MICROBIOLOGY BOC

100問 • 1年前

問題一覧

“Nutritionally deficient” streptococci are: a enterococci b group D nonenterococci c cell wall-deficient streptococci d in the genera Granulicatella and Abiotrophia

d in the genera Granulicatella and Abiotrophia

After 24 hours a blood culture from a newborn grows catalase-negative, gram-positive cocci. The bacterial colonies are small, translucent and beta-hemolytic on a blood agar plate. Biochemical test results of a pure culture are: bacitracin: resistant CAMP reaction: positive bile esculin: not hydrolyzed 6.5% NaCl broth: no growth Assuming that all controls react properly and reactions are verified, the next step would be to: a_ perform a Streptococcus group typing b report the organism as Streptococcus pneumoniae c report the organism as Staphylecoccus aureus d report the organism as Staphylococcus epidermidis

a_ perform a Streptococcus group typing

A beta-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 to determine if the organism is Enterococcus? a growth in 6.5% NaCl broth b growth in the presence of penicillin c optochin susceptibility d fermentation of 10% lactose

a growth in 6.5% NaCl broth

The organism most commonly associated with neonatal purulent meningitis is: a Neisseria meningitidis b Streptococcus pneumoniae c group B streptococci d Haemophilus influenzae

c group B streptococci

An important cause of acute exudative pharyngitis is: a Staphylococcus aureus (beta-hemolytic) b Streptococcus pneumoniae c Streptococcus agalactiae d Streptococcus pyogenes c

d Streptococcus pyogenes

Of the following bacteria, the most frequent cause of prosthetic heart valve infections occurring within 2-3 months after surgery is: a Streptococcus pneumoniae b Streptococcus pyogenes c Staphylococcus aureus d Staphylococcus epidermidis

d Staphylococcus epidermidis

Which of the 2 different antimicrobial agents listed below are commonly used and may result in Synergistic action in the treatment of endocarditis caused by Enterococcus faecalis? an aminoglycoside and a macrolide a penicillin derivative and an aminoglycoside a cell membrane active agent and nalidixic acid a macrolide and a penicillin derivative

a penicillin derivative and an aminoglycoside

A catheterized urine is inoculated onto blood and MacConkey agar using a 0.01 mL loop. After 48 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 colonies/mL of gram-positive cocci, optochin and bacitracin susceptibility tests to follow b growth of 6,800 colonies/mL of a Staphylococcus species, coagulase test to follow c growth of 6,800 colonies/mL of a Streptococcus species, esculin hydrolysis and NaCl growth test to follow d growth of 6,800 colonies/mL of a Streptococcus species, no further testing

c growth of 6,800 colonies/mL of a Streptococcus species, esculin hydrolysis and NaCl growth test to follow

Children who have infections with beta-hemolytic streptococci can develop: a acute pyelonephritis b acute glomerulonephritis c chronic glomerulonephritis d_ nephrosis

b acute glomerulonephritis

A gram-positive coccus isolated from a blood culture has the following characteristics: optochin susceptibility: negative bacitracin (0.04 U) susceptibility: negative bile esculin hydrolysis: negative hippurate hydrolysis: positive catalase: negative This organism is most likely: a Staphylococcus aureus b Streptococcus pneumoniae c Streptococcus pyogenes d Streptococcus agalactiae

d Streptococcus agalactiae

a 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 d beta-hemolytic, group D

b group A

beta-hemolytic Streptococcus that is bacitracin-resistant and CAMP-positive is: a group AorB b groupA c group B d beta-hemolytic, group D

c group B

Group B, beta-hemolytic streptococci may be distinguished from other hemolytic streptococci by which of the following procedures? a latex antigen typing b growth in 6.5% NaCl broth c growth on bile esculin medium d_ bacitracin susceptibility

a latex antigen typing

It is important to differentiate between Enterococcus and group D streptococci because: a viridans 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 enterococci often show more antibiotic resistance than group D streptococci

