AAB Microbiology
Which one of the following specimens may be inappropriate for culturing Neisseria gonorrhoeae?
а. еye b. urine 👍c. rectum d. oral cavity
Acid-fast bacteria appear what color microscopically?
a red👍 b. navy c. green d. purple
When performing a bacitracin differentiation test for Group A beta-hemolytic streptococci, disks should be used that have how many units?
a. 0.02-0.04 unit 👍b. 0.05-0.10 unit c. 0.20-0.40 unit d. 0.50-1.00 unit
How long does the morphological cycle of Rhodococcus equi from coccoid to rod form take?
a. 8 hours b. 12 hours c. 24 hour 👍d. 48 hours
A fastidious, small to filamentous, Gram-negative rod from a nasopharyngeal swab is most likely to be which organism?
a. Actinomyces israeli b. Neisseria meningitidis c. Moraxella catarrhalis d. Haemophilus influenzae👍
Which one of the following is anaerobic?
a. Actinomyces israelii 👍b. Nocardia brasiliensis c. Mycobacterium phlei d. Moraxella catarrhalis
A mucoid colony on blood agar medium indicates that which characteristics may be present?
a. Agar contains chemical inhibitors. b. Organism has a capsule👍. c. Plate was over incubated. d. Organism is a lactose fermenter.
A Brucella isolate that does not produce H2S, does not require CO2, and is not inhibited by thionin or basic fuchsin is probably which species of Brucella? a. B. melitensis b. B. abortus с. B. canis d. B. suis
a. B. melitensis
Babès-Ernst granules are characteristic of which organism?
a. Bacillus anthracis b. Listeria monocytogenes c. Mycobacterium tuberculosis d. Corynebacterium diphtheriae👍
Which aerobic, Gram-positive, sporulating rod can cause food poisoning?
a. Bacillus cereus 👍b. Mycobacterium phlei c. Clostridium ramosum d. Corynebacterium xerosis
Which of the following is used for quality control for the dry heat oven?
a. Bacillus subtilis 👍b.Yersinia enterocolitica c. Listeria monocytogenes d. Bacillus stearothermophilus
Which one of the following organisms causes whooping cough? a. Bordetella pertussis b. Haemophilus influenzae c. Legionella pneumophila d. Streptococcus pneumoniae
a. Bordetella pertussis
Why is it recommended to stab the blood agar plate when setting up throat cultures?
a. Capnophilic streptococci are easier to isolate. b. Streptococci grow only under aerobic conditions. c. Streptococci grow only under anaerobic conditions. d. Some streptococci may not produce beta hemolysis under aerobic conditions.👍
Which of the following diphtheroids is normal flora of the throat?
a. Corynebacterium pseudodiphtheriticum 👍b. Propionibacterium acnes c. Corynebacterium xerosis d. Rhodococcus equi
The terms "picket fence" and "Chinese letters" describe the common arrangement of cells for which organism?
a. Corynebacterium 👍b. Mycobacterium c. Actinomyces d. Nocardia
Which of the following tests can give a presumptive identification of Moraxella catarrhalis if the isolate is a Gram-negative diplococci that is oxidase positive and isolated from a body fluid from the middle ear?
a. DNase test b. catalase test c. coagulase test d. beta-lactamase test👍
Acid-fast organisms in tissue are best stained by which of the following methods?
a. Giemsa b. Kinyoun 👍c. Ziehl-Neelsen d. Wright-Giemsa
Which one of the following will stain acid-fast bacilli?
a. Gram stain b. Wright stain c. Gomori stain d. Kinyoun stain👍
Smears of cerebrospinal fluid are usually stained with which stain?
a. Gram stain 👍b. Wright stain c. Giemsa stain d. Kinyoun stain
What is the morphology of Corynebacterium diphtheriae?
a. Gram-positive, motile cocci b. Gram-negative, motile cocci c. Gram-positive, nonmotile rods 👍d. Gram-negative, nonmotile rods
The bile-esculin test is used to differentiate which two organisms?
