Practice test Lecture Flashcards by Tatiana Perez

True about the Elek test except:
I. a test strip of filter paper containing diphtheria antitoxin is placed in the center of the
agar plate
II. presence of precipitin lines considered positive of diphtheria toxin
III. Filter paper impregnated with diphtheria antitoxin placed perpendicular to bacterial
streaks
IV. test to detect the toxigenicity of Corynebacterium species.

A. IV
B. I, III, IV
C. III
D. III, IV

A. IV
Rationale: di true yung IV kase dapat specific na corynebacterium diptheriae ang for elek test

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Inhibit the beta-lysin property of Gram-positive cocci in clusters
A. Staphylokinase
B. CAMP factor
C. Lecithinase
D. Phospholipase D

Phospholipase D

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Which of the bacterial classifications were based on differences at the end product of
metabolism, presence of specific antigen and colonial morphology?
A. subspecies
B. family
C. strain
D. genus

subspecies

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A 28-year-old menstruating woman appeared in the emergency room with the following
signs and symptoms: fever, 104°F (40°C); VVBC, 16,000/uL; blood pressure, 90/65 mmHg a
scarlatiniform rash on her trunk, palms, and soles: extreme fatigue, vomiting and diarrhea.
The patient described in the case above most likely has
A. Staphylococcal food poisoning
B. Toxic shock syndrome
C. Scalded skin syndrome
D. Guillain-Barr syndrome
E. Chickenpox

Toxic shock syndrome

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Which of the ff tests should be performed for initial differentiation of Listeria
monocytogenes from group B streptococci?

A. Gram stain, CAMP test, blackening at TSI
B. oxidase and bacitracin
C. Gram stain, motility at Room temp, catalase
D. Oxidase, CAMP test, glucose

Gram stain, motility at Room temp, catalase

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Specimen for detection and diagnosis of diphtheria:
I. throat swab
II. nasopharyngeal swab
III. oropharyngeal swab
IV. bronchial aspirate
A. I, II, III, IV
B. I only
C. I, II, III
D. none of these

I, II, III

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Drug of choice of the treatment of bacterial vaginosis
A. Erythromycin
B. Clindamycin
C. Penicillin
D. Metronidazole

Metronidazole

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Which of the following is catalase negative?
I. Bacillus subtilis Listeria monocytogenes
II. Corynebacterium ulcerans, Erysipelothrix rhusopathiae
III. Streptococcus agalactiae, Neisseria baciliformis
IV. Neisseria elongate, Lactobacillus acidophilus
A. II, III, IV
B. III
C. I, II
D. III, IV

III, IV

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Which of the following characteristics best describe a gram-positive bacterium?
I. periplasmic: present
II. Periplasmic: absent
III. Outer membrane: present
IV. Outer membrane: absent

A. I, IV
B. II, IV
C. II, III
D. I, II

II, IV

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In identifying the presence of most group A β-hemolytic streptococci, versus those that are
non–group A, which of the following tests can be done?

A. PYR test, in which most non–group A β-hemolytic streptococci colonies would produce a bright red color after
addition of the PYR reagent to the filter paper
B. PYR test, in which most group A β-hemolytic streptococci colonies would produce a bright red color after
addition of the PYR reagent to the filter paper
C. Bile solubility test, in which most group A β-hemolytic streptococci colonies would be inhibited by an optochin
disk
D. Bile solubility test, in which most non–group A β-hemolytic streptococci colonies would be inhibited by an
optochin disk

B. PYR test
Rationale: in which most group A β-hemolytic streptococci colonies would produce a bright red color after addition of the PYR reagent to the filter paper

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Which of the following is associated with infections in humans often linked to deli meats
and improperly pasteurized dairy products?
A. Bacillus cereus
B. Leuconostoc
C. Streptococcus agalactiae
D. Listeria monocytogenes

Listeria monocytogenes
Rationale: 3C chicken, cheese, coleslaw

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A sputum sample from a patient with pneumonia produced many colonies of gramnegative diplococcic on chocolate plate that were also present in few numbers on Modified
Thayer-Martin after 48 hours. Given the results what is the most likely identification?
Catalase = positive Oxidase= positive
DNAse = positive
Tributyrin hydrolysis = positive Glucose = negative Sucrose = negative
Lactose = negative Maltose = negative Fructose =
negative

A. Neisseria sicca
B. Moraxella catarrhalis
C. Neisseria flavescens
D. Neisseria elongata

Moraxella catarrhalis

rationale: Moraxella lang yung nag iisa na negative sa lahat ng carbohydrate

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An Old citizen club had their monthly picnic, half of them experienced onset of vomiting
after 6 -8 hours of eating pre-heated food. The most likely bacterial cause of such
symptom would be food poisoning caused by?
A. Bacillus anthracis
B. Staphylococcus aureus
C. Bacillus cereus
D. Listeria monocytogenes

Bacillus cereus
Rationale: keyword is preheat food, only bacillus spp can strive in high temperature, the answer should be cereus due to clinical manifestations of food poisoning

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Colonies of Listeria monocytogenes on Sheep Blood Agar plate closely resembles the
colonies of?

A. Streptococcus agalactiae
B. Streptococcus bovis
C. Sreptococcus pyogenes
D. Streptococcus equisimilis

Streptococcus agalactiae

rationale: same sila na
narrow zone of ß hemolysis

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In the CAMP test, a single streak of a beta-hemolytic Streptococcus is placed
perpendicular to a streak of beta-lysin producing Staphylococcus aureus. After the
incubation, a zone of increased lysis in the shape of an arrowhead is noted, this indicates
the presumptive identification of.
A. Group D enterococcus
B. Group B Beta-hemolytic streptococci
C. Group D Non-enterococcus
D. Group A Beta-hemolytic streptococci

Group B Beta-hemolytic streptococci

rationale: S. agalactiae yung may arrowhead sa CAMP

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Identify the organism with the following biochemical reactions: Gram positive cocci in
pairs, Taxo P – resistant, Bile esculin test with blackening reaction, in 6.5% NaCl with
presence of turbidity, catalase without bubbles formation, PYRase with red color at the disk
and Bacitracin with no zone of inhibition.
A. Enterococcus
B. Group A Streptococci
C. Group D Non Enterococci
D. Group B Streptococci

Enterococcus

rationale: positive salt tolerance test and positive bile esculin

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Which feature distinguishes Erysipelothrix rhusiopathiae from other clinically significant
non-spore-forming, gram positive, facultatively anaerobic bacilli?

