birth weight infants - Bronchitis - Prematurity
Bronchitis
A parasite is found in blood, is sheathed, and measures 200 um. From the parasites listed, what is the correct identification? - Brugia malayi microfilaria - Loa loa microfilaria - Wuchereria bancrofti microfilaria - Onchocerca volvulus microfilaria
Brugia malayi microfilaria
An organism is recovered from a vaginal culture from a 24-year-old patient who is 32 weeks pregnant. The gram stain reveals gram positive cocci, colonies on blood agar are beta-hemolytic and biochemical testing shows that the organism is catalase negative. Which tests are necessary for further identification - PYR, bile solubility, optochin - Glucose, CAMP, oxidase - Methicillin, PYR, coagulase - CAMP, PYR, bacitracin
CAMP, PYR, bacitracin
Which of the following sample types should be processed first for a culture and Gram stain? - CSF - Wound swab in transport medium - Clean catch urine - Endotracheal aspirate
CSF
Which stain is a colorless dye that binds to chitin in fungi and fluoresces with ultraviolet light? - Gram stain - Calcofluor white - Acridine orange - Trichrome
Calcofluor white
After a one week visit in the Philippines, a 42-year-old male missionary had noticed a gradual onset of abdominal pain, belching, and intermittent diarrhea during the past month. Upon further examination, dehydration and electrolyte imbalances with low plasma levels of potassium, sodium, and calcium were detected. A 60 um ovum was observed in the stool preparation. Select the correct presumptive identification from the choices below. - Trichostrongylus - Necator americanus - Capillaria philippinensis - Trichuris trichuria
Capillaria philippinensis
Which of the following is the primary virulence factor in Streptococcus pneumoniae? - Lipoteichoic acids - Capsular polysaccharide - M protein - Protein A
Capsular polysaccharide
Human infection of the Schistosomes occurs following penetration of what morphologic form into the skin? - Eggs - Miracidia - Rediae - Cercariae
Cercariae
A conjunctival smear from a 3-week-old baby is sent to the lab for analysis. Upon examination of a Wright-stained smear, the microbiologist identifies granular cytoplasmic perinuclear inclusions. Which of the following is the most indicative of? - Cytomegalovirus - Varicella-Zoster virus - Chlamydia trachomatis - Herpes simplex virus
Chlamydia trachomatis
A specimen is sent to the lab from a male patient. The label indicates that is urethral discharge. Which of the following media should be used for culture? - Eosin-methylene blue and sheep blood agars - Sheep blood and phenylethyl alcohol agars - Chocolate and modified Thayer-Martin agars - Thioglycollate broth and chocolate agar
Chocolate and modified Thayer-Martin agars
A patient grew out Mycobacterium tuberculosis (MTB) from an acid fast bacilli (AFB) sputum culture. The physician called requesting information on alternative choices for the treatment of MTB, since the patient had tested resistant to the primary drugs of choice. Which of the following anti tubercular agents would be recommended for treatment? - Streptomycin - Isoniazid - Ciprofloxacin - Ethambutol
Ciprofloxacin
This member of the Enterobacteriaceae was isolated from a stool specimen and gave the following biochemical reactions: TSI = K/A with no gas & no H2S, Citrate = +, Lysine decarboxylase = -, Ornithine decarboxylase = +, Indole = -. This organism agglutinated in Group D Shigella antiserum. All of the above biochemical results are consistent with this identification, except? - TSI - Citrate - Lysine - Indole
Citrate
Consider the following information on a gram-positive bacilli recovered from blood cultures drawn on a 55-year-old patient with diabetes: Spore formation = -, Hemolysis = beta, double zone, Motility = -, Lecithinase = +, Volatile acids by gas-liquid chromatography (PYG) = A (acetic acid) & B (butyric acid) Which of the following organisms is most likely present? - Clostridium perfringens - Clostridium sporogenes - Clostridium tetani - Clostridium novyi (B)
Clostridium perfringens
The disease most commonly associated with the novobiocin-resistant staphylococcus illustrated in this photograph is: - Septic arthritis - Community-acquired urinary tract infections - Endocarditis - Wound infection
Community-acquired urinary tract infections
Presumptive identification of which of the following organisms could be made using the germ tube test, niger seed agar test, and urease test? - Trichosporon pullulans - Cryptococcus neoformans - Candida neoformans - Candida albicans
Cryptococcus neoformans
If you receive a transudate fluid for a Gram stain and bacterial culture, what is the ideal specimen preparation method for the Gram stain? - One drop of original sample on a slide to create an appropriate smear - Cytocentrifugation to create an appropriate smear - Use two slides smashed together with the original sample in between to create an appropriate smear - Dip a swab into the original sample and place it on a slide to create an appropriate smear
Cytocentrifugation to create an appropriate smear
The eggs of this parasite arrange themselves in membrane-enclosed clusters known as packets: - Hymenolepsis nana - Diphyllobothrium latum - Dipylidium caninum - Taenia species
Dipylidium caninum
A 19-year-old male is suspected of having HSV-2 (genital herpes simplex) infection. Which of the following tests would provide the most rapid definitive diagnosis? - Titer of serum and seminal fluid for antibodies to herpes simplex - Cell culture of vesicle fluid - Direct immunofluorescence test for viral antigen in vesicle fluid - Detection of antiheroes simplex in seminal fluid
Direct immunofluorescence test for viral antigen in vesicle fluid
