MICRO by MR. BIRAQUIT Flashcards
An 8 year old boy develops a severe sore throat. On examination, a grayish white exudate is seen on the tonsils and pharynx. The differential diagnosis includes group A streptococcal infection and severe adenovirus infection. The possible cause of the boy’s pharyngitis is most likely:
A. A catalase (-), gram (+) coccus that grows in chain
B. A single stranded positive sense RNA virus
C. A catalase (+), gram (+) coccus that grows in clusters
D. A catalase (-), gram (+) bacillus
A catalase (-), gram (+) coccus that grows in chain
A primary mechanism responsible for the pathogenesis of the boy’s disease is:
A. A net increase in intracellular cyclic adenosine monophosphate
B. Action of M protein
C. Action of IgA1 protease
D. Action of enterotoxin A
Action of M protein
Significant yellow colonies isolated from primary culture of a urine sample were subcultured on Mannitol Salt Agar (MSA). Colonies on MSA are shown in the picture. What is the most likely isolate?
What test can be used to confirm the identification of the isolated organism?
If S. aureus or S. saprophyticus were suspected to be isolated from the sample, what test can be used to differentiate the two organism?
S. aureus
Coagulase test
A 40 year old woman develops severe headache and fever. A brain scan shows a ring-enhancing lesion of the left hemisphere. During surgery, a brain abscess is found. Culture of the abscess fluid grows a catalase (-), gram (+) coccus that on gram stain is in pairs and chains. The organism is B-hemolytic and forms very small colonies. It agglutinates with group B antisera. The organism most likely:
A. Streptococcus pyogenes
B. Enterococcus faecalis
C. Streptococcus agalactiae
D. Streptococcus anginosus group
Streptococcus agalactiae
Enterococci can be distinguished from noneterococcal group D on the basis of which of the following characteristics?
A. y-hemolysis
B. Esculin hydrolysis
C. Growth in 6.5% NaCl
D. Growth in the presence of Bile
Growth in 6.5% NaCl
A 22-year-old woman who works in a plant nursery presents with a history of fever and cough for 2 months. Over this period of time she has lost 5 kg. Chest radiography shows bilateral upper lobe infiltrates with cavities. Her sputum smear shows acid-fast bacilli. The likely means by which the patient acquired her infection is
A. Sexual activity
B. Ingesting the microorganisms in her food
C. Holding onto contaminated handrails when she takes public transportation.
D. Handling potting soil
E. Breathing aerosolized droplets containing the
microorganism
Breathing aerosolized droplets containing the microorganism
Lysostaphin susceptibility is a test used to
differentiate:
A. Staphylococcus spp. from Streptococcus spp.
B. Staphylococcus spp. from Enterococcus spp.
C. Staphylococcus spp. from Micrococcus spp.
D. Streptococcus spp. from Micrococcus
Staphylococcus spp. from Micrococcus spp.
The blood bank reports that samples of banked blood stored at refrigerator temperature have become contaminated with nonfermentative gram-negative bacilli. The organisms known to be implicated in such cases are:
A. Alcaligenes faecalis and Alcaligenes odorans
B. Acinetobacter calcoaceticus and
Acinetobacter iwoffi
C. Pseudomonas fluorescens and Pseudomonas putida
D. Burkholderia cepacia and Pseudomonas stutzeri
E. Burkholderia mallei and Aggregatibacter aphrophilus
Pseudomonas fluorescens and Pseudomonas putida
Characteristically, species from the genus
enterococcus are:
A. Unable to grow in 6.5% NaCl
B. Bile esculin positive
C. Sensitive to Penicillin
D. Sodium hippurate negative
Bile esculin positive
Alpha-hemolytic streptococci recovered from a wound were found to be Penicillin resistant. The organism shows the following reactions:
BILE ESCULIN (+);
6.5% NaCl (+);
PYR (+);
SXT (Resistant).
What is the most likely identification?