A. Hydrogen sulfide production
B. more pronounced motility at 25C than 37C
C. end over end motility
D. Beta-hemolysis

Hydrogen sulfide production

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Which of the anaerobic utilization of pyruvic acid was used by Gram positive cocci in
chains organism?
I. Mixed acid
II. Heterolactic
III. Homolactic
IV. Butyric Acid
A. II
B. I, IV
C. II, III
D. III

III only

rationale:
streptococcus and lactobacillus are gram positive organism, other choices have gram negtive or gram positive bacilli

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A Gram’s stain of the CSF of a 33-year-old man revealed many polymorphonuclear
leukocytes and intra- and extra-cellular gram negative diplococcic. Culture and tests were
as follows: small, flat, gray colonies on chocolate agar, oxidase positive, Cystine trypticase
agar (CTA) maltose positive: CTA lactose negative. The most likely identity that isolate is:
A. Neisseria gonorrhoeae
B. Neisseria meningitidis
C. Moraxella catarrhalis
D. Acinetobacter species

Neisseria meningitidis

rartionale key word: maltose positive and polymorphonuclear
leukocytes and intra- and extra-cellular gram negative diplococcic.

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Identify the organism with the following characteristics: Gram positive cocci, SXT-resistant, mucoid colony, Taxo A – 0mm , Taxo P - .17mm; Bile solubility: soluble; DNAse: no clearing
of colony; PYRase: colorless; CAMP: no arrow head formation; Hippurate hydrolysis: clear;
6.5 % Salt tolerance: cleared and Bile esculin: absence of blackening.
A. Streptococcus pneumoniae
B. Staphylococcus aureus
C. Streptococcus agalactiae
D. Streptococcus pyogenes

Streptococcus pneumoniae

rationale: unique test for identification of strep.pneumoniae
Solubility test - positive (soluble)
Taxo P test - susceptible

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The Vogues- Proskauer test detects the production of:
A. p-dimethylaminobenzaldehyde
B. Decarboxylase activity
C. Acetylmethylcarbinol
D. phenylalanine

Acetylmethylcarbinol

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Corynebacterium species recovered from a throat culture is considered a pathogen when it
produces:
A. pseudomembrane of the oropharynx
B. Tinsdale halo
C. an endotoxin
D. A & B
E. B & C

A & B

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Which of the following microorganism is most likely to be isolated in cultures from the
anterior nares of the healthcare workers?
A. Streptococcus pneumoniae
B. Staphylococcus saprophyticus
C. Staphylococcus aureus
D. Bacillus cereus

Staphylococcus aureus

rationale: S.aureus are normal flora in anterior nares

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Which of the following statements are CORRECT, except?
I. All prokaryotes are unicellular and multicellular.
II. All eukaryotes are unicellular and multicellular.
III. Peptidoglycan is present at all prokaryotes
IV. Polysaccharides are present at eukaryotes
A. I only
B. II, III, IV
C. I, III
D. II, IV

I, III

rationale:
Prokaryotes are only unicellular.
Eukaryotes can be multicellular and unicellular.
Not all prokaryotes have peptidoglycan.
Mycoplasma spp. and Ureaplasma spp. don’t have a peptidoglycan

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Which of the following gram-negative diplococci causes endocarditis? I. Neisseria sicca II. Neisseria weaver III. Neisseria bacilliformis IV. Neisseria lactamica A. I, IV B. II, IV C. II, III D. I, III

I, III

Virulence factor causes severe type of skin localized infection. I. Exotoxin A II. Enterotoxin F III. Epidermolytic toxin A IV. Exopolysaccharide A. I, III B. III C. I, III, IV D. II, IV

I, III rationale I. Exotoxin A strep. pyogenes (scarlet fever) II. Enterotoxin F superantigen (toxic shock syndrome) III. Epidermolytic toxin A scalded skin syndrome IV. Exopolysaccharide biofilm for medical devices causing prosthetic valve endocarditis both scarlet fever and SSS may manifestation/symptoms na makikita sa skin

Encapsulated microorganism: I. Neisseria meningitidis II. Listeria monocytogenes III. Streptococcus pneumoniae IV. Bacillus anthracis A. I, II, III B. II, III C. I, II, IV D. I, III, IV

I, III, IV

Staining Technique of Lactophenol Cotton Blue with result

fungal cell wall: blue

Staining Technique of Acridine Orange with result

Nucleic acid: bright orange

Staining Technique of Calcofluor white with result

fungal cell wall: apple green

Found in renal biopsy after the beta-hemolytic infection of: A. Streptococcus pyogenes B. Streptococcus agalactiae C. Streptococcus pneumoniae D. Staphylococcus aureus

Streptococcus pyogenes

A 52-year-old woman with a medical history of complicated urinary tract infection readmitted due to high fever, severe chest pain, fatigue, aching joints and muscles and difficult urination. Colorless colonies were isolated on MacConkey agar, positive on indole, urease, citrate and malonate test. What is the possible microorganism? A. Serratia marcescens B. Citrobacter diversus C. Escherichia coli D. Proteus vulgaris

Proteus vulgaris rationale: UTI was mentioned, the most common bacteria causing UTI are E.coli, Staphylococcus saprophyticus and Proteus spp

Which of the following is/are best to cultivate the Nocardia species? I. 5-7 days of incubation at 37C II. Incubate at room temperature III. 3-6 days of incubation at 37C IV. Use BCYE and Chocolate Agar Plate

III and IV

The following results are obtained from a pure culture of gram negative rods recovered from the pulmonary secretions of a 10-year-old cystic fibrosis patient with pneumonia Oxidase =blue Motility = with turbidity at SIM Glucose OF (open) = yellow Gelatin =liquefied Pigment = green Arginine dihydrolase =purple Growth at 42'C = positive Flagella = polar monotrichous Which is the most likely organism? A. Pseudomonas stutzeri B. Pseudomonas pseudomallei C. Pseudomonas aeruginosa D. Pseudomonas cepacia

Pseudomonas aeruginosa rationale: unique growth at 42'C

High fever and an inflammatory swelling of the axilla and groin lymph nodes are signs and symptoms of 35-year-old female patient admitted at Emergency room. Four blood cultures were obtained, resulting in growth of gram-negative bacilli resembling safety pins and showing colorless colonies on MacConkey Agar. Testing demonstrated a non-motile bacilli that was biochemically inert. What is the most likely identification? A. Klebsiella oxytoca B. Yersinia enterocolitica C. Morganella morganii D. Yersinia pestis

Yersinia pestis rationale: resembling safety pins and non motile (Y.pestis the only non motile yersinia spp)

An isolate of Escherichia coli recovered from the stool of a patient with severe bloody diarrhea should be tested for which carbohydrate before sending it to reference laboratory for serological testing? A. Raffinose B. Mannitol C. Sucrose D. Sorbitol

Sorbitol EHEC is colorless in SMAC

True about the cell wall of partially acid-fast bacilli, except: I. contain shorter mycolic acid II. peptidoglycan made up of mesodiaminopimelic acid III. contain glucose and arabinose IV. forms the filaments