Which one of the following statements about Campylobacter jejuni is false? - Can occur in domestic animals, raw milk, and undercooked poultry - Does not require special incubation conditions to grow in culture - Is associated with neutrophils in the stool - Is a curved gram negative rod
Does not require special incubation conditions to grow in culture
Which of the following clinical symptoms are not a match with the corresponding disease listed? - Hemoptysis -- Paragonimiasis - Dysentery -- Enterobiasis - Central nervous system symptoms -- Toxoplasmosis in a compromised host - Watery diarrhea -- Cryptosporidiosis
Dysentery -- Enterobiasis
Found in a trichrome-stained mount of a stool specimen, are small 8-10 um amoebic cysts. There are 4 nuclei each containing a large karyosome with no peripheral chromatin. Select the presumptive identification: - Iodamoeba butschlii - Chilomastix mesnili - Endolimax nana - Entamoeba hartmanni
Endolimax nana
Which of the following parasites causes both intestinal and extraintestinal amebiasis? - Entamoeba coli - Endolimax nana - Iodamoeba butschlii - Entamoeba histolytica
Entamoeba histolytica
A unidentified colony was inoculated to the surface of a filter paper strip impregnated with cytochrome oxidase reagent (dimethyl-p-phenylenediamine dihydrochloride), resulting in a positive reaction. The family of bacteria rules out by this reaction is: - Pasteurellae - Neisseriaceae - Enterobacteriaceae - Pseudomonadaceae
Enterobacteriaceae
Which of the following is the salt tolerance test (6.5% NaCl broth) used for presumptive identification of? - Streptococcus bovis - Enterococcus faecalis - Streptococcus equinis - Streptococcus pneumoniae
Enterococcus faecalis
A non-hemolytic organism was isolated from the blood culture of a patient. The organism's reaction in 6.5% NaCl broth was positive and the reaction on bile esculin agar revealed + H2S. With further testing, this isolate will most likely be identified as: - Streptococcus pneumoniae - Enterococcus spp - Streptococcus agalactiae - Streptococcus bovis
Enterococcus spp
Consider the following test results on a 21-year-old female student with sore throat, extreme fatigue, and lymphadenopathy. Lab results indicated that the rapid test for infectious mononucleosis antibodies was negative. Bacterial cultures were also negative, as were serological tests for antistreptolysin O (ASO), CMV, Hepatitis B, HIV-1, Influenza A, and Influenza B. - West Nile Virus - Epstein-Barr Virus - Herpes simplex virus - Rubella
Epstein-Barr Virus
Which of the following viruses requires a complex lymphoblastic cell culture, and is rarely, if ever, diagnosed by culture? - Varicella-Zoster virus - Herpes Simplex virus - Cytomegalovirus - Epstein-Barr virus
Epstein-Barr virus
Which of the following organisms shows a characteristic "test tube brush-like" pattern at 22C? - Listeria monocytogenes - Pseudomonas fluorescens - Erysipelothrix rhusiopathiae - Enterococcus casseliflavus
Erysipelothrix rhusiopathiae
Which of the following is true regarding Streptococcus spp? - Facultative anaerobe, oxidase-negative, catalase-negative - Aerobic, oxidase-positive, and catalase-positive - Facultative anaerobe, beta hemolytic, catalase-positive - May be alpha, beta, or gamma hemolytic, catalase-positive
Facultative anaerobe, oxidase-negative, catalase-negative
A 20 mm mature adult fluke that has a normal habitat in the liver bile ducts. Humans become infected by ingesting raw or undercooked water plants contaminated with infective metacercaria. These adult flukes are only observed during surgery involving the liver or at autopsy. Intermittent upper abdominal discomfort and low grade jaundice may be experienced. Select the presumptive identification of this fluke. - Clonorchis sinensis - Fasciola hepatica - Faciolopsis buski - Paragonimus westermani
Fasciola hepatica
Which biochemical tests are used to differentiate between Micrococcus spp and Staphylococcus spp? - Catalase test - Oxidation of glucose (OF tube) - Fermentation of glucose (OF tube) - Gram stain
Fermentation of glucose (OF tube)
Trichomonas, Giardia, and Chilomastix belong to the following parasitic group based on the type of motility: - Amoebae - Flagellates - Ciliates - Microsporidia
Flagellates
In tissues infected with Histoplasma capsulatum, which of the following is usually true? - Hyphae usually invade blood vessels - Encapsulated yeast cells are typical - Conidiophores with metulae and phial ides are typical - Fungus is usually intracellular
Fungus is usually intracellular
At 48 hours of incubation, an anaerobic culture grew non-pigmented, gram-negative rods on BAP. Thin bacilli with pointed ends were observed on the gram stain and the colonies were irregular, dry, white breadcrumb-like in appearance with greening of the agar present. Consider the following results: Kanamycin = S, Vancomycin = R, Colistin = S, Growth on 20% bile agar = -, Nitrate = -, Indole = +, Catalase = -, Lipase = -, Urease = - Which of the following is most likely present? - Fusobacterium nucleatum - Clostridium perfringens - Peptostreptococcus spp - Bacteriodes fragilis
Fusobacterium nucleatum
Observation of each of the following characteristics is helpful in differentiating between Nocardia species and Mycobacterium species except: - Partial acid fast staining - Filamentous rods that branch - Musty basement smell of the colonies - Gram positive staining
Gram positive staining
All of the following would be suitable for identification of bacterial antigens, except? - Agglutination reactions - Gram stain reactions - Immunofluorescence methods - Precipitin reactions
Gram stain reactions
A medical technologist looking to differentiate Listeria monocytogenes and group B strep would likely perform which of the following tests? - Oxidase, bacitracin - Gram stain, CAMP test, TSI/H2S - Gram stain, catalase, motility at 20-25C - Oxidase, glucose, CAMP test
Gram stain, catalase, motility at 20-25C
