Microbiology - MLS
288) Examination of a fungal culture from a bronchial washing reveals white, cottony aerial mycelium. A tease preparation in lactophenol cotton blue shows the structures shown in the image: The most rapid test for definite identification is: A) nucleic acid probe B) animal inoculation C) exoantigen test D) slide culture
A
300) In the USA, the most common organism causing eumycotic mycetoma is: A) Pseudalledcheria boydii B) Nocardia brasiliensis C) Blastomyces dermatitidis D) Aspergillus fumigatus
A
174) 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 jejun C) Campylobacter coli D) Campylobacter laridis
B
182) A genus that is found in soil and water and causes infections in immunocrompromised patients has the following characteristics: sheep blood agar: violet pigment; MacConkey agar: growth; 42C incubation: growth; oxidase: positive; OF glucose: fermenter; indole: negative The genus is: A) Campylobacter B) Chromobacterium C) Aeromonas D) Serratia
B
124) An outbreak of Staphlococcus 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
147) Which of the following sets best differentiates Salmonella and Citrobacter species? A) KCN, malonate, beta-galactosidase, lysine decarboxylase B) dulcitol, citrate, indole, H2S production C) lactose, adonitol, KCN, motility D) lysine decarboxylase, lactose, sucrose, malonate, indole
A
151) 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
164) A blood culture bottle with macroscopic signs of growth is Gram stained and the technician note 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 C) utilize a pyridoxal disk to detect Aeromonas D) subculute the bottle to a medium containing X and V factors
A
249) Which organism is 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
255) Which one of the following anaerobes would be negative for indole? A) Bacteroides fragilis B) Fusobacterium nucleatum C) Porphyromonas asaccharolytica D) Proteus mirabilis
A
282) Structures important in the microscopic identification of Coccidioides immitis are: A) irregular staining, barrel-shaped arthrospores B) tuberculate, thick-walled macroconidia C) thick-walled sporangia containing sporangiospores D) small pyriform microconidia
A
200) 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; fluorescense: negative; lysine decarboxylase: positive The most likely organism is: A) Burkholderia cepacia B) Klebsiella pneumoniae C) Shewanella putrefaciens D) Stenotrophomonas maltophilia
A
248) 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
301) Crust from a cauliflower-like lesion on the hand exhibited brown spherical bodies 6-12 um in diameter when examined microscopically. After 3 weeks of incubation at room temperature, a slow-growing black mold grew on Sabouraud dextrose agar. Microscopic examination revealed Cladosporium, Phialophora and Fonsecaea types of sporulation. The probable identification of this organism is: A) Fonsecaea pedrosoi B) Pseudallescheria boydii C) Phialophora verrucosa D) Cladosporium carrionii
A
344) AFB smears of a lymph node biopsy from a child are positive. At the end of 8 weeks, the AFB cultures are no growth. To enhance the possibility of recovery of the causative organism, the technologist should: A) incubate the cultures an additional 4 weeks B) add mycobactin J to the media C) transfer the cultures to a 30C incubator D) subculture the liquid culture to chocolate agar
A
37) Sodium bicarbonate and sodium citrate are components of which of the following? A) JEMBEC system B) MTM agar C) NYC medium D) ML agar
A
62) Anaerobic susceptibility testing is helpful in the management of patients with: A) synovial infections B) rectal abscesses C) streptococcal pharyngitis D) pilonidal sinuses
A
107) Which of the 2 different antimicrobial agents listed below are commonly used and may result a synergestic 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 penicillin derivative
B
126) A light yellow 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. The organism was modified oxidase positive, bacitracin (0.04U) susceptible and resistant to lysostaphin. What is the identification of this organism? A) Staphylococcu aureus B) Micrococcus luteus C) Staphylococcus epidermidis D) Peptostreptococcus anaerobius
B
148) A fecal specimens, inoculated to xylose lysine deoxycholate (XDL) and Hektoen enteric (HE) produced colonies with black center. Additional testing results are as follows: Biochemical Result Serological Result glucose positive polyvalent no aglutination H2S positive group A no aglutination lysine decarboxylase positive group B1 no aglutination urea negative group C no aglutination ONPG negative group D no aglutination indole positive group Vi no aglutination The most probable identification is: A) Salmonella enterica B) Edwardsiella tarda C) Proteus mirabilis D) Shigella sonnei