III and IV

TRUE OR FALSE Morse code appearance is seen in gram staining of Aggregatibacter actinomycetemcomitans

FALSE rationale: should be bipolar staining

A curved gram-negative rod producing oxidase-positive colonies on blood agar was recovered from a stool culture. Given the following results, what is the most likely identification? Lysine decarboxylase = positive Arginine decarboxylase = Negative Indole = positive TSI = Alk/Acid VP = Negative Lactose = Negative Urease = variable String test = Negative TCBS agar = Green colonies A. Vibrio cholerae B. Salmonella spp C. Shigella spp D. Vibrio parahaemolyticus

Vibrio parahaemolyticus rationale: Stool culture - usually for vibrio spp Vibrio cholerae - yellow in TCBS Vibrio parahaemolyticus - Green colonies in TCBS

A 28-year-old female complained of a severe eye irritation after removing her softcontact lenses. Swab from the infected right eye was submitted in the microbiology for culture and sensitivity. At 24 hours, growth of a gram-negative rod that tested positive for cytochrome oxidase was noted. Bluish-green colonies were showed on Mueller-Hinton Agar. What is the most likely microorganism? A. Stenotrophomonas maltophilia B. Burkholderia cepacia C. Pseudomonas aeruginosa D. Acinetobacter baumanii

Pseudomonas aeruginosa RATIONALE Key word: Bluish-green colonies in MHA unique in aeruginosa

A catheterized urine specimen collected from a female patient who is residing in a nursing home reveals the following: TSI: K/A, no gas, H2S negative MacConkey: clear colonies indole: red ring Citrate: blue Motility: positive Urease: pink Deaminase: burgundy Identify the isolate: A. Providencia stuartii B. Klebsiella pneumoniae C. Escherichia coli D. Proteus mirabilis E. Serratia marcescens

Providencia stuartii rationale: KEY word in question: Deaminase: burgundy only PPM are R/A in LIA choices left are providencia and protues but due to H2S result the probable answer is providencia

An acid fast organism is isolated form a wound culture taken from the hand of a marine biology student The organism produces smooth, bright lemon-yellow colonies on Lowenstein-Jensen agar when exposed to light The organism is negative for nitrate reduction and is catalase and urease positive. The identity of this organism is: A. Mycobacterium scrofulaceum B. Mycobacterium tuberculosis C. Mycobacterium fortuitum D. Mycobacterium marinum E. Mycobacterium ulcerans

Mycobacterium marinum rationale key word: marine biology student

Which of the following tests best differentiate Shigella species from E. coli? A. Hydrogen sulfide, VP, citrate, and urea B. Hydrogen sulfide, ME, citrate, and urea C. Gas, citrate, and VP D. Lactose, indole. ONPG; and motility

Lactose, indole. ONPG; and motility

Which of the following Mycobacterium species is diagnosed by biopsy other than culture? A. M. bovis B. M. leprae C. M. avium D. M. canetti

M. leprae

Which are the best two tests to differentiate Aeromonas hydrophilia from Plesiomonas shigelloides? A. DNase and VP B. Growth on MacConkey and blood agar C. Oxidase and motility D. Indole and lysine decarboxylase

Growth on MacConkey and blood agar

1 Statement: All Non-fermentative Organisms are oxidase positive 2 Statement: Acinetobacter species is the negative in motility and oxidase. A. Neither Statements are correct B. 1 Statement is true, 2 Statement is true C. 1 Statement is false, 2 Statement is true D. 2 Statement is false, 1 Statement is true

C. 1 Statement is false, 2 Statement is true

A bloody stool cultured from a 35-year-old- woman after three days of severe diarrhea showed the following results at 48 hours after being plated on the following media: Mac Conkey agar: colorless colonies Hektoen Enteric Agar: Blue-green colonies Oxidase: colorless Indole: colorless ring SIM: No brush appearance from the stab line without H2S Urease: Orange ONPG: yellow A. Escherichia coli B. Salmonella cholerae- suis C. Salmonella typhi D. Shigella sonnei

Shigella sonnei rationale: siya lang non motile sa choices

A wound sample was submitted at Microbiology reveals non-motile gram-variable bacilli, aerobic and catalase positive. Identify the isolate: A. Streptomyces anulatus B. Gordonia bronchialis C. Actinomadura madurae D. Rhodococcus equi

Gordonia bronchialis

A gram-negative coccobacillus was isolated from an infected cat bite. The isolate grew on blood agar with a musty smell, but did not grow on MacConkey agar. It was catalase, indole, and oxidase positive and negative to urease. Which one of the following is the most likely identity of this isolate? A. Pasteurella multocida B. Eikenella corrodens C. Pasteurella canis D. Pasteurella bettyae

Pasteurella multocida

Xylose lysine deoxycholate (XLD) agar is a highly selective medium used for the recovery of which bacteria? A. Yersinia species that do not grow on Hektoen Enteric Agar B. Enterobacteriaceae from gastrointestinal specimens C. Streptococcus species from stool cultures D. Corynebacterium species from normal flora

Enterobacteriaceae from gastrointestinal specimens

TRUE OR FALSE Rosette form is the microscopic morphology of Cardiobacterium hominis

TRUE

Grown inhibition by thiophene-2-carboxylic hydrazide (T2H) is used to differentiate Mycobacterium tuberculosis from which otter Mycobacterium sp.? A. M. avium complex B. M. bovis C. M. marinum D. M. kansasii

M. bovis

Which test group best differentiates Acinetobacter species. from Pseudomonas. aeruginosa? A. Oxidase, motility, 42°C growth B. MacConkey growth, 37C growth, catalase C. Blood agar growth, oxidase, catalase D. Oxidase, TSI, MacConkeY growth

Oxidase, motility, 42°C growth

A suspected case of plague requires which of the following procedures in order to confirm Yersinia pestis? I. Satellitism pattern in broth culture II. Incubation of blood cultures at both 25°C and 30°C III. Culture aspirates from buboes to MacConkey agar at room temperature IV. safety pin appearance in leifson’s staining A. II only B. II, III C. I, IV D. II, III, IV

II only pero nung sa exam ang naalala ko is walang 2 only na choices, nag 2 and 3 nalang ako

Which of the biochemical tests best to differentiate Klebsiella pneumoniae from Klebsiella oxytoca? A. Citrate B. Indole C. Urease D. Sucrose

Indole

A gram negative, motile rod is isolated from a urine culture. On trypticase soy agar, the organism produces red pigmented, DNAse positive colonies. Additional biochemical testing revealed the following: KCN positive, ODC positive, ADC negative and LDC positive. The most probable organism is: A. Escherichia coli B. Proteus vulgaris C. Pseudomonas aeruginosa D. Enterobacter cloacae E. Serratia marcescens

