LabCE Modules - Microbiology Microbial Identification Using MALDI-TOF MS
How do T. marneffei yeast-forms replicate? A. Fission B. Budding C. Fusion D. Apoptosis
A
1. A hypervirulent strain, commonly referred to as "strain 027" is an aggressive strain of C. diff that produces more toxins and is more resistant to certain medications a. true b. false
A
10. Disease symptoms of prion diseases are believed to be the result of dense aggregates of amyloid fibers. A. True B. False
A
10. Once symptoms appear, human prion diseases are always fatal. A. True B. False
A
10. What is the median age for individuals with variant Creutzfeldt-Jakob (vCJD) disease? A. 28 B. 68 C. 50 D. 75
A
10. What types of tissues are considered to be at high risk of transmission of the bovine spongiform encephalopathy (BSE) agent? A. Tissues from the central nervous system (CNS) B. Liver and other organ meats C. Muscle tissue D. Fatty tissue
A
11. A class II, or higher, biological safety cabinet (BSC) must be used when manipulating potential bioterrorism agents or if aerosols are likely. A. True B. False
A
11. A respiratory culture is submitted to the microbiology laboratory for testing. An organism displaying the following characteristics is recovered: -Gram stain shows fat, gram-negative rods in single or short chains that may demonstrate bipolar staining -Faster growth at 25C -Gray-white, translucent colonies on sheep blood agar (SBA) at 24 hours that turn slightly yellow and opaque at 48 hours Irregular colonies that have a "fried egg" and/or "hammered copper" appearance after 48-72 hours -Catalase positive -Oxidase negative -Urea negative -Indole negative The organism should immediately be referred to a Laboratory Response Network (LRN) reference laboratory for confirmatory testing. A. True B. False
A
11. A sentinel laboratory should NOT accept or process environmental or animal samples or culture clinical specimens for viruses or toxins that are potential agents of bioterrorism. A. True B. False
A
11. Match the organism that MOST closely resembles the description of the Gram stain morphology provided. Large, gram-positive rods with square ends in short chains A. Bacillus anthracis B. Yersinia pestis C. Francisella tularensis D. Brucells species
A
11. When following sentinel laboratory procedures and protocols, any isolate that cannot be ruled out as one of the select agents should be immediately referred to your LRN reference laboratory. A. True B. False
A
11. Which of the 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
A
11. 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
12. If a smear is over-decolorized, it can be salvaged by repeating the Gram staining procedure. A. True B. False
A
12. Information from Gram stained direct smears may help the physician make a preliminary diagnosis when the Gram stain information is combined with clinical information. A. True B. False
A
12. The presence of intracellular gram-negative diplococci on a smear made from a purulent urethral discharge from a male can be confirmatory of the diagnosis of gonorrhea. A. True B. False
A
12. What color is the background material in a Gram-stained smear that has been adequately decolorized? A. pink B. blue C. purple
A
12. Which of the following best describes yeast cells on a Gram stain as to size and staining characteristics? A. About the same size as red blood cells/will stain blue B. About the same size as red blood cells/will stain pink C. About the same size as white blood cells/will stain blue D. About the same size as bacteria/will stain pink
A
13. Bacilli can have tapered or rounded ends. A. True B. False
A
13. Match the Gram stain characteristic to the organism it BEST describes. Branching, long, thin filamentous gram-positive rods; tend to stain with a beaded, gram-variable pattern A. Nocardia spp. B. Neisseria spp. C. Staphylococcus spp. D. Corynebacterium spp.
A
13. When reading the Gram stain of a DIRECT smear, the presence of characteristic cellular arrangements is helpful in providing information as to the organisms that are present. Reporting these cellular arrangements is an important component of the report. However, the arrangement of bacterial cells in a Gram stained smear prepared from a CULTURE should be noted, but not usually reported. A. True B. False
A
14. For tuberculosis (TB) patients, the success of sanatorium treatment was based on a combination of several different factors. Which of the factors listed was NOT part of the formula responsible for successful sanatorium treatment? A. Antibiotic therapy B. Isolation C. Rest and exposure to fresh air D. Good nutrition
A
14. What are the BEST general methods of Mycobacterium tubercolsis (MTB) treatment and control according to the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO)? A. The directly observed treatment short course (DOTS) program, genotyping, and the tuberculin skin test (TST) B. Use of the anti-tuberculosis drugs isoniazid (INH), rifampin (RIF), ethambutol (EMB), para-aminosalicylic acid (PAS), and streptomycin (SM) C. Linezolid and at least three other drugs for 7-8 months D. The TST, interferon-gamma release assays (IGRA), and bacille Calmette-Guerin (BCG) for children and high-risk adults
A
14. What factors BEST determine the advantages of the Xpert® method of rifampin (RIF) resistance detection? A. No infectious aerosols produced, short technician training, 2-hour results B. Real-time PCR assay amplifies the rpoB gene region C. The method is affordable for use in developing countries D. Use of molecular beams are highly specific for MTBC
A
5. Blood and tissue parasites are part of the Neglected Tropical Diseases which are diseases that affect 1 billion people worldwide in countries of low income. A. True B. False
A
5. Chloroquine-sensitive non-falciparum malaria is treated with chloroquine or artemisinin combination therapy (ACT). A. True B. False
A
5. In what part of the Anopheles' body do the sexual forms complete their life cycle? A. Midgut B. Ovary C. Testes D. Anus
A
5. Parasite density usually correlates with severity of illness. A. True B. False
A
5. Plasmodium falciparum, Plasmodium vivax, and Plasmodium ovale all have tertian (two-day) cycles. A. True B. False
A
5. Plasmodium ovale infections tend to be less severe than Plasmodium vivax. A. True B. False
A
5. Rapid diagnostic tests (RDT) provide a qualitative result, but cannot provide quantitative information regarding parasite density. A. True B. False
A
5. Red blood cells infected by malarial parasites can clog small vessels and cause cerebral malaria when small vessels are clogged in the brain. A. True B. False
A
5. The pathologist on call is on his/her way and you receive a thin smear to evaluate for the percent infected RBCs. Calculate the percent infected RBCs given that you find 10 infected RBCs and you count a total of 800. A. 1.3% B. 2.5% C. 3% D. 5%
A
5. There are more than 100 species of Plasmodium which can infect many animal species such as reptiles, birds and various mammals. A. True B. False
A
5. What is the erythrocytic cycle of Plasmodium knowlesi? A. 24 hours B. 36 hours C. 48 hours D. 72 hours
A
6 The two types of target plates primarily used for microorganism identification are reusable and disposable. A. True B. False
A
6. Both solid and liquid media can be used for bacterial identification by MALDI-TOF MS? A. True B. False
A
6. Clinical laboratories must verify or validate instrumentation and the associated databases prior to utilization for clinical diagnostics. A. True B. False
A
6. Shigella and Escherichia coli are so closely related that they cannot be distinguished by MALDI-TOF MS. A. True B. False
A
6. What are the three key/major components of a MALDI-TOF MS instrument? A. Laser, vacuum, and detector B. Matrix, organism, and template C. Template, matrix, and decontaminant D. Organism, toothpick, and template
A
6. When making a MALDI-TOF run, care must be taken in picking a colony from plated media, so as to avoid carry over of media proteins and other interfering substances. A. True B. False
A
6. Which best describes the type of workflow approach that relies on a single laboratory station to process the target plate? A. centralized B. decentralized
A
7. Which statement about molecular detection of Clostridium difficile is NOT true? A. Polymerase chain reaction (PCR) has a substantially better positive predictive value than other methods. B. PCR has a substantially better negative predictive value than other methods. C. Molecular detection is based on the detection of the tcd gene. D. Results can be made available within 2 to 3 hours.
