BOC Microbiology 6th Edition
A small, pleomorphic Gram-negative bacillus is isolated from an eye culture. It grows only on chocolate agar and is oxidase variable. The most likely organism is: a. Acinetobacter Iwoffii b. Haemophilus influenzae c. Stenotrophomonas maltophilia d. Pseudomonas aeruginosa
B
Characteristics of the genus Capnocytophaga include: a. grows in ambient air b. colonies are large and spreading after 2-4 days c considered "nonfermenter" d. Gram-positivev bacillus
B
The MOST important variable in the recovery of organisms in adult patients with bacteremia (bacterial sepsis) is: a. subculture of all bottles at day 5 of incubation b. the recommended volume of blood cultured c. collection of daily blood cultures set for 3 consecutive days d. collection of multiple blood culture sets from a single venipuncture
b
The ONPG test allows organisms to be classified as a lactose fermenter by testing for which of the following? a. permease b. beta-galactosidase c. beta-lactamase d. phophatase
b
The advantage of thick blood smears for malarial parasites is to: a. improve staining of the organisms b. improve detection of the organissm c. remove RBC artifacts d. remove platelets
b
The best test to differentiate Listeria monocytogenes form Corynebacterium species is: a. catalase b. motility at 25 degrees C c. motility at 35 degrees C d. gram stain
b
The genus of virus associated with anogenital warts, cervical dysplasia and neoplasia a herpes simplex virus b papillomavirus c cytomegalovirus d coxsackievirus
b
The lowest concentration of antibiotic that inhibits growth of a test organism is the: a. minimum bactericidal concentration b. minimum inhibitory concetration c. serum bactericidal concentration d. serum inhibitory concentration
b
The persistence of which marker is the best evidence of chronic HBV infection? a. HbeAg b. HbsAg c. anti-HBe d. anti-HBs
b
The presence of 20% bile in agar will allow growth of: a. Fusobacterium necrophorum b. Bacteroides fragilis c. Prevotella melaninogenica d. Prophyromonas asaccarolytica
b
Three sets of blood cultures were obtained from an adult patient with fever and suspected endocarditis. The aerobic bottle of one set had growth of Staphylococcus epidermidis at 5 days of incubation. This indicates that: a there was low-grade bacteremia b the organism is most likely a contaminant c the patient has a line infection d the blood culture bottles are defective
b
Upon review of a sputum Gram stain, the technician notes that all the neutrophil nucleiin the smear stained dark blue. The best explanation for this finding is the: a. iodine was omitted from the staining procedure b. slide was inadequately decolorized with acetone/alcohol c. sputum smear was prepared too thin d. cellular components have stained as expected
b
Virus transport medium should contain agents that: a. enable rapid viral growth during the transport time b. inhibit bacterial and fungal growth c. destroy nonpathogenic viruses d. inhibit complement fixing antibodies
b
When performing a Kovac indole test, the substrate must contain: a. indole b. tryptophan c. ornithine d. paradimethylaminobenzaldehyde
b
When performing a disk diffusion susceptibility test, the antibiotic disk are placed on the agar 30 minutes after organism inoculation and then incubated within 15 minutes of the disk placement. This procedure will result in: a. the antibiotic not diffusing into the medium, resulting in no zone b. decreased zone diameters c. increased zone diameters d. no effect on the final zone diameter
b
When stain Mycobacteria, the primary stain used in the acid-fast staining process is: a. 1% acid fuchsin b. carbol fuchsin c. crystal violet d. methylene blue
b
Where do Plasmodium sporozoites proliferate? a. bone marrow b. liver c. red blood cells d. nucleated erythrocytes precursors
b
Which 2 diseases are usually preceded by infection with beta-hemolytic streptococci? a rheumatic fever, undulant fever b glomerulonephritis, rheumatic fever c rheumatic fever, tularemia d glomerulonephritis, undulant fever
b
Which genera are positive for phenylalanine deaminase? a. Klebsiella, Serratia, Enterobacter b. Proteus, Providencia, Morganella c. Escherichia, Edwardsiella, Salmonella d. Citrobacter, Klebsiella, Pantoea
b
Which of the 2 different antimicrobial agents listed below are commonly used and may result m synergistic action in the treatment of endocarditis caused by Enterococcus faecahs? a an aminoglycoside and a macrolide b a penicillin derivative and an aminoglycoside c a cell membrane active agent and nalidixic acid d a macrolide and a penicillin derivative
b
Which of the following is the most appropriate specimen source and primary media selection? a. CSF Columbia CNA, MacConkey b. endocervical chocolate, Martin Lewis c. sputum sheep blood, Thayer-Martin, KV-laked blood d. urine sheep blood, chocolate, Columbia CNA
b
Which of the following organisms can grow in the small bowel and cause diarrhea in children, traveler's diarrhea, or a severe cholera-like syndrome through the production of enterotoxins? a. Yersinia enterocolitica b. E. coli c. Salmonella typhi d. Shigella dysenteriae
b
Which of the two different antimicrobial agentsnlisted below are commaonly used and may result in synergistic action in the treatment of endocarditis caused by Enterococcus faecalis? a. an aminoglycoside and a macrolide b. a penicillin derivative and an aminoglycoside c. a cell membrane active agent and nalidixic acid d. a macrolide and a pecicillin derivative
b
A young girl cuts her foot on a rock while swimming at the ocean. Her foot begins to show signs of infection and her parents take her to the ER. A culture grows a non-lactose fermenting Gram-negative rod that produces copious amounts of hydrogen sulfide and gas, is indole positive and motile. The organism is most likely isolated is: a. Shigella spp b. Escherichia spp c. Edwardsiella spp d. Klebsiella spp
c
The enterotoxin produced by certain strains of hemolytic, coagulase positive Staphlococcus aereus: a. is the primary cause of subacute endocarditis b. creates a biofilm on indwelling catheters c. causes a rapidly occuring (2-6 hours after ingestion) food poisoning d. is of extremely low virulence
c
The epstein-barr virus is associated with which of the following? a. chickenpox b. hodgkin lymphoma c. burkit lymphoma d. small pox
c
The following growth results were observed on media inoculated with a foot abscess aspirate and incubated in 3%-5% CO2. SBA: 2+ large gray colonies PEA: no growth chocolate: 3+ large gray colonies MacConkey: 3+ lactose fermenters Thioglycollate broth: Gram-negative bacilli and Gram-positive bacilli Biochemicals were set up on the colonies from the MacConkey agar plate. What should the microbiologist do next? a set up biochemicals on the colonies from SBA b Gram stain colonies on SBA c subculture thioglycollate broth to SBA aerobic and SBA anaerobic d test colonies on chocolate agar with hemin and NAD
c
The optimal collection of a wound specimen for culture of anaerobic organisms is a: a. swab of lesion obtained before administration of antibiotics b. swab of lesion obtained after administration of antibiotics c. syringe filled with pus, obtained before administration of antibiotics d. syringe filled with pus, obtained after administration of antibiotics
c
The organism most commonly associated with neonatal purulent meningitis is: a. Neisseria meningitidis b. Streptococcus pneumoniae c. group B strepcocci d. Haemophilus influenzae
c
The porphyrin test was devised to detect strains of Haemophilus capable of: a. ampicillin degradation b. capsule production c. hemin synthesis d. chloramphenicol resistance
c
The primary isolation of Neisseria gonorrhoeae requires: a. anaerobic conditions b. starch media c. carbon dioxide d. blood agar
c
The proper blood-to broth ratio for blood cultures to reduce the antibacterial effect of serum in adults is: a. 1:2 b. 1:3 c. 1:10 d. 1:30
c
The stock cultures needed for quality control testing of oxidase production are: a. Escherichia coli-Klebsiella pneumoniae b. Salmonella typhimurium-Escherichia coli c. Escherichia coli-Pseudomonas aeruginosa d. Proteus mirabilis-Escherichia coli
c
What are the most appropriate screening tests to presumptively differentiate and identify the nonfermentive Gram-negative bacilli from Enterobacteriaeceae? a. catalase, decarboxylation of arginine, growth on blood agar b. motility, urease, morphology on blood agar c. oxidase, nitrate reduction, growth on MacConkey agar d. oxidase, indole, and growth on blood agar
c
Which of the following groups of specimens would be acceptable for anaerobic culture? a. vaginal swab, eye swab b. intraoral surface swab, leg swab c. pleural fluid, brain, brain abscess fluid d. urine, sputum
c
Which of the following is the most reliable test to differentiate Neisseria lactamica from Neisseria meningitidis? a. growth on a modified Thayer-Martin agar b. nitrite reduction to nitrogen gas c. rapid ONPG d. utilization of maltose
c
Which of the following organisms is, to date, considered universally susceptible to penicillin: a. Haemophilus influenzae b. Neisseria gonorrhoeae c. Streptococcus pyogenese d. Corynbacterium diphtheriae
c
Which of the following sets of organisms may exhibit a brick red flourescence? a. Porphyromonas asaccharolytica and Clostridium ramosum b. Clostridium difficile and Fusobacterium sp c. Prevotella melaninogenica and Porphyromonas asaccharolytica d. Fusobacterium sp and Bacteroides fragilis
c