Serratia marcescens keyword: produces red pigmented

Which of the follow is noted for a positive result for niacin accumulation? A. Mycobacterium gordonae B. Mycobacterium fortuitum-chelonae C. Mycobacterium tuberculosis D. Mycobacterium avium-intracellulare

Mycobacterium tuberculosis

Colorless colonies on MacConkey Agar and yellow colonies on TCBS agar are presumptive identification of Vibrio cholerae. Which biochemical tests would be used to eliminate Aeromonas and Plesiomonas species in seafood food poisoning? I. Mannitol fermentation II. String test III. Gelatin Liquefaction IV. Oxidase A. II, IV B. I, II C. I, II, III D. III, IV

I, II

Which of the following is the best media for the cultivation of Vibrio species? A. TCBS, BAP, Alkaline Peptone Water B. TCBS, BCYE, MacConkey, SSA C. TCBS, Clary-Blair medium, SSA D. TCBS, Alkaline Peptone Water, MacConkey

TCBS, Alkaline Peptone Water, MacConkey

88 -year- old diabetic patient, rushed to the emergency department with abdominal pain, fever, vomiting, and nausea. A watery stool specimen producing no fecal leukocytes or erythrocytes was cultured and grew a predominance of gram- negative fermentative bacilli. The colonies were beta-hemolytic on Blood Agar Plate and colorless on Mac Conkey agar. The colonies were both catalase and oxidase positive. What is the most likely identification? a. Shigella dysenteriae b. Escherichia coli c. Aeromonas hydrophilia d. Salmonella species

Aeromonas hydrophilia

Smooth gray colonies showing no hemolysis are recovered from an infected cat scratch on blood and chocolate agar but fail to grow on MacConkey agar. The organisms are gram negative pleomorphic rods that are both catalase and oxidase positive and strongly indole positive. The most likely organism is: a. Proteus spp. b. Pasteurella spp. c. Pseudomonas spp. d. Capnocytophaga spp

Pasteurella spp.

Cultures obtain from a dog bite wound produce yellow, tan, and slightly pink colonies on blood and chocolate agar with margin of fingerlike projections appearing as a film around colonies. Given the following results at 24 hours, which is the most likely organism? Oxidase=0 catalase=0 Growth on MacConkey agar=0 Motility =+ (“gliding” appearance) A. Capnocytophaga species B. Acinetobacter species C. Pseudomonas species D. Eikenella species

Capnocytophaga species

The symptoms of diffuse, watery diarrhea that produces a relatively clear stool containing mucus flecks or rice water stool is most closely associated with an infection caused by: a. Escherichia coli b. Vibrio cholerae c. Shigella dysenteriae d. Yersinia enterocolitica

Vibrio cholerae rationale key word: rice water stool

Cefsulodin-Igrasan Novobiocin is used for the recovery of: I. Yersinia species II. Burkholderia pseudomallei III. Yersinia enterocolitica IV. Edwarsiella tarda A. II, IV B. I only C. III only D. I, III

Yersinia enterocolitica

Kingella kingae can best be differentiated from Eikenella corrodens using which medium? a. MacConkey agar b. Sheep blood agar c. Chocolate agar d. XLD agar

Sheep blood agar

A gram negative, non-motile rod is isolated from the sputum of a patient with pneumonia Biochemically, the organism is ONPG positive, citrate positive, and LDC positive. Negative results were obtained in the ADH, ODC and H2S tests. The organism isolated is: a. Serratia marcescens b. Klebsiella pneumoniae c. Streptococcus pneumoniae d. Pseudomonas aeruginosa e. Yersinia pestis

Klebsiella pneumoniae

Acinetobacter baumannii is: a. non saccharolytic b. non-hemolytic c. motile d. oxidase positive

non-hemolytic

Kingella kingae is usually associated with which type of infection? a. Meningitis b. Endocarditis c. Middle ear d. Urogenital

Endocarditis

A Bloody mucoid stool was submitted to the Microbiology for culture and sensitivity. Laboratory Diagnosis: Hektoen Enteric Agar: green colonies TCBS: no growth XLD: clear colonies MacConkey Agar: colorless colonies SSA: colorless colonies Which tests are most appropriate for identification of this enteric pathogen? A. TSI, Indole, Urease, Citrate B. TSI, motility, indole, LDC, Widal Test C. TSI, Indole, Methyl Red, Voges Proskauer, Citrate D. TSI, motility, indole, LDC, Serological typing

TSI, motility, indole, LDC, Serological typing

Which organism is associated with immunodeficiency syndromes and a glanders-like disease? a. Pseudomonas putida b. Pseudomonas aeruginosa c. Pseudomonas stutzeri d. Burkholderia pseudomallei

Burkholderia pseudomallei

Enterobacter sakazaki can best be differentiated from Enterobacter cloacae by its: a. Yellow pigmentation and positive urease b. H2S production on TSI c. Pink pigmentation and positive arginine dihydrolase d. Yellow pigmentation and negative sorbitol fermentation

Yellow pigmentation and negative sorbitol fermentation

Three consecutive stool cultures from a 10-year-old female patient produced bulls eye colonies on Cefsulodin-Irgasan-Novobiocin after 48 hours of incubation. The patient had suffering from enterocolitis with fever, diarrhea, and abdominal pain for 2 days. What is the most likely identification of this gram-negative bacilli? a. Yersinia enterocolitica b. Shigella boydii c. Enteropathogenic Escherichia coli d. Serratia mascescens

Yersinia enterocolitica rationale keyword: bulls eye colonies on Cefsulodin-Irgasan-Novobiocin

True about the 4 week of Typhoid fever. I. Ulceration of Peyer’s patches II. Osteomyelitis III. Liver cirrhosis IV. Acute Kidney Infection A. II, IV B. I, III C. III, IV D. II only

II only

Acid-fast staining of a smear prepared from a digested sputum showed slender, slightly curved. beaded' red mycobacterial rods. Growth on Middlebrook 7H10 slants produced buff-colored microcolonies with a serpentive pattern after 14 days at 37°C. Niacin and nitrate reduction tests were positive. What is the most probable presumptive identification? a. Mycobacterium avium complex b. Mycobacterhun kansasii c. Mycobacterium tuberculosis d. Mycobacterium ulcerans

Mycobacterium tuberculosis

A mixture of slender gram-negative rods and coccobacilli with rounded ends was recovered from blood cultures following a patient’s root canal surgery. Given the following results after 48 hours, what is the most likely organism? Catalase = Neg Ornithine decarboxylase = purple Urease = orange Lysine decarboxylase = purple Oxidase = blue X factor: with growth Indole = colorless ring Carbohydrates = red Colonial Morphology Growth on blood and chocolate agar = with pitting of agar Growth on MacConkey agar = colorless A. Cardiobacterium hominis B. Proteus species C. Actinobacillus species D. Eikenella corrodens