B
169) Acinetobacter lwoffi differs from Neisseria gonorrhoeae in that the former: A) exhibits a gram-negative staining reaction B) will grow on MacConkey and EMB media C) is indophenol oxidase-positive D) produces hydrogen sulfide on a TSI slant
B
194) 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 the "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) Kingela kingae D) Legionella pneumophila
B
195) Characteristicsos the genus Capnocytophaga include: A) grows in ambient air B) colonies are large and spreading after 2-4 days C) considered "nonfermenter" D) gram-positive bacillus
B
239) The lab has been using a latex agglutination assay to detect Clostridium difficile in stools, which identifies a nontoxin cell wall antigen. The lab is considering adoption of an EIA method that detects Clostridium difficile toxin A. Which of the following would provide the best comparison? A) latex agglutination vs culture on cycloserine cefoxitin-egg-fructose agar B) latex agglutination vs EIA vs cell culture cytotoxin assay C) EIA vc culture on cycloserine cefoxitin-egg-fructose agar D) EIA vs cell culture cytotoxin assay
B
242) At the present time Clostridium difficile toxin can be detected by: A) fluorescent staining B) EIA C) latex agglutination D) high-pressure liquid chromatography
B
247) 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 test (s) will give a presumptive identification of this microorganism? A) beta-hemolysis and oxidase B) catalase and spot indole C) esculin hydrolysis D) hydrolysis of gelatin
B
251) 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
256) The presence of 20% bile in agar will aloow growth of: A) Fusobacterium necrophorum B) Bacteroides ovatus C) Prevotella melaninogenica D) Porphyromonas gingivalis
B
274) A neonatal blood culture collected through a catheter grows a small yeast. Microscopically, the yeast appear round at one end, with a budlike structure on a broad base at the other end. Growth is enhanced around olive oil-saturated discs. The organism isolated is: A) Candida tropicalis B) Malassezia furfur C) Candida lipolytica D) Malassezia pachydermatis
B
276) Quality control testing of CHROMagar Candida medium shows very weakly colored colonies after incubation at 25C, ambient atmosphere for 48 hours. The technologist should: A) repeat the quality control tests to verify results B) repeat the quality control tests but incubate at 35C C) repeat the quality control tests using new subcultures of the quality control organisms D) discard this lot of CHROMagar and repeat the quality control tests on a new lot number
B
284) A mold grown at 25C exhibited delicate septate hyaline hyphae and many conidiophores extending at right angles from the hyphae. Oval, 2-5um conidia were formed at the end of the conidiophores giving a flowerlike appearance. In some areas "sleeves" of spores could be found along the hyphae as well. A 37C culture of this organism produced small, cigar-shaped yeast cells. This organism is most likely: A) Histoplasma capsulatum B) Sporothrix schenckii C) Blastomyces dermatitidis D) Acremonium falciforme
B
292) A specimen of hair that fluoresced under a Wood lamp was obtained from a child with low-grade scaling lesions of the scalp. Cultures revealed a fungus with mycelin and very few macroconidia or micronidia. This fungus is most likely: A) Microsporum gypseum B) Microsporum audouinii C) Trichophytin tonsurans D) Epidermophyton floccosum
B
324) A 2-week-old culture of urine specimen produced a few colonies of acid-fast bacilli, which were rough and nonpigmented. The niacin test was weakly positive and the nitrate test was positive. Which of the following is the most appropriate action when a presumptive identification has been requested as soon as possible? A) report the organism as presumptive Mycobacterium tuberculosis B) wait a few days and repeat the niacin test; report presumptive Mycobacterium tuberculosis if the test is more strongly positive C) subculture the organism and set up the routine battery of biochemicals; notify the physician that results will not be available for 3 weeks D) set up a thiophene-2-carboxylic acid hydrazide (T2H); if the organism is sensitive, report
B
328) A physician calls the laboratory to verify a result of Mycobacterium tuberculosis, stating that the clinical history of the patient is not compatible with tuberculosis. On review of the patient's culture, the smear was negative and the culture became positive at 5 weeks in the broth culture only. Additionally, it was determined that another patient's specimen that was processed the same day was 4+ AFB on smear and the culture was positive at 10 days for Mycobacterium tuberculosis. The lab should: A) include a positive control when processing specimens B) perform molecular fingerprinting on both isolates C) repeat the nucleic acid probe D) set up susceptibility tests