Blood cultures on a 5-day-old gave the following results: Gram stain = gpc in chains, Beta hemolysis, CAMP test = +, Hippurate hydrolysis = -, Salt tolerance = +, Bile solubility = -, Bile esculin = -, Bacitracin = resistant, PYR = -, Trimethoprim/sulfamthoxazole = resistant Which of the following is most likely present? - Group B streptococci - Group D streptococci - Group A streptococci - Nongroup A, nongroup B, nongroup D streptococci
Group B streptococci
All of the following organisms have been linked to cause endocarditis except? - Aggregatibacter aphrophilus - Cardiobacterium hominis - Eikenella corrodens - Haemophilus influenzae
Haemophilus influenzae
Small, minute, colonies are growing around a colony of Staphylococcus aureus on sheep blood agar. Which of the following is this a characteristic? - Haemophilus influenzae - Abiotrophia species - Moraxella catarrhalis - Haemophilus ducreyi
Haemophilus influenzae
The CSF of a 2-year-old, sent to the lab for culture produces the following results: Gram stain = gram-negative coccobacilli, Hemolysis = -, Indole = +, Urease = +, Lactose = -, Sucrose = -, Glucose = + (acid), X requirement = +, V requirement = + Which of the following organisms is most likely present? - Haemophilus aphrophilus - Haemophilus ducreyi - Haemophilus parainfluenzae - Haemophilus influenzae
Haemophilus influenzae
Which of the following would best assist in recovery and identification of most fecal pathogens from a stool culture? - MacConkey, blood, birdseed, and Campylobacter (Campy) agars - Blood, Campy, Mueller-Hinton agars, and thioglycollate media - CNA and Christensen urea agars and thioglycollate meda - Hektoen, MacConkey, Campy, colistin-nalidixic acid (CNA) agars
Hektoen, MacConkey, Campy, colistin-nalidixic acid (CNA) agars
H. pylori can be differentiated best from Campylobacter jejuni using which tests? - Hippurate hydrolysis, nitrate, urease - Sensitivity to cephalothin, oxidase, catalase - Nalidixic acid sensitivity, oxidase, catalase - Gram stain, catalase, oxidase
Hippurate hydrolysis, nitrate, urease
The transmission of which of the following organisms is associated with the guano of bats? - Blastomyces dermatitidis - Histoplasma capsulatum - Coccidioides immitis - Paracoccidioides brasilensis
Histoplasma capsulatum
Enteroviruses are common etiologic agents of pericarditis and myocarditis. To identify a viral infection, viral cultures or immunoassays are typically the tests of choice. However, viral nucleic acid probe testing may be most appropriate in which of the following situations? - If the immunoassay has increased specificity - If viral culture is too slow to grow or not possible - If the immunoassay has increased sensitivity - The viral load is low
If viral culture is too slow to grow or not possible
The following test many be performed on all swarming Proteus species to differentiate between P. mirabilis and P. vulgarisms: - Catalase - Indole - Oxidase - Motility
Indole
The acronym IMViC, used for identification and differentiation of Enterobacteriaceae, stands for: - Indole, Methyl Red, Voges-Proskauer, Coagulase - Indole, Methyl Red, Voges-Proskauer, Catalase - Methyl Red, Voges-Proskauer, Iron, Catalase - Indole, Methyl Red, Voges-Proskauer, Citrate
Indole, Methyl Red, Voges-Proskauer, Citrate
When differentiating between E. coli and Shigella spp, which would be most helpful? - Hydrogen sulfide, citrate, MR, urease - Indole, lactose, motility, ONPG - VP, citrate, gas - Hydrogen sulfide, VP, citrate, urease
Indole, lactose, motility, ONPG
In addition to colony morphology, which of the following biochemical tests and media would be most helpful in the rapid identification of the Enterobacteriaceae? - MRVP, urease, and blood agar - Indole, oxidase, MAC, and blood agar - Bacitracin, B-lactamase, and MAC - PAD, urease, and CDC agar
Indole, oxidase, MAC, and blood agar
Which of the following anthrax infections is also known as "wool sorter's disease"? - Cutaneous anthrax - Gastrointestinal anthrax - Inhalation anthrax - Injectional anthrax
Inhalation anthrax
A 27-year-old female graduate student recently returned from South America, where she completed a nature study of the rainforest. She spent months "living off the land". The women went to her physician seeking treatment for a sinus infection, which she thought was responsible for several recent bouts of diarrhea. Upon questioning the patient, the doctor decided to collect stool for culture and parasitic examination. The stool culture was reported as "no enteric pathogens isolated". A suspicious form was seen on both wet prep and on a permanent stain. It measures 17 um. The identity of this form is most likely: - Endolimax nana - Giardia lamblia - Iodamoeba butschlii - Pseudoparasite
Iodamoeba butschlii
The microscopic identification of Coccidiodes immitis relies on the presence of which of the following structures? - Tuberculate, thick-walled macroconidia - Small pyriform microconidia - Thick-walled sporangia containing sporangiospores - Irregular staining, barrel-shaped arthrospores
Irregular staining, barrel-shaped arthrospores
A technologist performed susceptibility testing via the disk diffusion method on 7H11 plates, on a specimen from a patient with classic TB. Which of the following are first-line antibiotics that would be prescribed for treatment of this? - Isonicotinic acid hydrazine (INH), rifampin, ethambutol - Ampicillin, penicillin, carbenicillin - Ampicillin, penicillin, methicillin - Vancomycin, methicillin, carbenicillin
Isonicotinic acid hydrazine (INH), rifampin, ethambutol
A tech is working on a wound culture and identifies Staph aureus in the culture. When inputting data into the patient report in the LIS, the tech accidentally enters Staph epidermidis instead. How should the tech handle correcting this report? - Simply remove S epidermidis and replace it with S aureus - Issue a corrected report which indicates both the initial incorrect report and the correct report - Issue a corrected report which indicates the correct result only - No correction is needed as these organisms would be treated the same in a wound culture
