MICROBIOLOGY BOC

100問 • 1年前

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Characteristics of the HACEK group of bacteria include: association with urinary tract infections Gram stain of pleomorphic gram-positive bacilli requirement of 5%-10% CO2 for growth requirement of 42°C for growth

requirement of 5%-10% CO2 for growth

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, smooth, 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 testing using an automated system d_ take extra safety precautions for possible Brucella

d_ take extra safety precautions for possible Brucella

203 The primary isolation of Neisseria gonorrhoeae requires: anaerobic conditions starch media carbon dioxide blood agar

carbon dioxide

Assuming the agent isolated from a patient's spinal fluid produces a positive oxidase test, the most likely diagnosis is: a tuberculous meningitis b meningococcal meningitis c viral meningitis d pneumococcal meningitis

b meningococcal meningitis

The following results were obtained from a culture of unknown origin: Gram stain: gram-negative diplococci indophenal oxidase: positive glucose: positive maltose: negative sucrose: negative The most likely source of the specimen would be the: a respiratory tract b blood c genitourinary tract d cerebrospinal fluid

c¢ genitourinary tract

An urethral swab obtained from a man with an urethral exudate was plated directly on chocolate agar and modified Thayer-Martin agar, and a Gram stain was made. The Gram stain showed gramnegative diplococci. The culture plates were incubated at 35°C, but had no growth at 48 hours. The most likely failure for organism growth is that the: wrong media were used Gram stain was misread organism only grows at room temperature organism requires CO2 for growth

organism requires CO2 for growth

A Gram stain performed on a sputum specimen revealed gram-negative diplococci within PMNs. Oxidase testing is positive and carbohydrate degradation tests are inert. The organism is: a Neisseria lactamica b Moraxella catarrhalis c Neisseria meningitidis d Neisseria sicca

b Moraxella catarrhalis

Coagglutination is assaciated with: a Chlamydia trachomatis b Neisseria gonorrhoeae c Streptococcus pneumoniae d_ Klebsiella pneumoniae

b Neisseria gonorrhoeae

Clinical resistance to penicillin correlates most frequently with beta-lactamase production in: a Neisseria gonorrhoeae b Neisseria meningitidis c Streptococcus agalactiae d Streptococcus pyogenes

a Neisseria gonorrhoeae

All species of the genus Neisseria have the enzyme to oxidize: a naphthylamine b dimethylaminobenzaldehyde c plucopyranoside d_ tetramethyl-phenylenediamine

d tetramethyl-phenylenediamine

The diagnosis of Neisseria gonorrhoeae in females is best made from: clinical history an endocervical culture a Gram stain of cervical secretions examination for clue cells

an endocervical culture

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 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 a new specimen due to number of white blood cells d not read or report a Gram stain on a vaginal specimen

not read or report a Gram stain on a vaginal specimen

Which of the following is the mast reliable test to differentiate Neisseria lactamica from Neisseria meningitidis? a acid from maltose b growth on modified Thayer-Martin agar c lactose degradation d nitrite reduction to nitrogen gas

c lactose degradation

Definitive identification of Neisseria gonorrhoeae is made with the: Gram stain oxidase test degradation of amino acids hydrolysis of carbohydrates

hydrolysis of carbohydrates

gram-negative diplococcus that grows on modified Thayer-Martin medium can be further confirmed as Neisseria gonorrhoeae if it is: oxidase positive, glucose positive, and maltose positive oxidase positive and glucose positive, maltose negative oxidase positive and maltose positive, glucose negative glucose positive, oxidase negative and maltose negative

oxidase positive and glucose positive, maltose negative

An organism previously thought to be nonpathogenic, Moraxella catarrhalis, is now known to be associated with opportunistic respiratory infection and nosocomial! transmission. Characteristic identification criteria include: a oxidase negative b carbohydrates negative (asaccharolytic) c beta-lactamase negative d_ gram-negative bacilli

b carbohydrates negative (asaccharolytic)