B
330) An unsual number of Mycobacterium gordonae have been isolated. The most likely source is: A) an outbreaks of infections due to Mycobacterium gorgonae B) contamination by water organisms C) contamination of commercial Lowenstein-Jensen tubes D) contamination of the specimen collection containers
B
336) A 27-year-old scuba diver has an abrasion on his left thigh. A culture of this wound grew an acid-fast organism at 30C. This isolate most likely is: A) Mycobacterium chelonae B) Mycobacterium marinum C) Mycobacterium tuberculosis D) Mycobacterium xenopi
B
339) An acid-fast bacillus recovered from an induced sputum had the following characteristics: pigmentation: yellow in the dark, turning a deeper yellow-orange after 2 weeks of light exposure nitrate reduction: negative Tween hydrolysis: positive at 5-10 days Urease: negative Based on this information, the organism is most likely Mycobacterium: A) scrofulaceum B) gordonae C) szulgai D) flavescens
B
340) Which of the following characteristics best distinguishes Mycobacterium scrofulaceum from Mycobacterium gordonae? A) iron uptake B) Tween hydrolysis C) good growth at 25C D) niacin production
B
41) When evaluating a new susceptibility testing system, if the new system characterizes a susceptible isolate as resistant, this is termed a: A) very major error B) major error C) minor error D) acceptable error
B
71) 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 zone size with minimum inhibitory concentrations C) correlating the zone size with minimum bacterial concentrations D) correlating the zone size with the antibiotic content of the disk
B
85) A pregnant patient is screened at 36 weeks gestation for group B Streptococcus (GBS). A vaginal swab is collected and cultured in Todd-Hewitt broth with 8 ug gentamicin/mL and 15 ug nalidixic acid/mL. 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 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 was collected instead of a vaginal/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
140) One of the enterotoxins produced by enterotoxigenic. Escherichia coli in traveler's diarrhea is similar to a toxin produced by: A) Clostridium perfrigens B) Clostridium difficile C) Vibrio cholerae D) Yersinia enterocolitica
C
154) A 64-year-old male with lymphoma has a positive blood culture culture at 19 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 hidrogen sulfide; motility: positive; indole: positive; citrate: positive; omithine decarboxylase: negative; urea; positive; phenylalanine deaminase: positive; VP: negative The genus is: A) Morganella B) Proteus C) Providencia D) Serratia
C
177) 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
183) Which one of the following results is typical of Campylobacter fetus subspecies fetus? A) optimal growth at 42C B) oxidase negative C) growth at 37C D) catalasse negative
C
184) 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% CO2; chocolate: growth in 5%-10% CO2; 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 actiomycetemcomitans C) Haemophilus aphrophilus D) Cardiobacterium hominis
C
201) Characteristics of the HACEK group of bacteria include: A) association with urinary tract infections B) Gram stain of pleomorphic gram-positive bacilli C) requirement of 5%-1-% CO2 for growth D) requirement of 42C for growth
C
232) 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; trypticase soy 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) send out final report to the physician after biochemicals are interpreted C) subculture TSB to SBA aerobic and SBA anaerobic D) test colonies on chocolate agar with hemin and NAD
C
241) Which one of the following anaerobes is inhibited by sodium polyanethol sulfonate (SPS)? A) Bacteroides fragilis B) Propionibacterium acnes C) Peptostreptococcus anaerobius D) Veillnole parvula
C
252) Which of the following sets of organisms may exhibit a brick red fluorescence? A) Porphyromonas asaccharolytica and Clostridium ramosum B) Clostridium difficile and Fusobacterium sp C) Veillonela parvula and Prevotella melaninogenica D) Fusobacterium sp and Veillonella parvula
C
253) A 1-2mm translucent, nonpigmented colony, isolated from an anaerobic culture of a lung abscess after 72 hours, was found to fluoresce 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) Prevotella oralis C) Prevotella melaninogenica D) Porphyromonas asaccharolytica
C
254) A thin, gram-negative bacillus with tapered ends isolated from an emphysema specimen grew 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) Bacterides distasonis B) Prevotella melaninogenica C) Fusobacterium nucleatum D) Clostridium septicum