A. Group B streptococcus
B. Streptococcus bovis
C. Streptococcus pneumoniae
D. Enterococcus faecalis
E. Streptococcus anginosus
Enterococcus faecalis
An enterococcus isolated from multiple blood
cultures in a patient with endocarditis should be:
A. Screened for high level Aminoglycoside
resistance
B. Checked for tolerance
C. Assayed for serum antimicrobial activity
D. Tested for beta-lactamase production
E. Tested with capsular swelling test.
Screened for high level Aminoglycoside
resistance
The Quellung test is used to identify which
Streptococcus spp.?
A. Streptococcus pyogenes
B. Streptococcus agalactiae
C. Streptococcus sanguis
D. Streptococcus pneumoniae
Streptococcus pneumoniae
Nutritionally variant Streptococci (NVS) require specific thiol compounds, cysteine or the active form of Vitamin B6. Which of the following supplies these requirements?
A. Bacitracin disk test
B. Staphylococcal cross-streak
C. CAMP test
D. Bile solubility test
E. Cysteine tryptic agar
Staphylococcal cross-streak
A sputum sample from a patient with pneumonia
produced many colonies of gram-negative
diplococci on chocolate agar that were also
present in fewer numbers on Modified Thayer Martin medium after 48 hours. Biochemical reactions results are:
CATALASE (+);
OXIDASE (+);
DNASE (+);
GLUCOSE (0);
MALTOSE (0);
SUCROSE (0);
FRUCTOSE (0).
What is the most likely
identification?
A. Moraxella catarrhalis
B. Neisseria sicca
C. Neisseria flavescens
D. Pnatoea agglomerans
E. Hemophilus influenzae
Moraxella catarrhalis
Which of the following is the specimen of choice
for detecting Rotavirus?
A. Throat swab
B. Bronchoalveolar wash
C. Feces sample
D. Urine sample
Feces sample
Germ tube formation is seen with which two
yeasts?
A. Candida albicans and Candida tropicalis
B. Candida albicans and Candida parapsilosis
C. Candida albicans and Candida glabrata
D. Candida albicans and Candida dubliniensis
Candida albicans and Candida dubliniensis
Which of the following correctly describes
Staphylococci?
A. Susceptible to 0.04 units Bacitracin
B. Produces oxidase enzyme
C. Susceptible to furazolidone
D. Can not ferment mannitol
E. Resistant to Lysostaphin
Can not ferment mannitol
An organism is a late or slow lactose fermenter
possesses:
A. Beta-galactosidase and lactose permease
B. Beta-galactosidase only
C. Lactose permease only
D. Neither beta-galactosidase nor lactose
permease
Beta-galactosidase only
An isolate of E.coli recovered from stool of a
patient with severe bloody diarrhea should be tested for what sugar before sending to a
reference laboratory for serotyping?
A. Sorbitol
B. Mannitol
C. Raffinose
D. Sucrose
E. Inositol
Sorbitol
Which of the following organisms is often
confused with Salmonella spp. biochemically
and on plated media?
A. Escherichia coli
B. Enterobacter cloacae
C. Citrobacter freundii
D. Shigella dysenteriae
E. Morganella morganii
Citrobacter freundii
A Staphylococcus produced a fibrin clot in
the tube coagulase test, but not in the slide
coagulase test. This organism:
A. Produces only free coagulase and is most
likely S.aureus
B. Produces only bound coagulase and is
most likely S.aureus
C. Is most likely S.epidermidis because of
the negative slide test
D. Is most likely S.epidermidis since the
slide test is unrealible
Produces only free coagulase and is most
likely S.aureus
Bacitracin A disks (0.04 units) are used for
the presumptive identification of which
group of beta-hemolytic Streptococcus?
A. Group A
B. Group B
C. Group C
D. Group D
E. Group F
Group A
A small, gram-negative coccobacillus recovered from CSF of a 2-year old child gave the following results:
X disk (+) Glucose (+)
V disk (+) Sucrose (-)
Indole (+) Lactose (-)
Urease (+) Hemolysis (-)
Which is most likely identification?
A. Hemophylus parainfluenzae
B. Hemophylus ducreyi
C. Hemophilus influenzae
D. Hemophilus aphrophilus
Hemophilus influenzae
Which is not a characteristic of Vibrio
cholerae?