Which of the following specimens is considered to be the most sensitive for the recovery of Brucella in cases of chronic infection? a. blood b. urine c. bone marrow d. lymph node
c
Which of the following would best differentiate Streptococcus agalactiae from Streptococcus pyogenes? a. ability to grow in sodium azide broth b. a positive bile-esculin reaction c. hydrolysis of sodium hippurate d. beta-hemolysis on sheep blood agar
c
Which one of the following anaerobes is inhibited by sodium polyanethol sulfonate (SPS)? a. Bacteroides fragilis b. Propionibacterium acnes c. Peptostreptococcus anaerobius d. Veillonella parvula
c
Which one of the following organisms could be used as the positive quality control test for lecithinase on egg yolk agar? a. Bacteroides fragilis b. Fusobacterium necrophorum c. Clostridium perfringens d. Clostridium sporogenes
c
Which one of the following organisms does not require susceptibility testing to the antimicrobial indicated when isolated from a clinically significant source? a. Staphylococcus aureus - clindamycin b. Proteus mirabilis - gentamicin c. Streptococcus pyogenes - penicillin d. Escherichia coli - levofloxacin
c
Which organism commonly causes food poisoning by consumption of foods containing excessive populations of organisms or performed enterotoxin? a. Salmonella enteritidis b. Shigella sonnei c. Bacillus cereus d. E. coli
c
Which organism fails to grow on artificial media or in cell cultures? a. Chlamydia trachomitis b. Neisseria gonorrhaeae c. Treponema pallidum d. herpes simplex virus
c
While swimming in a lake near his home, a young boy cut his foot, and an infection developed. The culture grew a nonfastidious gram-negative, oxidase positive, beta-hemolytic, motile bacilli that produced deoxyribonuclease (DNase). The most likely identification is: a Enterobacter cloacae b Serratia marcescens c Aeromonas hydrophila d Escherichia coli
c
a 6-year old male presents to his pediatrician with a severe case of tonsillitis. The physician collects a throat swab specimen and orders GAS (Group A streptococcus) probe test. The following day the probe comes back negative. A culture is requested. The following results are obtained: Catalase: negative Bacitracin disk: sensitive Hippurate hydrolysis: negative CAMP test: negative Gram stain: Gram positive cocci in chains Which of the following organism is most likely causing the tonsillitis? a. group A beta hemolytic streptococci b. group B beta hemolytic streptococci c. group C beta hemolytic streptococci d. group D beta hemolytic streptococci
c
A thin, Gram negative bacillus with tapered ends isolated from a empyema specimen grey only on anaerobic sheep blood agar. It was found to be indole positive, lipase negative, and was inhibited by 20% bile. The most probable identification of this isolate would be: a. Bacteroides distasonis b. Prevotella melaninogenica c. Fusobacterium nucleatum d. Clostridium septicum
c
A wet mount of vaginal fluid is examined microscopically and large sqamous epithelial cellsare seen with gram-variable bacilli clustered on the cell edges. The pH of the fluid is 5.0 The most likely pathogen is: a. Escherichia coli b. Arcanobacterium haemolyticum c. Gardnerella vaginalis d. Lactobacillus
c
A wet mount of vaginal fluid is examined microscopically and large squamous epithelial cells are seen with gram variable bacilli clustered on the cell edges. The pH of the lfuid is 5.0. The most likely pathogen is: a. Escherichia coli b. Arcanobacterium haemolyticum c. Gardnerella vaginalis d. Lactobacillus
c
A yellow colony from a wound culture tested catalase-positive and coagulase-negative. The organism stained as Gram-positive cocci in clusters. Which of the following tests wold differentiate between a coagulase-negative Staphylococcus and Micrococcus? a. novobiocin susceptibility b. leucine aminopeptidase (LAP production) c. furazolidone (100 ug/disk) susceptibility d. hydrolysis of bile esculin
c
A young boy who routinely bites his finger nails develops a wound on his right pointer finger. A culture reveals alpha hemolytic, dry colonies on the blood and CNA plates that are catalase negative, resistant to optochin, and 6.5% NaCl negative. Gram stain of the colony is Gram-positive cocci in chains. The organism most likely isolated is: a. Enterococcus faecium b. Enterococcus faecalis c. Streptococcus viridians d. Streptococcus agalactiae
c
A Gram positive coccus isolated from a blood culture has the following characteristics: Optochin susceptibility - negative bacitracin susceptibility - negative bile esculin hydrolysis - negative hippurate hydrolysis - positive catalase - negative The organism is most likely: a. Staphlococcus aureus b. Streptococcus pneumoniae c. Streptococcus pyogenes d. Streptococcus agalactiae
d
A Gram stain from a swab of a hand wound reveals: moderate neutrophils no squamous epithelial cells moderate gram-positive cocci in chains moderate large gram-negative bacilli Select the appropriate media that will selectively isolate each organism. a KV-laked agar, Thayer-Martin b sheep blood, MacConkey c Columbia CNA, chocolate d Columbia CNA, MacConkey
d
A Gram stain of organisms on Leoffler agar showed pleomorphic Gram-positive bacilli. A medium that will select for this organism is: a. blood b. chocolate c. MacConkey d. potassium tellurite
d
A TSI tube innoculated with an organism gave the following reactions: alkaline slant, acid butt; no H2S, no gas produced The organism is most likely: a. Yersinia enterolitica b. Salmonella typhi c. Salmonella enteritidis d. Shigella dysenteriae
d
A bronchoscopy sample with the request for culture of Legionella is sent to the laboratory. The correct plating protocol is: a. culture on thiosulfate citrate bile salt media b. incubate the culture media anaerobically c. reject the specimen and request a sputum sample d. culture of buffered charcoal yeast extract agar with antibiotics
d
A characteristic that is helpful in separating Pseudomonas aeruginosa from other members of the Pseudomonas family is: a. a positive test for cytochrome oxidase b. oxidatitive metabolism in the OF test c. production of fluroescein pigment d. growth at 42 degrees C
d
A characteristic that is helpful in separating Pseudomonas aeruginosa from other members of the Pseudomonas family is: a. a positive test for cytochrome oxidase b. oxidative metabolism in the OF test c. production of fluorescein pigment d. growth at 42 degrees C
d
Which of the following is the most appropriate organism and media combination? a. Vibrio species - Skirrow b. Enterohemorrhagic E coli - phenylethyl alcohol (PEA) c. Campylobacter species - charcoal yeast extract d. Yersinia enterocolitica - cefsulodin-irgasan-novobiocin
d
Which of the following may be used as a positive quality control organism for the bile esculin test? a. Stapylococcus epidermidis b. Staphylococcus aureus c. Streptococcus pyogenes d. Enterococcus faecalis
d
Which of the following specimen requests is acceptable? a. feces submitted for anaerobe culture b. Foley catheter tip submitted for aerobic culture c. rectal swab submitted for direct smear for gonococci d. urine for culture of acid-fast bacilli
d
Which one of the following Gram-negative bacilli ferments glucose? a. Alcaligenes faecalis b. Burkholderia cepacia c. Acinobacter Iwoffii d. Yersinia enterolitica
d
Which one of the following genera is among the least biochemically reactive members of the Enterobacteriaeceae? a. Proteus b. Pseudomonas c. Citrobacter d. Shigella
d
Which test is used to differentiate viridians streptococci from Streptococcus pneumoniae? a. CAMP test b. bacitracin disk test c. Streptococcus pyogenes d. Enterococcus faecalis
d
An organism recovered from a sputum has the following characteristics: Culture: growth at 6 days on buffered charcoal yest extract (BYCE) agar, incubated under aerobic conditions with CO2 at 35 degrees C Gram stain: delicate branching Gram positive bacilli modified acid-fast stain: branching, filamentous, "partially" acid fast bacterium a Nocardia b Mycobacterium c Actinomyces d Streptomyces
a
An organism that must be incubated in a microaerophilic environment for optimal recovery is: a. Camplobacter jejuni b. Escherichia coli c. Pseudomonas aeruginosa d. Proteus mirabilis
a
Appropriate culture requirements for a specimen from a patient suspected of having tularemia include: a a media with cysteine such as buffered charcoal yeast extract agar b colistin nalidixic acid agar c Mueller-Hinton agar with 5% sheep blood agar d Regan-Lowe media
a
Biochemical reactions of an organism are consistent with Salmonella. A suspension is tested in polyvalent antiserum A through G and Vi antiserum. There is agglutination in the Vi antiserum only. What should be done next? a. boil suspension of the organism for 10 minutes to inactivate the Vi antigen. b. test organism with individual antisera for agglutination c. report "no salmonella isolated" d. repeat biochemical identification of the organism
a
Camplyobacter jejuni isolation requires the fecal specimen to be: a. Inoculated onto selective plating media and incubated in reduced oxygen with added CO2 at 42 degrees C b. stored in tryptic soy broth before plating to ensure growth of organism c. inoculated onto selective plating media and incubated at both 35 degrees C and at room temperature d. incubated at 35 degrees C for 2 hours in Cary-Blair media before inoculating onto selective plating media
a
Chlamydia trachomitis infections have been implicated in: a. LGV and conjuctivitis b. gastroenteritis and urethritis c. neonatal pneumonia and gastroenteritis d. neonatal meningitis and conjunctivitis
