microbio Flashcards
1
Q
Substrate used in Kovacs Indole Test
A. Indole
B. Tryptophan
C. Para-dimethylaminobenzaldehyde
D. Para-dimethylaminocinnamaldehyde
A
B. Tryptophan
2
Q
Indole test differentiates which set of organisms? A. Morganella and Providencia
B. Salmonella and Shigella
C. P. vulgaris and P. mirabilis
D. E. coli and Klebsiella oxytoca
A
C. P. vulgaris and P. mirabilis
3
Q
Inhibitors for gram (+) bacteria on MAC:
A. Crystal violet and vancomycin
B. Colistin and anisomycin
C. Trimethoprim and vancomycin
D. Bile salts and crystal violet
A
D. Bile salts and crystal violet
4
Q
Colonies of Salmonella on SSA:
A. Colorless colonies with black center
B. Colorless colonies w/o black center
C. Red colonies with black center
D. Red colonies w/o black center
A
A
5
Q
Which of the following is a correct pair?
A. S. aureus — Pink colonies on MSA
B. K. pneumoniae — Colorless on MAC
C. S. pneumoniae — Non-hemolytic on SBA
D. E.coli — Yellow colonies on XLD
A
D
6
Q
All members of Enterobacteriaceae are motile at 37C except Klebsiella, Proteus, Shigella, Yersinia
A. 1, 2, and 3
B. 1, 3, and 4
C. 1 and 3
D. 1 and 4
A
B
7
Q
pH indicator of LIA: A. Neutral Red B. Phenol Red C. Bromthymol blue D. Bromcresol purple
A
D
8
Q
Yellow butt and Red slant in TSI tube indicate fermentation of: A. Lactose B. Glucose C. LActose and Glucose D. Lactose and/or Glucose
A
B
9
Q
Heat stable antigen of enterics located on their cell wall: A. O B. K C. H D. Vi
A
O
10
Q
ONPG test allows organisms to be classified as lactose fermenters by testing which of the following: A. B-lactamase B. B-galactosidase C. Lactose permease D. Tryptophanase
A
B
11
Q
Only oxidase-positive member of Enterobacteriaceae: A. Shigella B. Morganella C. Plesiomonas D. Edwardsiella
A
C
12
Q
Vibrio cholerae colonies on TCBS: A. Blue B. Green C. Yellow D. Red
A
C
13
Q
Which of the following sets of results represent the most common reactions for Moraxella catarrhalis when tested in CTA sugar tubes? A. Glucose: Negative; Maltose: Negative; Lactose: Negative; Sucrose: Negative
A
A
14
Q
Neisseria lactamica can be differentiated from Neisseria meningitidis through which of the following? A. Colony morphology B. Use of selective media C. Glucose and maltose utilization D. ONPG test
A
D
15
Q
Isolates of suspected C. diphtheriae must be tested for in vitro production of exotoxin through: A. Anton test B. Elek test C. Frei test D. Mantoux test
A
B
16
Q
Lecithinase production, double zone hemolysis on sheep blood agar, and gram-stained morphology are all useful criteria in the identification of which of the following? A. Clostridium perfringens B. Streptococcus agalactiae C. Escherichia coli D. Clostridium tetani
A
A
17
Q
Sensitivity test result of Group A streptococci (S. pyogenes) to Bacitracin and SXT respectively: A. Susceptible and resistant B. Resistant and susceptible C. Both susceptible D. Both resistant
A
A
18
Q
Correct about gram-positive bacteria: A. Has thinner peptidoglycan compared to gram-negative B. Cell wall has an outer layer which contains lipopolysaccharide (LPS) C. Takes up the crystal violet-iodine complex but is easily decolorized D. Uses selective isolation media like colistin-nalidixic acid (CNA) agar
A
D
19
Q
Responsible for dark/non-fluorescent background in Auramine Rhodamine stain for acid-fast bacilli: A. Auramine B. Rhodamine C. Potassium permanganate D. Acid-alcohol
A
C
20
Q
Stain for endospore: A. Wayson B. Leifson C. Schaeffer-Fulton D. Loeffler’s Alkaline Methylene Blue
A
c
21
Q
Most common gas for sterilization: A. Nitrogen dioxide B. Chlorine dioxide C. Ethylene oxide D. Chlorhexidine gluconate
A
C
22
Q
HEPA filter size used in laboratory hoods and isolation room: A. 0.3 um B. 0.6 um C. 0.9 um D. 1.2 um
A
A
23
Q
Incorrect about Autoclaving: A. Biologic indicator: B. stearothermophilus B. Can destroy all forms of microbial life including spores C. Dry heat sterilization D. 121C/ 15 psi/ 15 mins