A
8. The differentiation between Aspergillus species and Scedosporium species may be difficult when only hyphal elements are observed in stained tissue sections. It is important to obtain a culture to make this differentiation when possible because Scedosporium species, in contrast to Aspergillus species, tend to be resistant to: A. Amphotericin B B. The imidazoles C. Flucytosine D. Tolnaftate
A
8. The hyaline saprobic fungus that has microscopic features similar to the mold form of Coccidioides immitis is: A. Malbranchea species B. Geotrichum species C. Trichosporon species D. Microsporum canis
A
8. What classification of infection is Acremonium spp. most commonly assoicated? A. Opportunistic pathogen B. Obligate pathogen
A
8. What classification of infection is Aspergillus fumigatus most commonly assoicated? A. Opportunistic pathogen B. Obligate pathogen
A
8. What classification of infection is Rhizopus spp. most commonly assoicated? A. Opportunistic pathogen B. Obligate pathogen
A
8. What is the morphologic feature of Bipolaris spp.? A. Polar germ tubes B. Dictyospores C. Urn-shaped phialides D. Black yeast colony
A
8. What is the most likely disease caused by Cladosporium trichoides (Xylohypha bantianum)? A. Brain abscess B. Chronic sinusitis C. Chromomycosis D. Subcutaneous Phaeohyphomycotic cyst
A
8. What taxonomic category is Epidermophyton floccosum apart of? A. Dermatophyte B. Zygomycete (Mucorales)
A
8. What taxonomic category is Microsporum spp. apart of? A. Dermatophyte B. Zygomycete (Mucorales)
A
8. What taxonomic category is Trichophyton spp. apart of? A. Dermatophyte B. Zygomycete (Mucorales)
A
8. Which category is Aspergillus fumigatus apart of? A. Conidia in chains B. Conidia in clusters
A
8. Which category is Scopulariopsis spp. apart of? A. Conidia in chains B. Conidia in clusters
A
8. Which disease is Scedosporium apiospermum associated with? A. Chronic sinusitis B. Otitis externa C. Mycotic keratitis D. Tinea pedis
A
8. Which environmental condition is the hyaline mold, Mucor spp. most likely associated with? A. Stale bread B. Hospital construction C. Shared bath towels D. Fermenting stored grain
A
8. Which of the following species or organisms is the most likely to be the cause of mycotic keratitis (fungal eye infection)? A. Fusarium species B. Trichophyton rubrum C. Scedosporium apiospermum D. Aspergillus niger
A
6. Currently, there are no FDA cleared MALDI-TOF MS based assays for direct identification of microorganisms from positive blood cultures. A. True B. False
A Currently, there are no FDA cleared MALDI-TOF MS based assays for direct identification of microorganisms from positive blood cultures.
6. The College of American Pathologists (CAP) Microbiology checklist includes a section on MALDI TOF-MS. A. True B. False
A MALDI-TOF MS is now recognized as an accepted method in clinical microbiology for identification. As such, the CAP Microbiology checklist includes a section on MALDI TOF-MS
Regarding the two FDA-approved MALDI TOF-MS instruments discussed in this course, which of the following is not seen as a limitation? A. A gram-negative organism present in the specimen is not present in the database B. A mixture of more than one organism is spotted (eg, not a pure culture) C. Debris or residual protein is present on a reusable template (inadequately cleaned) D. Testing is performed to identify an amoeba or virus
A,B,C Identification on either instrument is limited to the organisms present in the respective database. Other limitations include spotting an organism from mixed culture or use of a reusable template that is not adequately cleaned. In the United States, the instruments discussed fall under the purview of the FDA for regulatory clearance. Both the VITEK® MS and the Bruker Microflex Biotyper™ have been granted clearance for select microorganisms, including aerobic/anaerobic bacteria and yeast. Amoeba and/or virus identifications are not currently available on these instruments.
10. Cooking meat until well-done is a very important step in preventing the transmission of Mad Cow Disease, or bovine spongiform encephalopathy (BSE), to humans. A. True B. False
B
10. How is a harmless prion protein (PrP) converted into the infective PrP? A. A virus binds to the normal protein and causes it to become misfolded B. An abnormal PrP binds to the normal protein and causes it to become misfolded C. Enzymes that break off parts of the harmless protein D. Interaction of a PrP from one species with that of a second species
B
10. Prions are believed to cause what type of diseases? A. Respiratory B. Neurodegenerative C. Sexually-transmitted D. Digestive
B
10. The World Health Organization (WHO) recommends that all blood and body fluid specimens from patients with prion diseases be considered infectious and handled with extreme caution. A. True B. False
B
10. What is the cause of Gerstmann-Sträussler-Scheinker (GSS) disease? A. Eating infected meat B. A change in codon 102 C. Copper deficiency D. A depletion of prion proteins
B
10. What is the most common form of Creutzfeldt-Jakob disease (CJD)? A. Variant B. Sporadic C. Iatrogenic D. Familial
B
11. Commercial identification systems can reliably identify the bioterrorism threat agents. A. True B. False
B
11. Match the organism that MOST closely resembles the description of the Gram stain morphology provided. Gram-negative rod resembling Enterobacteriaceae, demonstrates bipolar staining A. Bacillus anthracis B. Yersinia pestis C. Francisella tularensis D. Brucells species
B
11. What is the role of a sentinel clinical laboratory within the Laboratory Response Network (LRN)? A. Performs tests to detect and confirm or "rule-in" the presence of a threat agent B. Use standardized testing protocols to rule-out critical biological agents and refer them to one of the LRN reference laboratories for confirmation C. Act as the highest level in the LRN to handle highly infectious agents and have the ability to identify specific agent strains
B
11. Where can sentinel clinical laboratory staff find the standardized testing protocols? A. Centers for Disease Control (CDC) website B. American Society for Microbiology (ASM) website C. Laboratory Response Network (LRN) website D. Association of Public Health Laboratories (APHL)website
B
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
2. Which of the following statements concerning C. difficile is NOT true? A. It is the causative agent of an inflammatory condition of the large intestine. B. It is an aerobic organism. C. It produces potent toxins. D. It produces spores.
B
2. Which of these organisms is associated with the condition known as toxic shock syndrome? A. Clostridium difficile B. Staphylococcus aureus C. Enterococcus faecalis
B
4. Epidermophyton floccosum always produces microconidia. A. True B. False
B
5. Gametocytes are counted in the calculation for percent infected RBCs. A. True B. False
B
5. Hereditary spherocytosis is thought to prevent cerebral malaria in infected patients by preventing microvascular obstruction. A. True B. False
B
5. Molecular tests for malaria are primarily used for: A. Diagnosis B. Research and epidemiology C. Treatment D. Speciation
B
5. Plasmodium falciparum and Plasmodium knowlesi have dormant liver stages that can activate and invade the blood several months or years after initial infection. A. True B. False
B
5. Plasmodium malariae infects young and immature red blood cells. A. True B. False
B
5. Sexual and asexual reproduction occurs within vectors. A. True B. False
B
5. The drug used to treat uncomplicated malaria caused by Plasmodium falciparum is doxycycline. A. True B. False
B
5. The standard diagnostic method for malaria is culture. A. True B. False
B
5. What is the infective stage of the plasmodium life cycle? A. Hypnozoites B. Sporozoites C. Merozoites D. Zypnozoites
B
5. Which genus of mosquito is known to transmit Plasmodium? A. Asian tiger mosquito B. Anopheles C. Aedes D. Culex
B
5. Which species of Plasmodium is most commonly associated with cerebral malaria? A. Plasmodium vivax B. Plasmodium falciparum C. Plasmodium ovale D. Plasmodium knowlesi
B
6. MALDI-TOF MS instruments are used exclusively in the research setting and when using them in the clinical laboratory to report identifications, they require a special comment about laboratory developed tests (LDTs). A. True B. False
B
6. Using MALDI-TOF MS identification for early diagnosis of gram-negative bacteremia, compared to phenotypic tests, increases the result turnaround time by 48 hours. A. True B. False
B
6. Which of these MALDI-TOF MS systems IS NOT FDA-cleared and available in the United States? A. Bruker Daltonik, Microflex Biotyper™ B. Andromas, SAS C. bioMerieux VITEK® MS
B
7. Chlamydia and Neisseria were logical targets for the development of a commercial molecular assay for all reasons EXCEPT A. These organisms are of concern for significant patient populations. B. Cultivation methods were MORE expensive than molecular methods. C. The organisms are difficult to sustain in transport. D. The sensitivity of culture and antigen detection methods was not optimal.