A. Motile with single polar flagellum
B. Oxidase negative
C. Ferments glucose and sucrose
D. Positive string test
E. Resistant to bile salts
Oxidase negative
The presence of clue cells in vaginal smears is diagnostic with an infection caused by:
A. Campylobacter jejuni
B. Gardnerella vaginalis
C. Aeromonas hydrophila
D. Candida albicans
E. Trichomonas vaginalis
Gardnerella vaginalis
Complications that result from Streptococcus
pyogenes infections are the poststreptococcal diseases:
A. Meningitis and glomerulonephritis
B. Rheumatic fever and acute glomerulonephritis
C. Rheumatoid arthritis and anemia
D. Pyelonephritis and glomerulonephritis
E. Lupus erythematosus and meningitis
Rheumatic fever and acute glomerulonephritis
Two blood cultures on a newborn grew beta-hemolytic Streptococci with the following
reactions:
Bacitracin (Resistant)
PYR (-)
SXT (Resistant)
Bile solubility (-)
CAMP test (+)
6.5% NaCl (+)
What is the most likely identification?
A. Group A Streptococci
B. Group B Streptococci
C. Group C Streptococci
D. Group D Streptococci
Group B Streptococci
A college student attended a beach party where raw oysters and other shellfish were consumed. The next day, he had symptoms of septicemia. The blood cultures grew gram negative bacilli with the following characteristics:
OXIDASE (+);
Mac Conkey agar: Pink colonies
The most likely organism is:
A. Pseudomonas aeruginosa
B. Serratia marcescens
C. Vibrio vulnificus
D. Acinetobacter baumanii
E. Enterococcus faecalis
Vibrio vulnificus
Which test is used to differentiate the
Viridans Streptococci from group D
Streptococci?
A. Bacitracin disk test
B. CAMP test
C. Hippurate hydrolysis test
D. Bile esculin test
E. Neufeld Quellung reaction
Neufeld Quellung reaction
The salt tolerance test using 6.5% salt broth
is used to presumptively identify:
A. Streptococcus dysagalactiae
B. Streptococcus pneumoniae
C. Enterococcus faecalis
D. Streptococcus bovis
Enterococcus faecalis
What is the ideal specimen for the recovery of Bordetella pertussis?
A. Nasopharyngeal swab
B. Cough plate
C. Urine
D. Pleural fluid
E. Buccal swab
Nasopharyngeal swab
A 23-year-old woman has a history of recurrent urinary tract infections, including at least one episode of pyelonephritis. Blood
typing shows the P blood group antigen. Which of the following is likely to be the primary cause of her infections?
A. Escherichia coli that produce heat-stable
toxin
B. Escherichia coli with K1 (capsular type 1)
antigen
C. Escherichia coli O139 (lipopolysaccharide
O antigen 139)
D. Escherichia coli with P-pili (fimbriae)
E. Escherichia coli O157:H7
Escherichia coli with P-pili (fimbriae)
Which of the following best describes the
mechanism of action of diphtheria toxin?
A. Forms pores in red blood cells causing
hemolysis
B. Degrades lecithin in eukaryotic cell
membranes
C. Causes release of tumor necrosis factor
D. Inhibits protein synthesis elongation
factor 2 (EF-2)
E. Causes increased adenylate cyclase
activity
Inhibits protein synthesis elongation factor 2 (EF-2)
Which of the following is most likely to be
associated with the formation of a bacterial
biofilm?