a. Group D streptococci from enterococci👍 b. Group A streptococci from Group B streptococci c. Group B streptococci from Listeria monocytogenes d. Streptococcus pneumoniae from viridans streptococci
Nasopharyngeal swabs are recommended for the detection of which carriers?
a. H. influenzae, N. meningitidis 👍B. pertussis b.N.meningitidis, V. cholerae, B. pertussis c. H. influenzae, E. rhusiopathiae, V. cholerae d. E. rhusiopathiae, N. meningitidis, L. monocytogenes
Which of the following is a Gram-positive to Gram-variable coccobacillus?
a. Listeria monocytogenes 👍b. Наеторhilus influenzae c. Streptococcus pneumoniae d. Corynebacterium diphtheriae
A slow-growing, unbranched, acid-fast bacilli that is nitrate negative and niacin negative is most likely which organism?
a. Mycobacterium bovis 👍b. Mycobacterium simiae c. Mycobacterium kansasii d. Mycobacterium tuberculosis
Which one of the following organisms does NOT belong to Group IV (rapid growers)?
a. Mycobacterium phlei b. Mycobacterium gordonae 👍c. Mycobacterium fortuitum d. Mycobacterium smegmatis
Spore-forming cells in bamboo pole arrangement are characteristic of which organism?
a. Mycobacterium tuberculosis b. Erysipelothrix rhusiopathiae c. Listeria monocytogenes d. Bacillus anthracis👍
All of the following genera are oxidase positive except which one?
a. Neisseria b. Moraxella c. Aeromonas d. Haemорphilus👍
Gram-negative, coffee bean-shaped diplococci with adjacent sides flattened is descriptive of which of the following?
a. Neisseria 👍b. Chlamydia с. Наеторhilus d. Corynebacterium
Lumpy jaw is caused by which organism?
a. Nocardia brasiliensis b. Actinomyces israelii 👍c. Haemophilus ducreyi d. Moraxella catarrhalis
Which of the following media is clear so that colonies of mycobacteria can be examined microscopically?
a. Petragnani b. Mueller-Hinton c. Middlebrook 7H11 👍d. Löwenstein-Jensen
Why should beta-lactamase tests be performed with growth from primary isolation media?
a. Plasmid coding for the enzyme may 👍b. because of the absorbance of oxygen from the medium c. The primary isolation media contains X and V factors. d. may react with chemicals in the medium
A fastidious, oxidase-positive, Gram-negative cocci from a rectal swab might be presumptively identified as which organism?
a. Pseudomonas aeruginosa b. Listeria monocytogenes c. Neisseria gonorrhoeae 👍d. Moraxella catarrhalis
When performing the oxidase test, which of the following techniques CANNOT be used?
a. Put a drop of reagent directly on the colony b. Rub colony on a filter paper strip and add a drop of reagent. c. Use a nichrome loop to transfer the colony to the filter paper👍. d. Rub the colony on a piece of filter paper containing the reagent.
Which one of the following organisms is urease positive?
a. Salmonella b. Moraxella c. Nocardia 👍d. Shigella
Which organisms are nonmotile?
a. Shigella and Klebsiella 👍b. Salmonella and Shigella c. Klebsiella and Enterobacter d. Yersinia and Proteus
Why is a first morning urine specimen preferred for urine cultures?
a. Specimen is diluted. b. Bacteria are all motile. c. Specimen is more concentrated 👍. d. Specimen does not have epithelial contamination.