B
6. What is the most commonly used matrix in whole-cell microorganism identification for MALDI-TOF MS? A. 2, 5-dihydroybenzoic acid B. alpha-cyano-4-hydroxycinnamic acid (CHCA) C. Formic acid D. Acetic acid
B CHCA solubilized in a mixture of trifluoroacetic acid and acetonitrile is the most commonly used matrix in whole-cell microorganism identification for MALDI-TOF MS.
13. When describing microorganisms seen on a Gram stained smear, what do terms such as diplococci, tetrads, chains, and clusters describe? A. Gram stain reaction B. Organism shape C. Cellular arrangement
C
7. What are the two general categories of nucleic acid amplification (NAA) techniques? A. Polymerase chain reaction (PCR) and branched chain DNA (bDNA). B. Fluorescence in situ hybridization (FISH) and strand displacement amplification (SDA) C. Target amplification and signal amplification D. PCR and reverse transcriptase PCR (RT-PCR)
C
7. Which of the following is NOT a commercial methodology that Chlamydia and Neisseria have been based on? A. Ligase chain reaction B. Hybrid capture C. Branched chain DNA technology D. Strand displacement amplification
C
7. Which statement about bacterial culture for 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
8. Several saprophytic, hyaline molds have microscopic characteristics that mimic the mold forms of the dimorphic fungi (Histoplasma capsulatum, Blastomyces dermatitidis, etc.). Each of the following can be used to differentiate the saprophytic from the dimorphic fungi EXCEPT: A. Conversion of the mold form to the yeast form at 37oC incubation B. Ability of the dimorphic fungi to grow on cycloheximide-containing culture media C. Differential growth profiles on Trichophyton differential agars D. Positive reactions for the dimorphic fungi in commercially available nucleic acid probe assays.
C
8. The hyaline saprobic fungus that has microscopic features similar to the mold form of Histoplasma capsulatum is: A. Chrysosporium species B. Malbranchia species C. Sepedonium species D. Scopulariopsis species
C
8. What is the morphologic feature of Phialophora verrucosum? A. Polar germ tubes B. Dictyospores C. Urn-shaped phialides D. Black yeast colony
C
8. What is the most likely disease caused by Phialophora verrucosum? A. Brain abscess B. Chronic sinusitis C. Chromomycosis D. Subcutaneous Phaeohyphomycotic cyst
C
8. Which disease is Fusarium spp. associated with? A. Chronic sinusitis B. Otitis externa C. Mycotic keratitis D. Tinea pedis
C
8. Which environmental condition is the hyaline mold, Epidermophyton floccosum most likely associated with? A. Stale bread B. Hospital construction C. Shared bath towels D. Fermenting stored grain
C
9. The formation of germ tubes when fetal bovine serum is inoculated with the yeast isolate leads to the presumptive identification of which of the following yeasts? A. Candida glabrata B. Candida parapsilosis C. Candida albicans D. Cryptococcus neoformans
C
9. Which dimorphic fungus may produce black, yeast-like colonies after prolonged incubation at 37°C? A. Blastomyces dermatitidis B. Paracoccidioides brasiliensis C. Sporothrix schenckii D. Histoplasma capsulatum
C
9. Which of the following fungal infections is endemic in the southwestern United States' desert regions? A. Histoplasmosis B. Blastomycosis C. Coccidioidomycosis D. Sporotrichosis
C
A dermatophyte that produces thin-walled, two or three-celled macroconidia, and no microconidia, most likely belongs to which genus? A. Microsporum B. Trichophyton C. Epidermophyton D. Ajellomyces
C
6. What approximate concentration of organism is needed in order to achieve a valid identification? A. Approximately 10^2 cfu/mL B. Approximately 10^-6 cfu/mL C. Approximately 10^8 cfu/mL D. Approximately 10^5 cfu/mL
D
6. What are the different sample spotting methods for MALDI-TOF MS? A. Direct application with a toothpick B. Adding a drop of supernatant from a full extraction tube C. Mixing the specimen with formic acid D. All the above
D
6. What common gram-positive organism cannot be differentiated from closely related species by MALDI-TOF MS? A. Staphylococcus aureus B. Corynebacterium jeikeium C. Streptococcus agalactiae D. Streptococcus pneumoniae
D
6. What is the function of the matrix? A. Co-crystallization B. Absorbs energy from the laser C. Energy transfer to the analyte D. All the above
D
7. Polymerase chain reaction (PCR) copies DNA through repeated cycles of three basic steps. What is the correct order of these steps? A. Extraction, annealing, and synthesis B. Denaturation at 72° C, annealing, and synthesis C. Denaturation, annealing at 72° C, and synthesis D. Denaturation, annealing, and synthesis at 72°C
D
7. What is successful molecular identification of methicillin-resistant Staphylococcus aureus (MRSA) based upon? (Choose the BEST answer) A. The detection of a SPECIFIC variant of the mecA gene. B. The detection of the S. aureus orfX gene. C. The detection of SEVERAL variants of the mecA gene. D. SIMULTANEOUS detection of the S. aureus orfX gene and SEVERAL variants of the mecA gene.
D
8. What is the morphologic feature of Auerobasidium pullulans? A. Polar germ tubes B. Dictyospores C. Urn-shaped phialides D. Black yeast colony
D
8. What is the most likely disease caused by Phialophora richardsiae? A. Brain abscess B. Chronic sinusitis C. Chromomycosis D. Subcutaneous Phaeohyphomycotic cyst
D
8. Which disease is Trichophyton rubrum associated with? A. Chronic sinusitis B. Otitis externa C. Mycotic keratitis D. Tinea pedis
D
8. Which environmental condition is the hyaline mold, Fusarium spp., most likely associated with? A. Stale bread B. Hospital construction C. Shared bath towels D. Fermenting stored grain
D
5. Malarial parasites are best seen under what magnification? A. 40x B. 400x C. 600x D. 1000x
D
5. Plasmodium ovale is particularly found in which part of Africa? A. North B. South C. East D. West
D
5. Which species of Plasmodium infects macaques? A. Plasmodium vivax B. Plasmodium ovale C. Plasmodium falciparum D. Plasmodium knowlesi
D
11. Which of the following is NOT a characteristic of a sentinel clinical laboratory? A. Certified by the Centers for Medicare & Medicaid Services (CMS) as a high complexity laboratory performing the specialty of microbiology B. A biosafety cabinet (BSC) is NOT required C. Comply with biosafety level II (BSL-2) practices D. Have policies and procedures in place for the use of fit-tested respiratory equipment
B
11. Which of the following is NOT a characteristics of Burkholderia pseudomallei? A. Catalase positive B. Fat, gram-positive rod C. Oxidase positive D. Motility positive
B
11. Which of the following organisms display the characteristic "Medusa head" on sheep blood agar (SBA) after 18 hours of incubation at 35°C? A. Yersinia pestis B. Bacillus anthracis C. Francisella tularensis
B
12. The presence of gram-negative intracellular diplococci in a genital specimen from a FEMALE is diagnostic of gonorrhea. A. True B. False
B
12. What is the purpose of the iodine that is used in the Gram stain procedure? A. Is the primary stain that is used in the Gram stain procedure B. Fixes the crystal violet to the cellular components of gram-positive bacteria C. Allows the counterstain to permeate the gram-negative bacteria
B
13. A Gram stain is performed from a cerebrospinal fluid (CSF) culture. From a sterile body site, it is TYPICAL to expect more than one morphotype (such as gram-negative rods, gram-positive cocci, AND gram-positive rods) to be recovered. A. True B. False
B
13. A new batch of Gram stain reagents have been placed into use, so a control slide is used to verify the intended reactivity. Along with the control slide, a Gram stain is also performed on a smear made from a patient culture. The control slide is read first and BOTH control organisms have stained gram-positive (blue to deep purple). What is the BEST course of action prior to reading and reporting the patient results? A. Prepare and stain ONLY another control slide B. Prepare and stain BOTH a new control slide AND patient slide C. Proceed to read and report the patient slide
B
13. Match the Gram stain characteristic to the organism it BEST describes. Gram-negative diplococci with adjacent sides flattened (coffee bean shaped) A. Nocardia spp. B. Neisseria spp. C. Staphylococcus spp. D. Corynebacterium spp.
