Microbiology - Preanalytic Procedures
65. A tech is reviewing a Gram stain from a positive blood culture bottle. The background on the stain shows pink debris and the tech thinks that there is also Gram negative bacilli but is having difficulty differentiating the artifact and possible organisms. What could the tech do next to help determine if bacteria are present in the blood culture bottle? A. Stain with Wright-Giemsa B. Stain with Acridine Orange C. Use Calcofluor White D. Stain with Periodic Acid-Schiff
B
62. Which culture medium is specifically formulated to recover Salmonella typhi from stool specimens? A. Selenite broth B. Bismuth sulfite agar C. Salmonella/Shigella (SS) agar D. Deoxycholate citrate agar
B
5. Sheep's blood agar is least suitable for the growth of which of the following organisms? A. Haemophilus influenzae B. Staphylococcus aureus C. Streptococcus species D. Neisseria meningitidis
A
120. Which of the following is a selective medium for Campylobacter jejuni? A. CNA agar B. Skirrow agar C. Thayer-Martin media D. Cystine-tellurite blood agar
B
137. Which one of the following results is typical of Campylobacter jejuni? A. Optimal growth at 42 ºC B. Oxidase negative C. Catalase negative D. Nonmotile
A
51. What is the purpose of a trichrome stain? A. To identify protozoan trophozoites and cysts in fecal samples. B. To identify helminth eggs in fecal samples. C. To identify blood parasites in a peripheral blood sample. D. To identify fungal elements in skin scrapings.
A
52. To enhance recovery of bacteria, proper inoculation of broth media may be accomplished by: A. Placing a few drops of liquid specimen directly into the tube of broth B. Placing the inoculating loop into the liquid specimen, then sterilizing the loop before placing into the tube of broth C. Rehydrating a dried-up swab specimen with saline before adding the swab to the tube of broth D. Placing the swab specimen into the tube of broth, while maintaining the temperature at 4°C before and after inoculation
A
68. In order to prepare the acridine orange (AO) reagent, what is added to the AO powder? A. Sodium acetate buffer B. HCl C. NaCl D. Acetone
A
104. What is the purpose of calcofluor white in the direct examination of patient specimens for fungal elements? A. It breaks down the keratin and skin layers. B. It binds to the polysaccharides in the chitin of the fungus. C. It stains the melanin in the cell wall of phaeoid fungi. D. It is used to stain the capsule of Cryptococcus neoformans.
B
110. The appropriate media for the isolation of anaerobic bacteria from any source would normally include all of the following except: A. CDC blood agar B. MacConkey agar C. Phenylethyl alcohol agar (PEA) D. Kanamycin-vancomycin-laked blood agar (KVLB)
B
112. How does the modified acid-fast stain differ it from the conventional acid-fast stain? A. Heat B. Detergent C. Methylene blue D. Carbolfuchsin
B
146. The historical medium of choice for isolation of Francisella is: A. Chocolate agar B. Cysteine blood glucose agar C. Modified Thayer-Martin agar D. MacConkey agar
B
83. The ingredient added to culture media to enhance the recovery of the dimorphic fungi by preventing the overgrowth of more rapidly growing, saprophytic molds is: a. Brain heart infusion base b. Chloramphenicol c. Thiamine d. Cycloheximide
D
99. A tissue sample is received in the laboratory for fungal culture. How should the tech prepare the sample for inoculation onto agar plates? A. Roll the tissue across each agar plate B. Use a tissue grinder to homogenize the sample C. Add 1.0 mL of saline to the sample and vortex D. Cut/Mince tissue into small pieces with sterile scissors
D
32. Acridine orange is used for: A. Visualization of fungal structures with fluorescent microscopy B. Separation of bacteria into two categories based on cell wall composition C. Visualization of protozoa in direct wet mounts or smears D. Visualization of bacteria in specimens where debris may be present
D
33. Pseudomonas aeruginosa is often used as a bacterial species for the quality control of Kligler iron agar. What is the expected reaction? A. Acid slant/acid deep B. Alkaline slant/acid deep C. Alkaline slant/acid deep/H2S D. Alkaline slant/alkaline deep
D
37. Which of the culture media listed is selective for the isolation of Yersinia enterocolitica in stool samples? A. Cycloserine Cefoxitin Fructose Agar (CCFA) B. MacConkey Sorbitol Agar C. Bordet-Gengou Blood Agar D. Cefsulodin-Irgasan-Novobiocin (CIN)
D
42. Select from the multiple choices the specimen that is inadequate for the recovery of anaerobes and should be summarily rejected upon receipt in the microbiology laboratory. A. Swab specimens taken from of deep sub-cutaneous abscess B. Needle aspirate in an anaerobic E-swab tube C. Syringe aspirate hand-carried to microbiology laboratory D. Uterine cervical swab in Cary-Blair transport medium
D
126. Which stain is used specifically to detect Histoplasma capsulatum in blood and bone marrow? A. Periodic acid-Schiff B. Fontana-Masson C. Calcofluor white D. Giemsa
D
136. The modified acid-fast stain is primarily used to identify: A. Bacteria B. Mycobacteria C. Malarial parasites D. Cryptosporidium oocysts