A
C
24
Q
Uses a strip with varying concentration of antibiotic along its length and MIC can be obtained: A. Kirby Bauer B. Microplate dilution C. Vitek System D. E-Test
A
D
25
0.5 Macfarland standard provides an optical density comparable to density of a bacterial suspension of: A. 0.5 x 105 CFU/mL B. 1.5 x 108 CFU/mL C. 0.5 x 109 CFU/mL D. 1.5 x 109 CFU/mL
B
26
In disk diffusion testing, a delay of more than 15 minutes between placing the disks on an inoculated plate and incubation results to A. failure of antibiotic to diffuse in media B. zones of smaller diameter will result C. zones of larger diameter will result D. no effect of final zone diameter
C
27
The term “palisading”, “picket fence”, and “Chinese letter” describe the common arrangement of cells of: A. Corynebacterium spp. B. Mycobacterium tuberculosis but not other mycobacteria C. Actinomyces but not Nocardia D. Corynebacterium diphtheriae but not other corynebacteria
A
28
The exchange of cellular DNA between two living bacterial cells that involves an intercellular bridge is which of the following processes? A. Transformation B. Transduction C. Plasmadization D. Conjugation
D
29
The slide coagulase test is a rapid screening test for the production of which of the following? A. Clumping Factor B. Free Coagulase C. Extracellular coagulase D. Catalase
A
30
The bacterial species that can be described as susceptible to bile and optochin, a-hemolytic, a major cause of bacterial meningitis, and often carrying an antiphagocytic capsule is which of the following?
A. Enterococcus faecalis
B. Streptococcus pneumoniae
C. Streptococcus pyogenes
D. Streptococcus agalactiae
B
31
Which of the ff tests provide the best differentiation of L. monocytogenes & E. rhusopathiae? A. Gram-stained smear, oxidase, optochin B. Gram-stained smear, catalase, and motility C. CAMP test, H2S production, Esculin hydrolysis D. Reverse CAMP, gram-stained smear, b-hemolysis
C
32
Micrococcus and Staphylococcus species are differentiated by which test(s)?
O-F Tube
Gram Stain
Catalase Test
Lysostaphin Susceptibility
A. 1 and 3 B. 2 and 3 C. 1 and 2 D. 1 and 4
D
33
In the test for urease production, the presence of the enzyme hydrolyzes urea to which of the following? A. Ammonia and CO2 B. Putrescine C. Amines and CO2 D. Amines and water
A
34
All of the following are correct regarding methylene blue except: A. Inhibits gram-positive bacteria in enteric media B. Can be used as simple bacterial stain C. Indicator of anaerobiosis D. pH indicator in TCBS
D
35
LOA reaction of Klebsiella pneumoniae: A. +– B. ++- C. -+- D. +-+
A
36
All are correct regarding Staphylococcus saprophyticus except: A. Coagulase negative B. Causes UTI in young women C. Novobiocin sensitive D. DNase negative
C
37
Chocolate agar-based medium containing vancomycin, colistin, anisomycin & trimetoprim is known as A. Thayer-Martin B. Modified Thayer Martin C. Martin-Lewis D. New York City
C
38
Which of the following is a wrong pair? A. Brucella abortus - Bang’s bacillus B. Neisseria meningitides - Meningococcus C. Haemophilus influenzae - Koch Week’s bacillus D. Mycobacterium avium intracellulare - Battey bacillus
C
39
Positive result for DNase test: A. Green B. Pink C. Clearing of medium D. Hemolysis
C
40
Biosafety Cabinet where 30% is recirculated air and 70% is exhausted air outside of facility, A. Type II-A1 B. Type II-A2 C. Type II-B1 D. Type II-B2
C
41
Correct about satellite phenomenon:
1. S aureus grows around the hemolytic colonies of H. influenzae
2. H. influenzae grows around the hemolytic colonies of S. aureus
3. Also known as Nagler reaction
4. Uses SBA instead of Chocolate agar
a. 1 and 2
b. 2 and 3
c. 1 and 3
d. 2 and 4
d. 2 and 4
42
42. Growth requirement for H. influenzae:
1 X factor
2 V factor
3 5-10% CO2
4 Cystine
a. 1 only
b. 2 only
c. 1, 2, 3
d. 1, 2, 3, 4
c. 1, 2, 3
43
Limulus Lysate test detects ________ body fluids.