a
Gram stain examination from a blood culture bottle shows dark blue, spherical organisms in clusters. Growth on sheep blood agar shows small, round, pale yellow colonies. Further tests should include: a catalase production and coagulase test b bacitracin susceptibility and serological typing c oxidase and deoxyribonuclease reactions d Voges-Proskauer and methyl red reactions
a
Gram-positive cocci in chains are seen on a Gram stain from a blood culture. The organism grows as a beta-hemolytic colony. Further tests that could be performed include: a. PYR, bacitracin, and hippurate b. catalase and agglutination test for Protein A c. oxidase and mass spectrometry d. Voges-Proskauer and methyl red
a
Group B, beta-hemolytic streptococci may be distinguished from other hemolytic streptococci by which of the following procedures? a. latex antigen grouping b. growth in 6.5% NaCl broth c. growth on bile esculin medium d. bacitracin susceptibility
a
In the disk diffusion susceptibility testing, as an antimicrobial agent diffuses away from the disk the concentration of antibiotic is: a. increased b. decreased c. unchanged d. inoculum dependent
a
Individuals who lack the duffy antigen on the surface of their red blood cells are protected against which species of plasmodium? a. P. vivax b. P. falciparum c. P. malariae d. P. ovale
a
Multifocal brain lesion in AIDS patients is commonly caused by: a. Toxoplasma gondii b. Pneumocystitis jiroveci c. Cryptosporidium parvum d. Taenia solium
a
Plesiomonas shigelloides is a member of the family Enterobacteriaceae. The characteristic that differentiates Pleisiomonas from other Enterobacteriaea is: a. positive oxidase b. glucose fermentation c. reduction of nitrates to nitrites d. growth on MacConkey agar
a
Relapsing fever in humans is caused by: a. Borrelia recurrentis b. Brucella abortus c. Leptospira interoogans d. Spirillum minus
a
Representative beta-lactam antibiotics and their mechanism of action include: a. ampicillin, cefazolin and imipenem; and inhibition of cell wall synthesis b. ampicillin, cefazolin and imipenem; and inhibition DNA replication c. ciprofloxacin, levofloxacin, and aztreonam; and inhibition of cell wall synthesis d. ciprofloxacin, levofloxacin, and aztreonam; and inhibition of DNA replication
a
The gram stain of drainage from a pulmonary sinus tract shows many WBCs and 3+ branching Gram-positive bacilli. Colonies grow only on anaerobic media after 3 days incubation. They are yellow-tan and have a molar tooth appearance. The most likely genus is: a. Actinomyces b. Bacteroides c. Fusobacterium d. Nocardia
a
The organism that exhibits the satellite phenomenon around colonies of Staphylococcus aereus is: a. Haemophilus influenzae b. Neisseria meningitidis c. Neisseria gonorrhoeae d. Klebsiella pneumoniae
a
The reverse CAMP test, lecithinase production, double zone hemolysis, and Gram stain morphology are all useful criteria in the identification of: a Clostridium perfringens b Streptococcus agalactiae c Propionibacterium acnes d Bacillus anthracis
a
The specimen of choice for detection of RSV is: a. nasopharyngeal aspirate b. cough plate c. expectorated sputum d. throat swab
a
The steam autoclave method of sterilization requires: a. 15 lb of pressure for 15 minutes b. dry heat for 20 minutes c. a maximum temperature of 100 degrees C d. a source of ethylene oxide
a
Ureaplasma urealyticum is difficult to grow in the laboratory on routine media because of its requirement for: a.sterols b. horse blood c. ferric pyrophosphate d. surfactant such as Tween 80
a
Which characteristic best differentiates Acinebacter species from Moraxella species? a. production of oxidase b. growth on MacConkey agar c. motility d. susceptibility to penicillin
A
Penicillin resistance in Neisseria gonorrhoeae can be due to the organism producing: a. beta-D-galactosidase b. beta-lactamase c. butryrate esterase d. DNase
b
Psittacosis is transmissible to man via contact with: a. insects b. birds c. cattle d. dogs
b
Characteristics of the HACEK group bacteria include: a. association with urinary tract infections b. Gram stain of pleomorphic gram positive bacilli c. requirements of 5-10% CO2 for growth d. requirements of 42 degrees C for growth
C
Shigella species characteristically are: a. urease positive b. nonmotile c. oxidase positive d. lactose fermenters
b
Differentiating tests that will separate Burkholderia from Stenotrophomonas include: a. Gram stain reaction b. growth on MacConkey agar c. glucose fermentation d. oxidase
D
The one characteristic by which an unknown Cryptococcus species can be identified as Cryptococcus neoformans is: a. appearance of yellow colonies b. positive urease test c. presence of a capsule d. positive phenol oxidase test
D
An antimicrobial susceptibility method recommended to detect vancomyocin-intermediate Staphylococcus aureus is: a. MIC broth dilution b. agar dilution c. kinetic diffusion d. disk diffusion
a
An isolate from a stool culture gives the following growth characteristics and biochemical reactions: MacConkey agar: colorless colonies Hektoen agar: yellow-orange colonies TSI: acid slant/acid butt, no gas, no H2S Urea: Positive a. Yersinia enterocolitica b. Shigella sonnei c. Vibrio parahaemolyticus d. Camplobacter jejuni
a
An isolate on chocolate agar from a patient with epiglottitis was suggestive of Haemophilus species. Additional testing showed that the isolate required NAD for growth and was nonhemolytic. The organism is most likely Haemophilus: a. haemolyticus b. ducreyi c. influenae d. parainfluenzae
a
Which nonculture method is best for the diagnosis of Neisseria gonorrhaeae in an adult female? a. clinical history b. Gram stain of cervical secretions c. MALDI-TOF MS d. NAAT
d
A 17-year old female with cystic fibrosis is diagnosed wit pneumonia. A sputum sample grew Gram negative bacilli with yellow, smooth colonies that have the following biochemical reactions: OXIDASE: POS TSI: alk/alk GLUCOSE: OXIDIZED FLOURENCENCE: NEG LYSINE DEC: POS a. Burkholderia cepacia b. Klebsiella pneumoniae c. Shewanella putefaciens d. Stenotrophomonas maltophilia
a
A 55 year-old man presents to the emergency room with chest pain and is found to have suffered a heart attack. He has a past history of hypertension, and a high cholesterol. The patient is admitted and scheduled for a triple bypass procedure. During recovery, he becomes septic, developing a high grade fever and pneumonia. Gram positive cocci in clusters, isolated from both his lungs via an induced sputum specimen and the surgical incision, produce beta hemolytic, catalase-positive colonies on sheep blood agar. Identify the organism most likely isolated and the biochemical test performed to confirm the identification. a. Staphylococcus aureus and latex agglutination b. Streptococcus pyogenes and PYR c. Streptococcus agalactiae and latex agglutination d. Enterococcus faecium and PYR
a
A 56-year old male has two sets of blood cultures that grow Gram-positive cocci after being admitted to the hospital with an oozing leg wound post operation. The infected area is red, swollen and warm to the touch. A red line has appeared at the sight of the wound and is beginning to travel up the patient's leg. Biochemicals performed from the beta hemolytic colonies on the sheep blood agar plate revealed the following: CAMP test: negative Hippurate hydrolysis: negative PYR: positive Bacitracin: sensitive 65% NaCl: no growth bile esculin: negative The most likely identification is: a. Streptococcus pyogenes b. Streptococcus agalactiae c. Staphylococcus aureus d. Enterococcus faecalis
a
A blood culture bottle with macroscopic signs of growth is Gram stained and the technician notes small, curved Gram negative bacilli resembling "gull wings". It is subcultured to blood and chocolate agar, and incubated aerobically and anaerobically. After 24 hours, no growth is apparent. The next step should be to: a. subculture the bottle, and incubate in microaerophilic conditions b. assume the organism is nonviable, and ask for a repeat specimen c. utilize the oxidase and indole test to detect Aeromonas d. subculture the bottle to a medium containing X and V factors
a
A first morning sputum is received for acid-fast bacilli culture. It is digested and decontaminated by the N-acetyl-L-cysteine alkali method. Two Sabouraud dextrose slants are incubated in the dark at 35 degrees C with 5-10% CO2. The smears reveal acid fast bacilli, but the slants show no growth after 8 weeks. The explanation is: a. improper media used b. incorrect decontamination procedure used c. improper specimen submitted d. improper incubation temperature and atmosphere
a
A gastroenterologist submits a gastric biopsy from a patient with a peptic ulcer. To obtain presumptive evidence of H. pylori, a portion of the specimen should be added to which media? a. urea broth b. tetrathionate c. selenite d. tryptophan
a
A liquid fecal specimen from a three-month-old infant is submitted for culture. The stool culture should detect Salmonella, Shigella and: a. Campylobacter spp b. Clostridium botulinum c. Entamoeba hartmanni d. eterotoxigenic E. coli
a
A non-hemolytic streptococcus that has been isolated from an ear culture grows up to the edge of a 0.04 unit bacitracin disk. Which of the following tests would help determine if the organism is Enterococcus? a. hydrolysis of PYR b. growth in the presence of penicillin c. optochin susceptibility d. fermentation of mannitol
a
Acceptable specimens for culture of anaerobic bacteria that cause disease include: a abscesses b stool c. clean catch urine d. vaginal