Issue a corrected report which indicates both the initial incorrect report and the correct report
A sputum specimen submitted for culture is brick red in color. The organism causing this sputum color, also has a distinct polysaccharide capsule and is non-motile. What organism can be associated with this sputum? - Yersinia - Pasteurella - Salmonella - Klebsiella
Klebsiella
A MAC plate grows mucoid, lactose fermenting colonies. A Mueller-Hinton plate has a ceftazadime and ceftazadime/clavulanic acid mixed disk. There is a larger zone of inhibition around the combination disk which is an indicator for extended spectrum beta lactamase (ESBL) activity. Which of the following organisms fits this situation? - Proteus mirabilis - Klebsiella pneumoniae - Enterobacter aerogenes - Serratia marcescens
Klebsiella pneumoniae
Consider the following results on a leg culture from a nursing home patient: MacConkey = lactose-fermenter, oxidase-negative colonies, TSI = A/A, MR+VP = -, +, Indole = -, Citrate = +, Urease = +, H2S = -, Motility = - Antibiotic susceptibility testing indicated that the organism was resistant to carbenicillin and ampicillin. Which of the following organisms is most likely present? - Enterobacter cloacae - Proteus vulgaris - Klebsiella pneumoniae - Serratia marcescens
Klebsiella pneumoniae
Tiny gray-white, non-hemolytic colonies that are nondescript grew on blood agar. The Gram stain reveals elongated, rectangular gram-positive bacilli in short chains. Key to the identification would be the lack of biochemical activity. This bacterium is usually recovered as a genital tract commensal, but has also been found to provide protection against other infective bacteria. With these observations, what is the most likely identification of the isolate? - Bacillus cereus - Oerskovia xanthineolytica - Lactobacillus species - Actinomyces species
Lactobacillus species
A vaginal culture is submitted on a 23-year-old female. The gram stain shows a thin, non-spore forming bacilli, forming chains and palisades. The organism is subbed onto tomato juice agar where it grows well. Which of the following is most likely present? - Bacillus spp - Neisseria spp - Lactobacillus spp - Streptococcus spp
Lactobacillus spp
A beta-hemolytic gram-positive cocci, isolated from the CSF of an infant, grew on sheep blood agar under aerobic conditions and was resistant to a bacitracin disk. Which of the following tests should be performed for the presumptive identification of the organism? - Oxidase production - Catalase formation - Latex agglutination test - Esculin hydrolysis
Latex agglutination test
A 21-year-old pregnant woman in her 3rd trimester was brought to the ED with fever, diarrhea, and other flulike symptoms. Blood and urine were both taken for cultures. Urine cultures had no growth after 24 hours, while blood cultures grew short, gram-positive rods aerobically on BAP. Consider the following results from the blood cultures: Colony morph = smooth and small, similar to Strep spp, narrow zone of beta hemolysis, Catalase = +, Motility = + (wet mount = tumbling), Glucose = + (acid), Esculin hydrolysis = + Which of the following organisms is most likely present? - Streptococcus pneumoniae - Corynebacterium spp - Streptococcus agalactiae - Listeria monocytogenes
Listeria monocytogenes
Of the organisms listed, which is most likely to be contracted following consumption of unpasteurized milk? - Erysipelothrix rhusiopathiae - Listeria monocytogenes - Clostridium tetani - Pasteurella multocida
Listeria monocytogenes
Which organ is the primary target of the hepatitis B virus? - Heart - Liver - Lungs - Blood cells
Liver
Which of the following culture media should be used to attempt to recover mycobacteria from a clinical specimen? - MacConkey agar - Lowenstein-Jensen (LJ) medium - PPLO agar - Modified Thayer-Martin agar
Lowenstein-Jensen (LJ) medium
All of the following are virulence factors utilized by Streptococcus pneumoniae to evade host defenses when causing meningitis, except: - Polysaccharide capsule - Pneumolysin - Hyaluronidase - M protein
M protein
Which Mycobacterium species will have a negative result for niacin, nitrate reduction, Tween hydrolysis (5 days), and iron uptake? - M. tuberculosis - M. kansasii - M. bovis - M. gordonae
M. bovis
A 3-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 +, Nitrate reduction +, Arylsulfatase +, MAC growth 5 days + It should be identified as: - M. avium complex - M. fortuitum - M. chelonae - M. kansasii
M. fortuitum
A track star was in the locker room after a competition when one of his teammates noticed light brown circular lesions on his back. The agent most likely responsible for this condition is: - Candida albicans - Tinea versicolor - Sporobolomyces spp - Malassezia furfur
Malassezia furfur
A swab from a diabetic ulcer is sent to the lab for culture and yields the following results: Colony morph = creamy, pale yellow, B-hemolytic colonies on BAP, Catalase = +, Glucose OF = open tube +, sealed tube -, Mannitol salt = - Slide coagulase = - Which of the following is likely present? - Micrococcus spp - Staphylococcus epidermidis - Staphylococcus aureus - Streptococcus spp
Micrococcus spp
When performing sequence-based analysis to identify a bacterial isolate, all of the following must occur to ensure accurate results are obtained except? - 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