An autopsy performed on an 8-year-old child revealed Waterhouse-Friderichsen syndrome. Blood and throat cultures taken just prior to death were positive for which organism? a Neisseria gonorrhoeae b Neisseria meningitidis c Haemophilus influenzae d Klebsiella pneumoniae

b Neisseria meningitidis

An aspirated specimen of purulent material was obtained from a brain abscess. After 24 hours incubation, pinpoint colonies grew on sheep blood and small, yellowish colonies grew on chocolate. Gram stain of the organism showed gram-negative cocci. Results of carbohydrate degradation studies were as follows: glucose: acid maltose: acid sucrose: acid lactose: negative Additional testing revealed that the organism was oxidase positive and beta-galactosidase negative. The organism is most likely Neisseria: a meningitidis b sicca c lactamica d gonorrhoeae

b sicca

A Gram stain of organisms on Loeffler agar showed pleomorphic gram-positive bacilli. The organism should be subcultured to: blood chocolate MacConkey potassium tellurite

potassium tellurite

Which organism commonly causes food poisoning by consumption of foods containing excessive populations of organisms or preformed enterotoxin? a Salmonella enteritidis b Shigella sonnei c Bacillus cereus d Escherichia coli

c Bacillus cereus

An organism recovered from a sputum has the following characteristics: culture: growth at 7 days on Lowenstein-Jensen agar, incubated under aerobic conditions with COs at 35°C Gram stain: delicate branching gram-positive bacilli acid-fast stain: branching, filamentous, “partially” acid-fast bacterium These results are consistent with which of the following genera? a Nocardia b Mycobacterium c Actinomyces d Streptomyces

a Nocardia

The best procedure to differentiate Listeria monocytogenes from Corynebacterium species is: catalase motility at 25°C motility at 35°C Gram stain

motility at 25°C

Establishing the pathogenicity of a microorganism isolated from a child’s throat and identified as oO orynebacterium diphtheria would depend upon: 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 a positive toxigenicity test

Which feature distinguishes Erysipelothrix rhusiopathiae from other clinically significant non-spore-forming, gram-positive, facultatively anaerobic bacilli? “tumbling” motility beta-hemolysis more pronounced motility at 25°C than 37°C H2S production

H2S production

Listeria can be confused with some streptococci because of its hemolysis and because it is: nonmotile catalase negative oxidase positive esculin positive

oxidase positive

Fluid from a cutaneous black lesion was submitted for routine bacterial culture. After 18 hours of incubation at 35°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 organism is most likely: a_ Clostridium perfringens b Aeromonas hydrophila c Bacillus anthracis d Mycobacterium marinum

¢ Bacillus anthracis

branching gram-positive, partially acid-fast organism is isolated fromm a bronchial washing on a 63-year-old woman receiving chemotherapy. The organism does not hydrolyze casein, tyrosine or xanthine. ‘The most likely identification is: a Actinomadura madurae b Nocardia caviae c Streptomyces somaliensis d Nocardia asteroides

Nocardia asteroides

The characteristic that is most commonly associated with the presence of strict anaerobic bacteria and can be taken as presumptive evidence of their presence in a clinical specimen is the: a presence of a single bacterial species b production of gas in a thioglycollate broth culture ¢ growth on a blood agar plate incubated in an anaerobic jar d_ presence of a foul, putrid odor from tissue specimens and cultures

d_ presence of a foul, putrid odor from tissue specimens and cultures

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: on chocolate agar for 5 days under 5% CO, anaerobically

anaerobically

An aspirate of a deep wound was plated on blood agar plates aerobically and anaerobically. At 24 hours there was growth on the anaerobic plate only. The next step in the evaluation of this culture is to: reincubate for another 24 hours begin organism identification issue the final report set up a Bauer-Kirby sensitivity

begin organism identification

Anaerobic infections differ from aerobic infections in which of the following? they usually respond favorably with aminoglycoside therapy they usually arise from exogenous sources they are usually polymicrobic Gram stains of specimens are less helpful in diagnosis

they are usually polymicrobic

The following growth results were observed on media inoculated with a foot abscess aspirate and Mity incubated in 3%-5% COg. 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 subculture TSB to SBA aerobic and SBA anaerobic