C
258) 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
264) In preparing an India ink slide, the technician should ensure that the: A) CSF is unspun B) sputum is well mixed C) proper amount of reagent is added D) slide is properly dried first
C
277) The morphological characteristics of a yeast grown in rabbit plasma are shown in the image: The most likely identification of the yeast is: A) Candida tropicalis B) Candida krusei C) Candida albicans D) Candida glabrata
C
283) Which of the following is the most useful morphological feature in identifying the mycelial phase of Histoplasma capsulatum? A) arthrospores every other cell B) 2-5 um microspores C) 8-14 um tuberculate macroconidia D) 5-7 um nonseptate macroconidia
C
286) A fungal isolate from the sputum of a patient with a pulmonary infection is suspected to be Histoplasma capsulatum. Tuberculate macroconidia were seen on the hyphae of the mold phase, which was isolated at room temperature on Sabouraud dextrose agar containing chloramphenicol and cycloheximide (SDA-CC). A parallel set of cultures incubated at 35C showed bacterial growth on SDA, but no growth on SDA-CC. Which of the following is the appropriate course of action? A) repeat subculture of the mold phase to tubes of moist SDA-CC, incubate at 35C B) subculture the mold phase to tubes of moist BHI-blood media, incubate at 25C C) subculture the mold phase to moist BHI-blood media, incubate at 35C. D) perform animal inoculation studies
C
289) Penicillium species is isolated from a bone marrow culture of a patient that travelled to southeast Asia. After 7 days the isolate produces a red pigment that diffuses into the medium. The technologist should: A) prepare a slide culture B) repeat the tease preparation C) transfer a colony to BHI at 35C D) perform a nucleic acid probe
C
294) Culture of a strand of hair, that fluoresced yellow-green when examined with a Wood lamp, produced a slow-growing, flat gray colony with a salmon-pink reverse. Microscopic examination demonstrated racquet hyphae, pectinate bodies, chlamydospores, and a few abortive or bizarre-shaped macroconidia. The most probable identification of this isolate is: A) Epidermophyton floccosum B) Microsporum canis C) Microsporum audouinii D) Trichophyton rubrum
C
299) An isolate from a cornea infection had the following culture results: Sabouraud dextrose: white & cottony at 2 days, rose color at 6 days slide culture: slender sickle shape macroconidia The most likely organism is: A) Acremonium B) Aspergillus C) Fusarium D) Geotrichum
C
302) Pus from a draining fistula on a foot was submitted for culture. Gross examination of the specimen revealed the presence of a small (0.8mm in diameter), yellowish, oval granule. Direct microscopic examination of the crushed granule showed hyphae 3-4um in diameter and the presence of chlamydospores at the periphery. After 2 days a cottony, white mold was seen that turned gray with a gray to black reverse after a few days. When viewed microscopically. moderately large hyaline septate hyphae with long or short conidiophores, each with a single pear-shaped conidium, 5-7 x 8-10 um, were seen. The most likely identification is: A) Exophiala jeanselmei B) Fonsecaea pedrosoi C) Pseudodallescheria boydii D) Cladosporium carrionii
C
320) A digested and decontaminated sputum is inoculated into a Bactec 12B bottle and incubated in air at 37C. On day 14, a positive growth index is obtained, and the auramine-rhodamine stain is positive. Broth from the initial bottle is inoculated into one Bactec 12B bottle with NAP. After reincubation, the inoculated growth bottle shows an increase in growth index, while the bottle containing NAP shows no increase. The organism cultured from the sputum is most likely Mycobacterium: A) marinum B) kansasii C) tuberculosis D) avium-intracellulare
C
322) A positive niacin test is most characteristic of Mycobacterium: A) chelonae B) marinum C) tuberculosis D) xenopi
C
343) A mycobacterial isolate that causes multiple skin nodules, grows at 30C and requires hemin for growth is Mycobacterium: A) marinum B) genavense C) haemophilum D) bovis
C
345) The nitrate test for mycobacteria can be performed with a reagent impregnated paper strip or by the use of standard reagents. In order to quality control the test properly, which of the following should be used for a positive control? A) Mycobacterium bovis B) Mycobacterium gordonae C) Mycobacterium tuberculosis D) Mycobacterium intracellulare
C
40) SPS is used as an anticoagulant for blood cultures because it: A) inactivates penicillin and cephalosporins B) prevents clumbing of red cells C) inactivates neurtophils and components of serum complement D) facilitates growth of anaerobes