A. Airway colonization in a cystic fibrosis patient with a mucoid (alginate+) strain of Pseudomonas aeruginosa
B. Urinary tract infection with E.coli
C. Meningitis with Neisseria meningitidis
D. Tetanus
E. Purulent impetigo caused by Staphylococcus aureus
Airway colonization in a cystic fibrosis patient with a mucoid (alginate+) strain of Pseudomonas aeruginosa
Rapid assay useful for the detection of
Legionella spp is:
A. Bacterial culture
B. Gram staining
C. Urine antigen detection and DFA
D. Indirect fluorescent assay (IFA)
E. Broth microdilution assay
Urine antigen detection and DFA
Dangerous and exotic agents which pose a
high individual risk of aerosol-transmitted
laboratory infections and life-threatening
disease is classified as:
A. BSL 1
B. BSL 2
C. BSL 3
D. BSL 4
BSL 4
Gram positive bacilli that cause occupational disease of butchers, meat processors, farmers, poultry workers, fish handlers, and veterinarians:
A. Bacillus cereus
B. Listeria monocytogenes
C. Erysipelothrix rhusiopathiae
D. Bacillus subtilis
Erysipelothrix rhusiopathiae
Streptococcus pneumoniae and viridans
Streptococci can be differentiated by:
A. Optochin disk test
B. Bacitracin disk test
C. CAMP test
D. Bile esculin test
Optochin disk test
Which one of the following is an important
virulence factor of Bacillus anthracis?
A. Protective antigen and Lethal factor
B. Lipopolysaccharide
C. Pili and Lecithinase
D. A toxin that inhibits peptide chain
elongation factor EF-2
Protective antigen and Lethal factor
The bile solubility test causes lysis of:
A. Streptococcus bovis colonies on Blood agar plate.
B. Streptococcus pneumoniae colonies on
Blood agar plate.
C. Group A Streptococcus in broth culture.
D. Group B Streptococcus in broth culture.
Streptococcus pneumoniae colonies on
Blood agar plate.
A food commonly associated with Bacillus
cereus food poisoning is:
A. Fried rice
B. Baked potato
C. Hot freshly steamed rice
D. Green beans
E. Honey
Fried rice
A 45-year-old man who immigrated to the United States 5 years ago sustained a puncture injury to the lower part of his right leg when his rotary lawn mower threw a small stick into his leg. Six days later, he noticed spasms in the muscles of his right leg. On day 8, he had generalized muscle spasms, particularly noticeable in the muscles of his jaw. He was unable to open his jaw and came to the emergency department. Suddenly he has general muscle spasm with arching of his back. The correct diagnosis is which of the following?
A. Botulism
B. Anthrax
C. Gas gangrene
D. Tetanus
E. Toxic shock syndrome
Tetanus
Which of the following food items is most
frequently associated with infant botulism?
A. Corn syrup
B. Canned infant formula
C. Liquid multivitamins
D. Honey
E. Jarred baby food
Honey
All of the following statements regarding
Clostridium perfringens are correct except:
A. It produces an enterotoxin.
B. It produces a double zone of β-hemolysis
when grown on blood agar.
C. It is the most common cause of antibiotic-associated diarrhea.
D. It can cause intravascular hemolysis.
It is the most common cause of antibiotic-associated diarrhea.
Abiotrophia and Granulicatella will not grow on blood agar or chocolate agar unless it is supplied with:
A. Pyridoxal (vitamin B6)
B. Hematin
C. NAD
D. Thiamine
Pyridoxal (vitamin B6)
An infant has been diagnosed with bacterial
meningitis. Further testing of the CSF would
likely indicate:
A. Increased WBC with predominance of
lymphocytes, decreased glucose, increased protein.
B. Increased WBC with predominance of
neutrophils, increased glucose and protein
C. Increased WBC with predominance of
neutrophils, increased protein, decreased glucose
D. Decreased WBC with predominance of
neutrophils, increased protein, decreased glucose
Increased WBC with predominance of
neutrophils, increased protein, decreased glucose
An 11-year-old boy develops a mild fever and pain in his upper arm with a lytic lesion. He is taken to surgery, where the lesion is
debrided. Culture from the lesion yields gram-positive cocci. The test shows that the organism is a Staphylococcus and coagulase positive. Based on this information, you know the organism is:
A. Susceptible to nafcillin
B. β-Lactamase-positive
C. A producer of protein M
D. Encapsulated
E. Catalase positive
Catalase positive
A 65-year-old man develops an abscess on
the back of his neck. Culture yields S aureus.
The isolate is tested and found to be positive for the mecA gene, which means that:
A. The isolate is resistant to vancomycin.
B. The isolate is resistant to nafcillin.
C. The isolate is resistant to clindamycin.
D. The isolate is resistant to erythromycin
The isolate is resistant to nafcillin
Gram negative diplococci are isolated from a
female genital tract. Which of the following
is the most appropriate action?