Streptococcus pneumoniae can be differentiated best from the viridans group of streptococci by: Gram stain the type of hemolysis colonial morphology bile solubility

bile solubility

Characteristically, enterococci are: unable to grow in 6.5% NaCl relatively resistant to penicillin sodium hippurate positive bile esculin negative

relatively resistant to penicillin

A beta-hemolytic, catalase-positive, gram-positive coccus is coagulase negative by the slide coagulase test. Which of the following is the most appropriate action in identification of this organism? a report a coagulase-negative Staphylococcus b report a coagulase-negative Staphylococcus aureus c reconfirm the hemolytic reaction on a fresh 24-hour culture d do a tube coagulase test to confirm the slide test

d do a tube coagulase test to confirm the slide test

Which of the following would best differentiate Streptococcus agalactiae from Streptococcus pyogenes ? ability to grow in sodium azide broth a positive bile-esculin reaction hydrolysis of sodium hippurate beta-hemolysis on sheep blood agar

hydrolysis of sodium hippurate

The most critical distinction between Staphylococcus aureus and other Staphylococcus is: a phosphatase reaction b DNA production c coagulase production d hemolysis

c coagulase production

Which of the following organisms is, to date, considered universally susceptible to penicillin: a Haemophilus influenzae b Neisseria gonorrhoeae c Streptococcus pyogenes d Corynebacterium diphtheriae

c Streptococcus pyogenes

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 typing d esculin hydrolysis

c latex antigen typing

How many hours after eating contaminated food do initial symptoms of staphylococcal food poisoning typically occur? a 2-6 hours b 12-18 hours c 24-48 hours d 72 hours to a week

a 2-6 hours

During the past month, Staphylococcus epidermidis 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 epidermidis 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 there has been a break in proper skin preparation before drawing blood for culture

An outbreak of Staphylococcus aureus has occurred in a hospital nursery. In order to establish the epidemiological source of the outbreak, the most commonly used typing method is: a pulsed-field gel electrophoresis b serological typing c coagulase testing d catalase testing

a pulsed-field gel electrophoresis

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 would differentiate between a coagulase-negative Staphylococcus and Micrococcus? a novobiocin susceptibility b leucine aminopeptidase production c furazolidone (100 pg/disk) susceptibility d bile esculin

c furazolidone (100 pg/disk) susceptibility

light yellow colony from a skin lesion grew aerobically and tested as catalase positive and coagulase negative. The organism gram stained as positive cocci in clusters. The organism was modified oxidase positive, bacitracin (0.04U) 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 Micrococcus luteus

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 S$ agalactiae b CAMP test and S pyogenes c hippurate hydrolysis and S pyogenes d CAMP test and S agalactiae

d CAMP test and S agalactiae

Which of the following may be used as a positive quality control organism for the bile esculin test? a Staphylococcus epidermidis b Staphylococcus aureus c Streptococcus pyogenes d Enterococcus faecalis

d Enterococcus faecalis

Infection of the urinary tract is most frequently associated with: a Staphylococcus aureus b Escherichia coli c Enterococcus faecalis d Serratia marcescens

b Escherichia coli

MacConkey media for screening suspected cases of hemorrhagic E coli O157:H7 must contain: a indole b citrate c sorbitol d lactose

c sorbitol

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_ reduce nitrate to nitrite

Which one of the following genera is among the least biochemically reactive members of the Enterobacteriaceae? a Proteus b Pseudomonas c Citrobacter d Shigella

d Shigella

Which one of the following gram-negative bacilli ferments glucose? a Alcaligenes faecalis b Pseudomonas cepacia c Acinetobacter lwoffti d_ Yersinia enterocolitica

d_ Yersinia enterocolitica

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. ‘Ihe colonies yield the following test results: ONPG: + indole: - glucose: + oxidase: citrate: + VP: + The organism is most likely: a Edwardsiella tarda b Klebsiella pneumoniae c Escherichia coli d_ Proteus vulgaris

b Klebsiella pneumoniae

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 Salmonella typhimurium

An isolate from a stool culture gives the following growth characteristics and biochemical reactions: MacConkey agar: colorless colonies Hektoen agar: yellow-orange colonies TSE acid slant/acid butt, no gas, no HS urea: positive These screening reactions are consistent with which of the following enteric pathogens? a Yersinia enterocolitica b Shigella sonnei c Vibrio parahaemolyticus d Campylobacter jejuni

