Seminar 1 – SOUTH - ASSESSMENT EXAMINATION – BACTERIOLOGY

1. Culture on MTM media of a vaginal swab produced several colonies of gram (-) diplococcic that were catalase
and oxidase positive and superoxol negative. The ff carbohydrate reactions were obtained, Glucose, lactose, and
maltose (+) and sucrose & fructose (-). What is the most likely identification?
a. N. sicca (glu suc lac)
b. N. lactamica (glu lac)
c. N. flavescens (glu)
d. N. meningitidis (glu mal)
e. NOTA

ANS: _
Neisseria spp can be differentiated thru carbohydrate oxidation
Superoxol positive is N. gonorrhea
2. Sputum from patient with pneumonia produced many colonies of gram-negative diplococci on chocolate
agar plate. The ff results: catalase, DNase and Oxidase (+): Glucose Lactose Fructose (-). What is most likely the
organism isolated?
a. M. cattarhalis
b. N. sicca
c. S. aureus
d. N. flavescens

3. Gram negative diplococci recovered from a Modified Thayer Martin plate and giving a (+) oxidase can be
presumptively identified as:
a. N. gonorrhea
b. N. lactamica
c. N. meningitidis
d. All of the above

4. Nonpathogenic Moraxella spp capable of growing on selective media for Neisseria can be differentiated from
Neisseria spp by which test?
a. Catalase
b. Superoxol
c. 10u penicillin disk test (Neisseria is sensitive
d. Oxidase
e. B and A only

5. The PYR test is a presumptive test for which streptococci?

a. Group A and D (eneterococci) streptococci
b. Group A and B bert ahemolytic strep
c. S. pneumonia and Group D non-enterococcus
d. Non-group A or B beta hemolytic streptococci

6. The quellung test is used to identify which streptococcus species?

a. S. pyogenes
b. B. agalactiae
c. S. sanguis
d. S. bovis
e. NOTC

7. SXT disk are used along with bacitracin disks to differentiate which streptococci?
a. Alpha Hemolytic
b. Beta Hemolytic
c. S. pneumoniae
d. E. faecalis
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8. Streptococcus species exhibit which of the following properties?
a. Aerobic, Oxidase (+), and Catalase (+)
b. Facultative anaerobe, oxidase and catalase (-)
c. Facultative anaerobe, beta hemolytic, catalase (+)
d. May be Alpha, Beta, or Gamma, Catalase (+)

9. Furazolidone/Furoxone susceptibility test is used to differentiate

a. Staphylococcus spp from micrococcus spp
b. Streptococcus spp from staphylococcus spp
c. Staphylococcus spp from Moraxella
d. Streptococcus spp from micrococcus spp

10. A staphylococcus spp recovered from a woundwas negative for the slide coagulase test, and negative for
novobiocin resistance. The next test needed for identification is/are
a. Tube Coagulase
b. Mannitol Salt Agar Plate
c. Beta Hemolysis on BAP
d. A and C only

11. Lancefield classification of Streptococcus is based on:

a. Type of Hemolysis
b. Cell wall polysaccharide
c. Capsular Antigens
d. M protein serotype

12. Colonies of Streptococcus pneumonia at 24 hours are typically:

a. Mucoid and Alpha Hemolytic
b. Autolysed and Alpha Hemolytic
c. Mucoid and Beta Hemolytic
13. Beta Hemolytic Streptococci were isolated from the throat culture of a 15-year-old male. Select the best group of
test to identify this organism
a. Bacitracin and PYR
b. Bacitracin and CAMP
c. Bile Esculin and PYR
d. Optochin and CAMP
Group A – susceptible to Bacitracin, resistant to SXT
Group B- resistant to both bacitracin and SXT
14. Which of the following microorganisms are not matched correctly with the appropriate isolation media?
a. FUNGI – Sabourad’s Dextrose agar
b. Neisseria gonorrhea – pink colonies media
c. H. influenzae – choco agar
d. Mycobacterium tuberculosis – LJ agar
15. Neisseria meningitides can be carried ____ which serves as a reservoir for infection
a. In the nasopharynx
b. In the blood
c. IN the oral cavity
d. On the skin
16. Waterhouse friderichsen is associated with:
a. Autoimmune response to N. gonorrhoeae
b. Adrenal hemorrhage from N. meningitides
c. Septicemia from N. meningitides
d. Hemolytic reaction of N. meningitides