Carbapenemases are produced by various organisms such as Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter spp. Detecting the presence of carbapenemase activity in these organisms is important to prevent spreading of the resistant organisms. Which of the following methods is used to detect the presence of carbapenemase producing organisms? - D test - Modified Hodge test - ESBL test - Beta-lactamase test
Modified Hodge test
A CSF culture from an immunocompromised patient grew gram-negative coccobacilli on chocolate agar. Further testing revealed the following: Motility = -, Indophenol Oxidase = +, MacConkey = no growth Antibiotic testing showed that it was highly susceptible to penicillin. Which of the following organisms is most likely present? - Pseudomonas stutzeri - Moraxella lacunata - Acinetobacter spp - Pseudomonas aeruginosa
Moraxella lacunata
Which of the following would have a positive reaction for a PAD test? - Enterobacter, Escherichia, Salmonella - Klebsiella, Enterobacter - Morganella, Providencia, Proteus - Proteus, Escherichia, Shigella
Morganella, Providencia, Proteus
Which of the following would have a positive reaction for a phenylalanine deaminase (PAD) test? - Enterobacter, Escherichia, Salmonella - Morganella, Providencia, Proteus - Proteus, Escherichia, Shigella - Klebsiella, Enterobacter
Morganella, Providencia, Proteus
A gram negative, non-lactose fermenter was recovered from a culture from patient suffering from 2nd degree burns. Which of the following tests would best differentiate Acinetobacter spp and Pseudomonas aeruginosa? - String test and coagulase test - Growth on MacConkey, catalase, growth at 37C - Motility, oxidase, growth at 42C - Growth on blood agar, oxidase, growth at 35C
Motility, oxidase, growth at 42C
The Morganella and Proteus genera could be best identified by which of the following biochemical tests? - Malonate, glucose fermentation, and deoxyribonuclease (DNase) - Indole, citrate, and urease - Motility, urease, and phenylalanine deaminase - Indole, oxidase, MRVP
Motility, urease, and phenylalanine deaminase
Several patients developed subcutaneous abscesses at the sites of injection of a preparation labeled "adrenal cortex injection" administered as part of a weight loss regimen. Pale-staining, filamentous acid-fast bacilli were seen in the material aspirated from the lesions and the colonies grew out after 3 days incubation at 35C in CO2. The most likely identification is: - Mycobacterium marinum - Mycobacterium abscessus - Nocardia otitidiscaviarum (caviae) - Streptomyces somaliensis
Mycobacterium abscessus
Which of the following is the most common cause of nontuberculous mycobacteria (NTM) lung disease? - Mycobacterium ulcerans - Mycobacterium scrofulaceum - Mycobacterium kansasii - Mycobacterium avian complex (MAC)
Mycobacterium avian complex (MAC)
Small, gray-white colonies, growing on 7-H10 agar were recovered from an upper respiratory specimen after 7 days of incubation. This Mycobacterium species in the past was not often recovered from human infections until the discovery of AIDS when it became an agent of pulmonary infections, as well as other systemic infections. Most notably, the colony isolates exhibit a pale yellow pigmentation that does not intensify with light exposure. These acid fast bacilli are short and found singly or in loose clusters. From these observations, what is the most likely identification? - Mycobacterium marinum - Mycobacterium tuberculosis - Mycobacterium avium/intracellulare - Mycobacterium kansasii
Mycobacterium avium/intracellulare
Which Mycobacterium species has the shortest growing time on agar media when recovered from clinical specimens? - Mycobacterium tuberculosis - Mycobacterium leprae - Mycobacterium fortuitum/chelonae - Mycobacterium malmoense
Mycobacterium fortuitum/chelonae
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
Consider the following results from a digested sputum sample: Acid-fast stain: slender, slightly curved, beaded, red mycobacterial rods Growth on Middlebrook 7H10 slants: cream/buff-colored microcolonies with serpentine pattern after 14 days incubation at 37oC Niacin test = +Nitrate reduction test = + Which of the following is most likely present? - Mycobacterium avium-intracellulare complex - Mycobacterium tuberculosis - Mycobacterium ulcerans - Mycobacterium kansasii
Mycobacterium tuberculosis
Cultures from a hospital hot water system gave the following results: Growth at 42C = + Growth on Lowenstein-Jensen medium = no pigmentation after exposure to light Niacin accumulation = - Nitrate reduction test = - Which of the following organisms is most likely present? - Mycobacterium marinum - Mycobacterium haemophilum - Mycobacterium ulcerans - Mycobacterium xenopi
Mycobacterium xenopi
A gram stain on male, urethral discharge shows gram-negative diplococci that are both extracellular and intracellular within the patients segmented neutrophils. Which of the following organisms could this be a presumptive identification for? - Neisseria meningitidis - Moraxella catarrhalis - Neisseria lactamica - Neisseria gonorrhoeae
Neisseria gonorrhoeae
A vaginal swab was cultured using Thayer-Martin media. The colonies that grew stained as gram-negative diplococci. Additional testing yielded the following results: Catalase = +, Oxidase = +, Superoxol = -, Glucose = +, Lactose = +, Maltose = +, Sucrose = -, Fructose = - Which of the following is most likely present? - No answer text provided - Neisseria lactamica - Neisseria gonorrhoeae - Neisseria sicca
Neisseria lactamica
A 48-year-old male transplant patient arrived in the Emergency Department complaining of neurological difficulties after having a pulmonary infection. A lumbar puncture was performed and cloudy CSF was obtained, from which a gram-stain revealed gram positive long beaded bacilli. An acid-fast smear showed filamentous partially acid- fast bacilli. Which organism is most likely present? - Mycobacterium avium - Mycobacterium bovis - Nocardia asteroides - Legionella spp.