a Yersinia enterocolitica

A TSI tube inoculated with an organism gave the following reactions: alkaline slant, acid butt, no H2S, no gas produced ‘Ihis organism is most likely: a Yersinia enterocolitica b Salmonella typhi c Salmonella enteritidis d Shigella dysenteriae

d Shigella dysenteriae

An organism gave the following reactions: TS: acid slant/acid butt; no H2S gas produced indole: positive motility: positive citrate: negative lysine decarboxylase: positive urea: negative VP: negative This organism most likely is: a Klebsiella pneumoniae b Shigella dysenteriae c Escherichia coli d Enterobacteria cloacae

c Escherichia coli

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 Escherichia coli c Salmonella typhi d Shigella dysenteriae

b Escherichia coli

One of the enterotoxins produced by enterotoxigenic Escherichia coli in traveler's diarrhea is similar to a toxin produced by: Clostridium perfringens Clostridium difficile Vibrio cholerae Yersinia enterocolitica

Vibrio cholerae

Shigella species characteristically are: urease positive nonmotile oxidase positive lactose fermenters

nonmotile

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? test the organism with a new lot of antisera test with Vi antigen repeat the biochemical tests boil the organism and retest with the antisera

boil the organism and retest with the antisera

Biochemical reactions of an organism are consistent with Shigella. A suspension is tested in antiserum 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 sonnei

>100,000 CFU/mL of a gram-negative bacilli were isolated on MacConkey from a urine specimen. Biochemical results are as follows: glucose: acid, gas produced indole: negative urea: positive TDA: positive HoS: positive The organism is most likely: a Morganella morganii b Proteus mirabilis c Proteus vulgaris d Providencia stuartii

b Proteus mirabilis

A urine culture had the following culture results: sheep blood: swarming Columbia CNA: no growth MacConkey: 1. >100,000 CFU/mL nonlactose-fermenter 2. >100,000 CFU/mL nonlactose-fermenter with red pigment The isolates from MacConkey agar had the following biochemical reactions: Test Isolate 1 Isolate 2 TSI alk/acid aik/acid urea positive negative TDA positive negative H2S positive negative The organisms are most likely: a Proteus vulgaris and Enterobacter cloacae b Proteus mirabilis and Serratia marcescens c Morganella morganii and Klebsiella pneumoniae d Providencia stuartii and Serratia liquefaciens

b Proteus mirabilis and Serratia marcescens

An 8-year-old girl was admitted to the hospital with a three-day history of fever, abdominal pain, diarrhea, and vomiting. 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 ornithine decarboxylase: positive sucrose: positive H2S: negative motility at 25°C: positive The most probable identification of this organism is: a Escherichia coli b Providencia stuartii c Yersinia enterocolitica d Edwardsiella tarda

c Yersinia enterocolitica

Which of the following sets of tests best differentiates Salmonella and Citrobacter species? a KCN, malonate, beta-galactosidase, lysine decarboxylase b dulcitol, citrate, indole, H)S production c lactose, adonitol, KCN, motility d lysine decarboxylase, lactose, sucrose, malonate, indole

a KCN, malonate, beta-galactosidase, lysine decarboxylase

A fecal specimen, inoculated to xylose lysine deoxycholate (XLD) and Hektoen enteric (HE) produced colonies with black centers. Additional testing results are as follows: The most probable identification is: a Salmonella enterica b Edwardsiella tarda c Proteus mirabilis d Shigella sonnei

b Edwardsiella tarda

A 10-year-old boy was admitted to the emergency room with lower right quadrant pain and tenderness. The following laboratory results were obtained: Patient value Normal range % segmented neutrophils 75% 16% -60% WBC count 200 x 10°/uL (200 x 10%L) 13.0 x 103/uL (13.0 x 10%/L) The admitting diagnosis was appendicitis. During surgery the appendix appeared normal; an enlarged node was removed and cultured. Small gram-negative bacilli were isolated from the room temperature plate. The organism most likely is: a Prevotella melaninogenica b Shigella sonnei c Listeria monocytogenes d Yersinia enterocolitica

d Yersinia enterocolitica

A 25-year-old man who had recently worked as a steward on a transoceanic grain ship presented to the emergency room with high fever, diarrhea and prostration. Axillary lymph nodes were hemorrhagic and enlarged. A Wayson stain of the aspirate showed bacilli that were bipolar, resembling safety pins. The most likely identification of this organism is: a Brucella melitensis b Streptobacillus moniliformis ¢ Spirillum minus d Yersinia pestis

d Yersinia pestis

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. 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 boil suspension of the organism for 10 minutes to inactivate the Vi antigen