B
13. The bacteria on BOTH the positive and the negative control slides are observed to stain pink. This finding will NOT affect the rest of the slides in the batch. A. True B. False
B
13. Which of the following is TRUE of the Gram stain procedure? A. Used to distinguish between aerobic and anaerobic organisms B. Organism morphology is MOST characteristic in smears prepared from 18- to 24-hour broth subculture C. Gram-positive organisms demonstrate a bright orange fluorescence D. Gram-negative organisms stain blue to dark purple
B
14. After the first appearance of extensively drug-resistant tuberculosis (XDR-TB), which control measure was the MOST effective? A. Patient advocacy, communication, and social mobilization B. Initiation of the direct-observed treatment short course (DOTS) program and focus on HIV/AIDS patients with MDR- and XDR-TB C. Increased availability of vaccines and anti-tuberculosis drug therapy D. Increased staffing and new molecular diagnostic methods E. Use of second-line drugs added to first-line antibiotics in Africa
B
14. Compared to standard tests, what are the advantages of nucleic acid amplification tests (NAATs) for Mycobacterium tuberculosis complex (MTBC) in respiratory specimens? A. Phenotypic and biochemical confirmation are included B. Two hour results, highly specific, and sensitive for smear positive specimens C. Specialized equipment and technical expertise are required D. Typically performed in reference or public health laboratories
B
14. Robert Koch made several significant discoveries with regard to the tuberculosis (TB) bacillus. Which statement is FALSE? A. Koch was the first to demonstrate the growth and staining of the tuberculosis (TB) bacillus. B. Koch discovered that TB is the only organism that will grow in Petri dishes containing potato agar. C. Koch was the first to define a "cause and effect" relationship between an organism and a disease.
B
7. Ideally, a molecular section will have designated and separated areas for which of the following groups of activities? A. Specimen login; specimen extraction and reagent preparation; detection and identification B. Reagent preparation; sample preparation and extraction; amplification and detection/identification C. Specimen login and reagent preparation; specimen preparation and extraction; amplification and detection/identification D. Specimen login; reagent preparation; specimen prep and amplification; detection and identification
B
7. Which of the following does NOT represent a key skill, technique, or equipment that is essential in a molecular laboratory? A. Aseptic technique B. Sterile pipette tips of any kind C. Dedicated pipette devices for each area of the process D. Accurate pipetting skills
B
7. Which of the following is NOT a key benefit that molecular methods can offer over culture methods? A. Reduced cost per test B. Reduced turnaround time C. Improved sensitivity of detection D. Improved specificity of identification
B
7. Which of the following is NOT one of the chief incentives to employ molecular methods for the detection and identification of Mycobacterium species? A. The positive impact of early results for infection control and treatment decisions. B. Lability of the organism in transport. C. The slow growth rate of the organism.
B
7. Which of the following is a FALSE statement about peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) methods for Staphylococcus? A. PNA probes are built with a pseudopeptide, rather than a sugar. B. PNA-FISH assays provide differentiation between methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA). C. PNA-FISH assays provide differentiation between S. aureus and coagulase negative species. D. PNA-FISH assays offer the possibility of earlier adjustment of antimicrobial therapy.
B
7. Which statement about melt curve analysis is FALSE A. The melting temperature of double stranded DNA depends on its base composition and length. B. When hybridization probes are utilized, the temperature is incrementally decreased while fluorescence is monitored. C. All PCR products for a specific primer pair should have the same melting temperature. D. At the melting point, the probe separates from the target strand and fluorescence rapidly decreases.
B
8. The most helpful feature in differentiating the Zygomycetes/Mucorales from the other hyaline molds in the clinical mycology laboratory is: A. Rapid growth rate B. The production of spores within sporangia C. The production of rhizoids D. The formation of aseptate hyphae
B
8. What classification of infection is Blastomyces dermatidis most commonly assoicated? A. Opportunistic pathogen B. Obligate pathogen
B
8. What is the morphologic feature of Alternaria? A. Polar germ tubes B. Dictyospores C. Urn-shaped phialides D. Black yeast colony
B
8. What is the most likely disease caused by Bipolaris spp. ? A. Brain abscess B. Chronic sinusitis C. Chromomycosis D. Subcutaneous Phaeohyphomycotic cyst
B
8. What taxonomic category is Cunninghamella spp. apart of? A. Dermatophyte B. Zygomycete (Mucorales)
B
8. Which category is Acremonium spp. apart of? A. Conidia in chains B. Conidia in clusters
B
8. Which category is Gliocladium spp. apart of? A. Conidia in chains B. Conidia in clusters
B
8. Which disease is Aspergillus niger associated with? A. Chronic sinusitis B. Otitis externa C. Mycotic keratitis D. Tinea pedis
B
8. Which environmental condition is the hyaline mold, Aspergillus niger, most likely associated with? A. Stale bread B. Hospital construction C. Shared bath towels D. Fermenting stored grain
B
8. Which of the following dematiaceous fungal species produce conidia in clusters? A. Alternaria species B. Exophiala species C. Cladosporium species
B
8. Which of the following molds is classified as a zygomycete? A. Microsporum nanum B. Cunninghamella species C. Trichophyton schoenleinii D. Epidermophyton floccosum
B
9. All of the following observations are consistent with the laboratory identification of Cryptococcus neoformans EXCEPT: A. Colonies that appear mucoid on primary isolation culture medium B. Negative urease test C. Cornmeal agar morphology displaying spherical, irregular cells with no pseudohyphae D. Presence of capsular material E. Tan-brown pigment on bird seed agar
B
9. Although care should be taken when working with all fungus cultures in the laboratory, personnel are particularly prone to develop laboratory acquired infections from the inhalation of airborne species of which of the following fungi? A. Blastomyces dermatitidis B. Coccidioides immitis C. Sporothrix schenckii D. Histoplasma capsulatum
B
9. The transmission of which of the following organisms is associated with the guano of bats? A. Blastomyces dermatitidis B. Histoplasma capsulatum C. Coccidioides immitis
B
9. Which of the following is a phenotypic property of Saccharomyces yeast species that is helpful in establishing its species identification? A. Polysaccharide capsule B. Ascospore production C. Trehalose assimilation
B
9. Which of the organisms listed below has the unique property of producing germ tubes when fetal bovine serum is lightly inoculated with the yeast isolate and incubated at 35 - 37° C for 2.5 - 3 hours? A. Candida glabrata B. Candida albicans C. Cryptococcus species
B
In traditional culture or antigen detection methods, the sensitivity of detection is adversely affected by all of the following EXCEPT A. Fastidious growth requirements B. Large numbers of organisms C. Delays in transport D. Specialized media requirements
B
Potential disadvantages of molecular methods for methicillin-resistant Staphylococcus aureus (MRSA) include all EXCEPT: A. Throughput of the instrumentation system B. Turnaround time C. Hands on time for individual sample preparation D. Potential for false-positive reactions
B
6. Several studies have examined the effect of medium type on MALDI-TOF MS analysis and determined that all selective media affects the microorganism identification accuracy. A. True B. False
B Several studies have examined the effect of medium type on MALDI-TOF MS analysis and determined that medium type does NOT affect the microorganism identification accuracy. However, analysis of isolates cultivated using selective media may negatively affect the spectral quality, possibly by interfering with protein ionization. This may lead to identification failures or low-confidence, although it should not lead to erroneous identifications.