Nocardia asteroides
A sputum sample from a patient with a pulmonary abscess is received in the lab. After several days of incubation, the following findings are noted: Yellow, irregular colonies growing on a BAP under aerobic conditions Acid-fast stain shows that the organisms are partially acid-fast Which of the following organisms should be suspected? - Nocardia asteroides - Streptococcus pneumoniae - Actinomyces israelii - Actinomadura spp
Nocardia asteroides
A tech is working with a small Gram-negative coccobacillus that may be Burkholderia pseudomallei. Which of the following tests could the tech use to rule out this organism? - Growth on MacConkey agar - Oxidase negative - Indole negative - Resistant to polymyxin B or colistin
Oxidase negative
Which type of Plasmodium infection will have severe anemia, is very common to have CNS involvement, and has a 6-17-month duration for an untreated infection? - P. ovale - P. falciparum - P. malariae - P. vivax
P. falciparum
Oxacillin resistance of MRSA is due to production of which of the following penicillin binding proteins (PBPs)? - PBP2 - PBP2a - PBP3 - PBP4
PBP2a
The presence of parasites in human blood is termed: - Infection - Parasitism - Pathogenic - Parasitemia
Parasitemia
A medical technologist receives a wound specimen in the lab for culture. The colonies produced on blood agar are non-beta hemolytic and have a Medusa-head appearance. If the tech suspects that Bacillus anthrasis is present, which of the following should they perform next? - Lecithinase test - Penicillin (10-unit) susceptibility test - Glucose test - Motility test
Penicillin (10-unit) susceptibility test
In the microbiology lab, four specimens are received at the same time. The specimen that should be processed immediately is: - Unpreserved sputum - Feces in preservative - Tissue for quantitation - Pericardial fluid
Pericardial fluid
Which of the fungal species listed below is known to cause chromoblastomycosis? - Trichophyton schoenleinii - Phialophora verrucosa - Sporothrix schenckii - Tinea pedis
Phialophora verrucosa
A bone biopsy from a jaw sent to a microbiology lab for culture grew out an Actinomyces species. What would be the most probable contributing factor to this infection? - Poor circulation - Poor oral hygiene - Break in skin - Pelvic infection
Poor oral hygiene
Which of the following gram negative bacilli are characterized by the production of a black pigment and red fluorescence when exposed to UV light? - All of the answers are correct - Bacteroides spp and Fusobacterium spp - Fusobacterium spp and Actinomyces spp - Porphyromonas spp and Prevotella spp
Porphyromonas spp and Prevotella spp
An organism identified as Cryptococcus species can be accurately identified as Cryptococcus neoformans using which of the following characteristics? - Positive urease test - Presence of a capsule - Positive phenol oxidase test - Appearance of yellow colonies
Positive phenol oxidase test
A culture was ordered on pulmonary secretions from an 8-year-old cystic fibrosis patient who had come down with pneumonia. Consider the following results from a pure culture of gram-negative bacilli: Oxidase = +, Motility = +, Glucose OF (open) = +, Gelatin hydrolysis = +, Growth at 42C = +, Arginine dihydrolase = +, Pigment = red, non-fluorescent, Flagella = + with polar monotrichous Which of the following organisms is most likely responsible for the pneumonia? - Burkholderia (P.) pseudomallei - Burkholderia (P.) cepacia - Pseudomonas aeruginosa - Pseudomonas stutzeri
Pseudomonas aeruginosa
What bacterial species is rarely part of normal microbiota of healthy humans? - Pseudomonas aeruginosa - Burkholderia cepacia - Burkholderia mallei - Pseudomonas fluorescens
Pseudomonas aeruginosa
Which of the following bacterial species can be ruled out based on its non-lactose fermentation on MAC agar? - Pseudomonas aeruginosa - Klebsiella pneumoniae - Enterobacter aerogenes - Escherichia coli
Pseudomonas aeruginosa
Abiotrophia defectiva (formerly Streptococcus defectivus) and Granulicatella adiacens (formerly S. adiacens, 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 - Pyridoxyl - Sodiumpolyanethol sulfonate (SPS) - Synthetic resins
Pyridoxyl
HIV is known as a retrovirus because: - It can only attach to reticulocytes - RNA is used as the template for DNA synthesis - It can cause AIDS immediately upon entering the body - DNA is used as the template for RNA synthesis
RNA is used as the template for DNA synthesis
A 62-year-old female undergoing chemotherapy for breast cancer developed fever, abdominal pain, and foul-smelling diarrhea after receiving clindamycin for 5 days. The H&E stained section of colon biopsy reveals focal ulceration and pseudomembranous inflammation. Each of the following lab findings will confirm the presumptive diagnosis of Clostridium difficile-associated colitis except: - Recovery of C difficile in stool - Detection of cytotoxin B of C. difficile - Positive latex agglutination of glutamate dehydrogenase of C. difficile - Positive EIA for C. difficile enterotoxin
Recovery of C difficile in stool
A sputum specimen for culture is processed in the lab. Upon reviewing the Gram stain, the tech finds there are about 15 epithelial cells per low power field and a mix of bacterial flora present. What should the tech do next? - Report out the Gram stain and incubate sputum culture plates - Reject specimen - Report out Gram stain and discontinue culture - Discard specimen
Reject specimen