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17. A spherical, gram-positive coccus that is catalase-positive, non-motile, and is unable to produce acid from glucose
anaerobically is best identified as a member of the genus
a. Micrococcus
b. Streptococcus
c. Staphylococcus
d. Moraxella

18. Streptococci that do not grow both at 10 and 45 C are classified as:
a. Viridans
b. Pyogenic
c. Lactic
d. Enterococci

Bergey’s Classification
Viridans – grows at 45 and 37C
Pyogenic - 10C and 45 C
Lactic – 10 C and 37C
Enterococcus – 10, 37, 45C

19. Each of the following statements concerning the Gram stain is correct except:
a. Escherichia coli stains pink because it has a thin peptidoglycan layer
b. Streptococcus pyogenes stains blue because it has a thick peptidoglycan layer
c. Mycoplasma pneumonia is not visible in the Gram stain because it does not have a cell wall
d. Mycobacterium tuberculosis stains blue because it has a thick lipid layer

20. The following Streptococcus species are beta hemolytic on BAP except:
a. S. anginosus
b. S. equisimilis
c. S. mutans
d. Group B streptococcus

Beta-hemolytic – S. pyogenes, s. agalactiae, s. dysagalac, s.equi

Alpha or Beta – viridans and enterococci

21. A gram-positive coccus that shows susceptibility to Novobiocin, resistance to polymyxin. Positive to VP test
1. S epidermidis 2. S. saprophyticus 3. S. aureus
a. 1 and 2
b. 1 and 3
c. 2 and 3
d. 1 only

VP (+) S. aureus, S. lugdunensis, S. schleiferi, S. hemolyticus

VP (-) S. intermedius

22. S. agalactiae is inhibited by which of the following antibiotics

a. Optochin
b. Vancomycin
c. SXT
d. Bacitracin

23. It will not allow catalase testing of colonies, otherwise a false positive will occur
a. BAP
b. Nutrient Agar
c. Trypticase Soy Agar
d. MSA

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24. The following organisms can hydrolyze esculin and can grow in the presence of bile except:
a. S. salivarius
b. E. fecalis
c. S. bovis
d. S. sanguis
25. Which of the following are characteristics of enterococci?
1. bile soluble 2. Hydrolyzes esculin 3. Optochin positive 4 penicillin resistant
a. 1 and 3
b. 2 and 4
c. 1 2 and 3
d. 1 2 3 4
26. The PYR test is used as a presumptive test for which streptococci?
1. Group A 2. Group D nonentero 3. Group D entero 4. Group B
a. 1 and 2
b. 1 and 3
c. 1 2 and 3
d. 1, 2, 3, and 4
27. The quelling test is used to identify which strep spp
a. S. pyogenes
b. S. agalactiae
c. S. sanguis
d. S. pneumoniae
e. None of these

ANS:
S. pyogenes – PYR
S. agalactiae – CAMP
28. The salt tolerance test (6.5%) is used for presumptively identify:
a. Group D Non-enterococci
b. Enterococci
c. Viridans
d. S. pneumonia