C
69) Quality control results for disk diffusion susceptibility tests yield the following results: aminoglycoside zones too small and penicillin zones too large. This is most likely due to the: A) inoculum being too heavy B) inoculun being too light C) pH of Mueller-Hinton agar being too low D) calcium and magnesium concentration in the agar being too high
C
74) Salmonella enteritidis is isolated from multiple blood cultures in a patient with fever. Susceptibility results are as follows: ampicillin-susceptible, ceftriaxone-susceptible, ciprofloxacin-susceptible, trimethoprin/sulfamethoxazole-resistant. What is the next best step? A) report all of the susceptibilly testing results with no changes B) perform a beta-lactamase test on the isolate before reporting the ampicilin as susceptible C) test the isolate against nalidixic acid and if resistant report the ciprofloxacin as resistant D) report gentamicin since the trimethoprim/sulfamethoxazole is resistant
C
8) 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
275) Two blood cultures are positive for yeast from a patient with an intravenous catheter. One culture grew Candida albicans, while the other grew Candida krusei. Which medium should the technologist use to subculture the blood bottles to in order to verify that the cultures are pure? A) Sabouraud dextrose agar B) potato dextrose agar C) cornmeal agar D) chromogenic agar
D
12) A Staphylococcus aureus isolate has an MIC o 4 ug/mL to oxacillin. There is uncertainly as to whether this represents an oxacillin (heteroresistant) resistant strain or a hyperproducer of beta-lactamase. Strain Oxacilin Amoxicilin-clavulanic acid A Susceptible Susceptible B Susceptible Resistant C Resistant Susceptible D Resistant Resistant Based on the above for oxacilin and amoxicilin-clavulanic acid, which strain is heteroresistant? A) strain A B) strain B C) strain C D) strain D
D
149) 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 200x10^3/uL 13.0x10^3/uL 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) Prevotellla melaninogenica B) Shigella sonnei C) Listeria monocytogenes D) Yersinia enterocolitica
D
166) 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: A) Stenotrophomonas maltophilia B) Alcaligenes faecalis C) Moraxella lacunata D) Acinetobacter beumannii
D
186) 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
188) An aerobic, gram-negative coccobacillus was isolated on Bordet-Gengou agar from a nasoopharyngeal swab 49 hours after culture from a 6-month-old infant with suspected pertussis. The organism exhibited the following characteristic: MacConkey agar: no growth, urea: negative at 4 hours, positive at 24 hours, oxidase: negative, catalase: positive The most probable identification of this isolate is: A) Moraxella lacunata B) Pasteurella ureao C) Bordetella pertussis D) Bordetella parapertussis
D
189) Which of the following characteristics best differentiates Bordetella bronchiseptica from Alcaligenes species? A) flagellar pattern B) growth at 24C C) oxidase activity D) rapid hydrolysis of urea
D
198) A college student attended a beach party where raw oysters and other shellfish were consumed. The next day, he dad symptoms of septicemia. The blood cultures grew gram-negative bacilli with the following characteristics: oxidase: positive; MacConkey agar: pink colonies; O/129 (150 ug): susceptible The most likely organism is: A) Aeromonas hydrophila B) Pseudomonas putida C) Serratia marcescens D) Vibrio vulnificus
D
212) A vaginal smear is submitted for a Gram stain for Neisseria gonorrhoeae. The technologist finds the following results on the Gram stain: many white blood cells; few ephitelial cells; many gram-positive bacilli; few gram-negative diplococci; few gram-positive cocci in chains A) report out smear positive gonorrhea B) report out smear negative for gonorrhea C) request a new specimen due to number of white blood cells D) not read or report a Gram stain on a vaginal
D
25) Which of the following is the most appropriate method for collecting a urine specimen from a patient with an indwelling catheter? A) remove the catheter, cut the tip, and submit it for culture B) disconnect the catheter from the bag, and collet urine from the terminal end of the catheter C) collect urine directly from the bag D) aspirate urine aseptically from the catheter tubing
D
263) Antifungal susceptibility tests for yeasts are: A) performed routinely B) highly reproducible C) not clinically relevant D) more useful in identifying resistant strains
D
268) Staib medium (birdseed agar) is useful in the identification of which of the following? A) Candida albicans B) Candida glabrata C) Saccharomyces cerevisiae D) Cryptococcus neoformans