10. How should surgical and dental instruments that have come in contact with highly-infective prion tissue be handled after use? A. Washed thoroughly with hot soap and water B. Soaked in 100% alcohol for at least 12 hours C. Discarded and incinerated D. Autoclaved
C
10. Prions may be found throughout the brain of an individual suffering from a prion disease. In cases of fatal familial insomnia (FFI), in what region of the brain are prions found in the greatest concentration? A. Cerebellum B. Cerebral cortex C. Thalamus D. Brain stem
C
11. Match the organism that MOST closely resembles the description of the Gram stain morphology provided. Very tiny, pale staining, gram-negative coccobacillus; often difficult to see individual cells A. Bacillus anthracis B. Yersinia pestis C. Francisella tularensis D. Brucells species
C
11. Which of the following is NOT a characteristic of Burkholderia pseudomallei? A. Has been reported as the cause of laboratory-acquired infection B. Oxidase positive C. Non-motile D. Catalase positive
C
11. Which of the following is NOT a function of the Laboratory Response Network (LRN)? A. Provide a rapid response to public health emergencies B. Serve as a source of expert advice for agents of concern C. Eliminate bioterrorism D. Establish standardized protocols used to identify pathogens that carry a high consequence
C
11. Which of the following is a TRUE statement concerning the category A agents of bioterrorism? A. Category A agents carry the third highest priority. B. Category A agents are difficult to disseminate. C. Category A agents cause high mortality and the potential for major public health impact. D. Category A agents would NOT cause public panic.
C
11. Which of the following is a characteristic of Brucella species? A. Oxidase negative B. Catalase negative C. Urea positive D. Large, gram-negative rods
C
11. Which of the following statements is TRUE with regard to the agents of bioterrorism? A. The agents of bioterrorism CAN be manipulated on an open bench. B. NONE of the agents of bioterrorism have been known to cause laboratory-acquired infections. C. At least a class II biological safety cabinet (BSC) should be used if an aerosol is likely.
C
11. Who should a technologist contact if an organism is isolated that cannot be ruled out as a potential agent of bioterrorism? A. The local police department B. The Federal Bureau of Investigation(FBI) C. The appropriate internal staff and contact your Laboratory Response Network (LRN) Reference Laboratory D. The Centers for Disease Control (CDC)
C
12. A large number of which of these types of cells would indicate that a sputum specimen is sub-optimal and should not be used for culture? A. Yeast B. Polymorphonuclear white blood cells (PMNs) C. Squamous epithelial cells D. Bacteria
C
12. Which of the following cells are about the same size as red blood cells? A. Epithelial cells B. White blood cells C. Yeast
C
13. Match the Gram stain characteristic to the organism it BEST describes. Gram-positive cocci in clusters and tetrads A. Nocardia spp. B. Neisseria spp. C. Staphylococcus spp. D. Corynebacterium spp.
C
14. All of the following help to explain the mechanism that causes (pathogenesis) tuberculosis (TB) infection, EXCEPT which statement? A. Infected macrophage cells and monocytes characterize the early granuloma. B. Liquefaction and cavitation occur in the center of the granuloma. C. Children who are under 5 years old may have a poor prognosis. D. Typical droplet nuclei contain 1-10 TB bacilli, which are dispersed during coughing or sneezing. E. Infected macrophages are carried from the lung to other areas by the lymphatic system or blood.
C
14. How did Robert Koch lay the groundwork for the field of epidemiology? A. By inoculating guinea pigs with liquid glycerol extracts of tubercle bacilli B. By growing tubercle bacilli on potato agar and staining with methylene blue C. By proving a "cause and effect" relationship existed between TB bacilli and disease D. By convincing German scientists that guinea pigs contracted tuberculosis
C
14. In state-of-the-art culturing for mycobacteria, which the following is preferred? A. Broth 7H9 broth agar with TWEEN® 80 to disperse clumps B. The semi-automated system BACTEC™ 460 (Becton-Dickinson) C. The automated BACTEC™ MGIT™ 960 (Becton-Dickinson), as well as culture on 7H11 plates D. Lowenstein-Jensen agar slants and Mycobactosel™ agar
C
14. Of the failed treatment programs in India described in this course, which one of the following contributed MOST to the drug resistance increase? A. Lack of qualified staffing and specialists in TB B. Poor management by the government and the private sector C. Prescribing antibiotics without susceptibility testing D. Lack of required government reporting of positive cases
C
14. What is the primary safety-control factor used in tuberculosis (TB) specimen processing? A. Digestion and decontamination preparation of sputum and bronchial washings B. Avoidance of cross-contamination during specimen processing C. All procedures are performed in a class II biological safety cabinet (BSC) D. Regular inspections mandated by the Centers for Disease Control and Prevention (CDC)
C
14. Which of the following led to a significant reduction in the fear of tuberculosis (TB) transmission? A. Sanatorium treatment with good nutrition and fresh air B. Immunization with BCG vaccine in the 1900s C. Discovery of the antibiotic isoniazid (INH) in 1953 D. Discovery of streptomycin and para-aminosaliclic acid (PAS) in the 1940s
C
5. Which blood group antigen serves as a receptor site for the attachment of Plasmodium vivax? A. Kell B. Rhesus C. Duffy D. Kidd
C
5. You receive a thick smear in the lab to interpret from a very sick patient with recent travel to Africa. Calculate the number of parasites per μL of blood given that you have identified 3 parasites and counted 2000 WBCs: A. 48 B. 64 C. 12 D. 16
C
6. In addition to trifluoroacetic acid, which solvent is used for matrix preparation? A. Methanol B. Acetic acid C. Acetonitrile (ACN) D. Water
C
6. Which of the following is false regarding MALDI-TOF MS? A. The peaks detected by the system represent a fingerprint of mass to charge ratio of proteins. B. If the pump is nonfunctional, results are not read. C. Quality control (QC) must be run on a daily basis. D. A template under vacuum should be the "standby mode" when not making a run.
C QC must be included with EACH RUN of MALDI-TOF MS. The remaining statements are true. The basis for measurement is mass to charge ratio. The three functional components (laser, vacuum, and detector) must be functional to achieve results. A template under vacuum should be the "standby mode" to maintain the integrity of the system. This also affords more rapid time to vacuum for runs.
10. What is the proper scientific acronym for mad cow disease? A. MCD B. BCD C. TCE D. BSE
D
11. Match the organism that MOST closely resembles the description of the Gram stain morphology provided. Small, gram-negative coccobacilli that appear gram-positive due to retention of crystal violet stain; individual cells present A. Bacillus anthracis B. Yersinia pestis C. Francisella tularensis D. Brucells species
D
11. Which of the following statements are FALSE regarding automated identification systems? (Choose all that apply.) A. May misidentify the biological threat agents B. Designed to identify rapidly growing microorganisms C. Likely to produce aerosols during set-up D. Can reliably identify Francisella tularensis
D
12. What is the MINIMUM number of fields that should be examined before reporting a Gram-stained direct smear? A. 2 B. 5 C. 8 D. 10
D
12. Which of these would be a reason for performing a direct Gram stain on a clinical specimen? A. Judge the quality of the specimen. B. Provide the clinician with same-day information regarding possible pathogenic organisms, pending results of culture and sensitivity. C. Provide internal quality control when direct smear results are compared to culture results. D. All of the above reasons
D
13. All of the shapes below can be used to describe cocci EXCEPT for which of the following? A. Ovoid B. Lancet C. Round D. Tapered
D
13. Match the Gram stain characteristic to the organism it BEST describes. Small, palisading gram-positive rods demonstrating a picket-fence arrangement A. Nocardia spp. B. Neisseria spp. C. Staphylococcus spp. D. Corynebacterium spp.