D
21. Isolation and detection of Gardnerella vaginalis from vaginal secretions is improved by which of the following? A. Utilization of human blood agar B. Incubation at 35-37º C ambient air C. Cold enrichment D. Utilization of Thayer-Martin agar
A
26. Which of the following errors could most likely occur in the preanalytical phase? A. Incorrectly collected sample B. Wrong test method used C. Incorrectly performed instrument calibration D. Inaccurately handled critical test value
A
4. The trichrome stain is most commonly used to identify which class of parasites? A. Protozoa B. Nematodes C. Cestodes D. Trematodes
A
40. MacConkey agar contains all of the following except: A. Penicillin B. Bile salts C. Lactose D. Crystal violet
A
41. Which of the following sample types should be processed first for a culture and Gram stain? A. Cerebral spinal fluid (CSF) B. Wound swab in transport medium C. Clean catch urine D. Endotracheal aspirate
A
48. Which of the following is the most suitable specimen for the isolation of Bordetella pertussis? A. Nasopharyngeal swab B. Bronchial washing C. Wound aspirate D. Throat swab
A
105. In traditional culture or antigen detection methods, the sensitivity of detection is adversely affected by which of the following? A. Fastidious growth requirements and delays in transport B. Large numbers of organisms C. Proper collection technique D. Stable temperature
A
113. Which of the following is the best media for recovery and presumptive identification of Clostridioides (formerly Clostridium) difficile in suspected cases of pseudomembraneous colitis? A. CDC anaerobic blood agar B. Columbia agar with 5% sheep blood C. Cycloserine-cefoxitin fructose agar (CCFA) D. Phenylethyl agar
C
114. What is the medium of choice for isolating Gardnerella vaginalis? A. Modified Thayer-Martin (MTM) agar B. Malonate broth C. Human blood bilayer Tween (HBT) agar D. New York City (NYC) medium
C
116. Which of the following organisms are gram-positive? A. Neisseria gonorrhoeae B. Brucella species C. Clostridium difficile D. Pseudomonas aeruginosa
C
117. Which phrase describes enrichment media? A. Contains certain factors that allow colonies of specific organisms to appear different than other colonies. B. Contains pigments to differentiate lactose fermenters from non-lactose fermenters. C. Encourages the growth of specific types of organisms. D. Contains agents that inhibit all but one specific organism.
C
118. All of the following are characteristic of Burkholderia pseudomallei EXCEPT? A. Has been reported as the cause of laboratory-acquired infection B. Oxidase positive C. Non-motile D. Catalase positive
C
123. Cystine-tellurite blood agar is recommended for the isolation of which organism? A. Yersinia enterocolitica B. Legionella pneumophilia C. Corynebacterium diphtheriae D. Francisella tularensis
C
125. India Ink is used to: A. Visualize flagella B. Visualize shape C. Visualize capsule D. Visualize cytoplasm
C
127. Which of the following organisms appear Gram positive when using the Gram Stain? A. Haemophilus influenzae B. Escherichia coli C. Peptostreptococcus anaerobius D. Bacteroides fragilis
C
130. Buffered charcoal yeast extract agar (BCYE) is the nonselective solid culture medium used for the primary recovery of: A. Treponema pallidum B. Mycoplasma pneumoniae C. Legionella pneumophila D. Spirillum minus
C
103. What specimen type should be gently minced before inoculating fungal media? A. Cerebrospinal fluid (CSF) B. Sputum C. Urine D. Tissue
D
138. What is the proper method for examining a trichrome stained smear using bright field microscopy? A. Scan the slide using fluorescent microscopy, not bright field microscopy. B. Scan the thick areas of the slide using oil immersion (100X) only. C. Scan the thin areas of the slide on low power (10X or 40X) only. D. Scan the slide on low power (10X or 40X) first, then switch to oil immersion (100X) and scan the thin areas of the slide.
D
141. The formula for oxidative/fermentative (OF) culture media, for the determination of glucose oxidizers, differs from carbohydrate fermentation media by each of the following properties except: A. Relative decrease in the protein concentration B. Relative increase in the carbohydrate concentration C. Relative decrease in the agar concentration D. Relative increase in the salt concentration
D
150. When an unpreserved urine specimen cannot be cultured immediately, which storage method is most appropriate? A. Stored at room temperature for up to 8 hours B. Stored in freezer for up to 24 hours C. Stored in the incubator for up to 8 hours D. Stored in the refrigerator at 4° C for up to 24 hours
D
151. All of the following statements are true regarding the significance of performing direct microscopic examinations of specimens for culture, EXCEPT: A. Provide a quality control comparison to the culture for actual isolates recovered. B. It can provide the physician with a rapid presumptive diagnosis. C. May serve as a guide for selecting appropriate culture media based on microorganisms observed. D. Allows the microbiologist to discard the sample and cancel testing if no organisms are observed.