Eikenella corrodens key word: root canal surgery

Which is the best rapid test to differentiate Plesiomonas shigelloides from a Shigella species on selective enteric agar? a. TSI b. Urease c. Indole d. Oxidase

Oxidase

Four blood cultures were taken over a 24-hour period from a 17-year-old female with severe diarrhea. The cultures grew motile gram-negative rods at room temperature. Urine obtained by catheterization also showed gram-negative rods, 100,000 col/ml Given the results below, which is the most likely organism. TSI = A/A Indole= red ring VP = yellow MR= red H2S = no blackening Citrate = green Urea = orange Phenylalanine deaminase = colorless Lysine decarboxylase = purple A. Proteus vulgaris B. Yersinia enterocolitica C. Salmonella typhi D. Escherichia coli

Escherichia coli

1st Statement: Nocardiosis acquired by air droplets; 2nd Statement: Nocardiosis acquired through direct contact. a. 1st Statement is true, 2nd Statement is true b. 2nd Statement is false, 1st Statement is true c. Neither Statements are correct d. 1st Statement is false, 2nd Statement is true

1st Statement is true, 2nd Statement is true

Two blood cultures taken from a 75-year-old HIV patient receiving anti-viral treatment and admitted with a severe pneumonia grew lactose negative, motile, gram-negative rods. Given the following biochemical reactions, which is the most likely organism? VP: colorless Indole: red ring Methyl Red: red Citrate: green Urease: magenta H2S: with blackening Phenylalanine deaminase: green Lysine Deaminase: burgundy A. Salmonella paratyphi A B. Proteus vulgaris C. Edwarsiella tarda D. Arizonae species

Proteus vulgaris

Which of the Enterobacteriaceae are known to cause diarrhea and are considered enteric pathogens? a. Escherichia coli, Proteus mirabilis, Citrobacter freundii b. Yersinia pestis, Shigella sonnei, Enterohemorrhagic Escherichia coli c. Pseudomonas aeruginosa, Acinetobacter baumannii, Salmonella paratyphi d. Enterobacter aerogenes, Morganella morganii, Klebsiella oxytoca

Yersinia pestis, Shigella sonnei, Enterohemorrhagic Escherichia coli

A halophilic, gram-negative curved rod is isolated on TCBS agar from a stool specimen. The organism is lactose negative, lysine decarboxylase and oxidase positive. The organism isolated is: a. Vibrio parahaemolyticus b. Aeromonas hydrophilia c. Shigella dysenteriae d. Escherichia coli e. Salmonella typhi

Vibrio parahaemolyticus

Type of leprosy that causes extensive skin lesions, progressive and permanent nerve damage which also has ineffective cell-mediated response that causes faster spread of infection

Lepromatous leprosy

Type of leprosy that causes skin lesions and loss of sensation also has and effective cell mediated response

Tuberculoid leprosy

A gram-negative S-shaped rod recovered from selective media for Campylobacter species gave the following results: Catalase = with effervescence Oxidase = purple Motility = turbid Hippurate hydrolysis = purple Growth at 42°C = positive Growth at 25C = negative Nalidixic acid = Susceptible Pigment = Negative Cephalothin = Resistant Urease: orange The most likely identification is: a. Campylobacter fetus b. Campylobacter jejuni c. Pseudomonas putida d. Pseudomonas aeruginosa

Campylobacter jejuni

A small, gram-negative coccobacillus recovered from the blood samples of a 2-year-old child gave the following results: Indole = red ring Glucose = positive X requirement = no growth V requirement = with growth Nitrate reduction= red Lactose = Negative Sucrose = positive ALA= reddish orange Hemolysis= Negative Which is the most likely identification? A. Haemophilus influenzae B. Haemophilus ducreyi C. Haemophilus parahaemolyticus D. Haemophilus parainfluenzae

Haemophilus parainfluenzae

Which Haemophilus species is difficult to isolate and recover from genital ulcers and swollen lymph nodes? a. H. haemolyticus b. H. ducreyi c. H. parahaemolyticus d. H. aphrophilus

H. ducreyi

The gram-positive non–spore-forming anaerobic rods most frequently recovered from blood cultures as a contaminant are: a. Propionibacterium acnes b. Veillonella parvula c. Staphylococcus intermedius d. Clostridium perfringens

Propionibacterium acnes

A 5-year-old nonimmunized male with a persistent cough, fever, and flulike symptoms was admitted to the hospital. Nasopharyngeal swabs were cultured on 15% blood, chocolate, Bordet–Gengou, and Regan–Lowe (with 10% charcoal) agars. All media grew a gramnegative coccobacillus. Carbohydrate and biochemical tests were negative. What is the most likely identification? a. Bordetella bronchiseptica b. Bordetella pertussis c. Haemophilus influenza d. Haemophilus parainfluenzae

Bordetella pertussis

A 2-year-old child was admitted to the hospital with acute meningitis. The Gram stain revealed Gram-positive short rods, and the mother indicated that the child had received "all' of the meningitis vaccinations. What is the most likely cause of the disease? a. Listeria monocytogenes b. Neisseria meningitidis group A c. Streptococcus pneumoniae d. Neisseria meningitidis group C  e. Bacillus anthracis

Listeria monocytogenes

The most common etiologic agent of infections associated with the surgical insertion of prosthetic devices such as artificial heart valves and cerebrospinal fluid shunts is: I. Staphylococcus saprophyticus II. Streptococcus mutans III. Enterococcus faecalis IV. Staphylococcus epidermidis A. I, III, IV B. I, III C. I, II, III, IV D. IV only

IV only

A 6-year-old female patient was admitted to the hospital following 2 days of severe diarrhea. Cultures from three consecutive stool samples contained blood and mucus. Patient history revealed a hamburger lunch at a fast-food restaurant 3 days earlier. Which pathogen is most likely responsible for the following results? Growth on: XLD agar = yellow colonies HE agar = yellow colonies Mac agar = light pink and dark pink colonies Mac with sorbitol agar – few dark pink and many colorless colonies A. Yersinia enterocolitica B. Shigella spp C. Salmonella spp D. E. coli O157:H7

Shigella spp

36 years old women visited her Obstetrician to consult her discharge with unpleasant odor. The doctor advised her to collect and submit the vaginal discharge at the microbiology section of the laboratory for gram staining and culture. The medical technologist seen squamous epithelial cells with overlapping gram-positive bacilli. What is the microorganism? a. Neisseria gonorrhoeae b. Lactobacillus acidophilus c. Gardnerella vaginalis d. Ureaplasma urealyticum

