Microbiology Final Review

The addition of which chemical can enhance the staining of Legionella in the Gram's stain?

0.05% basic fuschin

Name the catalase test reagent

3% hydrogen peroxide

Screening for recto/vaginal carriage of group B streptococci should occur:

35th-37th week gestation

How does DNA synthesis occur?

5' -> 3'

Bacteremia and endocarditis with Streptococcus gallolyticus subspecies gallolyticus is associated with:

Colorectal carcinoma

Which statement about the vertical transmission of syphilis is FALSE?

Congenital syphilis is easily diagnosed at birth because all neonates demonstrate typical signs and symptoms of infection.

Which of the following best describes the typical symptoms of M. pneumoniae infection?

Constitutional symptoms that "mimic" influenza, including a dry unproductive cough

Foods that are most frequently implicated in Staphylococcus aureus food poisoning are:

Cream-based foods like potato salad, etc.

Which statement is FALSE regarding growth of aerobic actinomycetes?

Cycloheximide does NOT inhibit growth

Which is a method of postamplification analysis?

DNA sequencing

Which is true regarding microarray analysis?

Detect multiple targets at once

Plesiomonas shigelloides has been associated with which of the following?

Diarrhea of people that live in tropical and subtropical places

Which statement best describes the role of β-lactamases?

Different classification systems differentiate these enzymes based on their structure or structure and function.

Vancomycin-resistant enterococci (VRE) that possess the vanA genotype:

Display high-level resistance to both vancomycin and teicoplanin.

Which statement best describes the requirements of anaerobic culture?

Do not read plates for 2 days

What are the oxidative and fermentative parameters of Legionella pneumophila?

Does not oxidase or ferment

Which types of fluorophore(s) are used in traditional FRET (fluorescence resonance energy transfer) PCR?

Donor and acceptor

T/F: C. difficile produces three toxins that are responsible for inducing antibiotic-associated colitis.

FALSE

T/F: Colonies of the B. fragilis group on bile esculin agar (BBE) after 18 to 24 hours will be large and nonpigmented.

FALSE

T/F: Cutaneous nocardiosis occurs only in immunocompromised individuals.

FALSE

T/F: Gram-stained smears aspirated from myonecrosis show a necrotic background with a lack of inflammatory cells and large "boxcar"-shaped gram-negative bacilli.

FALSE

T/F: Lactobacillus spp. are UNIVERSALLY susceptible to vancomycin.

FALSE

T/F: Lemierre's syndrome (anaerobic postanginal septicemia or necrobacillosis) is caused by P. melaninogenica and usually begins with pharyngotonsillitis.

FALSE

T/F: Metronidazole is not active against >90% of the obligately anaerobic cocci, but is active against most strains of the microaerophilic streptococci.

FALSE

T/F: Modern anaerobic systems (i.e., anaerobic jars and glove boxes) rapidly establish anaerobiosis by establishing and maintaining a low Eh (pH?) environment, regardless of the presence of oxygen.

FALSE

T/F: Most Actinomyces spp. are highly resistant to penicillin but susceptible to metronidazole.

FALSE

T/F: Nocardia spp. should always be considered as the primary pathogen when isolated from either a nonsterile or sterile site.

FALSE

T/F: Once anaerobiosis has been established in an anaerobic culture incubation system, the atmospheric conditions do not need to be further monitored.

FALSE

T/F: Propionibacterium spp. are catalase-positive but indole-negative.

FALSE

T/F: Rapidly growing Mycobacterium spp., Nocardia, and other aerobic actinomycetes cause VERY DIFFERENT types of clinical disease.

FALSE

T/F: The acid-fast reaction for Nocardia spp. is positive ONLY when hydrochloric acid (HCl) is used as the decolorizer.

FALSE

T/F: The aerobic actinomycetes are aerobic, branching filamentous fungi.

FALSE

T/F: Tropheryma whipplei can be readily cultured from clinical samples using specialized media.

FALSE

Which statement best describes the anaerobic bacteria?

Facultative anaerobes grow under both aerobic and anaerobic conditions.

T/F: A Modified Hodge Test has excellent sensitivity and specificity for detection of all clinically relevant types of carbepenemases in Enterobacteriaceae.