29. Which of the following major throat flora? Use choices in 28 – C

30. 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

ANS: LAP test – Leucine Amino Peptidase test – None of the choices
31. S. pneumonia and the Viridans streptococci can be differentiated by which of the following test?
a. Optochin Disk Test
b. Bacitracin Disk Test
c. CAMP Test
d. Bile Esculin Test
32. Which group of Streptococci is associated with Erythrogenic Production
a. Group A
b. Group B
c. Group C
d. Group D
e. None of these
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33. Part of the bacterial cell that is antiphagocytic
a. Cell wall
b. Spore
c. Pili
d. Capsule
34. Bacterial cell structure that determines gram positivity/gram negativity of an organisms.
a. Cell wall
b. Spore
c. Pili
d. Capsule

35. Major virulence of Neisseria meningitidis?

a. Cell Wall
b. Spore
c. Pili
d. Capsule

36. The superoxol test is used as a rapid presumptive test for ____
a. N. gonorrhea --- c. N. lactamica
b. N. meningitides d. N. sicca

37. Each of the following organisms is an important shit

a. K. pneumonia
b. E. coli
c. Bacteriodes fragilis
d. Proteus mirabilis

38. The Bile Solubility test causes the lysis of

a. S. bovis colonies on BAP
b. S. pneumoinia colonies on BAP
c. Group a streptococci in broth
d. Group B in broth ^

39. Which of the following signs and symptoms is linked to H. influenzae except
a. Otitis media
b. Pneumonia
c. Malaria
d. Epiglottis
40. Micrococcus and Staphylococcus spp are differentiated by which tests
a. Fermentation of Glucose (OF) tube
b. Catalase
c. Gram Stain
d. All of these
41. The Dye used to stain Mycobacterium
e. Methylene blue
a. Carbol fuchsin
b. Crystal violet
c. Iodine
42. Lancefield classification of Streptococcus is based on:
a. Type of Hemolysis
b. Cell Wall polysaccharide
c. Capsular Antigens
d. M protein serotype

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43. Pili antigens are associated with
a. S. aureus
b. S. pneumonia
c. S. pyogenes
d. N. gonorrhea
44. Which statement correctly describes the mode of action of antibiotic listed for MTM medium?
a. Vancomycin inhibit gram neg bacteria
b. Colistin inhibits gram pos bacteria
c. Nystatin inhibits fungi and molds
d. Trimetophrim lactate inhibits gram pos
45. The symptoms of scarlet fever are due to
a. Streptolysin
b. Coagulase
c. Erythrogenic toxin
d. Alpha toxin
46. A spherical, gram positive coccus that is catalase positive…
a. Micrococcus
b. Streptococcus
c. Staphylococcus
d. Moraxella
47. The Schultz-Charlton phenomenon refers to a lab test for suspected cases of
a. Pneumonia
b. Scarlet Fever
c. Diphtheria
d. Erysipelas
48. Which of the following would differentiate S. aureus and S. epidermidis?
a. Mannitol fermentation
b. Catalase
c. Novobiocin
d. OF Test
49. Which of the following would differentiate N. meningitides and N. gonorrhea?
a. Glucose fermentation
b. Sucrose fermentation
c. Maltose fermentation
d. All of these
50. Slime production is associated with which staphylococcus species?
a. S. aureus
b. S. epidermidis
c. S. intermedius
d. S. saprophyticus
51. Which medium is preferred for the culture of most Hemophilus?
a. Nutrient agar
b. Tryptic soy agar
c. Bordet-Gengou plates
d. Enriched Chocolate Agar

52. Cultures of Staphylococcus supplies which of the following for cultures of Haemophilus
a. Factor I
b. Factor III
c. X factor
d. V factor

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53. Which of the PMP group is urease negative?
a. M. morgana
b. Prov. Stuartii
c. Prov. Rettgeri
d. Prov. Alcalifaciens

54. The following statements is true about E. coli except:

a. Has an IMViC reaction of + + - -
b. MUG positive
c. #1 cause of neonatal meningitis
d. None of these choices

55. Rice water stools often contain

a. A pure culture of Vibrio cholerae
b. Toxigenic Clostridium botulinum
c. Toxigenic S. aureus
d. Undigested aflatoxin rice kernels