a
An Enterococcus isolated from multiple blood cultures in a patient endocarditis should be: a. screened for high level aminoglycoside resistance b. checked for tolerance c. assayed for serum antimicrobrial activity d. tested for beta-lactamase production
a
When performing a stool culture, a colony type typical of an enteric pathogen is subcultured on a blood agar plate. The resulting pure culture is screened with several tests to obtain the following results: TSI: acid butt/alkaline slant, no gas, no H2S Phenylalanine deaminase: negative Motility: positive Serological testing: Shigella flexneri (Shigella subgroup B) The serological typing is verified with new kit and controls. The best course of action would be to: a. report the organism as Shigella flexneri without further testing b. verify reactivity of motility medium with positive and negative controls c. verify reactivity of the TSI slants with positive and negative controls for H2S production d. verify reactivity of phenylalanine deaminase with positive and negative controls
a
Which DNA+ organism's colony is not easily broken up and therefore displays the "hockey puck" characteristic where it can be pushed across the plate of medium? a. Moraxella catarrhalis b. Neisseria gonorrhoeae c. Neisseria meningitidis d. Vibrio cholera
a
Which of the following pairs of organisms usually grow on kanamycin, vancomycin, laked blood agar? a. Bacteroides and Prevotella b. Mobiluncus and Gardnerella c. Porphyromonas and Enterococcus d. Veilonella and Capnocytophaga
a
Which one of the following provides a presumptive identification of a viral infection? a. cytopathic effect on cell cultures b. intranuclear inclusions in RBCs c. cell lysis of sheep red blood cells d. presence of mononuclear inflammatory cells
a
Which one of the following results is typical of Campylobacter fetus species fetus? a. optimal growth at 42 degrees C b. oxidase negative c. growth at 35-37 degrees C d. catalase negative
a
Which one of the following results is typical of Campylobacter jejuni: a. optimal growth at 42 degrees C b. oxidase negative c. catalase negative d. nonmotile
a
Which organism is the most common anaerobic bacteria isolated from infectious processes of soft tissue and anaerobic bacteremia? a. Bacteroides fragilis b. Fusobacterium nucleatum c. Porphyromonas asaccharolytica d. Clostridium perfringens
a
Which selective medium is used for the isolation of gram-positive microorganisms? a Columbia CNA with 5% sheep blood b trypticase soy agar with 5% sheep blood c eosin methylene blue d modified Thayer-Martin
a
Which testing platform meets this description? An isolated colony is irradiated by a lazer, which ionizes the biomolecules and causes them to become acelerated in an electric field. The ionized biomolecules then enter a flight tube where they are separated by their mass to charge ratio a. MALDI-TOF b. multiplex PCR c. pulsed field gel eletrophoresis d. sequencing
a
Infection of the urinary tract is most frequently associated with: a Staphyloccus aureus b. Escherichia coli c. Engterococcus faecalis d. Serratia marcescens
b
A 21-year old patient presents with pharyngitis. A throat swab is collected and submitted for anaerobic culture. This specimen should be: a. set up immediately b. rejected as unacceptable c. inoculated into thioglycollate broth d. sent to a reference laboratory
b
A 26-year old female presents to her doctor with several lacerations on her right hand and a swollen knuckle. The patient tells the clinician she is a boxer and received the lacerations 2 days prior while sparring without gloves when she accidentally caught her partner in the mouth. At 48 hours a culture reveals: Colonies on the blood pate and chocolate plate with no growth on the MacConkey agar plate. Gram stain of the colonies reveals small, slender, Gram-negative rods Oxidase: Positive Indole: Negative Reduces Nitrate to Nitrite Does not require X and V factors Catalase: Negative What is the most likely identification of this organism? a. Pasturella multicoda b. Eikenella corrodens c. Pseudomonas aeruginosa d. Escherichia coli
b
A 29 year old man is seen for recurrence of a purulent urethral discharge 10 days after the successful treatment of culture proven gonorrhea. The most likely etiology of his urethritis: a. Mycoplasma hominis b. Chlamydia trachomatis c. Trichomonas vaginalis d. Neisseria gonorrheae
b
A Foley catheter urine specimen from a 88-year old male patient is received by the Microbiology Laboratory for culture. At 24 hours, the culture is growing 100,000 cfu/mL colonies of a non-lactose fermenting Gram-negative rods. The isolate also tested positive for indole, ornithine decarboxylase, urease, motility, and phenylalanine deaminase, and negative for hydrogen sulfide production. The organism is most likely: a. Edwardsiella spp b. Morganella spp c. Hafnia spp d. Shigella spp
b
A Gram stain performed on a sinus aspirate revealed Gram-negative diplococci within PMNs. Oxidase testing is positive and carbohydrate degradation tests are inert. The organism most likely is: a. Neisseria lactamica b. Moraxella catarrhalis c. Neisseria meningitidis c. Neisseria sicca
b
A Gram-negative bacillus with bipolar staining was isolated from a wound infection caused by a bite from a pet cat. The following characteristics reactions were seen: Oxidase: Positive Glucose OF: Fermentative Motility: Negative MacConkey agar: no growth Which of the following is the most likely organism? a. Pseudomonas aeruginosa b. Pasteurella multocida c. Aeromonas hydrophila d. Vibrio cholerae
b
A child was bitten on the arm by her sibling and the resulting wound grew a slender gram-negative bacilli that has the following characteristics: growth on SBA: colonies that "pit" the agar colonies odor: like bleach catalase: negative oxidase: positive TSI: no growth The identification of this organism is: a Moraxella catarrhalis b Eikenella corrodens c Kingella kingae d Legionella pneumophila
b
A college student who recently studied a semester abroad in Southeast Asia is admitted to the hospital with a diagnosis of "glanders-like" infection (melioidosis). A sputum specimen grows a small, Gram negative rod that is positive for oxidase, reduces nitrate to gas, and oxidizes glucose, lactose and mannitol. What is the most likely organism? a. Stenotrophomans maltophilia b. Burkolderia pseudomallei c. Pseudomonas aeruginosa d. Acinobacter baumanni
b
A gram negative diplococcus that grows on modified Thayer-Martin medium can be further confirmed as Neisseria Gonorrheae if it is: a. oxidase positive , glucose positive, and maltose positive b. oxidase postive, and glucose positive, maltose negative c. oxidase positive, maltose positive, and glucose negative d. glucose postive, oxidase negative and maltose negative
b
A light yellow colony from a skin lesion grew aerobically and tested as catalase positive and coagulase negative. The organism stained as Gram-positive cocci in clusters. The organism was modified oxidase positive, bacitracin (0.04 U) susceptible and resistant to lysostaphin. What is the identification of this organism? a. Staphylococcus aureus b. Micrococcus luteus c. Staphylococcus epidermidis d. Peptostreptococcus anaerobius
b
A medical technologist is working on a stool culture from a patient with severe, bloody diarrhea. She wants to set up biochemicals to differentiate Shigella and E coli. Which of the following tests would be the most appropriate? a. hydrogen sulfide, ONPG, motility, urease b. lactose, indole, ONPG, motility c. urease, citrate, VP hydrogen sulfide d. gas, MR, urease, citrate
b
A medium that can be used to recover Francisella tularensis is: a. Bordet-Gengou agar b. Buffered charcoal yest extract agar c. Loeffler agar d. MacConkey agar
b
A patient has a suspected diagnosis of subacute bacterial endocarditis. His blood cultures grow non spore forming pleomorphic Gram positive bacilli only in the anaerobic bottle. What tests will give a presumptive identification of the microorganism? a. beta-hemolysis and oxidase b. catalase and spot indole c. esculin hydrolysis d. hydrolysis of gelatin
b
A pregnant patient is screen at 36 weeks' gestation for group B streptococcus (GBS). A vaginal swab is collected and cultured in Todd-Hewitt broth with 8 ug/mL gentamicin and 15 ug/mL nalidixic acid. The broth is subcultured onto sheep blood agar after 24 hours of incubation. No GBS are seen on the subculture and the results are reported as negative. The patient later goes on to deliver an infant with early onset GBS disease. What is the most likely reason for the negative GBS culture? a. the patient was screened too early since screening after 38 weeks is recommended b. a vaginal swab collected instead of a vaginella/rectal swab c. the Todd-Hewitt broth used was inhibitory to the organism d. the selective broth was incubated only 24 hours before subculture
b
A reliable test for distinguishing Staphylococcus aureus from other staphylococci is. a oxidase b coagulase c catalase d optochin susceptibility
b
Mycobacteria that produce pigment only after exposure to light are classified as: a photochromogens b scotochromogens c rapid growers d nonchromogens
b
A sputum culture from an alcoholic seen in the ER grows gray, mucoid, stringy colonies on sheep blood agar. The isolate grows readily on MacConkey agar and forms mucoid, dark pink colonies. The colonies yield the following the test results; ONPG: POS INDOLE: NEG GLUCOSE: POS OXIDASE: NEG CITRATE: POS VP: POS The organism is most likely: a. Edwardsiella tarda b. Klebsiella pneumoniae c. Escherichia coli d. Proteus vulgaris