Aclean catch urine sample from a nursing home patient is cultured using a .001 mL loop. It grows 67 colonies of a lactose fermenter that has the following biochemical reactions: TSI: acid/acid oxidase: negative motility: positive indole: negative citrate: positive VP: positive lysine decarboxylase: negative ornithine decarboxylase: positive urea: negative What should the microbiologist report? a 670 CFU/mL Serratia marsecens sp b 6,700 CFU/mL Providencia stuartii ¢ 67,000 CFU/mL Enterobacter cloacae d 67,000 CFU/mL Klebsiella oxytoca

¢ 67,000 CFU/mL Enterobacter cloacae

Plesiomonas shigelloides is a relatively new member of the family Enterobacteriaceae. What characteristic separates it from other members of the Enterobacteriaceae? a it is oxidase positive b it ferments glucose c it produces pyocyanin d it requires 10% CO} for growth

a it is oxidase positive

A 64-year-old male with lymphoma has a 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 Providencia

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 Klebsiella pneumoniae/Escherichia coli

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 Escherichia coli/Pseudomonas aeruginosa

The stock cultures needed for quality control testing of deamination activity are: a Escherichia coli/Klebsiella pneumoniae b Salmonella typhimurium/Escherichia coli c Escherichia coli/Pseudomonas aeruginosa d Proteus mirabilis/Escherichia coli

d Proteus mirabilis/Escherichia coli

‘The stock cultures needed for quality control testing of deoxyribonuclease (DNase) production are: a Salmonella typhimurium/Escherichia coli b Escherichia coli/Pseudomonas aeruginosa c Proteus mirabilis/Escherichia coli d Serratia marcescens/Escherichia coli

d Serratia marcescens/Escherichia coli

Quality control of the spot indole test requires the use of ATCC cultures of: a Pseudomonas aeruginosa/ Proteus mirabilis b Salmonella typhi/Shigella sonnei ¢ Escherichia coli/Proteus vulgaris d Escherichia coli/Enterobacter cloacae

d Escherichia coli/Enterobacter cloacae

An organism that exhibits the satellite phenomenon around colonies of staphylococci is: a Haemophilus influenzae b Neisseria meningitidis c Neisseria gonorrhoeae d Klebsiella pneumoniae

a Haemophilus influenzae

An organism isolated from 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 aeruginosa

d Pseudomonas aeruginosa

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 Pseudomonas aeruginosa

A small, gram-negative bacillus is isolated from an eye culture. It grows only on chocolate agar and is oxidase-negative. The most likely organism is: a Acinetobacter lwoffi b Haemophilus influenzae c Stenotrophomonas maltophilia d Pseudomonas aeruginosa

Haemophilus influenzae

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 repeat specimen ¢ utilize a pyridoxal disk to detect Aeromonas d subculture the bottle to a medium containing X and V factors

a subculture the bottle, and incubate in microaerophilic conditions

The optimal incubator temperature for isolation of the Campylobacter jejuni/coli group is: a 4°C b 20°C c 25°C d 42°C

d 42°C

A patient with a nosocomial pneumonia 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: negative catalase: positive nitrate: negative ONPG: negative ornithine decarboxylase: negative lysine decarboxylase: negative The organism is: a Stenotrophomonas maltophilia b Alcaligenes faecalis c Moraxella lacunata d Acinetobacter baumannii

d Acinetobacter baumannii

A gastroenterologist submits a gastric biopsy from a patient with a peptic ulcer. To obtain presumptive evidence of Helicobacter pylori, a portion of the specimen should be added to which media? urea broth tetrathionate selenite tryptophan

urea broth

A 4-year-old boy is admitted to the hospital with suspected meningitis. He has not had most of the childhood vaccines. The suspected pathogen is: a Listeria monocytogenes b Haemophilus influenzae c Streptococcus agalactiae d Neisseria meningitidis