On a plate growing Streptococcus pneumoniae, the zone of inhibition around the disk was measured at 23 mm Based on this result, you should: - Report oxacillin-susceptibility - Repeat the test - Check the potency of the disk - Perform a minimum inhibitory concentration (MIC) test on the isolate
Report oxacillin-susceptibility
Which laboratory method is recommended for confirmation of an Influenza A H1N1 subtype infection? - Immunofluorescence assay (IFA) - Reverse transcriptase-polymerase chain reaction (RT-PCR) - Rapid Influenza A/B test - Cytopathic effect on a cell culture
Reverse transcriptase-polymerase chain reaction (RT-PCR)
Which of the following are necessary for the definitive diagnosis of Mycobacterium tuberculosis? - Buff color, slow growth at 37C, niacin production +, nitrate reduction - - Rough colony, slow growth at 37C, non-pigmented - Rough, non-pigmented colony, cording +, niacin production -, catalase - at ph 7/68C - Rough, non-pigmented colony, slow growth at 37C, niacin production +, nitrate reduction +
Rough, non-pigmented colony, slow growth at 37C, niacin production +, nitrate reduction +
Which of the following diagnostic procedures cannot be used to correctly identify the associated organism? - Modified acid-fast stain for Cryptospordium - Routine ova and parasite examination for Echinococcus granulosus - Examination of urine sediment for Schistosoma haematobium - Examination of skin snips for Onchocerca volvulus
Routine ova and parasite examination for Echinococcus granulosus
A lysine iron agar (LIA) tube inoculated with an organism shows a purple slant and blackened butt after incubation. The organism can be identified as which of the following? - Salmonella spp - Citrobacter spp - Proteus spp - E. coli
Salmonella spp
A large 140 um ovum with a prominent pointed spike from one side of its smooth, thin shell appears in a stool specimen preparation. The adult flukes reside in the portal veins of the large intestine where ova are discharged into the lumen and into the feces. Low grade diarrhea may be experienced. From the multiple choices select the species of fluke related to this ovum. - Schistosoma haematobium - Schistosoma mansoni - Fasciola hepatica - Schistosoma japonicum
Schistosoma mansoni
Of the following, when is the ONPG test most useful (ortho-nitrophenyl-B-galactopryanoside)? - Shigella app from some strains of E. coli - Klebsiella spp from Enterobacter spp - Proteus vulgarism from Salmonella spp - Salmonella spp from Pseudomonas spp
Shigella app from some strains of E. coli
Although some staines may possess K antigen, which member of Enterobacteriaceae is classified serologically by O antigen, because it lacks H antigen? - Escherichia coli - Salmonella typhi - Shigella spp - Proteus mirabilis
Shigella spp
A patient with bloody diarrhea submits a stool sample for culture and an isolate of E. coli is recovered. Which of the following sugars should it be tested for before being sent out for serotyping? - Sorbitol (fermentation) - Sucrose (fermentation) - Mannitol (oxidation) - Raffinose (fermentation)
Sorbitol (fermentation)
A Staph species recovered from a CSF shunt culture was found to produce acid from sucrose and maltose and showed alkaline phosphatase activity. The Staph was also coagulase negative. The most likely identification is: - Staph epidermidis - Staph aureus - Staph schleiferi - Staph saprophyticus
Staph epidermidis
A left arm abscess collected from an 8-year-old male patient grew small white colonies on 5% sheep blood agar after 24 hours incubation at 35C in 5-10% CO2. The Gram stain of the organism showed small tightly grouped Gram positive cocci. Which of the following is the most likely identification? - Staphylococcus epidermidis - Streptococcus milleri - Corynebacterium xerosis - Enterococcus faecium
Staphylococcus epidermidis
In a nitrate reduction test, a positive result is indicated by a red color change. Which of the following reagent(s) is (are) used in the reaction? - o-Nitrophenyl-B-D-galactopyranoside - Erlich's and Kovac's reagent - Potassium hydroxide and alpha-napthol - Sulfanic acid and alpha-naphthylamine
Sulfanic acid and alpha-naphthylamine
In a nitrate reduction test, a positive result is indicated by a red color change. Which of the following reagent(s) is (are) used in the reaction? - Sulfanilic acid and alpha-naphthylamine - Potassium hydroxide and alpha-naphthol - o-Nitrophenyl-B-D-galactopyranoside - Erlich's and Kovac's reagent
Sulfanilic acid and alpha-naphthylamine
A combination of nontreponemal testing (VDRL, RPR) and treponemal testing (TP-PA, EIA) is used to confirm: - Chlamydia - Genital herpes - Syphilis - Gonorrhea
Syphilis
A medical technologist receives a stool specimen on a patient with diarrhea who has just returned from visiting South America. The patient is suspected of having an infection caused by Vibrio cholerae. Which of the following media would be best for the identification and recovery of this organism? - Blood agar - TCBS agar - XLD agar - MacConkey agar
TCBS agar
Upon reviewing a fecal prep for O&P, a tech thought they had identified the egg of Taenia saginata. After a quick look, the microbiology supervisor reminded the tech that T. saginata eggs are indistinguishable from which of the following? - Diphyllidium caninum - Echinococcus gramulosus - Hyenolepsis diminuta - Taenia solium
Taenia solium
The ability to detect and identify human parasites is directly linked to the following except: - The quality of the specimen - The submission of the appropriate specimen - The appropriate handling and processing of the specimen - The genus and species of the parasite