b
A urine isolate Gram stain shows Gram-positive cocci in clusters. The organism tested catalase postive. To identify this organism from culture, the technician should perform a coagulase test and a/an: a. polymyxin B susceptibility b. novobiocin susceptibility c. oxidase d. beta-lactamase
b
A vaginal /rectal swab is collected from a pregnant patient to screen for group B Streptococcus colonization. The best medium to inoculate the specimen to is: a. CNA agar b. LIM broth c. sheep blood agar d. thioglycollate broth
b
A very bloody stool is received by the laboratory. The following day a pathogenic strain of E. coli is isolated. Which sugar should this isolate be tested against to begin the identification process? a. mannitol b. sorbitol c. lactose d. arabinose
b
Acinobacter Iwoffii differs from Neisseria gonorrhoeae in that Acinobacter: a. exhibits a Gram-negative staining reaction b. will grow on MacConkey and EMB media c. is oxidase-positive d. produces hydrogen sulfide on a TSI slant
b
An anaerobic, box care shaped, beta hemolytic Gram-positive bacilli isolated from a foot wound in most likely: a. Actinomyces israeli b. Clostridium perfringens c. Bacillus subtilis d. Eubacterium lentum
b
An aspirate of a deep wound was plated on blood agar plates and incubated aerobically and anaerobically. At 48 hours there was growth on the anaerobic plate only. This next step in the evaluation of this culture is to: a. reincubate both plates for another 24 hours b. Gram stain and begin organism identification c. call physician and request blood culture d. set up a Bauer-Kirby susceptibility test
b
An enterobacteriaeceae organism will appear to be more resistant on a disk diffusion susceptibility test if the: a. depth of the agar is too thin b. inoculum is too concentrated c. the antimicrobial agent in disk is too concentrated d. test interpretation occurs after 12 hours of ambient air incubation
b
An organism from a peritoneal abscess is isolated on kanamycin-vancomycin laked blood agar and grows black colonies on BBE agar. It is nonpigmented, catalase positive, and indole negative. The genus of this organism is: a Acidominococcus b Bacteroides c Porphyromonas d Prevotella
b
An organism previously thought to be nonpathogenic, Moraxella catarrhalis, is now known to be associated with opportunistic respiratory infection and nosocomial transmission. Characteristici dentification criteria include: a. beta-lactamase negative b. butyrate esterase positive c. gram-negative bacilli d. oxidase negative
b
An unusual number of Mycobacterium gordonae have been isolated. The most likely souice is. a an outbreak of infections due to Mycobacterium goidonae b contamination by water organisms c contamination of commercial Lowenstein- Jensen tubes d contamination of the specimen collection containers
b
Anaerobic Gram-positive bacilli with subterminal pores were isolated fro a peritoneal abscess. The colony has a swarming appearance. The most likely identification of this organism is: a. Bacillus cereus b. Clostridium septicum c. Eubacterium lentum d. Bifidobacterium dentium
b
Beta-hemolytic streptococci that is bacitracin-sensitive and CAMP-negative is: a. group B b. group A c. beta-hemolytic, not group A, B, or D c. group D
b
Characteristically, enterococci are: a unable to grow in 6.5% NaCl b relatively resistant to penicillin c sodium hippurate positive d bile esculin negative
b
Children who have infections with beta-hemolytic streptococci can develop: a acute pyelonephritis b acute glomerulonephritis c chronic glomerulonephritis d nephrosis
b
Clinical resistance to penicillin correlates most frequently with beta-lactamase production in: a. Chlamydia trachomatis b. Neisseria gonorrhoeae c. Neisseria meningitidis d. Trepnema pallidum
b
Clostridium Difficile can be detected by: a. flourescent staining b. glutamate dehydrogenase c. growth on LKV media d. high pressure liquid chromatography
b
Colds and other acute respiratory diseases are most often associated with: a. Epstein-Barr virus b. adenovirus c. coxsackie B d. reovirus
b
Encephalitis is most commonly associated with wich of the following viruses? a. Epstein-Barr b. herpes simplex viurs c. coxsackie B d. varicella zoster virus
b
Examples of Catagory A agents of bioterrorism include: a. Bacillus anthracis, MDR tuberculosis b. Francisella tularensis, Yersinia pestis c. Hanta virus, variola major virus d. VRE, Bacillus cereus
b
Haemophilus influenzae is most likely considered normal indigenous flora in the: a. oropharynx b. female genital tract c. large intestine d. small intestine
b
In a suspected cae of Hansen disease (leprosy), a presumptive diagnosis is established by: a. isolation of organisms on Lowestein-Jensen medium b. detection of weakly acidfast bacilli in infected tissue c. isolation of organisms in a cell culture d. detection of niacin production by the isolated bacterium
b
In the bacitracin susceptibility test, if there is a zone of inhibition surrounding the disk following overnight incubation at 37 degrees C, the colony most likely consists of: a. Staphylococcus aureus b. Group A Streptococcus c. Streptococcus pneumoniae d. Group B Streptococcus
b
In the disk diffusion method of determining antibiotic susceptibility, the size of the inhibition zone used to indicate susceptibility has been determined by: a. testing 30 strains of 1 genus of bacteria b. correlating the zone size with minimum inhibitory concentrations c. correlating the zone size with minimum bactericidal concentrations d. correlating the zone size with the antibiotic content of the disk
b
A 1-2 mm translucent , nonpigmented colony, isolated from an anaerobic culture of a lung abscess after 72 hours, was found to flouresce brick-red under ultraviolet light. A Gram stain of the organism revealed a coccobacillus that had the following characteristics: Growth in bile: inhibited Vancomycin: resistant Kanamycin: resistant Colistin: susceptible Catalase: negative Esculin hydrolysis: negative Indole: negative The identification of this isolate is: a. Bacteroides ovatus b. Propionibacterium acnes c. Prevotella melaninogenica d. Porphyromonas asaccharolytica
c
A CSF specimen containing only 2 drops of CSF was collected by lumbar puncture from a febrile 25-year old male and was submitted for a stat gram stain and culture. The direct specimen Gram stain was reported as many neutrophils and no microorganism seen. The remain drop of CSF should be inoculated to: a. blood agar b. CNA agar c. chocolate agar d. Thayer-Martin agar
c
A beta-hemolytic Gram-positive coccus was isolated from the cerebrospinal fluid of a 2-day old infant with signs of meningitis. The isolate grew on sheep blood agar under aerobic conditions and was resistant to a bacitracin disc. Which of the following should be performed for the identification of the organism? a. oxidase production b. catalase formation c. latex antigen grouping d. esculin hydrolysis
c
A beta-hemolytic Streptococcus that is bacitracin-reistant and CAMP-positive is: a. group A or B b. group A c. group B d. group D
c
A blood culture from a 64-year old male with lymphoma was positive blood culture at 18 hours incubation. The organism is a nonlactose fermenting Gram negative bacillus on MacConkey agar. Further testing gives the following reactions: Oxidase - negative TSI - alkaline/acid, no hydrogen sulfide Motility - positive Indole - positive Citrate - positive ornithine decarboxylase - negative urea - positive phenylalanine deaminase - positive VP - negative The genus is: a. Morganella b. Proteus c. Providencia d. Serratia
c
A branching Gram-positive partially acid fast organism is isolated form a bronchial washing on a 63 year old woman receiving chemotherapy. The organism does not hydrolyze casein, tryrosine or xanthine. The most likely genus causing the infection is: a. Actinomyadura b. Erysepelothrix c. Nocardia d. Streptomyces
c
A catheterized urine is inoculated on blood and MacConkey agar using a 0.01 mL loop. After 24 hours, 68 colonies of a small translucent nonhemolytic organism grew on blood agar but not MacConkey. Testing reveals small Gram-positive, catalase-negative cocci. The preliminary report and follow up testing would be: a. growth of 680 CFU/mL of Gram-positive cocci, optichin and bacitracin susceptibility tests to follow b. growth of 6,800 CFU/mL of a Staphylococcus species, latex agglutination test to follow c. growth of 6,800 CFU/mL of a Streptococcus speciess, esculin hydrolysis and 6.5% NaCl growth test to follow d. growth of 6,800 CFU/mL of a Streptococcus species, no further testing
c
A clean catch urine culture (obtained with a 0.01 mL calibrated loop) grows 60 colonies of Escherichia coli. Which of the following represents the final colony count in CFU/ mL? a. 60 CFU mL b. 600 CFU mL c. 6000 CFU mL d. 60000 CFU mL
c
A diabetic foot swab from an 82 year old woman with recurrent infections is submitted for culture. The gram stain reveals: Many neutrophils, no squamous epithelial cells Many Gram-negative bacilli Many Gram-positive cocci in chains The physician requests that all pathogens be worked up. In addition to the sheep blood, chocolate and MacConkey agar plates routinely used for wound cultures, the technologist might also process an: a. anaerobic blood agar plate b. BCYE agar plate c. CNA agar plate d. XLD agar plate
c
A fibrous skin nodule is removed from the back of a patient from Central America. A microfilaria seen upon microscopic exam of the nodule is most likely: a. Wuchereria bacrofti b. Brugia malayi c. Onchocerca volvulus d. Loa loa
