SP2 - MICROBIO Flashcards
Substrate used in Kovac’s indole test:
a. Indole
b. Tryptophan
c. Para-dimethylaminobenzaldehyde
d. Para-dimethylaminocinnamaldehyde
Tryptophan
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
c. P. vulgaris and P. mirabilis
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
Bile salts and crystal violet
Colonies of Salmonella on SSA:
a. Colorless colonies with black
center
b. Colorless colonies without black center
c. Red colonies with black center
d. Red colonies without black center
Colorless colonies with black
center
Which of the following is a correct pair?
a. S. aureus – pink colonies on MSA
b. K. pneumoniae – colorless colonies on
MAC
c. S. pneumoniae – non-hemolytic on SBA
d. E. coli – yellow colonies on XLD
E. coli – yellow colonies on XLD
All members of Enterobacteriaceae are motile at 37degC except:
- Klebsiella
- Proteus
- Shigella
- Yersinia
a. 1, 2, and 3
b. 1, 3, and 4
c. 1 and 3
d. 1 and 4
1, 3, and 4
(Proteus is the only motile enterobacteriaceae)
pH indicator of LIA:
a. Neutral red
b. Phenol red
c. Bromothymol blue
d. Bromcresol purple
Bromcresol purple
Yellow butt and red slant in TSI tube indicates fermentation of:
a. Lactose
b. Glucose
c. Lactose and glucose
d. Lactose and/or sucrose
Glucose
Heat stable antigen of enterics located on their cell wall:
a. O
b. K
c. H
d. Vi
O
ONPG test allows organism to be classified as lactose fermenter by testing which of the following:
a. B-lactamase
b. B-galactosidase
c. Lactose permease
d. Tryptophanase
B-galactosidase
Only oxidase positive member of Enterobacteriaceae:
a. Shigella
b. Morganella
c. Plesiomonas
d. Edwardsiella
Plesiomonas
V. cholerae colonies on TCBS:
a. Blue
b. Green
c. Yellow
d. Red
Yellow
Which of the following sets of results represents the most common reactions for Moraxella catarrhalis when tested in CTA sugar tubes?
a. Glucose (-); Maltose (-); Lactose
(-); Sucrose (-)
b. Glucose (+); Maltose (-); Lactose (-);
Sucrose (-)
c. Glucose (+); Maltose (+); Lactose (-);
Sucrose (-)
d. Glucose (+); Maltose (-); Lactose (+);
Sucrose (-)
Glucose (-); Maltose (-); Lactose
(-); Sucrose (-)
(Moraxella catarrhalis is asaccharolytic)
Neisseria lactamica can be differentiated from N. meningitidis through which of the following?
a. Colony morphology
b. Use of selective media
c. Glucose and maltose utilization
d. ONPG test
ONPG test
Isolates of the suspected C. diphtheriae must be tested for in vitro production of exotoxin thru:
a. Anton test
b. Elek test
c. Frei test
d. Mantoux test
Elek test
Lecithinase production, double zone hemolysis on SBA, and gram-stain morphology are all useful criteria in the identification of which of the following?
a. C. perfringens
b. S. agalactiae
c. E. coli
d. C. tetani
C. perfringens
Sensitivity test result of Group A Streptococci to Bacitracin and SXT respectively:
a. Susceptible and resistant
b. Resistant and susceptible
c. Both susceptible
d. Both resistant
Susceptible and resistant
Correct about gram-positive bacteria:
a. Has thinner peptidoglycan compared to gram-negative
b. Cell wall has an outer layer which
contains lipopolysaccharide
c. Takes up the crystal violet-iodine
complex but is easily decolorized
d. Uses selective isolation media like
colistin-nalidixic acid agar
Uses selective isolation media like
colistin-nalidixic acid agar
Responsible for dark / non-fluorescent
background in Auramine Rhodamine stain for acid-fast bacilli
a. Auramine
b. Rhodamine
c. Potassium permanganate
d. acid-alcohol
Potassium permanganate
Stain for endospore:
a. Wayson
b. Leifson
c. Schaeffer-Fulton
d. Loeffler’s alkaline methylene blue
Schaeffer-Fulton
Most common gas for sterilization:
a. Nitrogen dioxide
b. Chlorine dioxide
c. Ethylene oxide
d. Chlorhexidine gluconate
Ethylene oxide
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
0.3 um
Incorrect about autoclaving:
a. Biologic indicator: B. stearothermophilus
b. Can destroy all forms of microbial life
including spores
c. Dry heat sterilization
d. 121degC / 15 psi / 15 mins
Dry heat sterilization
Uses a strip with varying conc. of antibiotic along its length and MIC can be obtained:
a. Kirby Bauer
b. Microplate dilution
c. Vitek System
d. E test
E test
0.5 MacFarland standard provides an optical density comparable to density of a bacterial suspension of:
a. 0.5 x 10^8 CFU/mL
b. 1.5 x 10^8 CFU/mL
c. 0.5 x 10^9 CFU/mL
d. 1.5 x 10^9 CFU/mL
1.5 x 10^8 CFU/mL
In disk diffusion testing, a delay of more than 15 mins 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 on final zone diameter
Zones of larger diameter will
result
The term “palisading”, “picket fence”, and“Chinese letter” describe the common arrangement of cells of:
a. Corynebacterium spp
b. Mycobacterium tuberculosis but not the other mycobacteria
c. Actinomyces but not Nocardia
d. Corynebacterium diphtheriae but not
other corynebacteria
Corynebacterium spp
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. Plasmidization
d. Conjugation
Conjugation
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
Clumping factor
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. S. pneumoniae
c. S. pyogenes
d. S. agalactiae
S. pneumoniae
Which of the following sets of tests provides the best differentiation of L. monocytogenes and E. rhusiopathiae?