D
10. A vascular catheter tip is received in the laboratory for aerobic culture. How should the tech proceed in processing this specimen for culture? A. Touch each agar plate with the end of the catheter tip B. Roll the catheter tip across the surface of the agar 4 times C. Add 1.0 mL of saline to the catheter tip and vortex D. Inoculate the catheter tip in a thioglycolate broth
B
13. A quality control program is to be set up for the following tests: -Phenylalanine deaminase (PAD) -Indole production -Voges-Proskauer (V-P) Which pair of stock culture organisms would be most suitable to verify the performance of these three tests? A. Proteus vulgaris, Escherichia coli B. Klebsiella pneumoniae, P. vulgaris C. E. coli, Enterobacter aerogenes D. E. aerogenes, K. pneumoniae
B
54. In the microbiology laboratory, the following specimens are received at the same time. Which specimen is classified as a level 1 specimen, requiring immediate processing? A. Catheter tip for quantitation B. Swab in transport medium C. Amniotic fluid D. Unpreserved feces
C
1. When using an iodine mount to examine a fecal specimen for intestinal protozoa or helminth ova, is it still necessary to perform a saline mount? Why? A. No, the iodine mount is superior to a saline mount. B. No, the saline mount would yield the same results as the iodine mount. C. Yes, the iodine used in an iodine mount paralyzes the motility of protozoan trophozoites. D. Yes, the saline mount is used to confirm the iodine mount results.
C
15. Acridine orange is used to detect the presence of which of the following? A. Parasites B. Viruses C. Bacteria D. Molds
C
12. Which phase of the bacterial growth curve demonstrates the greatest growth activity? A. Lag phase B. Stationary phase C. Death phase D. Log phase
D
16. A KOH mount is used to detect which of the following microorganisms? A. Entamoeba histolytica B. Pseudomonas aeruginosa C. Staphylococcus aureus D. Aspergillus fumigatus
D
18. Which of the following media would you use to isolate Francisella tularensis: A. Sheep-blood agar B. Lowenstein-Jensen media C. Bordet-Gengou media D. Cysteine-blood agar
D
109. A vaginal swab for anaerobic culture is received in the laboratory. How should this specimen be handled? A. The specimen should be processed for culture B. The specimen should be rejected C. The order should be changed to an aerobic culture D. The specimen should be discarded
B
122. You are processing a Level 1 specimen for culture when two other specimens arrive for processing. The two specimens are: -Sputum for sputum culture -Urine in a boric acid transport tube for urine culture How would you handle the processing of these two new specimens? A. Stop processing the Level 1 specimen and process the sputum culture B. Place the sputum culture in the refrigerator, leave the urine at room temperature, and continue processing the Level 1 specimen C. Leave the sputum and urine specimens at room temperature and continue processing the Level 1 specimen D. Stop processing the Level 1 specimen and process the urine culture
B
132. At a minimum, the following class of biological safety cabinet (BSC) must be used when manipulating potential bioterrorism agents and if aerosols are likely: A. Class I BSC B. Class II BSC C. Class III BSC D. Class IV BSC
B
134. Which of the following organisms display the characteristic "Medusa head" on 5% sheep blood agar (SBA) after 18 hours of incubation at 35°C? A. Yersinia pestis B. Bacillus anthracis C. Francisella tularensis D. Brucella abortus
B
135. Which stain is a colorless dye that binds to chitin in fungi and fluoresces with ultraviolet light? A. Gram stain B. Calcofluor white C. Acridine orange D. Trichome
B
140. All of the following are true concerning clinical specimens that are gram stained before culturing, EXCEPT: A. The gram stain allows you to judge the quality of the specimen. B. The gram stain provides the clinician with same day information regarding possible pathogenic organisms. C. The gram stain eliminates the need for a culture. D. The gram stain provides internal quality control when direct smear results are compared to culture results.
C
142. Thick Giemsa-stained blood smears are primarily used to screen for the presence of: A. Paragonimus westermani B. Toxoplasma gondii C. Plasmodium species D. Onchocerca volvulus
C
143. Which organisms are the appropriate stock cultures for quality control testing of oxidase production? A. Escherichia coli / Klebsiella pneumoniae B. Salmonella typhimurium / Escherichia coli C. Escherichia coli / Pseudomonas aeruginosa D. Proteus mirabilis / Escherichia coli
C
145. Sodium thiosulfate is often added to selective culture media to: A. Detect hydrogen sulfide B. Inhibit the growth of gram positive bacteria C. Provide sulfur atoms for H2S positive isolates D. Serve as a pH buffer
C
149. Which site listed below should be accepted for a rapid strep screen? A. Tongue B. Cheek C. Peritonsillar fossae D. Nares
C
119. Which of the following is the ideal method for processing wound swab specimens for a Gram stain and culture? A. Specimen should be collected on a single swab that should be used to directly inoculate all media and prepare the smear. B. Specimen should be collected on a dual swab collection device, in order to allow for one swab to be used to directly inoculate all media and prepare the smear, while the second swab should be stored in case additional testing is requested. C. Specimen should be collected on a dual swab collection device, in order to prepare a smear with one swab, while the second swab should be centrifuged to create a concentrated specimen. D. Specimen should be collected on a single swab that will be placed in 1.0 mL of saline and vortexed. The saline solution should then be used to inoculate all media and prepare the smear.