a. endotoxin of gram-negative bacteria
c. endotoxin of gram-positive bacteria
b. exotoxin of gram-negative bacteria
d. exotoxin of gram-positive bacteria
a. endotoxin of gram-negative bacteria
44
Which serological test is done for Chlamydia trachomatis on genital smears?
a. ELISA
b. RIA
c. Direct FA using monoclonal antibodies
d. Indirect FA using Chlamydia Antigens
C
45
Catalase, oxidase, and coagulase reagents must be tested:
a. Once a week and when the vial is first opened
b. Once each day of use and when the vial is first opened
c. Once a month, running positive control only
d. Once a year, running negative control only
B
46
Positive for PYRase hydrolysis:
1. S. pyogenes 2. S. agalactiae 3. S. pneumoniae 4. E. faecalis
a. 1 and 3
b. 1 and 4
c. 2 and 3
d. 2 and 4
b. 1 and 4
47
All are examples of egg-based media for culture of Mycobacteria, except:
a. Lowenstein Jensen
b. Petragnani
c. Middlebrook 7H10 and 7H11
d. None of the choices
c. Middlebrook 7H10 and 7H11
48
What is the positive result of CAMP test?
a. Satelliting colonies around streaked colonies of S. aureus
b. Arrowhead-shaped growth at the juncture of suspected organism and S. agalactiae
colonies
c. Arrowhead-shaped zone of enhanced hemolysis at the juncture of suspected
organism and beta-lysin producing S. aureus
d. Inhibition of growth of suspected organism when S. aureus is present
c. Arrowhead-shaped zone of enhanced hemolysis at the juncture of suspected
organism and beta-lysin producing S. aureus
49
Selective media for P. aeruginosa:
a. CCFA
b. CIN agar
c. Cetrimide agar
d. MAC with sorbitol
C
50
Which group of tests best differentiates Helicobacter pylori from Campylobacter
jejuni?
a. Catalase, oxidase, and Gram stain
b. Catalase, oxidase, and nalidixic acid sensitivity
c. Catalase, oxidase, and cephalothin sensitivity
d. Urease, nitrate, and hippurate hydrolysis
d. Urease, nitrate, and hippurate hydrolysis
51
Which Haemophilus is difficult to isolate and recover from genital ulcers and swollen
lymph nodes?
a. H. aphrophilus
b. H. hemolyticus
c. H. ducreyi
d. H. parahaemolyticus
c. H. ducreyi
52
An enzyme produced by Streptococcus pyogenes that solubilizes the ground
substance of mammalian connective tissues and helping to spread infection
a. DNAse
b. Erythrogenic Toxin
c. Streptokinase
d. Hyaluronidase / “spreading factor”
d. Hyaluronidase / “spreading factor”
53
53. Infection caused by Legionella with febrile symptoms with no pulmonary involvement
(mild infection only):
a. Legionnaire’s disease
b. Pontiac fever
c. Undulant fever
d. Relapsing fever
b. Pontiac fever
54
Bacteria that prefers oxygen for growth but are able to grow also on anaerobic
conditions are termed as:
a. Microaerophilic
b. Aerotolerant anaerobes
c. Obligate aerobes
d. Facultative anaerobes
d. Facultative anaerobes
55
TSI agar is composed of 3 carbohydrate in a ratio such as:
a. 1% glucose, 1% lactose, 1% sucrose
b. 0.1% glucose, 1% lactose, 1% sucrose
c. 1% glucose, 1% lactose, 1% maltose
d. 1% glucose, 0.1% lactose, 1% maltose
b. 0.1% glucose, 1% lactose, 1% sucrose
56
The so-called red milk is the result of abundant multiplication of which chromogenic
bacterium?