Gardnerella vaginalis

Which of the following is not correct about spirochetes? I. Motility is via axial filaments II. They are visualized both in dark field and phase optics III. Spirochetes are gram positive IV. Those humans with disease are 0.1-0.5 um in diameter and 5-30um in length A. II, IV B. II, III C. III, IV D. I, III

III, IV

A direct smear of a specimen for aerobic and anaerobic culture revealed the presence of gram positive rods. A blood agar plate was inoculated and incubated in an aerobic environment and in a clinical laboratorian saw that the methylene blue strip was blue. Growth was observed in both the aerobic and anaerobic plate. Which of the following statements is most likely true? a. The isolate is most likely a strict aerobe b. The isolate is most likely facultative anaerobe c. The isolate is most likely a strict anaerobe d. Cannot be determined; the methylene blue was blue and this indicates that oxygen is present in the anaerobic jar

Cannot be determined; the methylene blue was blue and this indicates that oxygen is present in the anaerobic jar

Which of the following plates should be used in order to identify Haemophilus haemolyticus and Haemophilus parahaemolyticus? a. Sheep blood agar and chocolate agar b. Brain–heart infusion agar with sheep red cells added c. Horse blood agar and Mueller–Hinton agar with X and V strips d. Chocolate agar and Mueller–Hinton agar with X factor added

Horse blood agar and Mueller–Hinton agar with X and V strips

During the first week of leptospirosis, the most reliable way to detect the presence of the causative agent is by the direct I. culturing blood II. culturing urine III. Examination of blood IV. Examination of CSF A. I, III B. IV only C. II D. I only

I only

A 28-year-old menstruating woman appeared in the emergency room with the following signs and symptoms: fever, 104°F (40°C); VVBC, 16,000/uL; blood pressure, 90/65 mmHg a scarlatiniform rash on her trunk, palms, and soles: extreme fatigue, vomiting and diarrhea. The patient described in the case above most likely has a. Staphylococcal food poisoning b. Scalded skin syndrome c. Guillain-Barr syndrome  d. Chickenpox e. Toxic shock syndrome

Toxic shock syndrome

A gram positive, spore-forming bacillus growing on blood agar anaerobically produces a double zone of beta hemolysis and is positive for lecithinase. What is the presumptive identification of this isolate? a. Clostridium difficile b. Bacteroides urealyticus c. Bacteroides fragilis d. Clostridium perfringens

Clostridium perfringens

Borrelia burgdorferi, a spirochete transmitted by Ixodes dammini and the etiologic agent of? a. Q fever b. Lyme disease c. Relapsing fever d. Rat-like fever

Lyme disease

chlamydia spp that is causative agent of parrot fever

Chlamydia psittaci

The majority of Haemophilus influenzae infections are caused by which of the following capsular serotypes? a. b b. a c. c d. d

b capsular serotypes

A Porphyromonas spp. a. Bacteroides spp. b. Prevotella spp. c. Fusobacterium spp

Fusobacterium spp

The δ-ALA test is a confirmatory procedure for which test used for identification of Haemophilus species? a. V factor requirement b. Urease production c. Indole production d. X factor requirement

X factor requirement

Obligate anaerobic gram-negative bacilli that do not form spores grow well in 20% bile and are resistant to penicillin 2-unit disks are most likely: a. Prevotella spp. b. Bacteroides spp. c. Fusobacterium spp. d. Porphyromonas spp.

Bacteroides spp

An elderly woman who cared for several domestic cats was hospitalized with suspected cat-scratch disease. Blood cultures appeared negative, but a small, slightly curved pleomorphic gram-negative bacillus grew on BHI agar. What is the most likely identification? a. Haemophilus spp. b. Bartonella spp. c. Kingella spp. d. Brucella spp.

Bartonella spp

True about causative agent of pharyngitis: I. pseudomembranous formation of the pharynx are seen in respiratory diphtheria II. 80% developed cervical lymphadenopathy in pharyngitis of Arcanobacterium species III. Treated Strep throat most often developed into rheumatic heart disease in children IV. Gram positive, catalase negative bacilli often cause pharyngitis during stage of adolescence. A. I, III B. I, IV C. IV D. I, ll, lll, lV

I, IV

Gram stain of a smear taken from the periodontal pockets of a 30-year-old man with poor dental hygiene showed sulfur granules containing gram-positive rods-short diphtheroids and some unbranched filaments. Colonies on blood agar resembled “molar teeth” in formation. The most likely organism is: a. Staphylococcus intermedius b. Propionibacterium acnes c. Actinomyces israelii d. Peptostreptococcus anaerobius

Actinomyces israelii

An organism that cannot use oxygen as the final electron acceptor and is inhibited by its presence is a(an): a. obligate anaerobe b. obligate aerobe c. facultative anaerobe d. microaerophile

obligate anaerobe

Associated with epidemic cholera which is positive on oxidase, catalase, Voges Proskauer and polymyxin B susceptibility a. Vibrio cholerae O1 Inaba b. Vibrio cholerae O1 El Tor c. Vibrio cholerae Non O1 d. Vibrio cholerae O1 Classical

Vibrio cholerae O1 Inaba

Which of the following pairs is/are correct? I. rectal swab: cotton swab: Neisseria cinerea II. eye discharge: rayon swab: Neisseria gonorrhoeae III. blood: Blood culture bottle: Neisseria meningitidis IV. Cerebrospinal fluid: sterile screwcap bottle: Moraxella catarrhalis A. I, II, III B. I, IV C. II, III D. III

II, III

The following characteristics of an obligate anaerobic gram-negative bacilli best describe which of the listed genera? Gram stain: long, slender rods with pointed ends colonial appearance: dry bread crumbs or “fried-egg” appearance Penicillin 2-unit disk test: Susceptible a. Bacteroides spp. b. Fusobacterium spp. c. Porphyromonas spp. d. Prevotella spp

Fusobacterium spp.