D
121. Which Pseudomonas species produces pyocyanin (bright bluish pigment on Mueller-Hinton agar)? A. Pseudomonas fluorescens B. Pseudomonas putida C. Pseudomonas veronii D. Pseudomonas aeruginosa
D
124. All of the following are types of acid-fast stains, EXCEPT: A. Ziehl-Neelsen B. Fluorochrome C. Kinyoun D. Calcofluor white
D
129. All of the following aerobic agars can be set up along with the anaerobic media, EXCEPT? A. 5% sheep blood agar B. Chocolate agar C. MacConkey agar D. Columbia colistin-nalidixic acid agar
D
19. Cocci may arrange as diplococci, tetrads, chains and clusters. The morphologic arrangement of the genus Staphylococcus is: A. Singly B. Diplococci C. Chains D. Clusters
D
101. What is the main problem with the acridine orange stain? A. It is difficult to distinguish between organisms and debris. B. Once a bacterium is detected, a Gram stain must be used to determine differential staining characteristics. C. The reagents used are highly toxic. D. The stain will only detect live bacteria.
B
106. A presumptive identification of a bacterial species can often be made by observing the type of hemolysis when grown on 5% sheep blood agar. Which of the following organisms is nearly always alpha hemolytic? A. Streptococcus pyogenes B. Streptococcus pneumoniae C. Enterococcus spp. D. Streptococcus agalactiae
B
139. A gram-negative coccobacillus produces small gray colonies surrounded by a zone of hemolysis on potato-blood-glycerol agar. The organism also grew on chocolate agar, but NOT on sheep blood agar. This is MOST likely to be which organism? A. Alcaliqenes fecalis B. Bordetella pertussis C. Franciscella tularensis D. Hemophilus influenzae
B
49. Which of the following culture media bests supports the growth/identification of Salmonella species? A. Chocolate agar B. Chopped meat broth C. Columbia CNA agar w/blood D. Hektoen enteric agar
D
63. If you receive a transudate fluid for a Gram stain and bacterial culture, what is the ideal specimen preparation method for the bacterial culture? A. Use centrifugation to concentrate the sample; then using the pellet to inoculate the media. B. Use centrifugation to concentrate the sample; then using the supernatant to inoculate the media. C. Dip a swab in the original sample and use this swab to inoculate the media. D. Use a sterile pipette to draw up the original sample and use this fluid to inoculate the media.
A
8. The subsurface umbrella-shaped zone of motility seen in a SIM tube is characteristic of Listeria monocytogenes. The optimum temperature of incubation to best illustrate this property is: A. 25°C B. 30°C C. 35°C D. 42°C
A
81. A 27-year-old man who had recently worked as a medical laboratory scientist on the Navajo Native American reservation presented to the emergency department with high fever, diarrhea, and prostration. Axillary lymph nodes were hemorrhagic and enlarged. A smear was prepared from a lymph node aspirate and many Gram negative bacilli were noted. The bacilli demonstrated a marked bipolar staining reaction described as a "safety-pin appearance" with Wayson stain. What is the most likely identification of this organism? A. Yersinia pestis B. Streptobacillus moniliformis C. Capnocytophaga D. Brucella melitensis
A
85. Which of the the following bioterrorism agent categories is the easiest to spread, has the ability to cause major harm, panic, and death, and carries the highest level of risk with regard to national security? A. Category A B. Category B C. Category C D. Category D
A
9. All of the following choices are acceptable specimens for anaerobic culture, EXCEPT? A. Throat swab B. Tissue biopsy C. Abscess aspirate D. Synovial fluid
A
86. Which of the following stains binds the nucleic acids of the cells and requires a florescent microscope for reading? A. Calcoflour-white stain B. Acridine orange stain C. Acid-fast stain D. Lactophenol cotton blue stain
B
89. Which of the following stains binds to nucleic acid to aid in the detection of cell wall deficient organisms? A. Crystal Violet B. Acridine Orange C. Calcofluor White D. Auramine-Rodamine
B
90. Which of the following is a nonfermenter? A. Escherichia coli B. Pseudomonas aeruginosa C. Yersinia enterocolitica D. Serratia marcescens
B
97. A swab specimen from a wound culture is received in the laboratory. How should this specimen be processed for culture and Gram stain? A. Roll swab back and forth on the slide, then inoculate the agar plates for culture B. Inoculate organism plates for culture, then roll the swab back and forth on the slide C. Rub swab back and forth across the slide, then inoculate agar plates for culture D. Inoculate agar plates for culture, then touch one area of the slide with the swab
B
80. What biosafety level (BSL) is required by the Centers for Disease Control and Prevention (CDC) for working with Mycobacterium tuberculosis, if there is a possibility that aerosols might be released? A. BSL-1 B. BSL-2 C. BSL-3 D. BSL-4
C
11. Which is the most commonly reported organism in cases of laboratory-acquired bacterial infection? A. Francisella tularensis B. Brucella species C. Burkholderia species D. Yersinia pestis
B
17. Malassezia furfur is the cause of tinea versicolor. To cultivate this organism, the agar should be overlaid with: A. Water B. Olive oil C. India ink D. Ethanol
B
25. Which of the following is most commonly used as a routine staining technique in the clinical microbiology laboratory? A. Wright's B. Gram C. Giemsa D. Wright's/Giemsa
B
27. The infectious disease process in which large numbers of activated macrophages and histiocytes are collected at the site of inflammation is called? A. Purulent B. Granulomatous C. Chronic D. Opportunistic