D
270) 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
271) A urine culture from a patient with a urinary tract infection yields a yeast with the following characteristics: failure to produce germ tubes, hyphae not formed on cornmeal agar, urease-negative, assimilates trehalose The most likely identification is: A) Saccharomyces cerevisiae B) Cryptococcus laurentii C) Candida pseudotropicalis D) Candida glabrata
D
287) Skin scrapings obtained from the edge of a crusty wrist lesion were found to contain thick-walled, spherical yeast cells (8-15 um in diameter) that had single buds with a wide base of attachment. Microscopic examination of the room temperature isolate from this specimen would probable reveal the presence of: A) "rosette-like" clusters of pear-shaped conidia at the tips of delicate conidiophores B) thick-walled, round to pear-shaped tuberculate macroconidia C) numerous conidia along the lenght of hyphae in a "sleevelike" arrangement D) round or pear-shaped small conidia attached to conidiophores of irregular lenghts
D
290) The microscopic structures that are most useful in the identification of dermatophytes are: A) septate and branching hyphae B) racquet and pectinate hyphae C) chlamydospores and micronidia D) macroconidia and microconidia
D
293) Which of the following is the best aid in the identification of Epidermophyton floccosum macroconidia? A) parallel side walls with at least 10 cells B) spindle-shaped spore with thin walls C) spindle-shaped spore, thick walls and distinct terminal knob with echinulations D) smooth walls, club-shaped
D
297) Penicillium can best be separated from Aspergillus by: A) color of the colonies B) optimum growth temperature C) presence of rhizoids D) arrangement of the conidia on the conidiophore
D
298) A fungus superficially resembles Penicillium species but may be differentiated because its phialides are long and tapering and bend away from the central axis. The most probable identification is: A) Exophiala B) Acremonium C) Cladosporium D) Paecilomyces
D
309) In reviewing the number of Mycobacterium isolates for the current year, it was noted that there were 76% fewer isolates than the previous year (115vc28). The technologist in charge of the area has documented that the quality control of media, reagents and stains has been acceptable and there has been no gross contamination of the cultures noted. The most appropriate course of action to pursue would be: A) stop use of commercial media and produce in-house B) change to different formulation of egg and agar based media C) change over to the Bactec system for isolation of Mycobacterium D) review the digestion and decontamination procedure
D
319) The species of mycobacteria that will give a positive niacin test is Mycobacterium: A) leprae B) kansasii C) fortuitum D) tuberculosis
D
321) On a culture suspected to be Mycobacterium tuberculosis, the most important test to perform is: A) catalase production B) tellurite reduction C) Tween 80 hydrolysis D) niacin production
D
323) Characteristic necessary for the definitive identification of Mycobacterium tuberculosis are: A) buff color, slow growth at 37C, niacin production-positive, nitrate reduction-negative B) rough colony, slow growth at 37C, nonpigmented C) rough, nonpigmented colony, cording positive, niacin production-negative, catalase-negative at pH 7/68C D) rough, nonpigmented colony, slow growth at 37C, niacin production-positive, nitrate reduction-positive
D
331) When grown in the dark, yellow to orange pigmentation of the colonies is usually demonstrated by: A) Mycobacterium tuberculosis B) Mycobacterium kansaii C) Mycobacterium fortuitum D) Mycobacterium scrofulaceum
D
337) A nonchromogen that grows best at 42C and is highly resistant to antibiotics is: A) Mycobacterium chelonae B) Mycobacterium marinum C) Mycobacterium tuberculosis D) Mycobacterium xenopi
D
341) 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) DNA probe
D
38) Chocolate agar base containing vancomycin, colistin, anisomycin, and trimethoprin is also known as: A) EMB agar B) modified Thayer-Martin agar C) Columbia CNA agar D) Martin Lewis agar
D
50) Diagnosis of typhoid fever can be confirmed best by culture of: A) stool B) urine C) blood D) bone marrow
D
57) 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 techniques on clinical specimens D) polymerase chain reaction
D
68) Which of the following tests is used to monitor bactericidal activity during antimicrobic therapy in cases of endocarditis? A) Elek B) tolerance C) Sherris synergism D) Schlichter
D
79) Enzymatic drug modification is a mechanism of resistance for which antimicrobial? A) levofloxacin B) sulfamethoxazole C) vancomycin D) gentamicin
D