b Haemophilus influenzae

Acinetobacter lwoffii differs from Neisseria gonorrhoeae in that the former: exhibits a gram-negative staining reaction will grow on MacConkey and EMB media is indophenol oxidase-positive produces hydrogen sulfide on a TSI slant

will grow on MacConkey and EMB media

A4-year-old is admitted with symptoms of meningitis, and a Gram stain of the cerebrospinal fluid reveals small, pleomorphic, gram-negative coccobacilli. After 24 hours incubation at 35°C, small, moist, gray colonies, which are oxidase negative, are found on the chocolate agar plate only. Which of the following biochemical data would be consistent with this isolate? a CTA dextrose: positive CTA maltose: positive ONPG: negative b sodium hippurate hydrolysis: positive A disc: negative CAMP test: positive c X factor: no growth V factor: no growth XV factor: growth horse blood: no hemolysis d catalase: positive esculin hydrolysis: positive methyl red: positive “umbrella” motility at room temperature

c X factor: no growth V factor: no growth XV factor: growth horse blood: no hemolysis

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 cepacia b Corynebacterium urealyticum c Helicobacter pylori d Pasteurella multocida

c Helicobacter pylori

A cerebrospinal fluid has been inoculated onto sheep blood and chocolate agar plates and into a tube of trypticase soy broth. All media were incubated in an atmosphere of 5% CO . Which of the following organisms would usually be isolated by this procedure? a Francisella tularensis b Haemophilus influenzae c Bordetella pertussis d Bacteroides fragilis

b Haemophilus influenzae

If present, 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°C

d_ growth at 42°C

A Campylobacter species isolated from a stool culture gives the following biochemical reactions: nalidixic acid: susceptible cephalothin: resistant hippurate hydrolysis: positive oxidase: positive catalase: positive This biochemical profile is consistent with: a Campylobacter fetus b Campylobacter jejuni ¢ Campylobacter coli d Campylobacter laridis

b Campylobacter jejuni

Which one of the following results is typical of Campylobacter jejuni: optimal growth at 42°C oxidase negative catalase negative nonmotile

optimal growth at 42°C

Optimum growth of Campylobacter jejuni is obtained on suitable media incubated at 42°C in an atmosphere containing: 6% O2, 10%-15% CO2, 85%-90% nitrogen 10% H2, 5% CO2, 85% nitrogen 10% H2, 10% CO2, 80% nitrogen 25% O2, 5% CO», 70% nitrogen

6% O2, 10%-15% CO2, 85%-90% nitrogen

The porphyrin test was devised to detect strains of [Haemophilus capable of: a ampicillin degradation b capsule production c synthesis of hemin d chloramphenicol resistance

c synthesis of hemin

Haemophilus influenzae is most likely considered normal indigenous flora in the: a oropharynx b female genital tract c large intestine d small intestine

a oropharynx

Haemophilus influenzae becomes resistant to ampicillin when the organism produces a(n): a capsule of polysaccharide material b affinity for the beta-lactam ring of the ampicillin c porphobilinogen d beta-lactamase enzyme

d beta-lactamase enzyme

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 influenzae d parainfluenzae

d parainfluenzae

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

¢ bone marrow

A genus that is found in soil and water and causes infections in immunocompromised patients has the following characteristics: sheep blood agar: violet pigment MacConkey agar: growth 42°C incubation: growth oxidase: positive OF glucose: fermenter indale: negative ‘The genus is: a Campylobacter b Chromobacterium c Aeromonas d Serratia

b Chromobacterium

Which one of the following results is typical of Campylobacter fetus subspecies fetus? optimal growth at 42°C oxidase negative growth at 37°C catalase negative

growth at 37°C

Multiple blood cultures from a patient with endocarditis grew a facultatively anaerobic, pleomorphic gram-negative bacilli with the following characteristics: hemolysis: negative MacConkey agar: no growth sheep blood agar: growth in 5%-10% CO, chocolate agar: growth in 5%-10% COs catalase: negative V factor: not required X factor: not required oxidase: negative nitrate: positive, reduced to nitrites indole: negative The most likely identification is: a Brucella abortus b Actinobacillus actinomycetemcomitans c Haemophilus aphrophilus d Cardiobacterium hominis

c Haemophilus aphrophilus

A gram-negative bacillus with bipolar staining was isolated from a wound infection caused by a bite from a pet cat. The following characteristic reactions were seen: oxidase: positive glucose OF: fermentative catalase: positive 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 Pasteurella multocida