c
A gamma-hemolytic Streptococcus that blackens bile esculin agar but does not grow in 6.5% NaCl broth is most likely: a. group B Streptococcus b. Enterococcus c. group D Streptococcus (Strep bovis group) d. Streptococcus pneumoniae
c
A gram stain of a peritoneal fluid showed large Gram-positive bacilli. There was 3+ growth on anaerobic media only, with colonies producing a double zone of hemoysis. To assist with the classic identification of the organism, the microbiologist could: a. determine if the organism ferments glucose b. perform the oxidase test c. set up egg yolk agar plate d. test for bile tolerance
c
A gram stain of a touch prep from a gastric biopsy shows Gram-negative bacilli that are slender and curved. The most likely pathogen is: a. Burkholderia capacia b. Corynebacterium urealyticum c. H. pylori d. Pasteurella multocida
c
A method for the definitive identification of neisseria gonorrhoeae is: a. degradation of amino acids b. EIA c. utilization of carbohydrates d. resistance to penicillins and cephalosporins
c
A patient with a prosthetic heart valve visits the dentist for her yearly checkup. Two weeks later, she presents to her primary care physician with a high fever, chills, and shortness of breath and receives a diagnosis of subacute endocarditis. Multiple blood culture sets are drawn on the patient and sent to the lab. Twenty-four hours later the bottles are positive for bacterial growth. Which organism would you expect to grow? a. Staphylococcus lugdenensis b. Staphylococcus saprophyticus c. Streptococcus viridans d. Streptococcus agalactiae
c
An 8-year old girl was admitted to the hospital with a 3-day history of fever, abdominal pain, diarrhea, and vomitting. A stool culture grew many lactose-negative colonies that yielded the following test results: Oxidase: negative TSI: acid slant/acid butt Indole: negative Urease: Positive Ornithinine decarboxylase: positive Sucrose: positive H2S: negative motility at 25 degrees C: positive a. E. coli b. Providencia stuartii c. Yersinia enterocolitica d. Edwardsiella tarda
c
An antibiotic that inhibits cells wall synthesis is: a. chloramphenicol b. colistin c. penicillin d. sulfamethozole
c
An organism was inoculated to a TSI tube and gave the following reactions: alkaline slant/acid butt, H2S, gas produced This organism most likely is: a Klebsiella pneumoniae b Shigella dysenteriae c Salmonella typhimurium d Escherichia coli
c
Antibiotics routinely tested and reported for Pseudomonas aeruginosa isolates include: a. clindamycin b. erythromycin c. gentamicin d. penicillin
c
Anticoagulants acceptable for use with blood, bone marrow, and synovial fluid specimens that are to be cultured include: a. EDTA and sodium citrate b. heparin and sodium citrate c. sodium polyanethol sulfonate (SPS) and heparin d. sodium polyanethol sulfonate (SPS) and EDTA
c
Darkfield microscopy is used to visualize: a. Borrelia recurrentis b. Mycoplasma pneumoniae c. Treponema pallidum d. Legionella pneumophila
c
During the previous month, Staphyloccus epidermis has been isolated from blood cultures at 2-3 times the rate from the previous year. The most logical explanation for the increase in these isolates is that: a. the blood culture media are contaminated with this organism b. the hospital ventilation system is contaminated with Staphylococcus epidermis c. there has been a break in proper skin preparation before drawing blood for culture d. a relatively virulent isolate is being spread from patient to patient
c
Establishing the pathogenicity of a microorganism isolated from a child's throat and identified as Corynebacterium diphtheria would depend on: a. the morphological appearance as revealed by Gram stain b. the type of hemolysis on blood agar c. a positive toxigenicity test d. the appearance of growth on Tinsdale tellurite agar
c
Fluid from a subcutaneous black lesion was submitted for routine bacterial culture. After 18 hours of incubation at 35 degrees C there was no growth on MacConkey agar, but 3+ growth on sheep blood agar. The colonies were nonhemolytic, nonmotile, 4-5 mm in diameter and off-white with a ground glass appearance. Each colony had an irregular edge with comma-shaped outgrowths that stood up like "beaten egg whites" when gently lifted with an inoculating needle. A Gram stain of a typical colony showed large, Gram-positive rectangular bacilli. The oganism is most likely: a. Clostridium perfringens b. Aeromonas hydrophila c. Bacillus anthracis d. Mycobacterium marinum
c
If a stool sample is sent to the laboratory to rule out Clistridium difficile, what medium should the microbiologist use and what is the appearance of this organism on this medium? a. BBE: colonies turn black b. Brucella agar: red pigmented colonies c. CCFA: yellow. ground glass colonies d. CNA: double zone hemolytic colonies
c
In general, anaerobic infections differ from aerobic infections in which of the following ways? a. they usually respond favorably to aminoglycoside therapy b. they usually arise from exogenous sources c. they are usually polymicrobic d. Gram stains of specimens are less helpful in diagnosis
c
MacConkey media for screening suspected cases of hemorrhagic E coli 0157:117 must contain: a indole b citrate c sorbitol d lactose
c
Media used to support growth of Legionella pneumophila should contain which of the following additives? A. X and V factors B. hemin and Vitamin K C. charcoal and yeast extract D. dextrose and laked blood
c
Proper collection of a sample for recovery of Enterobius vermicularis includes collecting: a. a 24 hours urine collection b. a first morning stool collection with proper preservative c. a scotch tape prep from the perianal region d. peripheral blood from a finger
c
Sodium polyanetholsulfonate (SPS) is used as an anticoagulant for blood cultures because it: a. inactivates penicillin and cephalosporins b. prevents clumping of red cells c. inactivates neutrophils and components of serum complement d. facilitates growth of anaerobes
c
Susceptibility testing performed on quality control organisms using a new media lot number yeilded sizes that were too large for all antibiotics tested. The testing was repeated using media from a previously used lot number, and all zone sizes were acceptable. The unacceptable zone sizes are best explained by the: a. antibiotic disks were not stores with the proper desiccant b. depth of the media was too thick c. depth of the media was too thin d. antibiotic disks were not properly applied to the media
c
Tests for Haemophilus influenzae beta lactamase production: a. are not commercially avaialable b. include tests that measure a change to an alkaline pH c. should be performed on all blood and CSF isolates d. are not valid for any other bacterial species
c
The Gram stain from a blood culture shows gram-positive cocci in chains. No growth occurs on blood agar plates incubated both aerobically and anaerobically. Additional testing should be done to detect the presence of: a. Staphlococcus saprophyticus b. Aerococcus urinae c. Abiotrophia defectiva d. Streptococcus pneumoniae
c
The antibiotic used to suppress or kill contaminating fungi in media is: a. amphotericin B penicillin b. chloramphenicol c. cycloheximide d. streptomycin
c
The best medium for culture of Bordetella pertussis is: a . phenylethyl alcohol agar b. potassium tellurite blood agar c. Regan-Lowe agar d. Tinsdale agar
c
The colony count from a suprapubic urine culture growing 10 colonies of Staphyloccocus saprophyticus is: a. 0 CFU b. 1000 CFU c. 1,000 CFU d. 100,000 CFU
c
The disease producing capacity of Mycobacterium tuberculosis depends primarily upon: a. production of exotoxin b. production of endotoxin c. capacity to withstaind intracellular digestion by macrophages d. lack of susceptibility to the myeloperoxidase system
c
An aspirate of a deep wound was plated on blood agar plates and incubated aerobically and anaerobically. At 24 hours there was growth on both plates. This indicates that the organism is a(n): a nonfermenter b obligate anaerobe c aerobe d facultative anaerobe
d
"Nutritionally variant" streptococci are: a. enterococci b. group D enterococci c. beta hemolytic streptococci d. in the genera Granulicatella and Abiotrophia
d
A 25-year old man who had recently worked as a steward on a transoceanic gran ship presented to the emergency room with high fever, diarrhea and prostration. Axillary lymph nodes were hemorrhagic and enlarged. A Wright-Giemsa stain of the aspirate showed bacilli that were bipolar, resembling safety pins. The most likely identification of this organsim is: a. Brucella melitensis b. Streptobacillus monoliliformis c. Spirillum minus d. Yersinia pestis
d
A 3-year old unimmunized female presented in the ER with a severe cough, fever and flulike symptoms. The parents reported that the child had vomited a few times due to the severe coughing. A nasopharyngeal swab was used to collect the specimen and plated on a chocolate, Bordet-Gengous, and Regan Lowe media. After 5 days of incubation, colonies grew on all of the media with the growth of Bordet-Gengou described as "drops of mercury". The Gram stain showed minute coccobacilli that were catalase and oxidase positive. The most likely identification of the isolate is: a. Bordatella parapertussis b. Yersinia pestis c. Francisella tularensis d. Bordetella pertussis
d
Which nematode produces eggs with characteristic hyaline polar plugs at each end? a. Ascaris lumbricoides b. Nector americanus c. Strongylooides sterocoralis d. Trichuris trichiura