A. Report “Neisseria gonorrheae isolated”
and perform susceptibility test.
B. Report the amount of “gram-negative
diplococci” and the number of neutrophils present.
C. Report “normal flora isolated” and
discard specimen
D. Plate the specimen in blood agar plate
Report the amount of “gram-negative
diplococci” and the number of neutrophils present.
Waterhouse-Friderichsen syndrome is associated with:
A. Autoimmune response to group A streptococcal infection.
B. Septicemia from Neisseria gonorrheae
infection.
C. Hemolytic reaction from Staphylococcus
aureus infection.
D. Adrenal hemorrhage from Neisseria
meningitidis infection
Adrenal hemorrhage from Neisseria
meningitidis infection
Which of the following statements regarding
the role of protein A in the pathogenesis of
infections caused by S aureus is correct?
A. It is responsible for the rash in toxic shock syndrome.
B. It converts hydrogen peroxide into water
and oxygen.
C. It is directly responsible for lysis of
neutrophils.
D. It is a bacterial surface protein that binds
to the Fc portion of IgG1
It is a bacterial surface protein that binds
to the Fc portion of IgG1
Pili antigens are associated with:
A. Neisseria gonorrheae
B. Streptococcus pyogenes
C. Bacillus subtilis
D. Mycoplasma pneumoniae
Neisseria gonorrheae
Cultures obtained from a dog bite produced
yellow, tan, and slightly pink colonies on
blood agar and chocolate agar with a margin
of fingerlike projections appearing as film
around the colonies. Given the following
results at 24 hours, which is the most likely
organism?
OXIDASE (-)
CATALASE (-)
MOTILITY: (+)
Gliding appearance
Mac conkey agar: No growth
A. Capnocytophaga
B. Actinobacillus
C. Eikenella
D. Pseudomonas
Capnocytophaga
Clostridium difficile is most commonly
identified by:
A. Demonstration of cytotoxin
B. Identification of C. difficile antigen
C. Isolation of organism from tissue culture
D. Demonstration of lecithinase
Demonstration of cytotoxin
Which of the following is not a characteristic
of Corynebacterium diphtheriae?
A. Pleomorphic morphology
B. Gram positive bacillus
C. Spore former
D. Nonmotile
Spore former
An antibiotic that inhibits cell wall synthesis
is:
A. Chloramphenicol
B. Penicillin
C. Sulfamethoxazole
D. Ciprofloxacin
E. Cotrimoxazole
Penicillin
Food poisoning due to Clostridium botulinum
is often caused by?
A. Contaminated poultry products
B. Inhalation of spores
C. Improperly home-canned foods
D. Dairy products and custards
E. Contaminated poorly-cooked seafoods
Improperly home-canned foods
In the Kirby-Bauer disc diffusion susceptibility test, which variable is critical when testing Pseudomonas spp. for
antibiotic susceptibility to aminoglycosides?
A. Incubation temperature
B. Duration of incubation
C. Cation content of media
D. Depth of agar
Cation content of media
On Potassium tellurite medium, Corynebacterium diphtheriae produces:
A. Beta-hemolytic colonies
B. Enhanced pleomorphic properties
C. Black colonies
D. Pink to red colonies
Black colonies
Which of the following organism is DNAse
positive?
A. Neisseria gonorrheae
B. Moraxella catarrhalis
C. Klebsiella oxytoca
D. Campylobacter jejuni
Moraxella catarrhalis
A gram positive bacillus isolated from the spinal fluid of a 1-month old infant is catalase positive, beta hemolytic, and bile esculin positive, and exhibits tumbling motility in a wet preparation. This organism is most likely:
A. Lactobacillus acidophilus
B. Corynebacterium jeikeium
C. Erysipelothrix rhusiopathiae
D. Listeria monocytogenes
Listeria monocytogenes
Which test is used for the determination of
Inducible Clindamycin resistance in
Staphylococci and Streptococci?