A colony of nonhemolytic, catalase-positive, coagulase-negative, Gram-positive is most likely to be which organism?
a. Staphylococcus aureus b. Staphylococcus epidermidis 👍c. Streptococcus pyogenes d. Streptococcus pneumoniae
An oxidase-positive, Gram-negative cocci from a throat culture might be which organism?
a. Staphylococcus b. Streptococcus с. Наеторhilus d. Neisseria👍
What is the most common pathogen in throat cultures?
a. Streptococcus pyogenes 👍b. Listeria monocytogenes с. Streptococcus pneumoniae d. Corynebacterium diphtheriae
Which of the following is not the cause of a venereal disease?
a. Treponema pallidum b. Neisseria gonorrhoeae c. Chlamydia trachomatis d. Haemophilus aegyptius👍
The Elek test is for the detection of which toxin?
a. Vibrio cholerae toxin b. Bacillus anthracis toxin c. Clostridium botulinum toxin d. Corynebacterium diphtheriae toxin👍
Refrigeration of the specimen for several months may enhance isolation of which organism?
a. Yersinia enterocolitica b. Listeria monocytogenes 👍c. Aeromonas hydrophila d. Mycobacterium thermoresistible
What term is used to describe bacteria that grow in the absence of atmospheric oxygen and obtain oxygen from oxygen-containing compounds?
a. aerobes b. anaerobes 👍c. capnophiles d. aerotolerants
is incubated uncovered. When is the covered tube observed? One tube of Löwenstein-Jensen medium is incubated covered with foil, and one tube
a. after 1 week of incubation b. after 2-3 weeks of incubation c. after 1 month of incubation d. when growth appears on the uncovered tube👍
Which of the following should be used to remove antimicrobials before culturing?
a. antimicrobial removal device 👍b. personnel protective equipment c. Septi-Chek d. Isolator
Which statement is true concerning acid-fast bacilli from a nasal mucosa specimen?
a. are called "lepra" cells b. are diagnostic for leprosy c. are not a diagnostic characteristic 👍d. must be cultured on Hansen's agar for definitive identification
Which differential test for identifying the species of mycobacterium splits phenolphthalein from tripotassium phenolphthalein-sulfate within 2-3 days?
a. arylsulfatase test 👍b. pyrazinamidase test c. nitrate reduction test d. Tween 80 hydrolysis test
How should mycobacterial cultures be incubated?
a. at 25°C b. in 5 % CO2 👍c. anaerobically d. in increased humidity
On blood agar plates a small zone of alpha hemolysis surrounded by a zone of beta hemolysis after refrigeration is known as what type of hemolysis?
a. beta b. alpha c. gamma d. alpha-prime👍
What is the most abundant normal flora in throat cultures?
a. beta-hemolytic streptococci b. alpha-hemolytic streptococci👍 c. Streptococcus pneumoniae d. Bordetella pertussis
Which one of the following is NOT used for the identification of mycobacteria?
a. biochemical reactions b. pigment production c. spore formation👍 d. growth rate
What is the most effective method of sterilization?
a. boiling b. filtration c. autoclaving 👍d. fractionalization
What is the preferred method of differentiating S. aureus from S. epidermidis?
a. catalase test b. phage typing c. coagulase test 👍d. mannitol fermentation
Listeria monocytogenes produces a positive in which one of the following biochemical tests?
a. catalase 👍b. coagulase c. beta-lactamase d. lactose fermentation test
All of the following are methods for testing for the production of beta-lactamase EXCEPT which one?
a. chromogenic cephalosporin method b. saccharogenic method👍 c. acidometric method d. iodometric method
Which of the following tests for bacterial antigen on cultures isolated from CSF is more sensitive and faster?
a. coagglutination tests b. latex agglutination tests 👍c. counterimmunoelectrophoresis test d. enzyme-multiplied immunoassay technique
Which of the following differentiates Thayer-Martin medium from modified Thayer- Martin medium?
a. colistin b. nystatin c. vancomycin d. trimethoprim lactate👍
Which of the following indicates a positive reaction for the beta-lactamase chromogenic cephalosporin method?
a. color change 👍b. production of acid c. reduction of nitrates d. decolorization of a starch-iodine mixture
Capsules are the basis of which test?