a. Gram-stained smear, oxidase, optochin
b. Gram-stained smear, catalase, motility
c. CAMP test, H2S production, esculin hydrolysis
d. Reverse CAMP, gram-stained smear, b-hemolysis
CAMP test, H2S production, esculin hydrolysis
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
1 and 4
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
Ammonia and CO2
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
pH indicator in TCBS
(pH indicator for TCBS is bromthymol blue)
LOA reaction of Klebsiella pneumoniae:
a. + - -
b. + + -
c. - + -
d. + - +
+ - -
All are correct regarding S. saprophyticus except:
a. Coagulase negative
b. Causes UTI in young women
c. Novobiocin sensitive
d. DNase negative
Novobiocin sensitive
(S. saprophyticus is novobiocin resistant)
Chocolate agar-based medium containing vancomycin, colistin, anisomycin, and trimethoprim is known as:
a. Thayer-Martin
b. Modified Thayer Martin
c. Martin-Lewis
d. New York City
Martin-Lewis
Which of the following is a wrong pair?
a. Brucella abortus – Bang’s bacillus
b. N. meningitidis – Meningococcus
c. H. influenzae – Koch Week’s
bacillus
d. M. avium intracellulare – Battery
bacillus
H. influenzae – Koch Week’s
bacillus
(H. influenzae is Pfeiffer’s Bacillus)
(H. aegypticus is Koch Week’s Bacillus)
Positive result for DNase test:
a. Green
b. Pink
c. Clearing of medium
d. hemolysis
Clearing of medium
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
Type II - B1
Correct about satellite phenomenon:
- S. aureus grows around the hemolytic colonies of H. influenzae
- H. influenzae grows around the hemolytic colonies of S. aureus
- Also known as Nagler reaction
- Uses SBA instead of Chocolate agar
a. 1 and 2
b. 2 and 3
c. 1 and 3
d. 2 and 4
2 and 4
Growth requirement for H. influenzae
- X factor
- V factor
- 5-10% CO2
- Cystine
a. 1 only
b. 2 only
c. 1, 2, 3
d. 1, 2, 3, 4
1, 2, 3
Limulus Lysate test detects ___ in body fluids.
a. Endotoxin of gram (-) bacteria
b. Exotoxin of gram (-) bacteria
c. Endotoxin of gram (+) bacteria
d. Exotoxin of gram (+) bacteria
Endotoxin of gram (-) bacteria
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
Direct FA using monoclonal
antibodies
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
Once each day of use and when the vial is first opened
Positive for PYRase hydrolysis:
- S. pyogenes
- S. agalactiae
- S. pneumoniae
- E. faecalis
a. 1 and 3
b. 1 and 4
c. 2 and 3
d. 2 and 4
1 and 4
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
Middlebrook 7H10 and 7H11
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 enhance 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
Arrowhead-shaped zone of enhance hemolysis at the juncture of suspected organism and beta-lysin producing S. aureus
Selective media for P. aeruginosa:
a. CCFA
b. CIN agar
c. Cetrimide agar
d. MAC with sorbitol
Cetrimide agar
Which group of tests best differentiates H. pylori from C. jejuni?
a. Catalase, oxidase, gram stain
b. Catalase, oxidase, nalidixic acid sensitivity
c. Catalase, oxidase, cephalothin sensitivity
d. Urease, nitrate, hippurate hydrolysis
Urease, nitrate, hippurate hydrolysis
Which Haemophilus is difficult to isolate and recover from genital ulcers and swollen lymph nodes?