56. Stain for Flagella

a. Schaeffer and Fulton Stain
b. Dorner’s Stain
c. Wirtz and Conklin Stain
d. Gray’s Stain

57. Capsules can be used for

a. Complement Fixation
b. Serotyping by Swelling
c. Hemagglutination test
d. Precipitation test

58. On TSI agar, a gram-negative bacillus produces a yellow slant and a yellow butt. Select the organism from the list
below that would produces this reaction
a. S. sonnei
b. Escherichia coli
c. P. mirabilis
d. S. typhimurium

59. A patient has burning sensation during urination. Microbiologic profile of the organism include: Pink Colonies in
MacConkey, oxidase and motility negative, nitrite and indole positive. What could be the organism?
a. E. coli
b. K. pneumonia
c. P. aeruginosa
d. K. oxytoca

ANS:
(Indole positive – K. oxytoca and K. ornitholytica)

60. Which of the following culture media uses phenol red as its indicator?
1. XLD 2. MacConkey Agar 3. TSI 4. SSA
a. 1 and 2
b. 1 and 3
c. 2 and 3
d. 2 and 4

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61. A 1-week-old newborn develops meningitis. Short, gram-positive rods are isolated. History reveals that the
mother had eaten unpasteurized cheese from Mexico during pregnancy, and she recalled having a flu-like illness.
Which of the following is the most likely etiologic microorganism?
a. Corynebacterium diphtheriae
b. E. coli
c. Listeria monocytogenes
d. Streptococcus pneumoniae

Listeria: Gram (+) bacilli, motile, can grow at 4C, can cause miscarriage/abortion and neonatal
meningitis, media: McBride

62. Which of the following specimen requests is accepted?

a. Feces submitted for anaerobic culture
b. Foley catheter tips submitted for aerobic culture
c. Rectal Swab submitted for direct smear for gonococci
d. Urine Culture of Acid-Fast organism

63. Which of the following genera is not an oxidase positive?

a. Moraxella
b. Aeromonas
c. Neisseria
d. AOTC
e. NOTC

Oxidase Positive: PVNCH: Pasteurella, Pseudomonas,Vibrio, Neisseria, Hemophilus, Bordetella

64. 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 with presence of turbidity
a. Group D non entero
b. Enterococcus
c. Group B
d. Group A

65. Which of the following laboratory test can differentiate salmonella spp from citrobacter spp
a. H2S production and citrate
b. Lysine dercarboxylase and ONPG
c. H2S production and ONPG
d. Lysin decarboxylase and H2S production

66. Virulence factor of Staphylococcus aureus that can block phagocytosis by binding the Fc portion of
immunoglobulin.
a. Toxic Shock Syndrome Toxin
b. Protein A
c. Staphylococcal Leukocidin
d. Hyaluronidase

67. Paul, a 25-year old medical intern has submitted a genital discharge for gram stain and culture. The gram stain
revealed gram negative diplococcic found intracellularly to the neutrophils. Which of the following media should
be used for the initial cultivation of the organism?
a. New York City Agar
b. Chocolate Agar
c. Blood Agar
d. MacConkey Agar

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68. A 2-year-old infant is brought to the emergency room with hematuria, fever, and thrombocytopenia. Which one of
the following bacteria would most likely be isolated from a stool specimen?
a. Enterobacter aerogenes
b. Escherichia coli
c. Salmonella enteritidis
d. Shigella flexneri

The question describes Hemolytic Uremic Syndrome associated with E. coli serotype 0157 H7
69. An organism with a TSI reaction A/A exhibited mucoid, lactose fermenting colonies in MacConkey agar. Further
testing proved the organism is non-motile and indole positive. The organism is most likely:
a. K. pneumonia
b. E. aerogenes
c. E. coli
d. K. oxytoca
70. Which of the following biochemical test can differentiate Morganella spp. from Providencia spp.
a. Urease and phenylalanine deaminase
b. H2S production and Tryptophan deaminase
c. Citrate and gas production
d. Indole and H2S