The genus and species of the parasite
The likelihood of colonization and/or infection with Clostridium difficile is enhanced by all of the following except: - The balance of GI flora is altered by previous antibiotic therapy - The patient has previously been hospitalized - The patient has been previously treated at an orthopedic sports clinic - The patient has a chronic health condition
The patient has been previously treated at an orthopedic sports clinic
Which of the following would not be appropriate when collecting a urine for culture? - The collected sample must be plated within 2 hours unless refrigerated - The container must be sterile - The sample may be held at 2C - 8C for up to 48 hours prior to plating - The midstream void technique must be used
The sample may be held at 2C - 8C for up to 48 hours prior to plating
A lab test flags as a critical result. The technologist repeats the test and it again flags as a critical result. Which of these scenarios correctly describes all the actions that need to be taken after this occurs? - The tech immediately releases the result - The tech phone the clinical person handling the patient's care (caregiver) and reports the critical test result - The tech phones the patient's caregiver, reports the critical result, documents his placement of the call, who was notified, time and date of notification - The tech phones the patient's caregiver, reports the result and asks the caregiver to read back the information; documents his placement of the call, who was notified, time and date of notification
The tech phones the patient's caregiver, reports the result and asks the caregiver to read back the information; documents his placement of the call, who was notified, time and date of notification
Which of the following has the inability to grow on artificial media or in cell culture? - Chlamydia trachomatis - Treponema pallidum - Herpes simplex virus - Neisseria gonorrhoeae
Treponema pallidum
A circulating trypomastigote measuring 20 um is stained in a blood smear. The disease represented by this smear most commonly occurs in South and Latin America, often affecting children. Human infection is transmitted via arthropod vector, the reduviid bug, resulting in an inflamed ulcer of the skin called chagoma. Chronic infections in the form of tissue granulomas may disseminate to distant organs, often to the muscle of the heart. With this background, select the name of the protozoan flagellate causing this disease. - Trypanosoma gambiense - Trypanosoma rhodesiense - Trypanosoma cruzi - Trypanosoma rangeli
Trypanosoma cruzi
A 58-year-old patient from Brazil with a history of congestive heart failure (CHF) and cardiac irregularities dies suddenly. Mycobacterium examination reveals the presence of many amastigotes. Which of the following is most likely the cause of death? - Trypanosomiasis with Trypanosoma gambiense - Leishmaniasis with Leishmania donovani - Trypanosomiasis with Trypanosoma cruzi - Leishmaniasis with Leishmania braziliense
Trypanosomiasis with Trypanosoma cruzi
A tech is working with a small, Gram-negative coccobacillus that may be Brucella spp. Which of the following tests could the tech use to rule out this organism? - Oxidase positive - Urease negative - Catalase positive - Motility negative
Urease negative
A methicillin-resistant Staphylococcus aureus was recovered from a wound infection. Which antibiotic would be used for treatment? - Methicillin - Nafcillin - Vancomycin - Oxacillin
Vancomycin
Which of the following conditions is caused by HPV? - Mononucleosis - Venereal warts - Common cold - Gastroenteritis in infants
Venereal warts
A microbiologist isolates a curved, gram-negative rod from a stool culture. Consider the additional information: Indole = +, VP = +, Urease = +/-, Oxidase = +, KIA = K/A, Lactose = -, String test = -, Growth on TCBS = green colonies, Lysine decarboxylase = +, Arginine decarboxylase = - Which of the following organisms is most likely present? - Vibrio cholerae - Vibrio parahemolyticus - Shigella spp - Salmonella spp
Vibrio parahemolyticus
Which of the following would best differentiate H. influenzae from H. aegypticus? - Oxidase and catalase - Xylose and indole - Oxidase and indole - Urease and glucose
Xylose and indole
An immunocompromised 55-year-old female patient undergoing chemotherapy treatment received three units of packed RBCs. Three days later, the patient passed away and the results from the autopsy listed septic shock as the cause of death. Cultures of the blood bags gave the following results: Growth on BAP and MAC = aerobic, gram-negative rods, Lactose = -, Sucrose = +, Citrate = -, Indole = -, VP = -, H2S = -, Urease = +, Motility @ 22C = +, Motility @ 37C = - Which of the following is most likely present? - Citrobacter freundii - Escherichia coli - Yersinia entercolitica - Enterobacter cloacae
Yersinia entercolitica
Which of the following organisms causes disease by direct invasion of tissues? - Clostridium botulinum - Vibrio cholerae - Yersinia enterocolitica - Shigella sonnei
Yersinia enterocolitica
Which of the following is the correct IMViC reaction for E. coli? - negative, positive, negative, positive (- + - +) - positive, negative, positive, negative (+ - + -) - negative, negative, positive, positive (- - + +) - positive, positive, negative, negative (+ + - -)
positive, positive, negative, negative (+ + - -)