True about the Gram staining, except? I. Due to over decolorization, gram positive appears negative organism. II. Prolonged heat fixation all bacteria as a result appear gram-positive III. Under decolorization all gram positive appears as gram negative organism IV. Old culture smears all bacteria as a result appear gram negative

I, III

Klebsiella pneumoniae

Identify the following bacterium and specimen pairing that is mismatched (specimen not appropriate for isolation). a. Chlamydia trachomatis: first voided urine b. Chlamydia psittaci: fecal swab c. Chlamydia trachomatis: endocervical swab d. Chlamydia pneumonia: throat swab or sputum

Chlamydia psittaci: fecal swab

The mild type of typhus fever that is caused by recrudescence of an initial attack of epidemic typhus is known as: a. Brill-Zinsser disease b. Q fever c. Tsutsugamushi disease d. Relapsing fever

Brill-Zinsser disease

The diagnosis of Lyme disease can be made by: A. silver impregnation techniques to demonstrate spirochete in tissue B. serological demonstration of antibody in patient's serum using enzyme immunoassay C. growth on blood and chocolate agar D. both A and B E. all of the above

all of the above rationale: in stages I and II of Lyme disease, EIA testing is performed on serum for antibodies. PCR testing and culture of Borrelia spp. are performed on a skin biopsy. In stage III, synovial fluid, skin biopsy, and CSF are tested for Borrelia spp. by PCR

A gram-negative coccobacillus was isolated from upper respiratory tract sections with these biochemical reactions: Hemin factor: no growth; NAD factor with growth, with red end-colored in fermentation of mannose and mannitol, and colorless at ONPG a. H. Parainfluenzae b. H. influenzae c. H. ducreyi d. H. parahaemolyticus e. H. Haemolyticus

H. parahaemolyticus

A halophilic, gram-negative curved rod is isolated on TCBS agar from a stool specimen. The organism is lactose negative, lysine decarboxylase and oxidase positive. The organism isolated is: a. Vibrio parahaemolyticus b. Shigella dysenteriae c. Aeromonas hydrophilia d. Escherichia coli e. Salmonella typhi

Vibrio parahaemolyticus

Many α-hemolytic streptococci recovered from a wound were found to be penicillin resistant. Given the following results, what is the most likely identification? Bile esculin = with blackening PYR = red 6.5% salt = turbid Bile solubility= negative Hippurate hydrolysis = positive SXT = Resistant A. Streptococcus pneumoniae B. Enterococcus faecalis C. Group B streptococci D. Streptococcus bovis

Streptococcus bovis

Which gram-negative bacilli produce black pigment and brick red fluorescence when exposed to an ultraviolet light source? a. Bacteroides spp. and Fusobacterium spp. b. Porphyromonas spp. and Prevotella spp. c. Fusobacterium spp. and Actinomyces spp. d. All of these options

Porphyromonas spp. and Prevotella spp.

A bloody stool cultured from a 26-year-old woman after 3 days of severe diarrhea showed the following results at 48 hours after being plated on the following media: MacConkey agar: little normal flora with many non–lactose-fermenting colonies Hektoen enteric agar: many blue-green colonies Campylobacter blood agar and C. difficile agar: no growth Clear colonies from MacConkey agar tested negative for oxidase, indole, urease, motility, and H2S The most likely identification is: A. Salmonella spp B. Escherichia coli C. Shigella spp D. Proteus spp

Shigella spp

Rocky Mountain Spotted fever is transmitted by the bite of a tick infected with. a. Rickettsia prowazekii b. Rickettsia conorii c. Rickettsia rickettsii d. Rickettsia akari

Rickettsia rickettsii

The causative agent of endemic or murine typhus is A. Rickettsia conorii B. Rickettsia typhi C. Rickettsia akari D. Rickettsia prowazekii

Rickettsia typhi

Haemophilus influenzae causes ocular infections and requires X and V factors in the primary medium for growth. The subspecies Haemophilus influenza biogroup aegyptius can further be identified and differentiated by which two tests? a. Indole and xylose b. Oxidase and catalase c. ALA test and oxidase d. Glucose and urease

Indole and xylose

Which are the best two tests to differentiate Aeromonas hydrophilia from Plesiomonas shigelloides? a. Indole and lysine decarboxylase b. Growth on MacConkey and blood agar c. DNase and VP d. Oxidase and motility

DNase and VP

Detection of antibody against cardiolipin is useful for the diagnosis of which of the following disease? A. Relapsing fever B. Lyme disease C. Leptospirosis D. Syphilis

Syphilis

A leg-wound culture from a hospitalized 70-year-old diabetic man grew motile, lactosenegative colonies on MacConkey agar. Given the following biochemical reactions at 24 hours, what is the most probable organism? H2S (TSI) = negative Indole = colorless ring MR = yellow VP = red DNase = with of clearing of zone Citrate = blue Urease = orange Phenylalanine deaminase = colorless Ornithine and lysine decarboxylase = purple Arginine decarboxylase = yellow Gelatin hydrolysis = liquified A. Proteus mirabilis B. Enterobacter cloacae C. Serratia marcescens D. Proteus vulgaris

Serratia marcescens

Which of the following tests may be used to differentiate Cardiobacterium hominis from Actinobacillus spp.? a. Indole b. Anaerobic incubation c. Oxidase d. Gram stain

Indole

Drugs incorporated in the New York City medium: I. vancomycin II. Colistin III. Amphotericin B IV. Anisomycin V. Trimethoprim lactate A. I, II, V B. I, II, III, V C. all except 3 D. all of these

I, II, III, V

Found in renal biopsy after the beta-hemolytic infection of: a. Streptococcus pneumoniae b. Streptococcus pyogenes c. Staphylococcus aureus d. Streptococcus agalactiae

Streptococcus pyogenes

Identify the Haemophilus species: Requirement for X factor: positive Requirement for V factor. positive Hemolysis: negative ALA: negative Fermentation of glucose: positive Fermentation of sucrose: negative Fermentation of lactose: negative Fermentation of fructose: negative A. H. influenzae B. H. parahaemolyticus C. H. ducreyi D. H. Parainfluenzae E. H. Haemolyticus

H. influenzae

All of the following genera are anaerobic cocci that stain gram positive except: a. Peptostreptococcus spp. b. Streptococcus spp. c. Peptococcus spp. d. Veillonella spp.

Veillonella spp

Anaerobic bacteria are routinely isolated from all of the following types of infections except: A. Urinary tract infections B. Dental infections C. Brain abscesses D. Lung abscesses

Urinary tract infections

Anaerobic gram-positive diphtheroids , non-spore formers were cultured from two separate blood culture bottles (at 5 days) obtained from a 25-year-old patient admitted to the hospital with dehydration, diarrhea, and other flulike symptoms. Four other blood culture bottles did not grow any organisms at 7 days and were discarded. The following results were obtained from the recovered anaerobe: positive in Indole, Nitrate, and Catalase test. Susceptible in Susceptible in kanamycin and vancomycin while resistant in Colistin. What is the correct identification? a. Eubacterium lentum b. Actinomyces spp. c. Propionibacterium acnes d. Peptostreptococcus spp.

Propionibacterium acnes

Francisella tularensis is the bacterium that causes tularemia, a disease not uncommonly seen in hunters. Which of the following statements best characterizes this bacterium? A. It produces at least one protein toxin consisting of two subunits. A and R, that causes severe spasmodic cough usually in children. B. It secretes erythrogenic toxin that causes the characteristic signs of scarlet fever. Strep. pyogenes C. It secretes exotoxin that has been called "verotoxin" and 'Shiga-like toxin"; Infection is mediated by a specific attachment to mucosal Membranes. D. It requires cysteine for growth E. It produces toxin that blocks protein synthesis in an infected cell and carries a lytic bacteriophage that produces the genetic information for toxin production.