A. E-test
B. D-zone test
C. A-test
D. CAMP test
E. Taxo P
D-zone test
Sputum samples for TB culture may contain
normal flora and other contaminating
microorganisms, so samples must be:
A. Digested with N-acetyl-L-cysteine
B. Decontaminated with 2% NaOH
C. Digested with trisodium phosphate
D. Decontaminated with dithiothreitol
Decontaminated with 2% NaOH
Which of the following is noted for a positive result for Niacin accumulation?
A. Mycobacterium tuberculosis
B. Mycobacterium avium-intracellulare
complex
C. Mycobacterium fortuitum-chelonae
complex
D. Mycobacterium gordonae
Mycobacterium tuberculosis
The superoxol test is used as presumptive
test for:
A. Neisseria gonorrheae
B. Neisseria lactamica
C. Gardnerella vaginalis
D. Lactobacillus spp.
E. Enterococcus faecium
Neisseria gonorrheae
The single most important method for
classifying and speciating streptococci is:
A. Biochemical testing
B. Hemolytic properties (α-, β-, nonhemolytic)
C. Capsular swelling (quellung) reaction
D. None of the above
None of the above
Resistance to Clindamycin can be induced in vitro by:
A. Ampicillin
B. Erythromycin
C. Gentamycin
D. Penicillin
E. Oxacillin
Erythromycin
Which of the following viral families are
associated with reactivation of latent
infections?
A. Hepatitis viruses
B. Influenza viruses
C. Parvoviruses
D. Herpesviruses
E. HIV
Herpesviruses
Cultivation of this fungal organism, such as from a positive blood culture, requires an agar medium overlaid with a long-chain fatty acid (olive oil)
A. Cryptococcus neoformans
B. Coccidioides immitis
C. Malassezia furfur
D. Candida tropicalis
E. Aspergillus flavus
Malassezia furfur
Vaginal swab culture on modified Thayer-Martin medium produced several colonies of gram negative diplococci that were catalase and oxidase positive and superoxol negative.
Given the following carbohydrate reaction,
select the most likely identification:
Glucose (+) Maltose (+)
Lactose (+) Sucrose (-)
A. Neisseria gonorrheae
B. Neisseria meningitidis
C. Neisseria lactamica
D. Neisseria sicca
E. Moraxella catarrhalis
Neisseria lactamica
Which statement correctly describes the
antigens of Enterobacteriaceae?
A. The O antigen is heat labile.
B. The O antigen is located on the cell wall.
C. The Vi antigen is a flagellar antigen.
D. The K antigen is the somatic antigen.
The O antigen is located on the cell wall.
Which of the following viruses is implicated
along with Epstein-Barr virus as a cause of
Infectious mononucleosis?
A. Cytomegalovirus
B. Coxsackie A virus
C. Coxsackie B virus
D. Hepatitis B virus
E. All of the above
Cytomegalovirus
Cultures for Brucella should be incubated in
5%-10% CO2 in a humidified atmosphere;
inoculated plates are incubated for up to
______ before they are considered negative
and discarded.
A. 5 days
B. 1 week
C. 2 weeks
D. 3 weeks
3 weeks
Which of the following sets of tests best
differentiates Salmonella and Citrobacter species?
A. KCN, malonate, beta-galactosidase, Lysine decarboxylase
B. Dulcitol, citrate, indole, H2S production
C. Lactose, adonitol, KCN, motility
D. Lysine decarboxylase, lactose, sucrose, malonate, indole
KCN, malonate, beta-galactosidase, Lysine decarboxylase
Which of the following is a cause of community-acquired atypical pneumonia, often referred to as walking pneumonia?
A. Chlamydophila pneumoniae
B. Streptococcus pneumoniae
C. Mycoplasma hominis
D. Mycoplasma pneumoniae
E. Klebsiella pneumoniae
Mycoplasma pneumoniae
Which Trichophyton spp causes the favus
type of tinea capitis?