D
13. Which of the following is NOT a bacterial arrangement that can be observed on a Gram stained smear? A. Clusters B. Singles C. Tetrads D. Flowering
D
14. At what point in the pathogenesis cycle of Mycobacterium tuberculosis is transmission at the highest level? A. During phagocytosis of the infected macrophage cells B. After the formation of a fibrous capsule in the granuloma C. When the caseum center is formed around foamy macrophage cells D. Liquefaction, cavitation, and emptying of the caseous center
D
14. In the 1980s, what major factor directly caused the escalation of multidrug-resistant tuberculosis (MDR-TB)? A. Lifting of government control measures and closing of sanatoria B. Start of HIV/AIDS epidemic in 1985 C. Immigration to the United States of people from TB endemic countries D. Patients who were non-compliant with prescribed therapy
D
14. Upon which principle is the acid-fast bacilli (AFB) smear based? A. Sensitivity of the method may be as high as 80% or as low as 20%. B. Confirmation requires a Ziehl-Neelson stain. C. The smear is prerequisite to a complete work-up for MTB. D. The mycolic acid in the cell wall of AFB renders them resistant to decolorization with acid alcohol.
D
9. A yeast identification system gave a biotype number for an unknown isolate that did not differentiate between Candida tropicalis and Candida parapsilosis. This isolate could be identified as C. parapsilosis in a cornmeal agar preparation if it produced which of the following? A. Chlamydospores B. Dense clusters of blastoconidia regularly along the pseudohyphae C. Blastoconidia with a "logs in stream" pattern D. "Spider" or "crossed matchstick" colonies
D
9. Which of the following ingredients is added to culture media to enhance the recovery of the dimorphic fungi by preventing the overgrowth of more rapidly growing, saprophytic molds? A. Brain heart infusion base B. Chloramphenicol C. Thiamine D. Cycloheximide
D
How is the abnormal form of the prion protein designated? A. PrP^Abnormal B. PrP^C C. PrP^Cs D. PrP^Sc
D
The MALDI-TOF MS CANNOT identify which of the following organisms? A. Gram-positive organisms B. Gram-negative organisms C. Yeast D. Viruses
D
Which of the following key parameters can impact the quality of the identification (ID) by MALDI-TOF MS? A. Age of colony B. Type of extraction method C. Quality and age of matrix D. All the above
D Each of the described parameters can affect ID. Discrepancies have been noted when colonies age or come directly from the refrigerator. Extraction methods may need to be enhanced in order to release and concentrate proteins. The matrix has a shelf life and performs poorly after about one week.
4. Mucormycetes grow rather slowly both in vivo and in culture. A. True B. False
B
1. Laboratory-based tests to help diagnose CDI typically examine a serum or blood sample for certain toxins and/or specific enzyme antigen produced by the C diff bacteria. A. True B. False
B
1. Taking or having recently taken antibiotics is NOT really considered a risk factor for CDI but staying in a health care facility is considered a risk factor. A. True B. False
B
5. Which species of Plasmodium is the most common cause of death from malaria worldwide? A. Malariae B. Falciparum C. Vivax D. Ovale
B
The Centers for Disease Control and Prevention (CDC) has published on their web site clearly defined methods for the prevention of infections from Balamuthia mandrillaris. a. True b. False
B
The pathogenicity of S. aureus, as well as the frequency with which this organism produces infections, can be attributed to all EXCEPT: A. Exfoliative toxin and enterotoxins B. A porous cell wall C. Natural colonization/reservoir for infection D. Hyaluronidase
B
4. Which cells are H. capsulatum yeast cells often found within? A. Neutrophils B. Plasma cells C. Histiocytes and reticuloendothelial cells D. Pneumocyte
C
3. What did Byers base his 1991 classification of the genus Acanthamoeba species on? a. Cyst morphology b. Environmental diversity c. RNA sequences d. Trophozoite acanthopodia
C
4. Which is a feature that can differentiate a rapidly growing dematiaceous mold from a slowly growing dematiaceous mold? A. Only microconidia B. Only macroconidia C. Conidia separated with transverse septae and those with transverse and longitudinal septae D. Resistance to aminoglycosides
C
1. A number of laboratory stool tests are available to help diagnose CDI. Which test has been used in the past as a gold standard test for CDI diagnosis and is usually sensitive, but tends to be less widely available, more cumbersome to perform and requires 24-48 hours for test results? A. Cell culture cytotoxicity assay B. NAAT C. Selective anaerobic culture D. EIA for toxins A and/or B and GDH antigen
A
1. CDI should be suspected in a patient with acute diarrhea (> 3 loose stools in 24 hours) with no obvious explanation for the diarrhea especially with risk factors. A. True B. False
A
1. Commercially-available testing for CDI currently favors the employment of a rapid, technologically simple and low cost assay. A. True B. False
A
1. The risk of a recurrence of CDI is usually higher if the individual is older than 65 and taking other antibiotics while being treated for CDI a. true b. false
A
1. The updated IDSA/SHEA guidelines recommend for the treatment of the initial episode of CDI either the antibiotic vancomycin or fidaxomicin and not metronidazole. A. True B. False
A
1. Using WBC counts and creatinine levels may help clinicians classify the severity of CDI. If the WBC count is <15,000 and serum creatinine is <1.5mg/dL, these results may be an indication of what classification of CD severity? A. Mild to moderate infection B. Severe CDI C. Fulminant CDI
A
5. Red cell lysis stimulates the release of what factors? A. Prothrombin B. Factor VII C. Proinflammatory cytokines D. Apoptosis factor
C
1. Which choice is false when discussing the Clostridium difficile bacterium? A. It is a spore-forming, toxin-producing gram negative, aerobic bacterium. B. It may be present as part of normal bacterial flora in 3% of healthy adults. C. The most common toxins produced are A and B which can both cause diarrhea and inflammation. D. Spores produced by C diff tend to protect the bacteria from antibiotics.
A
2. Detection of the mecA gene in a clinical isolate of S. aureus is an indication of resistance to which of these antibiotics? A. Oxacillin B. Vancomycin C. Novobiocin
A
2. Enterococci can possess both intrinsic and acquired resistance. The following represent the intrinsic resistance of a typical enterococcal strain EXCEPT: A. High level resistance to glycopeptides B. Aminoglycoside resistance C. Resistance to clindamycin and trimethoprim-sulfamethoxazole D. Resistance to cephalosporins
A
2. PBP2a is the altered penicillin-binding protein responsible for resistance of MRSA strains to the beta-lactam class of antibiotics. A. True B. False
A
2. Which of the following is a selective media recommended for the isolation of C. 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
2. Which of these gene phenotypes is found most often in vancomycin-resistant strains of Enterococcus faecium? A. VanA B. VanB c. VanC
A
2. Which statement regarding carapenemase-resistant Enterobacteriaceae (CRE) is true? A. The use of current breakpoints in antimicrobial susceptibility testing (AST) is the best detection method for CREs. B. The modified Hodge test (MHT) should be performed routinely on all Enterobacteriaceae recovered from clinical isolates to detect the presence of carbapenemase. C. When performing antimicrobial susceptibility testing (AST) on possible CRE isolates, it can be assumed that current AST breakpoints are in place when using a commercially-available automated AST system. D. Patients with CRE can be treated with a vast number of antimicrobial agents.