A culture from an infected dog bite on a small boy’s finger yielded a small, gram-negative coccobacillus that was smooth, raised and beta-hemolytic on blood agar. The isolate grew on MacConkey agar, forming colorless colonies. The organism was motile, catalase positive, oxidase positive, reduced nitrate, and was urease positive within 4 hours. No carbohydrates were fermented. The most likely identification of this isolate is: a Brucella canis b Yersinia pestis c Francisella tularensis d Bordetella bronchiseptica

d Bordetella bronchiseptica

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. The most likely identification is: a Enterobacter cloacae b Serratia marcescens c Aeromonas hydrophila d Escherichia coli

c Aeromonas hydrophila

An aerobic, gram-negative coccobacillus was isolated on Bordet-Gengou agar from a nasopharyngeal swab 48 hours after culture from a 6-month-old infant with suspected pertussis. The organism exhibited the following characteristics: MacConkey agar: no growth urea: negative at 4 hours, positive at 24 hours oxidase: negative catalase: positive The mast probable identification of this isolate is: a Moraxella lacunata b Pasteurella ureae c Bordetella pertussis d Bordetella parapertussis

d_ Bordetella parapertussis

Which of the following characteristics best differentiates Bordetella bronchiseptica from Alcaligenes species? flagellar pattern growth at 24°C oxidase activity rapid hydrolysis of urea

rapid hydrolysis of urea

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 culture was not incubated long enough

Which characteristic best differentiates Acinetobacter species from Moraxella species? a production of indophenol oxidase b growth on MacConkey agar c motility d susceptibility to penicillin

a production of indophenol oxidase

An organism has been identified as a member of the fluorescent group of Pseudomonas. Which of the following sets of tests should be used to determine the species of the organism? a growth at 42°C, pyocyanin production, gelatinase production b pyocyanin production, gelatinase production, OF glucose c growth at 37°C, pyocyanin production, OF glucose d gelatinase production, growth at 52°C, H»S

a growth at 42°C, pyocyanin production, gelatinase production

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 a media with cysteine such as buffered charcoal yeast extract agar

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 Eikenella corrodens

Characteristics of the genus Capnocytophaga include: a grows in ambient air b colonies are large and spreading after 2-4 days ¢ considered “nonfermenter” d gram-positive bacillus

b colonies are large and spreading after 2-4 days

A laboratory aid receives a bronchoscopy sample with the request for culture of Legionella. The assistant asks a microbiologist for direction on plating protocol. The correct response from the microbiologist 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 on buffered charcoal yeast extract agar with antibiotics

d culture on buffered charcoal yeast extract agar with antibiotics

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 Campylobacter c mannitol salt agar for Enterococcus species fo") d thiosulfate citrate bile salts sucrose for Vibrio species

d thiosulfate citrate bile salts sucrose for Vibrio species

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 0/129 (150 pg): susceptible The most likely organism is: a Aeromonas hydrophila b Pseudomonas putida c Serratia marcescens d. Vibrio vulnificus

d. Vibrio vulnificus

Differentiating tests that will separate Burkholderia from Stenotrophomonas include: a Gram stain reaction b growth on MacConkey agar c glucose fermentation d oxidase

d oxidase

100

A 17-year-old female with cystic fibrosis is diagnosed with pneumonia. A sputum sample grew gram-negative bacilli with yellow, smooth colonies that have the following biochemical reactions: oxidase: positive TSI: alk/alk glucose: oxidized fluorescence: negative lysine decarboxylase: positive The most likely organism is: a Burkholderia cepacia b Klebsiella pneumoniae c Shewanella putrefaciens d_ Stenotrophomonas maltophilia

a Burkholderia cepacia

other names parasitology

Yves Laure Pimentel · 70問 · 2年前

other names parasitology