a. H. aphrophilus
b. H. haemolyticus
c. H. ducreyi
d. H. parahaemolyticus
H. ducreyi
An enzyme produced by S. pyogenes that solubilizes the ground substance of mammalian connective tissues and helping to spread the infection:
a. DNase
b. Erythrogenic toxin
c. Streptokinase
d. Hyaluronidase
Hyaluronidase
Infection caused by Legionella with febriles ymptoms with no pulmonary involvement
a. Legionnaires disease
b. Pontiac fever
c. Undulant fever
d. Relapsing fever
Pontiac fever
Bacteria that prefers O2 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
Facultative anaerobes
TSI agar is composed of 3 carbohydrate in 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
0.1% glucose, 1% lactose, 1% sucrose
The so-called red milk is the result of abundant multiplication of which chromogenic bacterium?
a. Serratia marcescens
b. Proteus vulgaris
c. Pseudomonas syncynea
d. Aerobacter aerogenes
Serratia marcescens
Catalase test should not be performed on:
a. Blood agar, because blood 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
Blood agar, because blood has
catalase
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
Yellow-orange fluorescence in dark background
Cycloserine-cefoxitin-fructose agar (CCFA) is used for the recovery of:
a. Y. enterocolitica
b. Y. intermedia
c. C. perfringens
d. C. difficile
C. difficile
Which of the following amino acids are required for growth of Francisella tularensis?
a. Leucine and ornithine
b. Arginine and lysine
c. Cysteine and cystine
d. Histidine and tryptophan
Cysteine and cystine
Edwardsiella tarda biochemically may be confused with Salmonella in that it is:
a. Lactose (+)
b. Hydrogen sulfide (+)
c. Urea (+)
d. Non-motile
Hydrogen sulfide (+)
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
Growth on medium, change of color from green to blue
Coagulase test uses what primary reagent for testing?
a. Para-dimethylaminobenzaldehyde
b. 3% H2O2
c. Sheep RBCs
d. Rabbit plasma
Rabbit plasma
The Moeller test for the detection of
decarboxylase activity is dependent upon:
a. An alkaline pH shift in the medium
b. The oxidation of gluconate
c. An acid pH basal medium
d. A deamination of tryptophan
An alkaline pH shift in the medium
Urea hydrolysis test is performed on what medium?
a. Simmons medium
b. Christensen medium
c. Moeller’s medium
d. Krigler’s iron agar
Christensen medium
Which is the best rapid, non-cultural test to perform when Gardnerella vaginalis is suspected?
a. 3% H2O2
b. 10% KOH
c. 30% KOH
d. 10% H2O2
10% KOH
Specimens that may be cultured anaerobically
- Sputum
- Needle aspirate
- Swabs of infected wounds
- Suprapubic-aspirated urine
a. 1, 2, 3, 4
b. 1 and 3
c. 2 and 4
d. 2 and 3
2 and 4
The recommended medium for the recovery of Chlamydia from clinical specimen is:
a. McCoy cells
b. A549 cells
c. Charcoal yeast extract medium
d. W1-38 cells
McCoy cells (also called HELA cells)
When clinical specimens are being processed for the recovery of M. tuberculosis, the generally
recommended method for digestion and decontamination of the sample is:
a. 6% NaOH
b. 1% HCl
c. NALC-NaOH
d. TSP
NALC-NaOH
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
c. Hemin
d. Thiophene-2-carboxylic hydrazide
Pyridoxal
Exfoliatin produced by S. aureus is responsible for causing:
a. Toxic shock syndrome
b. Enterocolitis
c. Staphylococcal pneumonia
d. Scalded skin syndrome
Scalded skin syndrome
Culture media that contains antibiotic vancomycin will inhibit growth of:
a. Gram (+) bacteria
b. Gram (-) bacteria
c. Yeast and molds
d. Normal flora
Gram (+) bacteria
If a specimen is not transported within 30 mins, it should be placed in which of the following media?
- Amie’s
- Stuart’s
- Kelly’s Medium
- Fletcher’s semi-solid medium
a. 1 and 2
b. 1 and 3
c. 2 and 3
d. 3 and 4
1 and 2
LIA reaction: red slant / acid butt, no H2s:
a. E. coli
b. K. pneumoniae
c. P. vulgaris
d. M. morganii
P. vulgaris & M. morganii
What atmospheric condition is needed to recover Campylobacter spp at 35-37degC and 42degC?
a. 10% O2, 10% CO2, 80% N2
b. 5% O2, 10% CO2, 85% N2
c. 20% O2, 20% CO2, 60% N2
d. 15% O2, 5% CO2, 80% N2
5% O2, 10% CO2, 85% N2
Which test will differentiate Pseudomonas spp from Enterobacteriaceae?
a. Catalase test
b. Indole test
c. Urease test
d. Oxidase test
Oxidase Test
A urine specimen from a maternity patient with the complaint of cystitis was received in the laboratory. The culture of this sample grew a
lactose-positive (LF), gram-negative bacillus that was presumptively identified as E. coli. On differential and selective medium, this organism
would demonstrate which reaction?