B
47. Which of the following organisms are Gram positive? A. Pasteurella B. Erysipelothrix C. Aeromonas D. Fusobacterium.
B
100. A tissue sample is received in the laboratory for routine aerobic culture. How should the tech prepare the sample for inoculation onto agar plates? A. Touch each agar plate with the piece of tissue B. Roll the tissue across each agar plate C. Use a tissue grinder to homogenize the sample D. Add 1.0 mL of saline to the sample and vortex
C
2. A tech in the laboratory is reading a Gram stain from a cerebrospinal fluid. After searching the entire length of the slide for a few minutes, the tech was unable to location any material (cells or bacteria) on the slide. How should the tech proceed? A. Report out Gram stain as no organisms seen and no white blood cells seen B. Continue searching more of the slide C. Prepare a new slide by using cytocentrifugation D. Request a new specimen
C
22. The calcofluor white stain can be used not only to help in the identification of fungi, but can be used to visualize which of the following? A. Bacteria B. Mycobacteria C. Microsporidia D. Amoeba
C
24. Bordet-Gengou plates are used to isolate: A. Mycobacterium tuberculosis B. Corynebacterium diphtheriae C. Bordetella pertussis D. Haemophilus influenzae
C
45 Which of the following choices represents the characteristic indicator, fermentable sugar(s), and bacteriostatic agent(s) that are present in MacConkey agar respectively? A. Phenol red / lactose, sucrose, and xylose / sodium desoxycholate and bile salts B. Eosin Y and methylene blue / lactose and sucrose / Eosin Y and methylene blue C. Bromothymol blue / lactose, salicin and sucrose / bile salts D. Neutral red / lactose / bile salts and crystal violet
D
14. All of the following media types should be inoculated for cerebrospinal fluid (CSF), EXCEPT: A. Brucella agar plate (BRU) B. Sheep blood agar plate (SAP) C. Chocolate agar plate (CHOC) D. Trypticase soy broth (TSB)
A
23. The following media contains specific nutrients that encourage the growth of a pathogen over the growth of other bacteria from a specimen. It is useful in the isolation of stool pathogens such as Salmonella and Shigella, the isolation of anaerobes, and the selective isolation of group B streptococci. A. Nutritive media B. Selective media C. Enrichment media D. Differential media
C
28. Gram positive cocci in clusters and tetrads were seen on a clinical Gram stain taken from an open wound. Which of the following would be the MOST appropriate preliminary report? A. Gram positive cocci resembling staphylococci B. Gram positive cocci resembling micrococci C. Gram positive cocci in clusters and tetrads D. Insufficient data to issue a preliminary report
C
30 Which statement about bacterial culture for Clostridioides (Clostridium) difficile is TRUE? A. Routine bacteriological media will provide adequate recovery. B. The culture is specific for toxigenic strains. C. Culture on appropriate media provides an effective means of recovering the organism. D. Culture for C. difficile provides desirable turnaround times.
C
44. The Thayer-Martin agar plate exhibits marked growth. The most likely organism found here would be: A. Staphylococcus aureus B. Streptococcus pyogenes C. Neisseria gonorrhoeae D. Shigella sp.
C
34. All of the following statements about blood cultures are correct, EXCEPT: A. The volume of blood collected is important. Short draws will reduce the likelihood of successfully growing out bacteria. B. If two separate sets of blood cultures are requested, do not draw them both from the same site at the same time. C. Be sure to allow the iodine prep to dry on the patient's skin prior to performing the blood culture. D. Since latex gloves are sterile, you may use your gloved finger without further preparation to feel the vein on a prepped arm before making the stick.