It requires cysteine for growth

Which mechanism is responsible for botulism in infants caused by Clostridium botulinum? a. Virulence of the organism b. Ingestion of preformed toxin in food c. Lipase activity of the organism d. Ingestion of spores in food or liquid

Ingestion of spores in food or liquid

Which of the following is noted for a positive result for niacin accumulation? a. Mycobacterium fortuitum-chelonae b. Mycobacterium avium-intracellulare c. Mycobacterium gordonae d. Mycobacterium tuberculosis

Mycobacterium tuberculosis

Cold enrichment of feces in phosphate-buffered saline prior to subculture onto enteric media enhances the recovery of: a. Salmonella paratyphi b. Y. enterocolitica c. Enterotoxigenic E. coli d. Hafnia alvei

Y. enterocolitica

Which of the following products is responsible for satellite growth of Haemophilus spp. around colonies of Staphylococcus and Neisseria spp. on sheep blood agar? a. Oxidase b. Hemin c. Indole d. NAD

NAD

A pure culture of β-hemolytic streptococci recovered from a leg wound ulcer gave the following reactions: CAMP test = negative Hippurate hydrolysis = negative Bile esculin = negative 6.5% salt = negative PYR = negative Bacitracin = 6mm Optochin = 8mm SXT = 32mm The most likely identification is: A. Group B streptococci B. Enterococcus faecalis C. Group A streptococci D. Nongroup A, nongroup B, nongroup D streptococci

Group A streptococci

Egg yolk agar is used to detect which enzyme produced by Clostridium species? a. β-Lactamase b. Lecithinase c. Catalase d. Oxidase

Lecithinase

Anaerobic gram-positive, spore-forming bacilli were recovered from the feces of a chemotherapy patient with severe diarrhea. The patient had undergone antibiotic therapy 1 week prior. The fecal culture produced growth only on the CCFA plate. No aerobic growth of normal flora was seen after 48 hours. The following results were noted: Kanamycin = Sensitive Vancomycin = Sensitive Colistin = Resistant Lecithinase = negative Lipase = negative Nitrate = negative Indole = colorless ring Urease = orange Catalase = Neg Spores = positive Colonial morphology CCFA agar = Growth of yellow, “ground-glass” colonies that fluoresce chartreuse (yellow-green) A. Clostridium sordellii B. Clostridium tetani C. Clostridium difficile D. Clostridium perfringens

Clostridium perfringens

A gram-negative rod is recovered from a catheterized urine sample from a nursing home patient. The lactose-negative isolate tested positive for indole, urease, ornithine decarboxylase, and phenylalanine deaminase and negative for H2S. The most probable identification is: a. Morganella spp. b. Edwardsiella spp. c. Shigella spp. d. Ewingella spp.

Morganella spp

Which of the ff tests should be performed for initial differentiation of Listeria monocytogenes from group B streptococci? a. Gram stain, motility at Room temp, catalase b. Gram stain, CAMP test, blackening at TSI c. oxidase and bacitracin d. Oxidase, CAMP test, glucose

Gram stain, motility at Room temp, catalase

Gram negative coccobacilli was isolated from ear discharge after 48 hours of incubation on Horse Blood agar plate. The isolates were positive on ornithine and Urea tests. What most likely is the organism? a. H. Parainfluenzae Biotype II b. H. Haemolyticus Biotype I c. H. influenzae Biotype I d. H. parahaemolyticus Biotype IV e. H. ducreyi Biotype III

H. influenzae Biotype I

Which of the following is NOT true about Chlamydia pneumoniae? I. Common agent of lower respiratory tract infection II. Humans become infected from animal reservoirs. III. High risk for patients with nerve ending damages IV. Hep 2 cell culture and Macro-immunofluorescence a. II, IV b. I, III c. II, III d. I, IV

I, III

A Staphylococcus spp. recovered from a wound was negative for the slide coagulase test and negative for novobiocin resistance. The next test(s) needed for identification is (are): a. Tube coagulase test b. All of these options c. Mannitol salt agar plate d. β-Hemolysis on blood agar

All of these options

Staphylococcus aureus recovered from a wound culture gave the following antibiotic sensitivity pattern by the standardized Kirby–Bauer method: Penicillin = R Ampicillin = S Cephalothin = R Cefoxitin = R Vancomycin = S Methicillin = R Which is the drug of choice for treating this infection? A. Penicillin B. Ampicillin C. Vancomycin D. Cephalothin

Vancomycin

A wound sample was submitted at Microbiology reveals non-motile gram-variable bacilli, aerobic and catalase positive. Identify the isolate: a. Rhodococcus equi b. Gordonia bronchialis c. Actinomadura madurae d. Streptomyces anulatus

Gordonia bronchialis

Anaerobic gram-positive bacilli with subterminal spores were recovered from several blood cultures obtained from a patient diagnosed with a malignancy of the colon. The following results were recorded: Indole = Neg Urease = Neg Lipase = Neg Catalase = Neg Lecithinase = Neg Growth on blood agar = Swarming colonies What is the correct identification? a. Clostridium sordellii b. Clostridium septicum c. Clostridium perfringens d. Propionibacterium acnes

Clostridium septicum

A Gram's stain of the CSF of a 33-year-old man revealed many polymorphonuclear leukocytes and intra- and extra-cellular gram negative diplococcic. Culture and tests were as follows: small, flat, gray colonies on chocolate agar, oxidase positive, Cystine trypticase agar (CTA) maltose positive: CTA lactose negative. The most likely identity that isolate is: a. Neisseria meningitidis b. Neisseria gonorrhoeae c. Acinetobacter species d. Moraxella catarrhalis

Neisseria meningitidis

A physician inquiry about repeated sputum specimens, negative on routine bacterial culture, that are reported to contain only normal oropharyngeal flora on routine bacterial culture. The patient is a 67-year- old man who smokes 15 to 20 cigarettes a day and persistent cough, malaise, and a fever of 102-105°F. Empiric antimicrobial therapy and the cough and fever persist. The most recent direct Gram's stain of sputum shows 3+ PMNs, mucus present, and rare epithelial cells. A likely etiologic agent is? a. Haemophilus influenzae b. Legionella pneumophila c. Pseudomonas aeruginosa d. Streptococcus pneumoniae

Legionella pneumophila

The ortho-nitrophenyl-β-galactopyranoside (ONPG) test is most useful when differentiating: a. Proteus vulgaris from Salmonella spp. b. Shigella spp. from some strains of Escherichia coli c. Salmonella spp. from Pseudomonas spp. d. Klebsiella spp. from Enterobacter spp.

Shigella spp. from some strains of Escherichia coli