A
3. What is the one commonality between all the pathogenic free-living amoeba? a. They are all amphizoic amoeba. b. Symptoms for all appear 5-15 days after infection. c. All infections result from swimming in polluted water. d. They all have an identical life cycle
A
3. Where is Naegleria fowleri found most often in nature? A. Warm, fresh water (ponds, lakes, rivers) B. Warm salt water C. The arctic oceanAll of the above
A
4. Candida glabrata can be morphologically difficult to distinguish from Histoplasma capsulatum when observed in tissue sections. Which of the following can aid in distinguishing between C. glabrata and H. capsulatum when small yeast are seen in tissue sections? A. Neutrophilic response B. Circumferential budding C. Macrophage response D. Cycloheximide resistance
A
4. Dematiaceous molds are darkly pigmented on both the surface and reverse side of the culture plate. A. True B. False
A
4. Diagnosis of blastomycosis can also be made with an antigen test performed on urine or serum. A. True B. False
A
4. Diagnosis of blastomycosis can also be made with an antigen test performed on urine or serum. A. True B. false
A
4. Lomentospora prolificans has a gray or black surface and reverse. A. True B. False
A
4. Paracoccidioides brasiliensis gives the appearance of a mariner's wheel in tissues sections or primary wet preparations. A. True B. False
A
4. Saccharomyces cerevisiae is a yeast that is characterized by round to oval multilateral budding yeast cells and short, rudimentary pseudohyphae. A. True B. False
A
4. The Mucor spp. do not produce rhizoids. A. True B. False
A
4. The features that are most useful for distinguishing Cryptococcus spp. from other yeasts include the presence of a capsule, narrowed-necked budding, and the size variability of the yeasts. A. True B. False
A
4. The rapid diagnosis of dermatophytosis can be made with a bedside KOH or calcofluor white preparation of skin scrapings. A. True B. False
A
4. Trichosporon yeast forms arthroconidia and hyphal elements are larger than those of Candida spp. a. True b. False
A
4. Which enzymes do dermatophytes employ to digest hair, nails, and the stratum corneum of skin? A. Keratinases B. Elastases C. Proteases D. Pepsin
A
4. Which features distinguishes Candida glabrata from other infectious Candida species? a. The ability to produce hyphae or pseudohyphae b. Encapsulation c. Larger size d. Germ tube production
A
5. Fevers from malaria are cyclical and can occur in: A. 48-hour and 72-hour cycles B. 10-hour cycles C. 30-hour and 60-hour cycles D. 100-hour cycles
A
5. Plasmodium ovale and Plasmodium vivax are the only species to have dormant liver stages. A. True B. False
A
Which of the following enzymes, produced by S. aureus, is responsible for preventing penicillin antibiotics from being effective against a Staph infection? A. Beta-lactamase B. Coagulase C. Catalase D. Hyaluronidase
A
1. A C Diff Quik Chek Complete® test result showed vertical blue lines on both the "Ag line" and "Toxin line" with a vertical dotted blue line on the "control line." What do these result mean? A. A negative test result for both the GDH antigen and toxins A and/or B B. A valid positive test result for both the GDH antigen and toxins A and/or B C. The results suggest a potential carrier for C. difficile. D. An invalid test result.
B
2. Assume you perform microbiology for an institution submitting surveillance cultures for MRSA. Which isolate should receive further workup to rule out methicillin (oxacillin) resistance? A. On Baird Parker, a gray brownish colony with no clear zone. Gram-positive cocci in clusters, catalase positive. B. Black colonies on Chromagar. Catalase-positive, gram-positive cocci in clusters. C. Yellow colonies on mannitol salt agar; catalase-positive, coagulase-positive. D. Clear colonies on mannitol salt agar; catalase-positive, coagulase-negative.
B
2. Based on the Centers for Disease Control and Prevention's (CDC's) definition, which statement describes a carbapenemase-resistant Enterobacteriaceae (CRE)? A. Any Klebsiella pneumoniae isolate, regardless of antimicrobial susceptibility testing (AST) results, is considered CRE. B. Any Enterobacteriaceae isolates that are resistant to any carbapenem drug during AST are considered CRE. C. Any Proteus isolates are considered CRE due to intrinsic nonsusceptibility to imipenem (one of the carbapenem antimicrobials).
B
2. MRSA is only a problem for patients who are hospitalized. A. True B. False
B
2. New Delhi metallo-beta-lactamase (NDM) is the most common carbapenemase produced among CRE in the United States. A. True B. False
B
2. The increased resistance of MRSA strains to beta-lactam antibiotics is due to production of which of the following penicillin binding proteins (PBPs)? A. PBP 2 B. PBP 2a C. PBP 3 D. PBP 4
B
2. What carbapenemase is produced most commonly by CRE encountered in the United States? A. The production of AmpC beta-lactamase B. The production of Klebsiella pneumoniae carbapenemase (KPC) C. The production of oxacillin (OXA) carbapenemase D. The production of metallo-beta lactamase (MBL)
B
2. When testing for C. difficile or its toxins, either a formed or liquid stool is an acceptable specimen. A. True B. False
B
2. When using current antimicrobial susceptibility testing (AST) breakpoints, it is recommended by CLSI that laboratories should also routinely implement testing, such as the modified Hodge test (MHT) or Carb NP test (CNPt), to detect the presence or absence of carbapenemase. A. True B. False
B
2. Which one of these characteristics distinguishes vancomycin-resistant Enterococcus faecium and E. faecalis from other Enterococcus species? A. PYR positive reaction B. Non-motility C. Catalase negative D. Growth on bile esculin agar
B
2. _______________ is predominantly associated with skin and soft tissue infections (SSTIs), such as abscesses, cellulitis, folliculitis, and impetigo. A. HA-MRSA B. CA-MRSA
B
3. All of the following are free-living amoebae EXCEPT: a. Acanthamoeba species b. Entamoeba polecki c. Naegleria fowleri d. Balamuthia mandrillaris
B
3. Although both Naegleria and Acanthamoeba are found in many water supplies, where are they especially abundant? a. The Great Salt Lake b. Warm fresh waters carrying high concentrations of bacteria c. The Atlantic and Pacific oceans d. All of the above
B
3. People may become infected with Naegleria fowleri by drinking contaminated water. A. True B. False
B
3. What is the most common way for humans to acquire a free-living amoeba infection? a. Infective flagellates in soil or water b. Infective cysts or trophozoites in soil or water c. Infective cysts obtained from an intermediate host d. Infective cysts or trophozoites in food
B
4. Arthroconidia of Coccidioides spp. are oblong shaped and alternate with empty cells. A. True B. False
B
4. Blastomyces spp. are only found in the Mississippi and Ohio River valleys. A. True B. False
B
4. How does one confirm that a fungus is thermally dimorphic? A. By converting from the yeast form to mold form by reincubating at 37ºC B. By converting from the mold form to yeast form by incubating mold subcultures at 37°C C. By converting from the yeast form to mold form by reincubating at 23ºC D. By converting from the mold form to the yeast form by reincubating at 23ºC
B
4. Immune suppression is the major mechanism that predisposes patients to cryptococcal disease. Which one of the following is an example of an immune suppression state? A. Hashimoto's thyroiditis B. Organ transplant C. Ehlers-Danos syndrome D. Epilepsy
B
4. In addition to culture, diagnosis of coccidioidomycosis can be accomplished by which of the following? A. KOH B. Antigen testing performed on urine or serum or with antibody testing C. Catalase testing D. Whiff test
B
4. Microscopically, S. schenckii mold-forms produce very delicate hyaline septate hyphae producing conidiophores topped by clusters of macroconidia ("rosettes"). A. True B. False
B
4. The thermally dimorphic fungi grow as yeast when incubated at 25° C, but grow as molds when incubated at 30° or 37° C. A. True B. False
B
4. What are the colony colors of Aspergillus fumigatus? A. Yellow-red B. Blue-green C. Yellow-green D. Orange-brown
B
4. What is the characteristic budding morphology that can help identify Blastomyces spp.? A. Narrow-based budding B. Broad-based budding C. Circumferential budding D. Radial budding
B
4. What shape is commonly associated with the description of the macroconidia of Fusarium spp.? A. Sword-like B. Sickle-shaped C. Ovoid D. Oblong
B
4. Which supplement is necessary to add to culture media to ensure proper growth of Malassezia species? a. Short chain fatty acid b. Olive oil c. KOH d. Catalase
B
5. How are most blood parasites transmitted? A. Porcine vector B. Arthropod vector C. Equine vector D. Ovine vector
B
5. Once inside the red blood cell, the parasite digests hemozoin. A. True B. False
B
5. What shape uniquely identifies the P. falciparum gametocyte? A. Pear shaped B. Crescent shaped C. Apple shaped D. Square shaped
B
1. A patient with diarrhea was suspected of having CDI. A stool specimen was submitted to the laboratory for analysis using the C Diff Quik Chek Complete® test. The results of the test showed the appearance of a vertical blue line in both the "Ag line" and the "Toxin line" as well as a vertical dotted blue line on the "control line." What is the interpretation of the test results? A. Negative for toxigenic C diff B. Positive for GDH antigen but negative for toxin A and/or B. The results indicate a potential carrier for C diff. C. Positive for toxigenic C diff D. An invalid test result because of a dotted vertical blue line in the control line.