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 Veillonella and Capnocytophaga

a Bacteroides and Prevotella

Acceptable specimens for culture of anacrobic bacteria that cause disease include: abscesses gingival swabs skin swabs vaginal swabs

abscesses

Propionibacterium acnes is most often associated with: a normal oral flora b post-antibiotic diarrhea c tooth decay d blood culture contamination

d blood culture contamination

The etiologic agent of botulism is: highly motile non-spore-forming Clostridium perfringens an exotoxin producer

an exotoxin producer

A strict anaerobe that produces terminal spores is: a Clostridium tetani b Corynebacterium diphtheriae c Bacillus anthracis d Propionibacterium acnes

a Clostridium tetani

An anaerobic, spore-forming, nonmotile, gram-positive bacillus isolated from a foot wound is most likely; a Actinomyces israelii b Clostridium perfringens c Bacillus subtilis d Eubacterium lentum

b Clostridium perfringens

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 cytatoxin assay c EIA vs culture on cycloserine cefoxitin-egg-fructose agar d EIA vs cell culture cytotoxin assay

b latex agglutination vs EIA vs cell culture cytatoxin assay

The reverse CAMP test, lecithinase production, double zone hemolysis, and Gram stain morphology are all useful criteria in the identification of: Clostridium perfringens Streptococcus agalactiae Propionibacterium acnes Bacillus anthracis

Clostridium perfringens

Which one of the following anaerobes is inhibited by sodium polyanethol sulfonate (SPS)? a Bacteroides fragilis b Propionihacterium acnes c Peptostreptococcus anaerobius d Veillonella parvula

Peptostreptococcus anaerobius

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 EIA

An anaerobic gram-positive bacilli with subterminal spores was isolated from a peritoneal abscess. The most likely identification of this organism is: a Bacillus cereus b Clostridium septicum ¢ Eubacterium lentum d Bifidobacterium dentium

b Clostridium septicum

The most meaningful laboratory procedure in confirming the diagnosis of clinical botulism is: a demonstration of toxin in the patient’s serum b recovery of Clostridium botulinum from suspected food c recovery of Clostridium botulinum from the patient’s stool d Gram stain of suspected food for gram-positive, sporulating bacilli

a demonstration of toxin in the patient’s serum

stool sample is sent to the laboratory for culture to rule out Clostridium difficile. What media should the microbiologist use and what is the appearance of the organisms on this media? a BBE: colonies turn black b Brucella agar: red pigmented colonies c CCFA: yellow, ground glass colonies d CNA: double zone hemolytic colonies

c CCFA: yellow, ground glass colonies

A Gram stain of a necrotic wound specimen showed large gram-positive bacilli. There was 3+ growth on anaerobic media only, with colonies producing a double zone of hemolysis. To identify the organism, the microbiologist should: 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 set up egg yolk agar plate

A patient has a suspected diagnosis of subacute bacterial endocarditis. His blood cultures grow noen-spore-forming pleomorphic gram-positive bacilli only in the anaerobic bottle. What test(s) will give a presumptive identification of this microorganism? beta-hemolysis and oxidase catalase and spot indole esculin hydrolysis hydrolysis of gelatin

catalase and spot indole

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 Actinomyces

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 Bacteroides fragilis

Which of the following genera include anaerobic gram-negative nonsporulating bacilli? a Brucella b Pasteurella ¢ Actinomyces d Bacteroides

d Bacteroides

An organism from a peritoneal abscess is isolated on kanamycin-vancomycin laked blood agar and grows black colonies on BBE agazr. It is nonpigmented, catalase positive, and indole negative. The genus of this organism is: a Acidominococcus b Bacteroides ¢ Porphyromonas d Prevotella

b Bacteroides

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 Veillonella parvula and Prevotella melaninogenica d Fusobacterium sp and Veillonella parvula

Veillonella parvula and Prevotella melaninogenica

A 1-2 mm 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 asaccharalytica

c Prevotella melaninogenica

A thin, gram-negative bacillus with tapered ends isolated from an empyema 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 Bacteroides distasonis b Prevotella melaninogenica c Fusobacterium nucleatum d Clostridium septicum

c Fusobacterium nucleatum

Which one of the following anaerobes would be negative for indole? a Bacteroides fragilis b Fusobacterium nucleatum c Porphyromonas asaccharolytica d Proteus mirabilis

a Bacteroides fragilis

The presence of 20% bile in agar will allow growth of: a Fusobacterium necrophorum b Bacteroides ovatus c Prevotella melaninogenica d Porphyromonas gingivalis