a. Serratia marcescens
b. Proteus vulgaris
c. Pseudomonas syncyanea
d. Aerobacter aerogenes
a. Serratia marcescens
57
Catalase test should not be performed on:
a. Blood agar, because blood [naturally] has catalase
b. Nutrient agar, because it is not enriched
c. Tryptic soy agar, because the protein interferes
d. Glass slides, because agar is required
a. Blood agar, because blood [naturally] has catalase
58
Resulting color of Auramine-Rhodamine stain for M. tuberculosis:
a. Green fluorescence in dark background
b. Yellow-orange fluorescence in dark background
c. Red fluorescence in blue background
d. No fluorescence
b. Yellow-orange fluorescence in dark background
59
Cycloserine cefoxitin-fructose agar (CCFA) is used for the recovery of:
a. Yersinia enterocolitica
c. Clostridium perfringens
b. Yersinia intermedia
d. Clostridium difficile
d. Clostridium difficile (chartreuse fluorescence)
60
Which of the following amino acids are required for growth of Francisella tularensis?
a. Leucine and ornithine
c. Cysteine and cystine
b. Arginine and lysine
d. Histidine and tryptophan
c. Cysteine and cystine
61
Edwardsiella tarda biochemically may be confused with Salmonella in that it is:
a. Lactose positive
c. Urea positive
b. Hydrogen sulfide positive
d. Non-motile
b. Hydrogen sulfide positive
62
What are the resulting changes in Simmons citrate agar if the organism can utilize
sodium acetate as its only carbon source? (positive reaction)
a. growth on medium, change of color from green to blue
b. growth on medium, change of color from blue to green
c. no growth on medium, retaining the original color green of medium
d. no growth on medium, retaining the original color blue of medium
a. growth on medium, change of color from green to blue
63
Coagulase test uses what primary reagent for testing?
a. para-dimethylaminobenzaldehyde
c. sheep RBCs
b. 3% H2O2
d. rabbit plasma
d. rabbit plasma
64
The Moeller test for the detection of decarboxylase activity is dependent upon:
a. an alkaline pH shift in the medium
c. an acid pH basal medium
b. the oxidation of gluconate
d. a deamination of tryptophan
a. an alkaline pH shift in the medium
(product detected: Amines),
POSTIVE PURPLE COLOR
65
Urea hydrolysis test is performed on what medium?
a. Simmons medium
c. Moellers medium
b. Christensen medium
d. Krisler's iron agar
b. Christensen medium
66
Which is the best rapid, noncultural test to perform when Gardnerella. vaginalis is
suspected?