D
43. Which combination of test/quality control organisms is correct? (One organism positive for the test and one organism negative for the test) A. Coagulase: Staphylococcus saprophyticus and Staphylococcus epidermidis B. H2S production: Proteus mirabilis and Salmonella serotype Typhi C. Phenylalanine deamination: Escherichia coli and Yersinia enterocolitica D. Indole: Escherichia coli and Proteus mirabilis
D
46. In the microbiology laboratory, four specimens are received at the same time. The specimen that should be processed immediately is: A. Unpreserved sputum B. Feces in preservative C. Tissue for quantitation D. Pericardial fluid
D
57. All of the following sample types should be accepted for a lower respiratory culture, EXCEPT: A. Endotracheal aspirate B. Expectorated sputum C. Bronchoalveolar lavage D. Posterior pharynx swab
D
60. Which one of the following combinations of organisms would be appropriate positive and negative controls to verify the specific test functions listed? A. Beta hemolysis - Escherichia coli and Streptococcus pyogenes B. Catalase - Staphylococcus aureus and Staphylococcus epidermidis C. Hydrogen sulfide production - Proteus mirabilis and Salmonella typhi D. Indole - Escherichia coli and Klebsiella pneumonia
D
69. This medium is used for the cultivation and identification of Corynebacterium diphtheria. It contains serum and egg which stimulates growth and the production of metachromatic granules in the cells. Select this media from the following. A. CIN medium B. TCBS medium C. Modified Tinsdale medium D. Loeffler medium
D
74. A mixture of Gram positive and Gram negative bacteria may be present within the same field of a slide of all of the following EXCEPT: A. Mixed wound infections B. Urine sediment from a mid-stream catch specimen C. Expectorated sputum specimen D. Sterile cerebrospinal fluid
D
66. The process of freeze drying of bacteria is called: A. Agglutination B. Inhibition C. Lyophilization D. Precipitation
C
88. Chocolate agar is recommended for the detection of Haemophilus species as it contains the following: A. NADase B. Lactose C. Whole blood D. Hemin and NAD
D
70. If a Brucella species is suspected in a blood culture, it should be held for a maximum of how many days on a commercial blood culture system? A. 2-5 B. 5-7 C. 10-14 D. 14-21
C
91. What is the first test always performed on organisms growing on solid or liquid mycobacterial media? A. Rate of growth B. Pigment production C. Catalase D. Acid-fast staining
D
59. A pleural fluid specimen is received in the laboratory for aerobic culture. The specimen measures about 0.5 mL. How should the tech process this specimen for culture? A. Use a sterile pipette and add a drop of fluid per agar plate B. Insert a swab into the specimen container and inoculate all agar plates C. Add 0.5 mL of saline to the 0.5 mL of fluid, vortex, and inoculate plates D. Reject the specimen due to insufficient quantity for culture
A
72. A swab is submitted for an influenza screen. The swab used is a cotton swab with a wooden shaft that was placed in a moist transport container. What is the most appropriate next step in this scenario? A. Call the RN or physician to confirm that the site of collection was the nasopharyngeal area. B. Call the RN or physician to let them know that the specimen is unacceptable, and it should be recollected. C. Proceed with processing the specimen in the LIS and begin testing. D. Do not proceed, the specimen is unacceptable, and you should throw the swab in the trash.
B
78. Which culture agar combinations below will be MOST sufficient for routine urine culture investigations? A. 5% sheep blood and Chocolate B. 5% sheep blood and MacConkey C. 5% sheep blood and Thayer-Martin D. MacConkey and Eosin Methylene Blue
B
84. The staining reaction for yeast is: A. Gram negative B. Gram positive C. Kinyoun positive D. Ziehl-Neelsen positive
B
91. A patient is showing signs of an intravenous catheter associated infection. The physician has removed the catheter and sent the catheter tip along with a skin swab of the catheter site to the laboratory for testing. The physician ordered a Gram stain of the skin entry site and a culture of the catheter tip. On which of the following media should the catheter tip be plated? A. GN Broth and Sheep Blood Agar B. Sheep Blood Agar and Thioglycollate Broth C. Thayer Martin and SIM Broth D. Sheep Blood Agar and Bismuth Sulfite Broth
B
93. Which of the following stains is commonly used to stain chitin in fungal cell walls? A. Modified acid-fast stain B. Calcoflur-white stain C. Giemsa stain D. Gram stain
B
94. Host cells (e.g., white blood cells, epithelial cells) will appear what color on a properly stained Gram stain? A. Violet B. Pink C. Orange D. They do not pick up either stain and will appear colorless
B
95. MacConkey agar without crystal violet is a culture medium useful in the presumptive identification of: A. Mycoplasma pneumoniae B. Mycobacterium fortuitum C. Legionella pneumophila D. Vibrio parahemolyticus
B
98. A thick peptidoglycan cell wall is MOST often associated with which of the following? A. Gram negative bacteria B. Gram positive bacteria C. Both Gram negative and Gram positive bacteria D. Yeast
B
56. All of the following are roles of a sentinel microbiology laboratory, EXCEPT? A. Rule out pathogens B. Make the determination that a bioterrorist event has occurred C. Transfer suspicious specimens to reference laboratories D. Be familiar with likely agents involved in a bio crime
B
58. All of the following information should be included in a direct microscopic examination of a Gram stained culture smear report EXCEPT: A. Shape and morphological arrangement of bacterial cells B. Size of bacteria C. Gram stain reaction D. White blood cells and squamous epithelial cells.