A. Trichophyton violaceum
B. Trichophyton tonsurans
C. Trichophyton schoenleinii
D. All of the above
Trichophyton schoenleinii
A 37-year-old woman with a history of urinary tract infections comes to the emergency department with burning on urination along with frequency and urgency. She says her urine smells like ammonia. The cause of her urinary tract infection is likely to be:
A. Proteus mirabilis
B. Citrobacter freundii
C. Escherichia coli
D. Serratia marcescens
E. Streptococcus agalactiae
Proteus mirabilis
The yeast form of which dimorphic fungus appears as oval or elongated cigar shapes, some with multiple buds?
A. Coccidioides immitis
B. Sporothrix schenckii
C. Blastomyces dermatitidis
D. Histoplasma capsulatum
Sporothrix schenckii
All members of the family
Enterobacteriaceae:
A. Oxidize glucose
B. Ferment glucose
C. Ferment lactose
D. Produce urease enzyme
E. All of the above.
Ferment glucose
Which of the following is the most useful
morphological feature in identifying the mycelial phase of Histoplasma capsulatum?
A. Arthrospores
B. Microspores
C. Tuberculate macroconidia
D. Nonseptate macroconidia
Tuberculate macroconidia
A 64-year-old patient with lymphoma has a
positive blood culture at 18 hours incubation. The organism is a nonlactose
fermenting gram negative bacillus on Mac
Conkey agar. Further testing gives the
following reactions:
OXIDASE (-) UREA (+)
TSI: K/A, H2S (-) ODC (-)
INDOLE (+) VP (+)
CITRATE (+)
PHENYLALANINE DEAMINASE (+)
What is the identification?
A. Morganella
B. Proteus
C. Providencia
D. Serratia
E. Klebsiella
Providencia
A 17-year old female with cystic fibrosis is diagnosed with pneumonia. A sputum sample grew gram negative bacilli with yellow, smooth colonies that have the following reactions:
OXIDASE (+)
TSI: K/K
GLUCOSE: OXIDIZED
LDC (+)
The most likely organism is:
A. Burkholderia cepacia
B. Klebsiella pneumoniae
C. Shewanella putrefaciens
D. Sternotrophomonas maltophilia
Burkholderia cepacia
Which genera are positive for phenylalanine
deaminase enzyme?
A. Enterobacter, Escherichia, Salmonella
B. Morganella, Providencia, and Proteus
C. Klebsiella and Enterobacter
D. Proteus, Escherichia, and Shigella
Morganella, Providencia, and Proteus
Chlamydial infections have been implicated
in:
A. Urethritis and conjunctivitis
B. Gastroenteritis and urethritis
C. Neonatal pneumonia and gastroenteritis
D. Neonatal meningitis and conjunctivitis
Urethritis and conjunctivitis
The stage of Lyme disease characterized by
the appearance of erythema chronicum
migrans is:
A. Primary
B. Secondary
C. Tertiary
D. Latent
Primary
Characteristics of the HACEK group of
bacteria include:
A. Association with urinary tract infections
B. Requirement of 5-10% CO2 for growth
C. Pleomorphic gram-positive bacilli
D. Requirement of 42C for growth
Requirement of 5-10% CO2 for growth
The Mycobacteria are described as “acid
fast” because:
A. The organism cannot be stained with
acidic dyes
B. The organisms are deeply decolorized
with acid alcohol
C. The organism are easily stained with
acidic dyes
D. Once stained, the organisms cannot be
decolorized with acid alcohol
Once stained, the organisms cannot be
decolorized with acid alcohol
Supplementation with Hemin and Vitamin K
will enhance the recovery of
A. Gram-positive cocci
B. Aerobic bacteria
C. Anaerobic bacteria
D. Fungi
Aerobic bacteria
“Owl’s eye” cytological inclusions are
characteristic of infection caused by:
A. HIV
B. CMV
C. HSV
D. VZV
CMV
When specimen delay is anticipated, virology
specimens are optimally maintained:
A. At room temperature
B. Incubated at 35 C
C. Held at 4 C and snap-frozen to -70 C
D. Frozen immediately at -20 C
E. Stored at 42 C oven
Held at 4 C and snap-frozen to -70 C
A 55-year-old homeless man with alcoholism presents with severe multilobar pneumonia. He requires intubation and mechanical ventilation. A Gram stain of his sputum reveals numerous polymorphonuclear leukocytes and gram-negative rods that appear to have a capsule. The organism is a lactose fermenter on MacConkey agar and is very mucoid. It is nonmotile and lysine decarboxylase positive. What is the most likely organism causing his illness?