Bacteroides ovatus

A control strain of Clostridium should be used an anacrobe jar to assure: a that plate media is working b that an anaerobic environment is achieved c that the jar is filled with a sufficient number of plates d that the indicator strip is checked

b that an anaerobic environment is achieved

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 Clostridium perfringens

The major features by which molds are routinely identified are: macroscopic characteristics and microscopic morphology biochemical reactions and microscopic morphology macroscopic characteristics and selective media specialized sexual reproductive structures

macroscopic characteristics and microscopic morphology

sputum specimen from a patient with a known Klebsiella pneumoniae infection is received in the laboratory for fungus culture. The proper procedure for handling this specimen is to: a reject the current specimen and request a repeat culture when the bacterial organism is no longer present b incubate culture tubes at room temperature in order to inhibit the bacterial organism ¢ include media that have cycloheximide and chloramphenicol added to inhibit bacterial organisms and saprophytic fungi d_ perform a direct PAS stain; if no fungal organisms are seen, reject the specimen

¢ include media that have cycloheximide and chloramphenicol added to inhibit bacterial organisms and saprophytic fungi

Many fungal infections are transmitted to man via inhalation of infectious structures. Which of the following is usually contracted in this manner? a Sporothrix schenckii b Trichophyton rubrum c Malassezia furfur d Histoplasma capsulatum

d Histoplasma capsulatum

A smear of skin tissue reveals fluorescent septate hyphae. The smear was prepared using: acridine orange calcofluor white auramine rhodamine periodic acid-Schiff

calcofluor white

Antifungal susceptibility tests for yeasts are: a_ performed routinely b highly reproducible c not clinically relevant d more useful in identifying resistant strains

d more useful in identifying resistant strains

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

€ proper amount of reagent is added

An organism that demonstrates budding yeast cells with wide capsules in an India ink preparation of spinal fluid is probably: a Cryptococcus neoformans b Histoplasma capsulatum c Blastomyces dermatitidis d Candida albicans

a Cryptococcus neoformans

The formation of germ tubes presumptively identifies: a Candida tropicalis b Candida parapsilosis c Candida glabrata d Candida albicans

d Candida albicans

An HIV-positive patient began to show signs of meningitis. A spinal fluid was collected and cultured for bacteria and fungus. A budding, encapsulated yeast was recovered. Which organism is consistent with this information? a Cryptococcus neoformans b Aspergillus fumigatus c Microsporum audouinii d Sporothrix schenckii

a Cryptococcus neoformans

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

Cryptococcus neoformans

Gram stain examination of a CSF specimen indicates the presence of yeast-like cells with grampositive granular inclusions. Which of the following techniques should be used next to assist in the identification of this organism? a 10% KOH b lactophenol cotton blue c India ink d_ periodic acid-Schiff

c India ink

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_ positive phenol oxidase test

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 trenalose The most likely identification is: a Saccharomyces cerevisiae b Cryptococcus laurentii c Candida pseudotropicalis d Candida glabrata

d Candida glabrata

yeast isolate from a CSF specimen produced the following results: India ink: no encapsulated yeast cells cryptococcal antigen: negative urea: negative germ tube: negative What should the technologist do next to identify this organism? inoculate bird seed agar ascospore stain cycloheximide susceptibility carbohydrate assimilation

carbohydrate assimilation

The recovery of some Cryptacoccus species may be compromised if the isolation media contains: a cycloheximide b gentamicin c chloramphenicol d penicillin

a cycloheximide

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 Malassezia furfur

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 chromogenic agar

quality control testing of CHROMagar™ Candida medium shows very weakly colored colonies after incubation at 25°C, 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 35°C 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 repeat the quality control tests but incubate at 35°C

The morphological characteristics of a yeast grown in rabbit plasma are shown in the image: The most likely identification of this yeast is: a Candida tropicalis b Candida krusei c Candida albicans d Candida glabrata

c Candida albicans

The most sensitive test for the initial diagnosis of cryptococcal disease is: a Indiaink b Gram stain c cryptococcal antigen d Giemsa stain

c cryptococcal antigen

Which of the following statements concerning the germ tube test is true? a using a heavy inoculum enhances the rapid production of germ tubes b germ tubes should be read after 2 hours incubation at 25°C c Candida albicans and Candida tropicalis can be used as positive and negative controls, respectively d serum will be stable for 1 year if stored at 4°C prior to use

c Candida albicans and Candida tropicalis can be used as positive and negative controls, respectively