B
67. Which of the following organisms are Gram negative? A. Bacillus B. Vibrio C. Staphylococcus D. Nocardia
B
71. The recommended temperature/time/pressure for routine steam sterilization of media is: A. 121° C for 8-10 minutes @ 10 psi B. 121° C for 12-15 minutes @ 15 psi C. 220° C for 8-10 minutes @ 10 psi D. 220° C for 12-15 minutes @ 15 psi
B
29. Gram stains are performed on positive blood culture bottles. Each of the following responses correctly matches the organism with its description EXCEPT: A. Large, gram-positive rods with square ends occurring in short or long chains = Bacillus anthracis B. Small gam-negative coccobacillus or bacillus demonstrating bipolar staining = Yersinia pestis C. Very tiny, pale staining, gram-negative coccobacillus often arranging in pairs = Fusobacterium species D. Small, gram-negative coccobacilli that may stain very faintly or appear gram-positive due to retention of crystal violet stain; individual cells present = Brucella species
C
31. Which of the following is the preferred specimen type to culture a soft tissue infection? A. Swab from the surface of the wound B. .Swab from deep in the center of the wound. C. Fluid or exudate expressed directly into a sterile specimen cup. D. Swab from any portion of the wound.
C
82. An expectorated sputum specimen is received for culture at your laboratory. You are preparing to make slides and inoculate the media and are observing the gross appearance of the specimen. The specimen is a mixture of watery, bloody, and purulent material. Which area(s) of the specimen is most likely indicated for culture and slides? A. Any area is acceptable for culture and slide preparation. B. Only the watery portion of the specimen is most indicated for culture and slide preparation. C. The bloody and purulent areas of the specimen are most indicated for culture and slide preparation. D. An equal sampling of the watery, bloody, and purulent areas are most indicated for culture and slide preparation.
C
20. A microbiologist performed a Gram stain procedure on a sputum specimen and was unable to determine if what was seen on the smear were tiny, Gram negative organisms or stain debris. Which of the following stains would help the microbiologist make a correct determination? A. Acridine Orange B. Crystal Violet C. Calcofluor White D. Auramine-Rhodamine
A
6. In order to obtain an appropriate specimen before preparing a smear for acid-fast bacilli staining in a sputum sample, what must be done to the original sample? A. Mincing or grinding B. Concentration and centrifugation C. Digestion and decontamination D. Nothing needs to be done to the original specimen
C
61. In the following list of organisms, which organism is considered cryophilic (can grow as low as 4° C)? A. Escherichia coli B. Pseudomonas aeruginosa C. Yersinia enterocolitica D. Campylobacter jejuni
C
128. From the four specimens listed for Gram stain and culture, which one should be rejected? A. Synovial fluid in a sterile heparinized syringe for aerobic culture B. Peritoneal fluid in sterile sodium polyanethol sulfonate (SPS) tube for aerobic culture C. Expectorated sputum in sterile container for anaerobic culture D. Vaginal secretions on polyester swab in sterile saline for aerobic culture
C
148. Which of the following characteristics will produce the most desirable smear to be examined using a Gram stain? A. A single drop of cerebrospinal fluid on a slide B. Thick, opaque material from an abscess on a slide C. Thin, monolayer of material from an abscess on a slide D. Six drops of blood from an EDTA tube on a slide
C
35. Smears that are appropriately stained using acridine orange should be examined using which of the following? A. Bright field microscopy B. Polarizing microscopy C. Ultraviolet microscopy D. Phase contrast microscopy
C
36. Each of the following practices will better ensure the successful recovery of Campylobacter jejuni from stool specimens except: A. Incubation at 42°C B. Use of Campy BAP medium C. Use of selenite enrichment broth D. Incubation in an atmosphere of 5% O2, 10% CO2 and 85% N2
C
38. A tech in the laboratory receives a cerebrospinal fluid (CSF) culture for Gram stain and culture. What steps are needed for best slide preparation of the specimen? A. Use a sterile swab to spread CSF on slide B. Use a sterile swab to obtain CSF and roll swab back and forth on the slide C. Use cytocentrifugation to prepare slide D. Place a portion of sample on the slide, press a second slide onto the sample, and pull the slide away to provide a thin film of sample
C
39. Regarding specimens for legal testing, which one of the following is false? A. Chain of custody must be maintained at all times. B. Sealed collection kits should be opened in the presence of the donor individual. C. Use an alcohol prep pad when cleaning the phlebotomy site prior to collecting a blood alcohol specimen. D. Carefully follow the instructions in the collection kit, as you may be called to testify as to how you collected the specimen, and documented its authenticity.
C
53. Each of the following characteristics is prerequisite for a bacterial species to be classified within the family Enterobacteriaceae except: A. Gram negative organism B. Bacilli shaped C. Motility via peritrichous flagellae D. Fermentation of glucose
C
54. Which of the following media contains the X and V factors necessary for the growth of Haemophilus influenzae? A. Thayer-Martin agar B. Xylose lysine deoxycholate agar C. Chocolate agar D. Thiosulfate citrate-bile salts agar
C
64. A large container of peritoneal fluid is received in the laboratory (about 50 mL). How should the tech process this sample for aerobic culture? A. Use a sterile pipette and add a drop of fluid per agar plate B. Insert a swab into the specimen container and inoculate all agar plates C. Centrifuge the specimen and use the sediment to inoculate the agar plates D. Add 1 mL of saline to 1 mL of fluid, vortex, and inoculate plates
C
73. All of the following organisms stain with an acid-fast stain, or one of its variants, EXCEPT? A. Mycobacterium spp. B. Cryptosporidium spp. C. Actinomyces spp. D. Nocardia spp.