A. Enterobacter aerogenes
B. Proteus mirabilis
C. Klebsiella pneumoniae
D. Morganella morganii
E. Serratia marcescens
Klebsiella pneumoniae
The spores of Clostridium tetani are located:
A. Centrally
B. Subterminally
C. Terminally
D. Spores are absent
Terminally
Which of the following test methods is the
least sensitive procedure for diagnosis of colitis caused by Shiga toxin–producing Escherichia coli?
A. Culture on sorbitol MacConkey agar
B. Toxin testing using an enzyme immunoassay
C. Cell culture cytotoxin assay using Vero cells
D. Polymerase chain reaction for detection
of the genes that encode Shiga toxin
Culture on sorbitol MacConkey agar
Which nonpathogenic Mycobacterium species is isolated most often from clinical specimens and is called the “tap water bacillus”?
A. Mycobacterium kansasii
B. Mycobacterium gordonae
C. Mycobacterium bovis
D. Mycobacterium avium
Mycobacterium gordonae
An organism isolated from urine culture with
significant colony count produces the following reactions. What is the presumptive identification of the organism?
TSI: K/A Indole (+)
H2S (+) Deaminase (+)
Urease (+)
Motility: swarming
A. Citrobacter freundii
B. Proteus vulgaris
C. Pantoea agglomorens
D. Proteus mirabilis
E. Serratia marcescens
Proteus vulgaris
All of the following are characteristics of
Helicobacter pylori except:
A. Curved gram-negative bacillus
B. Microaerophilic and capnophilic
C. Oxidase positive
D. Urease negative
Urease negative
Regan – Lowe agar is an enriched and selective medium for the isolation of :
A. Bordetella pertussis
B. Campylobacter jejuni
C. Legionella pneumophila
D. Haemophilus ducryei
E. Listeria monocytogenes
Bordetella pertussis
Rickettsiae infecting man multiply preferentially within which of the following cells?
A. Reticuloendothelial cells
B. Hepatic cells
C. Endothelial cells
D. Renal tubular cells
E. All of the above
Endothelial cells
The preferred specimen for laboratory diagnosis of acquired cytomegalovirus
infection is:
A. Blood
B. Urine
C. Stool
D. Cutaneous vesicular fluid
Blood
A non-spore forming, slender gram-positive
rod forming palisades and chains was
recovered from a vaginal culture and grew
well on Tomato juice agar. The most likely
identification is:
A. Lactobacillus spp.
B. Neisseria spp.
C. Bacillus spp.
D. Streptococcus spp
Lactobacillus spp.
Sputum samples for tuberculosis screening
are optimally collected:
A. in the morning on 3 consecutive days
B. in the evening on 3 consecutive days
C. 24-hour sputum collection
D. Randomized sputum collection
in the morning on 3 consecutive days
Which virus is the most common etiologic agent of viral respiratory diseases in infants and children?
A. Retrovirus
B. Respiratory syncytial virus (RSV)
C. Measles virus
D. Coxsackie A virus
E. Poxviruses
Respiratory syncytial virus (RSV)
Fastidious, gram-negative bacilli produce colonies that pit the agar surface and produce a characteristic bleach like odor can be identified as:
A. Bacteroides fragilis
B. Eikenella corrodens
C. Pasteurella multocida
D. Listeria monocytogenes
Eikenella corrodens
The characteristics of Shigella spp. include all
of the following except:
A. Motile by single polar flagellum
B. Non-lactose fermenter
C. Oxidase negative
D. Nitrate positive
Motile by single polar flagellum
Cerebrospinal fluid should be cultured
immediately, but if delayed, the specimen
should be:
A. Refrigerated at 4-6 C
B. Frozen at -20 C
C. Stored at room temperature for 24 hours
D. Incubated at 37 C and cultured as soon
as possible
Incubated at 37 C and cultured as soon
as possible