d
A college student attended a beach party where raw oysters and other shellfish were consumed. The next day, he had symptoms of septicemia. The blood cultures grew Gram-negative bacilli with the following characteristics: oxidase - positive MacConkey agar - pink colonies O/129 - susceptible The most likely organism is: a. Aeromonas hydrophilia b. Pseudomonas putida c. Serratia marcescens d. Vibrio vulnificus
d
A common cause of acute exudative pharyngitis is: a. staphlococcus aureus b. Streptococcus pneumoniae c. Streptococcus agalactiae d. Streptococcus pyogenes
d
A community hospital microbiology laboratory is processing significant numbers of stool cultures because of an outbreak of diarrhea following heavy rains and flooding in the county. A media that should be incorporated in the plating protocol is: a. colistin nalidixic acid for Listeria b. MacConkey agar with sorbitol for Camplobacter c. mannitol salt agar for Enterococcus species d. thiosulfate citrate bile salts sucrose for Vibrio species
d
A differential medium that can be used as a primary isolation agar producing predictable colored colonies that can be distinguished from other organism colony types describes: a. buffered charcoal yeast extract agar b. blood phenylethyl alcohol agar c. campylobacter blood agar d. chromagar
d
A first morning sputum specimen is received for acid fast culture. The specimen is centrifuged and the sediment is inoculated on 2 Lowenstein-Jensen slants, which are incubated at 35 degrees C in CO2. After 1 week, the slants show abundant growth over the entire surface. Stains reveal Gram-negative bacilli. To avoid this problem: a. utilize a medium that inhibits bacterial growth b. add sodium hypochlorite to the sediment before inoculation c. incubate the tubes at room temperature to retard bacterial growth d. decontaminate the specimen with sodium hydroxide
d
A first morning sputume is receiving for culture of mycobacteria. It is digested and concentrated by the N-acetyl-L-cystein alkali method. Two Lowenstin-Jenen slants are incubated in the dark at 35 degrees C with 5-10 % CO2. The smears reveal acid-fast bacilli and after 7 days no growth appears on the slants. The best explanation is: a. improper specimen submitted b. incorrect concentration procedure c. exposure to CO2 prevents growth d. cultures held for insufficient length of time
d
A gram-negative bacillus has been isolated from feces, and the confirmed biochemical reactions fit those of Shigella. The organism does not agglutinate in Shigella antisera. What should be done next? a. test the organism with a new lot of antisera b. test with Vi antigen c. repeat the biochemical tests d. boil the organism and retest with the antisera
d
A jaundiced 7-year-old boy, with a history of playing in a pond in a rat infested area, has a urine specimen submitted for a direct darkfield examination. Several spiral organisms are seen. Which of the following organisms would most likely be responsible for the patient s condition? a. Cardiobacterium hominis b. Streptobacillus moniliformis c. Listeria monocytogenes d. Leptospira interrogans
d
A male urethral discharge specimen submitted for culture should be innoculated to: a. sheep blood and phenylethyl alcohol agars b. eosin-methylene blue and sheep blood agars c. thioglycollate broth and chocolate agar d. chocolate and modified Thayer-Martin agars
d
A nonfermenting gram-negative bacillus is isolated from a wound. The nitrate and oxidase are strongly positive. The growth on sheep blood agar has a grape-like odor. The organism is: a Burkholderia cepacia b Moraxella lacunata c Chryseobacterium (Flavobacterium) meningosepticum d Pseudomonas aeruginosa
d
A patient with a nosocomial pneumoia has a sputum Gram stain that shows many neutrophils and numerous small Gram-negative coccobacilli. The organism grew in 24 hours as a mucoid, hemolytic colony on blood agar and a colorless colony on a MacConkey agar. The organism had the following characteristics: OXIDASE: NEG CATALASE: POS NITRATE: NEG ONPG: NEG ORNITHINE DEC:NEG LYSINE DEC: NEG The organism is: a. Stenotrophomonas maltophilia b. Alcaligenes faecalis c. Moraxella lacuata d. Acinobacter baumannii
d
A positive niacin test is characteristic of Mycobacterium: a. avium complex b. fortuitum c. kansasii d. tuberculosis
d
A primary drug used for the treatment of Mycobacterium tuberculosis is: a. ethionamide b. kanamycin c. rifabutin d. rifampin
d
A specimen from a foot ulcer of a 52-year old male diabetic patient was sent to the microbiology laboratory for culture. The following results were obtained from a clear colony growth on the MacConkey: Oxidase: Positive Catalase: Positive OF tubes: Oxidation positive Pigment production: blue/green Growth at 42 degrees C: Positive The results indicate which of the following organisms has been isolated from the culture? a. Acinobacter baumannii b. Serratia marcescens c. Stenotrophomonas maltophilia d. Pseudomonas aeruginosa
d
A urethral swab obtained from a man with a urethral exudate was plated directly on chocolate agar and modified Thayer-Martin agar and a Gram stain was made. The Gram stain showed Gram negative diplococci. The culture plates were incubated at 35 degrees C in ambient air, but had no growth at 48 hours. The most likely failure for the organism growth is that the: a. wrong media were used b. anaerobic chocolate agar not set up c. organism only grows at room temperature d. organism requires CO2 for growth
d
A wound specimen grew 2 colony types on sheep blood agar and a single, clear colony type on MacConkey gar. Sheep blood agar growth was documented as: colony type #1 swarming over entire plate, Gram stain: Gram negative rod colony type #2 white colony, Gram stain: Gram positive cocci in clusters The best way to isolate colony type #2 from colony type #1 is to subculture: a. colony #1 to sheep blood agar and chocolate agars b. colony #1 to sheep blood agar and/or MacConkey agar c. colony #2 to sheep blood agar and chocolate agar d. colony #2 to CNA and/or PEA agar
d
All species of the genus Neisseria have the enzyme to oxidize: a naphthylamine b dimethylaminobenzaldehyde c glucopyranoside d tetramethyl-phenylenediamine
d
An 18-year old boy is admitted to the hospital with suspected meningitis. He is lethargic and presents with a rigid neck. He has not had most of the recommended vaccines from childhood to now. Gram stain of his spinal fluid shows many PMNS with intra and extra cellular Gram-negative diplococci. The suspected pathogen is: a. Listeria monocytogenes b. Haemophilus influenzae c. Streptococcus agalactiae d. Neisseria meningitidis
d
An expectorated sputum is sent to the laboratory for culture from a patient with respiratory distress. The Gram stain of the specimen shows many squamous epithelial cells (>25/lpf) and rare neutrophils. The microscopic appearance of the organisms present include: moderate gram-positive cocci in chains and diplococci moderate gram-negative diplococci moderate palisading gram-positive bacilli all in moderate amounts This Gram stain is most indicative of: a a pneumococcal pneumonia b an anaerobic infection c an Haemophilus pneumonia d oropharyngeal flora
d
An isolate of an unknown beta-hemolytic Streptococcus is streaked perpendicular to a streak of beta-lysin-producing Staphylococcus aureus. After incubation a zone of arrowhead hemolysis is noted at the interface of the 2 streaks. What is the name of the test and the presumptive identification of the unknown Streptococcus? a hippurate hydrolysis and 5 agalactiae b CAMP test and S pyogenes c hippurate hydrolysis and S pyogenes d CAMP test and S agalactiae
d
An organism isolated form the surface of a skin burn is found to produce a diffusible green pigment on a blood agar plate. Further studies of the organism would most likely show the organism to be: a. Staphylococcus aureus b. Serratia marcescens c. Flavobacterium meningosepticum d. Pseudomonas auruginosa
d
An organism that may be mistaken for Neisseria gonorrhaeae in Gram-stain smears of uterine cervix exudates is: a. Lactobacillus species b. Streptococcus agalactiae c. Pseudomonas aeruginosa d. Moraxella osloensis
d
An organism that may be mistaken for Neisseria gonorrhoeae in Gram stained smears of uterine cervixe exudate is: a. Lactobacillus species b. Streptococcus agalactiae c. Pseudomonas aeruginosa d. Moraxella osloensis
d
Artifacts found in stool specimen that can be confused with ova or cysts are: a. partially digested meat fibers b. degenerated cells from the gastrointestinal mucosa c. dried chemical crystals d. pollen grains
d
BSL-3 organisms are those that: a. cause human disease but are not readily trasmitted among hosts b. do not ordinarily cause human disease: they require minimal safety procedures c. have very high risk of serious disease and no available treatment or vaccine d. produce serious disease and are transmitted by respiratory route
d
Biochemical reactions of an organism are consistent with Shigella . A suspenion is tested in antisera without resulting agglutination. However, after 15 minutes of boiling, agglutination occurs in group-D antisera. The Shigella species is: a. dysenteriae b. flexneri c. boydii d. sonnei
d
Cerebrospinal fluid tests results that are most consistent with viral meningitis include: a. decreased protein level b. increased glucose level c. increased lactate level d. increased mononuclear leukocyte count
d