Rationale:
Providencia: citrate positive, gas (+) morganella
PPM: Pad (+), NLF, Proteus: H2S (+) to differentiate Providencia from Morganella: Citrate

71. A clinically depressed farmer complains of extreme weakness, a daily rise and fall in fever and night sweats.
Small gram-negative rods are isolated form blood cultures after a 2-week incubation period. Which of the
following organisms is the most likely etiologic agent?
a. Campylobacter jejuni
b. Brucella melitensis
c. Francisella tularensis
d. Serratia marcescens

Undulant Fever, induces abortion. MOT: Direct Contact, Ingestion, inhalation

Biosafety Level 3; Media: TSA, Castaneda, BAP
Obligate Aerobes, localized in tissues rich in erythritol, catalase, oxidase (+), rapid urease producer
Preferred specimen: Blood, Bone marrow

Francisella tularensis: Obligate Aerobe, BSL 3, High Mortality Rate

Tularemia - transmitted through ingestion, inhalation, arthropod bite (deer flies and tick) inhalation
72. Which of the following culture medium has matched its classification?
1. Martin-Lewis Agar: Selective for pathogenic Neisseria
2. Xylose-Lysine-Deoxycholate: Selective and differential for stool pathogens
3. Eosin Methylene Blue Agar: Selective and differential for Gram Negative Bacilli
4. Selenite Broth: enrichment media for stool pathogens
a. 1 and 2 only
b. 1, 2 and 3 only
c. 1, 3 and 4 only
d. AOTC
73. After the application of primary stain, decolorizer, and counterstain, the acid fast-negative bacilli will:
a. Stain Red
b. Become Colorless
c. Stain Blue
d. Stain Purple

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74. Which of the following species matches its colonial characteristics in MacConkey?
1. K. pneumonia: pink mucoid colonies
2. E. coli: green metallic sheen
3. S. marcescens: red pigmented colonies at Room Temperature
4. S. sonnei: colorless colonies with black centers
a. 1 and 3
b. 2 and 4
c. 3 and 4
d. AOTC
75. Which of the following species matches its corresponding laboratory characteristics?
1. P. mirabilis: swarming motility
2. S. marcescens: DNAse, lipase, and gelatinase (+)
3. K. pneumonia: possesses Vi Antigen
4. M. morganii: phenylalanine deaminase (+)
a. 1 and 3
b. 2 and 4
c. 3 and 4
d. AOTC
76. Which of the following species matches its corresponding disease?
1. S. typhi: Bacillary dysentery
2. S. dysenteriae: enteric fever
3. Y. pestis: bubonic plaque
4. E. coli: Hemolytic Uremic Syndrome
a. 1 and 2
b. 1 and 3
c. 2 and 4
d. 3 and 4
77. Which of the following reaction is correct for Pseudomonas aeruginosa?
1. Produces pyocyanin pigment
2. Positive alkalinization of acetamide
3. Produces pyoverdin pigment
4. Grows at 42°C

a. 1 and 3
b. 1, 3, and 4
c. 2, 3, and 4
d. All of the above
78. Which statement correctly describes infection attributed to Pseudomonas aeruginosa
a. Common cause of wound infections in burn patients
b. Resistant to many antibiotics for Gram Negative Infections
c. Cause of pneumonia in patients with cystic fibrosis
d. All of these
79. Tuberculosis is typically spread through:
a. Contact with contaminated inanimate objects
b. The fecal-oral route
c. Contaminated blood products
d. Contaminated respiratory droplets