a. 3% H2O2
с. 30% КОН
b. 10% KOH
d. 10% H202
b. 10% KOH (whiff test), POSITIVE RESULTS: fishy amine-like odor
67
Specimens that may be cultured anaerobically:
1. Sputum
2. Needle Aspirate
3. Swabs of infected wounds
4. Suprapubic-aspirated urine
a. 1, 2, 3 and 4
c. 2 and 4
b. 1 and 3
d. 2 and 3
c. 2 and 4
68
The recommended medium for the recovery of Chlamydia from clinical specimen is:
a. McCoy cells (or HeLa cells)
c. Charcoal yeast extract medium
b. A549 cells
d. WI-38 cells
a. McCoy cells (or HeLa cells)
69
When clinical specimens are being processed for the recovery of Mycobacterium
tuberculosis, the generally recommended method for digestion and decontamination of
the sample is:
a. 6% NaOH
c. NALC-NaOH
b. 1% HCI
d. TSP
c. NALC-NaOH (NALC for digestion, NaOH for decontamination)
70
Abiotrophia formerly known as nutritionally variant streptococci (NVS) will not grow
on routine blood or chocolate agars because they are deficient in:
a. Vitamin B12
b. Pyridoxal (or VITAMIN B6)
d. Thiophene-2-carboxylic hydrazide
b. Pyridoxal (or VITAMIN B6)
71
Exfoliatin produced by Staphylococcus aureus is responsible for causing:
a. Toxic shock syndrome
c. Staphylococcal pneumonia
b. Enterocolitis
d. Scalded skin syndrome /Ritter’s disease
d. Scalded skin syndrome /Ritter’s disease
72
Culture media that contains antibiotic vancomycin will inhibit growth of:
a. gram-positive bacteria
c. yeast and molds
b. gram-negative bacetria
d. normal flora
a. gram-positive bacteria
73
If a specimen is not transported within 30 minutes, it should be placed in which of the ff. media?
1. Amie’s 2. Stuart 3. Kelly’s Medium 4. Fletcher’s semi-solid medium
a. 1 and 2
b. 1 and 3
c. 2 and 3
d. 3 and 4
a. 1 and 2
74
Lia reaction: red slant / acid butt, no H2S
a. Escherichia coli
b. Klebsiella pneumoniae
c. Proteus vulgaris
d. Morganella morganii
c. Proteus vulgaris b (H2S producer but not sensitive to LIA)
d. Morganella morganii
???
74
Which atmospheric condition is needed to recover Campylobacter spp. at 35°C-37°C
and 42°C?
a. 10% O2, 10% CO2, and 80% N2
b. 5% O2, 10% CO2, and 85% N2
c. 20% O2, 20% CO2, and 60% N2
d. 15% O2, 5% CO2, and 80% N2
b. 5% O2, 10% CO2, and 85% N2
75
Which test will differentiate Pseudomonas spp. from Enterobacteriaceae?
a. Catalase test
b. Indole test
c. Urease test
d. Oxidase test
d. Oxidase test
76
A urine specimen from a maternity patient with the complaint of cystisis was recieved in the lab. The culture of this sample grew a lactose- positive. Gram negative bacillys that was presumtively identified as E. Coli. On differential and selective media this organism would demonstrate which reaction?
a. MacConkey Agar= Colorless colonies
b. Hektoen Enteric Agar= blue to green colonies
c. xylose-lysine-Desoxycholate Agar = yellow colonies
d. all of the above are possible reactions
c. xylose-lysine-Desoxycholate Agar = yellow colonies
77
Which of the following is not a correct statement regarding blood cultures?
a. Collection of 20 mL per culture for adults is recommended
b. Two or three blood cultures are recommended as optimum
c. Volume of blood cultured is more critical than timing of culture
d. Blood drawn for culture may be allowed to clot
d. Blood drawn for culture may be allowed to clot
78
An example of a selective enrichment broth would be:
a. Thioglycollate broth
b. Trypticase soy broth
c. Brain Heart Infusiojn broth
d. Selenite broth
d. Selenite broth
79
All of the following contain resident (normal flora except:
a. oral cavity
b. Skin
c. Colon
d. Cerebrospinal fluid
d. Cerebrospinal fluid
80
An optimal wound specimen for culture of anaerobic organisms should be:
a. a swab of lesion obtained before administration of antibiotics
b. a swab of lesion obtained after administration of antibiotics
c. a syringe filled with pus obtained before administration of antibiotics
d. a syringe filled with pus obtained after administration of antibiotics
c. a syringe filled with pus obtained before administration of antibiotics
81
Colistin-Nalidixic agar is used for selective isolation of:
a. gram-positive bacteria
b. gram-negative bacteria
c. aerobic bacteria
d. anaerobic bacteria
a. gram-positive bacteria
82
Bacteria when growth occurs evenly on thioglycollate broth:
a. obligate aerobes
b. obligate anaerobes
c. Microaerophiles
d. aerotolerant anaerobes
d. aerotolerant anaerobes
83
Purpose of adding sodium polyanethol sulfonate (SPS) to nutrient broth media for
blood culture
a. enhances growth of anaerobes
b. functions as a preservative
c. inhibits phagocytosis and complement
d. promotes formation of a blood clot
c. inhibits phagocytosis and complement
84
Slime production is associated with which Staphylococcus specie?