a. complement fixation b. hemagglutination c. serotyping👍 d. chemiluminescence
What is a term that describes a process or treatment that renders a medical device, instrument, or environmental surface safe to handle?
a. decontamination 👍b. disinfectant c. antisepsis d. sterile
Which one of the following best describes Thayer-Martin media?
a. enriched blood agar b. selective blood agar c. enriched chocolate agar 👍d. differential chocolate agar
Which medium is preferred for the culture of most Haemophilus species?
a. enriched chocolate agar👍 b. 5% sheep blood agar c. Bordet-Gengou agar d. MacConkey agar
What is the purpose of potassium tellurite in tellurite medium?
a. enriches the medium b. inhibits the normal flora 👍c. enhances the pleomorphism d. enhances granule production
What is the most probable identity of a bile-esculin positive, beta-hemolytic streptococci that grows in 6.5 % NaCl?
a. enterococci b. pneumococci c. Group B streptococci d. Group D streptococci👍
How are smears of cerebrospinal fluid prepared?
a. filtered CSF sediment b. centrifuged CSF sediment 👍c. incubated CSF supernatant d. uncentrifuged CSF supernatant
Media that cannot be heated can be sterilized by what alternate method?
a. filtration👍 b. chemical disinfectants c. antiseptics d. cannot be sterilized
Neisseria meningitidis degrades which of the following sugars?
a. glucose and lactose b. lactose and maltose c. glucose and maltose👍 d. maltose and sucrose
What indicates vaginal or urethral contamination of urine?
a. greater than 10 squamous epithelial cells per hpf 👍b. less than 25 white blood cells per hpf c. amorphous crystals d. mycelial hyphae
Hippurate hydrolysis is used to differentiate which organisms?
a. group A streptococci from group 👍B streptococci b. group B streptococci from Listeria monocytogenes c. Streptococcus faecalis from Streptococcus faecium d. Streptococcus pneumoniae from viridans streptococci
If pneumococci are resistant to penicillin, then they should be tested for which of the following?
a. growth in 6.5% NaCl b. resistance to bacitracin c. bile-esculin hydrolysis d. beta-lactamase production 👍
How is Mycobacterium tuberculosis best differentiated from Mycobacterium bovis?
a. growth rate b. pigment production c. colony morphology d. niacin and nitrate tests👍
Nocardia will grow on any medium that does not contain which one of the following?
a. hemin b. blood c. peptone d. antibiotics👍
Cultures of Staphylococcus aureus supply which of the following cultures of Наеторhilus?
a. hemin b. hematin c. X factor d. V factor👍
What is the function of N-acetyl-L-cysteine-NAOH?
a. inhibit mycobacteria other than tuberculosis b. liquefy mucus and control contaminants 👍c. concentrate the sputum specimen d. enhance pigment production
In the bacterial growth cycle, growth ceases because nutrients are exhausted or toxic metabolic products have accumulated in which phase?
a. lag phase b. stationary phase 👍c. logarithmic phase d. decline phase
What is the medium of choice for culturing gonococci and meningococci?
a. modified Thayer-Martin 👍b. Löwenstein-Jensen c. potassium tellurite d. chocolate agar
What are "lepra" cells?
a. neutrophils containing Gram-negative diplococci b. monocytes containing Gram-negative bacilli c. histiocytes containing Gram-positive cocci d. macrophages containing acid-fast bacilli👍
Which of the following will differentiate Listeria monocytogenes from Corynebacteria species?
a. nitrate positive and niacin positive b. nonmotile and salicin negative 👍c. motile and salicin positive d. motile and urease negative
Which atmospheric conditions best describe Campylobacter? a. obligate microaerophilic b. facultative anaerobe c. obligate anaerobe d. obligate aerobe
a. obligate microaerophilic
What is the temperature at which bacteria grow best known as?