C
102. Which of the following is a selective media recommended for the isolation of Clostridium difficile? A. Cefoxitin-cycloserine-fructose agar (CCFA) B. Buffered-charcoal yeast extract(BCYE) agar C. Kanamycin Vancomycin laked blood (LKV) agar D. Thiosulphate citrate bile salts sucrose (TCBS) agar
A
107. To ensure quality within the preanalytical phase of laboratory testing, quality assurance activities includes monitoring all of the following preanalytical variables EXCEPT: A. Selection of reference materials used for validation purposes. B. Laboratory test utilization. C. Positive patient identification. D. The stability of patient specimens during transport.
A
108. Carbolfuchsin binds to mycolic acid in cell walls with high lipid/wax content and is retained after decolorizing, preventing counterstaining with methylene blue. This principle describes: A. Kinyoun acid-fast staining B. Gram staining C. Negative staining of yeast capsules D. Schaefer-Fulton bacterial endospore staining
A
131. Identification of intestinal microsporidial spores is usually done by using which of the listed stains? A. Modified trichrome stain B. Modified acid-fast stain C. Gram stain D. Giemsa stain
A
133. What is the purpose of allowing a prepared KOH mount to sit for 30 minutes? A. To dissolve the background keratin and reveal fungal elements. B. To dissolve the chitin in the fungal elements. C. To dissolve the peptidoglycan of the bacteria. D. A prepared KOH mount should not be allowed to sit, it should be viewed immediately.
A
144. Which of the following is a characteristic of Francisella tularensis? A. Tiny, weak-staining, gram-negative coccobacilli B. Oxidase and urease positive C. Subcultures grow easily and quickly on sheep blood agar (SBA) D. Tiny, gram-positive rods
A
147. Bordet-Gengou potato infusion agar is the medium of choice for the recovery of which one of the following organisms? A. Bordetella pertussis B. Corynebacterium diphtheriae C. Haemophilus influenzae D. Neisseria meningitidis
A
111. The best clinical specimen for the recovery of Legionella pneumophilia is: A. Nasopharyngeal swab B. Wound aspirate C. Stool D. Bronchial washings
D
113. Which of the following two media are appropriate for Bordetella pertussis isolation? A. Thayer-Martin media and Lowenstein-Jenson media B. Cefsolodin-Irgasin-Novobiocin agar and kanamycin-vancomycin agar C. Buffered charcoal yeast extract and thiosulfate citrate bile salts sucrose agar D. Regan-Lowe charcoal agar and Bordet Gengou media
D
3. Procedures that may enhance the recovery of Streptococcus pyogenes from throat cultures include: A. Extraction of streptococcal grouping antigen B. Incorporation of sulfamethoxazole and trimethoprim in the culture media C. Incubation at 42° C D. Use of culture media with increased concentrations of glucose
B
50. What reagent should be used in conjunction with calcofluor white when preparing the fungal slide for interpretation? A. India ink B. Potassium hydroxide (KOH) C. Periodic-acid Schiff (PAS) D. Fontana-Masson
B
7. A gram positive bacillus that has a rod-coccus cycle (short, thin rods in young cultures and cocci in older cultures) and an odor resembling cheese is: A. Rothia spp. B. Corynebacterium diphtheriae C. Brevibacterium spp. D. Dermabacter hominis
C
75. A flagellar stain would show peritrichous flagella for each of the following organisms except: A. Bordetella bronchiseptica B. Alcaligenes faecalis C. Pseudomonas aeruginosa D. Escherichia coli
C
76. The federal government has categorized critical biological agents into three groups: A, B, and C. Why are the agents in category A classified as the highest-priority? A. These organisms cause moderate morbidity and low mortality. B. These organisms could be engineered for mass dissemination at some future date. C. These organisms can be easily disseminated or transmitted person-to-person. D. The organisms are not easily disseminated and do not cause high morbidity rates.
C
77. Loeffler's medium is useful in making the presumptive identification of isolates suspicious for Corynebacterium diphtheriae recovered from oropharyngeal cultures because it: A. Inhibits the growth of contaminating bacteria B. Detects the production of H2S C. Enhances granule formation as seen in methylene blue stains D. Screens out the toxin producing strains
C
79. Lysine iron agar is a less commonly used culture medium that is most helpful in the identification of: A. Shigella sonnei B. Citrobacter freundii C. Salmonella enteritidis D. Proteus mirabilis
C
87. The media used to isolate Legionella pneumophilia should contain which of the following additives? A. X and V factors B. Hemin and vitamin K C. Charcoal and yeast extract D. Dextrose and laked blood
C
96. With regard to blood cultures, which blood to broth ratio is most conducive to growth? A. 1 : 1 B. 1 : 2 C. 1 : 10 D. 10 : 1
C