a. S. aureus
b. S. epidermidis
c. S. saphrophyticus
d. S. intermedius
b. S. epidermidis
85
Metachromatic/Volutin granules are inclusions of what specie of bacteria:
a. Mycobacterium tuberculosis
b. Yersinia pestis
c. Listeria monocytogenes
d. Corynebacterium diphtheria
d. Corynebacterium diphtheria
86
This is also known as capsular swelling test:
a. India ink test
b. Limulus Lysate test
c. Modified ELEK test
d. Neufeld (Quellung) Reaction
d. Neufeld (Quellung) Reaction
87
These are hair-like extension extensions of the cell used for adherence of bacteria to
host cell:
a. Flagella
b. Capsule
c. Slime Layer
d. Fimbriae/Pili
d. Fimbriae/Pili
88
All are correct matches for types of flagella except:
a. Monotrichous
b. Lopotrichous
c. Peritrichous
d. None of the Above
b. Lopotrichous
89
Mordant used in Kinyoun method (Cold Method) of acid-fast staining:
a. Steam
b. Thiosulfate
c. Thermal heat
d. Tergitol
d. Tergitol
90
Which of the following techniques is performed first before doing smears for Gram stain on CSF?
a. Incubate at 37C for one hour.
b. Refrigerate CSF for 12 to 24 hours and observe for pellicle formation
c. Centrifuge CSF specimen to concentrate cells and microorganisms if present
d. Evaluate using Bartlett’s classification.
c. Centrifuge CSF specimen to concentrate cells and microorganisms if present
91
This staining method is specifically designed for bacteria whose cell walls contain
long chain fatty acids (Mycolic acid) (ex. Mycobacteria)
a. Gram Stain
b. India Ink
c. Leifson Stain
d. Acid-Fast Stain
d. Acid-Fast Stain
92
Culture media that contains antibiotic vancomycin will inhibit growth of:
a. Gram-positive bacteria
b. Gram-negative bacteria
c. Yeast and molds
d. Normal flora
a. Gram-positive bacteria
93
Indicator used in MSA used for selective isolation of staphylococcus spp.
a. Neutral red
b. Bromthymol Blue
c. Phenol red (pH indicator)
d. Bromcresol Green
c. Phenol red (pH indicator)
94
Motility medium such as SIM (Sulfur-Indole-Motility) is classified as:
a. Liquid-type medium
b. Semi-solid medium
c. Solid-liquefiable medium
d. Solid-non-liquefiable medium
b. Semi-solid medium
95
Reagent used in oxidase test of bacteria:
a. 1% paradimethylaminocinnamaldehyde
b. 1% tetramethyl-p-phenylenediamine dihydrochloride
c. L-pyrollidonyl-b-naphthylamide
d. Hydrogen peroxide
b. 1% tetramethyl-p-phenylenediamine dihydrochloride
96
Negative reaction in Decarboxylase Tests (Moeller’s Method) is indicated by which
color?
a. Purple
b. Yellow
c. Magenta
d. Blue
b. Yellow (Decarboxylase test negative)
97
Positive result in Acetamide Utilization test:
a. Purple
b. Yellow
c. Magenta
d. Blue
d. Blue
98
Positive result in Bacitracin Susceptibility test (0.04 units) is a zone of inhibition
greater than ___ mm
a. 5
b. 10
c. 15
d. 20
b. 10
99
Which of the following Streptococcal species has the enzyme hippuricase? (hippurate hydrolysis positive: purple)
a. S. pyogenes
b. S. pneumoniae
c. S. agalactiae
d. S. bovis
c. S. agalactiae