a. MacConkey agar – colorless colonies
b. Hektoen enteric agar – blue to green colonies
c. XLD agar – yellow colonies
d. All of the above are possible reactions
XLD agar – yellow colonies
Which of the following is not a correct statement regarding blood cultures?
a. Collection of 20 mL per culture for
adults is recommended
b. 2 or 3 blood cultures recommended as optimum
c. Volume of blood cultures could be more critical than timing of cultures
d. Blood drawn for culture may be
allowed to clot
Blood drawn for culture may be
allowed to clot
An example of a selective enrichment broth would be:
a. Thioglycollate broth
b. Trypticase soy broth
c. Brain Heart Infusion broth
d. Selenite broth
Selenite broth
All of the following contain resident (normal) flora except:
a. Oral cavity
b. Skin
c. Colon
d. Cerebrospinal fluid
Cerebrospinal fluid
An optimal wound specimen for culture and 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
A syringe filled with pus obtained
before administration of antibiotics
CNA is used for selective isolation of:
a. Gram (+) bacteria
b. Gram (-) bacteria
c. Aerobic bacteria
d. Anaerobic bacteria
Gram (+) bacteria
Bacteria where growth occurs evenly on
thioglycollate broth:
a. Obligate aerobes
b. Obligate anaerobes
c. Microaerophiles
d. Aerotolerant anaerobes
Aerotolerant anaerobes
Purpose of adding sodium polyanethol sulfonate (SPS) to nutrient broth media for blood culture
a. Enhances growth of anaerobes
b. Functions as preservatives
c. Inhibits phagocytosis and complement
d. Promotes formation of a blood clot
Inhibits phagocytosis and complement
Slime production is associated with which Staphylococcus specie?
a. S. aureus
b. S. epidermidis
c. S. saprophyticus
d. S. intermedius
S. epidermidis
Metachromatic / Volutin granules are inclusions of what specie of bacteria?
a. M. tuberculosis
b. Y. pestis
c. L. monocytogenes
d. C. diphtheriae
C. diphtheriae
This is also known as Capsular Swelling Test:
a. India ink test
b. Limulus lysate test
c. Modified ELEK test
d. Neufeld (Quellung) reaction
Neufeld (Quellung) reaction
These are hair-like extensions of the cell used for adherence of bacteria to host cell:
a. Flagella
b. Capsule
c. Slime layer
d. Fimbriae / Pili
Fimbriae / Pili
All are correct matches for types of flagella except:
a. Monotrichous – flagellum on one pole
b. Lopotrichous – single flagellum at
both poles
c. Peritrichous – flagella all over the organism
d. None of the above
Lopotrichous – single flagellum at
both poles
Mordant used in Kinyoun method of acid-fast staining:
a. Steam
b. Thiosulfate
c. Thermal heat
d. Tergitol
Tergitol
Which of the following techniques is performed first before doing smears for gram stain on CSF?
a. Incubate at 37degC for 1 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
Centrifuge CSF specimen to concentrate cells and microorganisms if present
This staining method is specifically designed for bacteria whose cell walls contain long chain of fatty acids (Mycolic acid)
a. Gram stain
b. India ink
c. Leifson stain
d. Acid-fast stain
Acid-fast stain
Culture media that contains antibiotic
vancomycin will inhibit growth of:
a. Gram (+) bacteria
b. Gram (-) bacteria
c. Yeast and molds
d. Normal flora
Gram (+) bacteria
Indicator used in MSA used for selective
isolation of Staphylococcus spp.
a. Neutral red
b. Bromthymol blue
c. Phenol red
d. Bromcresol green
Phenol red
Motility medium such as SIM is classified as:
a. Liquid-type medium
b. Semi-solid medium
c. Solid-liquefiable medium
d. Solid-non liquefiable medium
Semi-solid medium
Reagent used in oxidase test of bacteria:
a. 1% para dimethylaminocinnamaldehyde
b. 1% tetramethyl-p-phenylenediamine
dihydrochloride
c. L-pyrrolidonyl-b-naphthylamide
d. Hydrogen peroxide
1% tetramethyl-p-phenylenediamine
dihydrochloride
Negative reaction in Decarboxylase tests (Moeller’s method) is indicated by which color?
a. Purple
b. Yellow
c. Magenta
d. Blue
Yellow
Positive result in Acetamide Utilization test:
a. Purple
b. Yellow
c. Magenta
d. Blue
Blue
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
10
Which of the following Streptococcal species has the enzyme hippuricase?
a. S. pyogenes
b. S. pneumoniae
c. S. agalactiae
d. S. bovis
S. agalactiae