C
1. The treatment for CDI typically depends on the severity of the infection. Which of the following steps and/or therapies or procedures is NOT involved in treating CDI? A. The usual first step in treatment is to eliminate any antibiotics that may have triggered the infection. B. The usual initial therapy for CDI is the use of one or more courses of antibiotics, either vancomycin or fidaxomicin. C. The antibiotic metronidazole (Flagyl) should never be used for treatment since it has been found to not be effective. D. FMT or stool transplant can be used if there is recurrent CDI's.
C
1. Which of the following does NOT describe(s) the Clostridium difficile bacterium? A. C difficile is a grampositive, anaerobic bacterium that is sporeforming and toxin producing. B. Under the microscope, the C difficile bacteria appear as long irregular cells often drumsticklike or spindleshaped. C. Under normal conditions, the bacteria produce spores that are not very stable. D. Usually, C difficile bacteria colonize the intestinal tract after normal gut flora has been disrupted.
C
1. Which statement is not true relative to the treatment of CDI? A. The treatment for CDI typically depends on the severity of the infection B. The usual first step in treating CDI is to eliminate any antibiotic(s) that may have triggered the infection. C. The initial therapy for CDI usually involves the use of the antibiotic metronidazole. D. FMT also known as stool transplant can be used to treat recurrent CDI.
C
2. Pseudomembranous colitis (PMC) is an inflammatory disease of the colon caused by toxins of which of these organisms? A. Staphylococcus aureus B. Enterococcus faecium C. Clostridium difficile
C
2. Which of these describes the mode of action of the beta-lactam class of antibiotics? A. Inhibits protein synthesis B. Inhibits DNA synthesis C. Inhibits cell wall synthesis D. Inhibits RNA synthesis
C
2. With regards to identifying resistance in enterococci, which general statement is FALSE? A. Both disk diffusion and broth microdilution tests should be incubated a full 24 hours to detect vancomycin resistance. B. BHI agar with 6 µg/mL vancomycin can be employed as a screening methodology for vancomycin resistance. C. All antibiotics on a gram-positive panel should be reported. D. Methodologies employed should also address the detection of high level resistance to gentamicin and streptomycin.
C
3. What is the etiologic agent for primary amoebic meningoencephalitis (PAM)? a. Entamoeba polecki b. Balamuthia mandrillaris c. Naegleria fowleri d. Entamoeba hartmanni
C
3. Which of the following is the pathogenic free-living amoeba with a flagellate state? a. Acanthamoeba species b. Balamuthia mandrillaris c. Naegleria fowleri d. Sappinia pedata
C
4. What is a distinguishing feature of Aspergillus spp. in tissue identification? A. Tendency to be invasive B. Pseudohyphae C. Septate and dichotomous 45 degree branching angle D. Broad and ribbon like branching
C
4. What is a useful stain for the identification of Cryptococcus? a. Oil red O b. Acid fast c. Mucicarmine d. Movat pentachrome
C
4. What is the characteristic appearance of the microconidia and hyphae of Trichophyton rubrum on lactophenol cotton blue preparations? A. Club-shaped B. Broad-based budding C. Birds on a telephone wire D. Mariner's wheel
C
4. Which Candida spp. is the most commonly encountered human pathogen? A. Candida glabrata B. Candida tropicalis C. Candida albicans D. Candida krusei
C
4. Which antibiotic is used in growth media to help isolate dermatophytes? A. Fluconazole B. Penicillin C. Cyclohexamide D. Aminoglycoside
C
1. Traditionally, CDI is diagnosed in a patient by using which of the following? A. A review of past medical history. B. An examination of signs and symptoms. C. Use of laboratory-based testing. D. All of the above
D
2. Beta-lactam antibiotics interfere with cell wall synthesis by: A. Binding with a transpeptidase B. Preventing the final stage of peptidoglycan synthesis C. Interfering with PBPs D. All of the above
D
2. Moving forward, important strategies for dealing with MRSA strains will include which of the following? A. Antimicrobial stewardship to guide the use of both existing alternatives and newer drugs. B. Identification of MRSA strains in all settings (inpatient as well as outpatient). C. Possible development of vaccines. D. All the above
D
2. Which are true statements regarding HA-MRSA and CA-MRSA? A. Resistance for both strains is conferred by the mecA gene. B. HA strains tend to demonstrate resistance to more drug classes than CA strains. C. CA tends to be associated with the PVL gene and skin and soft tissue infections. D. All the above
D
2. Which of the following scenarios represents appropriate detection of MRSA by the Kirby Bauer method? A. Mueller-Hinton agar (MHA); direct colony suspension; 37°C; cefoxitin disk; 24 hour incubation B. MHA; direct colony suspension; 35°C; oxacillin disk; 24 hour incubation C. MHA; direct colony suspension; 35°C; cefoxitin disk; 18 hour incubation D. MHA; direct colony suspension; 35°C; cefoxitin disk; 24 hour incubation
D
3. What is the most frequently used method for the diagnosis of primary amoebic meningoencephalitis (PAM)? a. Examination of blood smear b. Hemagglutination serological test c. Liver biopsy d. Examination of cerebrospinal fluid (CSF)
D
3. Which pathogenic free-living amoeba is most commonly isolated from soil, but has also been isolated in both fresh and salt waters, and appears to equally infect both immunocompetent and immunocompromised individuals? a. Naegleria fowleri b. Acanthamoeba species c. Sappinio pedata d. Balamuthia mandrilliaris
D
4. If zygomycosis is clinically suspected, then how should the specimen be prepared prior to culture? A. The specimen should be blended B. The specimen should be grinded C. The specimen should be frozen D. The speimcen should be minced.
D
4. The endospores of Coccidioides spp. often spill from their spherules and can be confused with which other thermally dimorphic fungi? A. Sporothrix B. Blastomyces C. Talaromyces marneffei D. Histoplasma
D
5. How many species of Plasmodium can cause infections in humans? A. 1 B. 2 C. 3 D. 5
D
In making a diagnosis of Acanthamoeba species, which of the following form(s) may be observed in brain tissue or corneal scrapings? a. Only trophozoites b. Only cysts c. Trophozoites and/or flagellates d. Trophozoites and/or cysts
D