Which of the following procedures should be performed to confirm that an unknown mold is one of the pathogenic dimorphic fungi: a animal inoculation b culture conversion to yeast form c demonstration of sexual and asexual reproduction d serological studies

b culture conversion to yeast form

Lab workers should always work under a biological safety hood when working with cultures of: a Streptococcus pyogenes b Staphylococcus aureus ¢ Candida albicans d Coccidioides immitis

d Coccidioides immitis

Structures important in the microscopic identification of Coccidioides immitis are: irregular staining, barrel-shaped arthrospores tuberculate, thick-walled macroconidia thick-walled sporangia containing sporangiospores small pyriform microconidia

irregular staining, barrel-shaped arthrospores

Which of the following is the mest useful morphological feature in identifying the mycelial phase of Histoplasma capsulatum? a_arthrospores every other cell b 2-5 pm microspores c 8-14 um tuberculate macroconidia d 5-7 pm nonseptate macroconidia

c 8-14 um tuberculate macroconidia

mold grown at 25°C exhibited delicate septate hyaline hyphae and many conidiophores extending at right angles from the hyphae. Oval, 2-5 pm 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. A37°C 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 Sporothrix schenckii

Which of the following is a dimorphic fungus? a Sporothrix schenckii b Candida albicans c Cryptococcus neoformans d Aspergillus fumigatus

a Sporothrix schenckii

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 mald phase, which was isolated at room temperature on Sabouraud dextrose agar containing chloramphenicol and cycloheximide (SDA-CC). A parallel set of cultures incubated at 35°C 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 35°C b subculture the mold phase to tubes of moist BHI-blood media, incubate at 25°C c subculture the mold phase to moist BHI-blood media, incubate at 35°C d perform animal inoculation studies

c subculture the mold phase to moist BHI-blood media, incubate at 35°C

Skin scrapings obtained from the edge of a crusty wrist lesion were found to contain thick-walled, spherical yeast cells (8-15 tm in diameter) that had single buds with a wide base of attachment. Microscopic examination of the room temperature isolate from this specimen would probably 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 length of hyphae in a “sleevelike” arrangement d_ round or pear-shaped small conidia attached to conidiophores of irregular lengths

d_ round or pear-shaped small conidia attached to conidiophores of irregular lengths

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 definitive identification is: a nucleic acid probe b animal inoculation ¢ exoantigen test d slide culture

a nucleic acid probe

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 35°C d_ perform a nucleic acid probe

c transfer a colony to BHI at 35°C

The microscopic structures that are most useful in the identification of dermatophytes are: a septate and branching hyphae b racquet and pectinate hyphae ¢ chlamydospores and microconidia d macroconidia and microconidia

d macroconidia and microconidia

Which of the following is most often used to prepare a slide from a plate culture of a dermatophyte for microscopic observation? lactophenol cotton blue potassium hydroxide iodine solution Gram stain

lactophenol cotton blue

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 mycelium and very few macroconidia or microconidia. This fungus is most likely: a Microsporum gypseum b Microsporum audouinii ¢ Trichophyton tonsurans d_ Epidermophyton floccosum

Microsporum audouinii

Which of the following is the best aid in the identification of Epidermophyton floccosum macroconidia? parallel side walls with at least 10 cells spindle-shaped spore with thin walls spindle-shaped spore, thick walls and distinct terminal knob with echinulations smooth walls, club-shaped

smooth walls, club-shaped

Culture of a strand of hair, that fluoresced yellow-green when examined with a Wocd 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 bizarreshaped macroconidia. The most probable identification of this isolate is: a Epidermophyton floccosum b Microsporum canis c Microsporum audouinii d Trichophyton rubrum

c Microsporum audouinii

On day 3 of a fungal culture, grayish cottony growth is observed that is filling the container. The most likely mold isolated is a: a dermatophyte b dimorphic mold c zygomycete d dematiaceous mold

c zygomycete

The appropriate specimen for the diagnosis of mucormycosis is: a nasal swab b sputum c sinus washing d_ eschar biopsy

d_ eschar biopsy

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 arrangement of the conidia on the conidiophore

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 Paecilomyces

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 da Geotrichum

Fusarium

100

In the USA, the most common organism causing eumycotic mycetoma is: a Pseudallescheria boydii b Nocardia brasiliensis c Blastomyces dermatitidis d Aspergillus fumigatus

a Pseudallescheria boydii

other names parasitology

Yves Laure Pimentel · 70問 · 2年前

other names parasitology