Differentiation of Mycobacterium avium from Mycobacterium intracellulare can be accomplished by: a. nitrate reduction test b. Tween hydrolysis test c. resistance to 10 ug thiophene-2-carboxylic acid hydrazide (TCH) d. molecular testing
d
Gram stain of a thigh wound showed many gram-positive spore-forming bacilli. The specimen was placed on brain heart infusion blood agar and incubated aerobically at 35°C for 3 days. At the end of that time, the plates showed no growth. The most likely explanation is that some of the specimen should have been incubated: a on chocolate agar b for 5 days c under 5% CO2 d anaerobically
d
Haemophilus influenzae becomes resistant to ampicillin when the organism produces: a. a capsule a polysaccharide material b. NAD c. porphobilinogen d. the beta-lactamase enzyme
d
It is important to differentiate between Enterococcus and group D streptococci because: a. viridians streptococci are often confused with enterococci b. several enterococci cause severe puerperal sepsis c. group D streptococci are avirulent d. enterococci often show more antibiotic resistance than group D streptococci
d
Listeria can be confused with some streptococci because of its hemolysis and because it is: a nonmotile b catalase negative c oxidase positive d esculin positive
d
Members of the family Enterobacteriaceae share which one of the following characteristics? a. produce cytochrome oxidase b. ferment lactose c. produce beta-hemolysis d. reduce nitrate to nitrite
d
Microorganisms resembling Mycoplasma pneumonia have been isolated from the blood of patients treated with antibiotics that: a. complex with flagellar protein b. interfere with cell membrane function c. inhibit protein synthesis d. interfere with cell was synthesis
d
Propionibacterium acnes is most often associated with: a. food poisoning b. post-antibiotic diarrhea c. tooth decay d. blood culture contamination
d
Serum samples collected from a patient with pneumonia demonstrate a rising antibody titer to Legionella. A bronchoalveolar lavage (BAL) specimen from this patient had a positive antigen test for Legionella but no organisms were recovered on buffered charcoal yeast extract medium after 2 days of incubation. The best explanation is that the: a. antibody titer represents an earlier infection b. positive antigen test is a false positive c. specimen was cultured on the wrong media d. culture was not incubated long enough
d
Streptococcus pneumoniae can be differentiated best from the viridans group of streptococci by: a. Gram stain b. the type of hemolysis c. colonial morphology d. bile solubility
d
The characteristic that is most commonly associated with the presence of strict anaerobic bacteria can be taken as presumptive evidence of their presence in a clinical specimen is the: a. presence of a single bacteria species b. production of gas in a thioglycollate broth culture c. growth on a blood agar plate incubated in an anaerobic jar d. presence of a foul, putrid odor form tissue specimens and cultures
d
The formation of germ tubes presumptively identifies. a Candida tropicalis b Candida parapsilosis c Candida glabrata d Candida albicans
d
The function of N-acetyl-L-cystein in the reagent for acid fast digestion decontamination procedure is to: a. inhibit growth of normal respiratory flora b. inhibit growth of fungi c. neutralize the sodium hydroxide d. liquefy the mucus
d
The laboratory aid prepared and performed a Gram stain of a vaginal smear for Neisseria Gonorrhoeae, as requested by a resident. The findings on the stain were: many white blood cells few epithelial cells many Gram-positive bacilli few Gram-negative diplococci few Gram-positive cocci in chains The technologist should: a. report out smear positive for gonorrhea b. report out smear negative for gonorrhea c. request new specimen due to number of white blood cells d. not red or report a Gram stain on a vaginal specimen
d
The laboratory is considering adoption of a rapid and sensitive "stand alone" method that detects Clostridium diffificile" toxins A and B. Which one of the following testing methodologies will provide this? a. cell culture cytotoxin assay b. latex agglutination c. lecitithinase production d. NAAT
d
The laboratory receives a blood culture from a veterinarian who has been ill for many weeks with fevers in the afternoon and evenings, arthritis and fatigue. The blood culture is positive after 5 days, and the organism has the following characteristics: Gram stain- small, gram negative coccobacilli sheep blood agar - growth after 48 hours with small, raised colonies. What should the microbiologist do next? a. consider the growth contamination and perform another gram stain b. perform biochemical identification for HACEK organisms c. perform identification and susceptibility using an automated system d. take extra safety precautions for possible Brucella
d
The most appropriate method for collecting a urine specimen from a patient with an indwelling catheter is: a. remove the catheter, cut the tip and submit it for culture b. disconnect the catheter from the bag, and aseptically collect urine from the terminal end of the catheter c. asepticaly collect urine directly from the drainage bag d. aspirate urine aseptically from the catheter bag
d
The most frequent cause of prosthetic heart valve infections occurring within 2-3 months after surger is: a. Streptococcus pneumoniae b. Streptococcus pyogenes c. Staphlococcus aureus d. Staphlococcus epidermidis
d
The most rapid method for detection of Francisella tularensis is: a. serological slide agglutination utilizing specific antiserum b. dye stained clinical specimens c. fluorescent antibody staining technique on clinical specimens d. polymerase chain reaction
d
The most sensitive substrate for the detection of beta-lactamase is: a. penicillin b. ampicillin c. cefoxtin d. nitrocefin
d
The mycobacteria that produce a deep yellow or orange pigment both in the dark and light are: a photochromogens b scotochromogens c nonchromogens d rapid growers
d
The optimal incubator temperature for isolation of the Camplobacter jejuni/ coli group is: a. 4 degrees C b. 20 degrees C c. 25 degrees C d. 42 degrees C
d
The preferred specimen for the diagnosis of paragonimiasis is: a. bile drainage b. blood smear c. skin snips d. sputum
d
The principle difference between the Ziehl-Neelsen acid fast stain techniqueand the Kinyoun acid-fast stain technique is the: a. type of dyes used b. type of microscope used to interpret stained smears c. strength of acid decolorizer d. use of heat to allow the dye to penetrate organism
d
The procedure that assures the most accurate detection of mecA-mediated oxacillin resistance in routine broth microdilution susceptibility testing against S aureus is: a. addiotion of 4% NaCl b. incubation at 30 degrees C c. incubation for 48 hours d. testing with cefoxitin
d
The stock cultures needed for QC testing of deoxyribonuclease (DNase) production are: A. Salmonella typhimurium/ E coli B. E coli/ Pseudomonas aeruginosa C. Proteus mirabilis/ E coli D. Serratia marcescens/ E coli
d
The stock cultures needed for quality control testing of deamination activity are: a. Escherichia coli-Klebsiella pneumonia b. Salmonella typhimurium-Escherichia coli c. Escherichia coli-Pseudomonas aeruginosa d. Proteus mirabilis-Escherichia coli
d
The stock cultures needed for quality control testing of motility are: a. Salmonella typhimurium-Escherichia coli b. Escherichia coli-Pseudomonas aeruginosa c. Serratia marcescens-Escherichia coli d. Klebsiella pneumoniae-Escherichia coli
d
Vibrio parahaemolyticus is best isolated from feces on: a. Eosin methylene blue (EMB) agar b. Hektoen enteric (HE) agar c. Salmonella Shigella (SS) agar d. Thiosulfate citrate bile salts (TCBS) agar
d
Viridians streptococci can be differentiated from streptococcus pneumoniae by: a. alpha hemolysis b. colony morphology c. catalase reaction result d. bile solubility
d
What organism combination is appropriate to quality control the listed test or organism characteristic? a. beta-hemolysis: Staphylococcus aureus and Streptococcus pyogenes b. catalase: Staphylococcus aureus and Staphyloccocus epidermis c. H2S production: Proteus mirabilis and Salmonella d. indole: Escherichia coli and Proteus mirabilis
d
When grown in the dark, yellow to orange pigmentation of the colonies is usually demonstrated by: a Mycobacterium tuberculosis b Mycobacterium kansasii c Mycobacterium fortuitum d Mycobacterium scrofulaceum
d
When performing a control strain of Staphylococcus aureus, the technologist notices that the zone around the cefoxitin disk is too small. Which of the following is the most likely explanation? a. incoculation of the plates 10 minutes after preparing the inoculum b. incubation of the Meuller Hinton plates at 35 degrees C c. use of a 0.25 McFarland standard to prepare inoculum d. use of outdated cefoxitin disks
d
When processing a patient specimen for Gram stain and culture, the proper use of a biological safety cabinet includes: a. bringing into the cabinet all required media and equipment just prior to setting up each individual specimen b. keeping the ultraviolet light on for the first 30 minutes of working in the cabinet c. not using any heat generating equipment such as open flames or microburner/incinerators d. not disrupting the air curtain barrier by keeping air flow and exhaust grills unobstructed
d
Which feature distinguishes Erysipelothrix rhusiopathiae from other clinically significant non-spore-forming, Gram positive, facultatively anaerobic bacilli? a. tumbling motility b. beta-hemolysis c. morep ronounced motility at 25 degrees C than 37 degrees C d. H2S production
d