80. The Mycobacteria are described as “acid fast” because:

a. The organism cannot be stained with acidic dyes
b. The organisms are rapidly decolorized with acid-alcohol.
c. The organisms are easily stained with acidic dyes
d. Once stained, the organisms cannot be decolorized with alcohol
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81. Which of the following is destroyed by oxygen?
a. Botulism toxin
b. Streptolysin O
c. Catalase
d. Coagulase
82. Neisseria meningitidis degrades which of the following sugars?
a. Glucose
b. Maltose
c. Lactose
d. A and B
83. Non-fermenters produce what reaction in triple sugar iron agar (TSI)?
a. Alkaline Slant, Alkaline or Neutral Butt
b. Acid Slant, Acid Butt
c. Alkaline Slant, Alkaline Butt
d. Alkaline Slant, Acid Butt
84. Most Enterobacteriaceae give what type of methyl red and voges-proskauer reactions?
a. Opposite
b. Similar
c. Identical
d. NOTA
85. What is the indicator in Simmons citrate agar?
a. Phenol Red
b. Bromthymol Blue
c. Bromcresol Purple
d. Neutral Red
86. A positive urease test for ureaplasmas is indicated by a:
a. Clear Zone surrounding the colonies
b. Green zone surrounding the colonies
c. Brown Halo surrounding the colonies
d. Red halo surrounding the colonies
87. What are broad-spectrum antibiotics?
a. Act against gram-negative bacteria
b. Act against gram-positive bacteria
c. Act against bacterial and nonbacterial organisms
d. AOTA
88. Substances produced by microorganisms that in very small amounts, inhibit other microorganisms are called:
a. Antibiotics
b. Antibody
c. Antiseptic
d. A and B
89. Bacteriostatic agents do which of the following?
a. Cause death of the organism
b. Inhibit the growth of the organism
c. A and B
d. Neither A nor B
90. What is the cause of primary atypical pneumonia?
a. K. pneumonia
b. Streptococcus pneumonia
c. S. aureus
d. Mycoplasma pneumonia

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91. In the Kirby-Bauer susceptibility test, the 0.5 McFarland standard is used to:
a. Measure the thickness of the media in the petri plate
b. Determine how close the antibiotic discs should be placed
c. Adjust the turbidity of the inoculums
d. AOTA
92. After inoculating the Mueller Hinton plated for the Kirby Bauer susceptibility test, how long should the plates dry
before adding the disks?
a. 3-5 minutes
b. Not more than 15 minutes
c. 30 minutes
d. A and B
93. How does one measure the zone of growth inhibition for the Kirby-Bauer susceptibility test?
a. On the underside of the plate
b. With the unaided eye
c. Using a ruler, caliper or template
d. AOTA
94. What does the size of the zone of growth inhibition correlate with if the correct procedure has been used?
a. Maximum Inhibitory Concentration
b. Minimum Inhibitory Concentration
c. Minimum Lethal Concentration
d. Minimum Bactericidal Concentration
95. What is the hydrogen sulfide indicator in triple sugar iron agar?
a. Tryptophan – it is the substrate
b. Sodium thiosulfate
c. Ferric ammonium citrate
d. Alpha naphthol – for VP

96. IMViC is a series of which of the following test?

a. Indole, Methyl-Red, Voges-Proskauer, Citrate
b. Indole, Motility, Voges-Proskauer, Carbohydrate
97. What is the indicator in the methyl red test?
a. Brom thymol blue
b. Phenol red
c. Bromcresol purple
d. Methyl Red
98. The Best Medium for the isolation of Legionella is:
a. Iron-Cystine
b. Campy-thio agar
c. V agar
d. BCYE agar
99. Which of the following is used for the identification of mycobacteria?
a. Biochemical reactions
b. Pigment production
c. Growth rate
d. AOTA
Biochemical reaction: M. tuberculosis: Niacin, Nitrate, NAP inihinitin

100. Which of the following will differentiate listeria monocytogenes from the corynebacteria?
a. Nonmotile and salicin negative
b. Motile and salicin positive
c. Nitrate-positive and sucrose negative
d. Motile and urease negative
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