a. optimum 👍b. mesophilic c. thermophilic d. psychrophilic
Which one of the following disinfectants fungi, is the most effective germicide against bacteria, spores, tubercle bacilli, and viruses?
a. phenol b. chlorine👍 c. quarternary ammoniums d. 2% aqueous glutaraldehyde
What color is a negative enzymatic hydrolysis Tween 80 test?
a. pink b. blue с. green d. amber👍
When culturing Corynebacterium enhance pleomorphism and granule production? diphtheriae, which of the following media will
a. potassium tellurite b. Loeffler serum agar👍 c. blood-cystine-glucose agar d. thiosulfate citrate bile salts sucrose agar
Which statement concerning sodium polyanethol sulfonate (SPS) is NOT true?
a. prevents blood from clotting b. prevents phagocytosis C. neutralizes the bactericidal effect of human serum d. activates some antimicrobials👍
What term describes the morphology of organisms that vary in size and shape?
a. psychrophilic b. thermophilic c. mesophilic d. pleomorphic👍
Potassium tellurite medium produces what color colonies of Corynebacterium diphtheriae?
a. red b. blue c. green d. gray-black👍
16. What color do Gram-positive bacteria stain?
a. red b. pink c. purple👍 d. green
What are dark staining granules called?
a. spores b. capsules c. budding yeast d. metachromatic👍
What specimen is usually used for the diagnosis of Hansen's disease?
a. tissue fluid 👍b. cerebrospinal fluid c. blood culture bottle d. nasopharyngeal swab
What color is a positive oxidase test?
a. yellow b. purple 👍c. green d. red
Which of the following species of Bordetella are urease-positive and oxidase- positive? a. B. bronchiseptica b. B. parapertussis с. В. Pertussis d. B. abortus
b. B. parapertussis
Which genera of bacteria form spores?
b. Bacillus and Fusobacterium a. Corynebacterium and Veillonella c. Clostridium and Bacteroides d. Bacillus and Clostridium👍
A motile, Gram-negative, slender, curved rod that is the cause of enteritis is best isolated on which agar? a. 5% sheep blood agar b. Campylobacter blood agar c. MacConkey agar d. chocolate agar
b. Campylobacter blood agar
A relatively slow growing and fastidious, Gram-negative rod that produces a characteristic brown pigment on Feeley-Gorman iron cysteine agar is most probably which organism? а. Наеторhilus influenzae b. Legionella pneumophila c. Bordetella pertussis d. Brucella melitensis
b. Legionella pneumophila
What is the BEST medium for the isolation of Legionella? a. thiosulfate citrate bile salts sucrose agar b. buffered charcoal yeast extract agar c. Feeley-Gorman iron cysteine agar d. potato-blood-glycerol agar
b. buffered charcoal yeast extract agar
A positive coagulase test is observed for which of the following?
b. hemagglutination a. bubble production d. clot liquefaction c. clotting of plasma 👍
A curved, Gram-negative rod that is nonfermentative, nitrate positive, and microaerophilic is probably which organism? a. Vibrio cholerae b. Spirillum minus c. Campylobacter jejuni d. Leptospira interrogans
c. Campylobacter jejuni
Which Gram-negative, fastidious bacillus has been isolated from air-conditioning towers? a. Vibrio alginolyticus b. Haemophilus influenzae c. Legionella pneumophila d. Corynebacterium diphtheriae
c. Legionella pneumophila
What does Campy gas mixture consist of? a. 5% CO2, 10% N2, 85 % O2 b. 5% O2, 10 % N2, 85 % CO 2 c. 5 % N2, 10 % O2, 85 % CO 2 d. 5% O2, 10 % CO2, 85 % N2
d. 5% O2, 10 % CO2, 85 % N2
What is the preferred medium for the isolation of Bordetella pertussis? a. Bordet-Gengou medium b. enriched chocolate agar c. potassium tellurite agar d. Regan-Lowe medium
d. Regan-Lowe medium