False

T/F: A patient with Mycobacterium kansasii pulmonary disease and a sputum specimen that is positive for acid-fast bacilli should be placed in airborne precautions when hospitalized.

False

T/F: A scotochromogen is pigmented in the light and nonpigmented in the dark.

False

T/F: Actinomyces graevenitzii and A. gerencseriae only cause thoracic actinomycosis.

False

T/F: Agar disk diffusion is a common method for in vitro susceptibility testing of mycoplasmas.

False

T/F: Antibiotic susceptibility testing does not need to be done for typhoidal Salmonella (S. Typhi and Salmonella Paratyphi A-C), even from invasive isolates from extraintestinal sites/sources.

False

T/F: Antibiotic susceptibility testing of clinical pathogens is done to guarantee that a particular agent or drug combination will be effective in therapy.

False

T/F: Bacteroides distasonis has been reclassified as Porphyromonas distasonis.

False

T/F: Because mycoplasmas and ureaplasmas lack a typical bacterial cell wall, they are resistant to aminoglycosides.

False

T/F: Because of low-level expression of the gene for OXA-51-like enzymes (i.e., a class D carbapenemase), the MICs for carbapenem drugs for Acinetobacter baumannii may be read as resistant when the isolate is really susceptible.

False

T/F: Both Ureaplasma urealyticum and Mycoplasma genitalium have been shown to cause pneumonia, bacteremia, and meningitis in newborns.

False

T/F: By definition, a mycobacterial isolate is considered a rapidly growing mycobacterium if it grows in broth in 5 days or less.

False

T/F: CLSI defines oxacillin resistance in Staphylococcus aureus as an MIC ≥ 8 μg/mL.

False

T/F: CLSI revised the Enterobacteriaceae MIC breakpoints and zone diameters for cephalosporins based on the pharmacokinetic/pharmacodynamics properties of these drugs, clinical data, and the MIC distribution of only wild-type fully susceptible isolates.

False

T/F: Carbapenem susceptibility results for Pseudomonas aeruginosa cannot be reported based on CLSI's MIC breakpoints alone without performing confirmatory testing.

False

T/F: Cardiovascular complications such as myopericarditis are the most common extrapulmonary complications of M. pneumoniae infection.

False

T/F: Cefoxitin is a less sensitive substrate for the mecA gene than oxacillin.

False

T/F: Clostridium spp. are usually susceptible to penicillins, metronidazole, and carbapenems but resistant to cephalosporins.

False

T/F: Cold agglutinins that may be produced during M. pneumoniae infection are IgG antibodies that react in the cold with human erythrocyte I antigens.

False

T/F: Conventional antibiotic susceptibility testing of Pseudomonas aeruginosa isolates from cystic fibrosis patients is difficult because they have a highly mucoid phenotype and often do not grow enough to get valid results unless incubation is extended for 96 hours.

False

T/F: Cultivation of mycoplasmas and ureaplasmas requires an enriched medium that contains precursors for only nucleic acid and protein.

False

T/F: Cultures for Nocardia should ONLY be held for 7 days.

False

T/F: Daptomycin should be tested on bacterial isolates from the lower respiratory tract because this agent is not inhibited by surfactant in the lungs.

False

T/F: ESBL-producing isolates of E. coli, Klebsiella spp., or Proteus mirabilis should be reported resistant to penicillins and all cephalosporins including the cephamycins.

False

T/F: Enterococcus casseliflavus and Enterococcus gallinarum have high-level resistance to vancomycin encoded by either a vanA or vanB gene.

False

T/F: Enterococcus develops high-level resistance to aminoglycosides because of decreased uptake of the drug into the cell.

False

T/F: Food-borne botulism is confirmed by a reference laboratory by isolation of C. botulinum from serum, feces, and gastric contents of vomitus.

False

T/F: Gram-positive bacteria more commonly have multiple β-lactamases of different types that are expressed in the same isolate compared with gram-negative bacteria.

False

T/F: If Streptococcus pneumoniae is resistant to erythromycin and has a positive D-zone test for clindamycin inducible resistance, the organism has an altered cell wall encoded by an ermA or ermC gene.

False

T/F: If carbapenem resistance is detected in Enterobacteriaceae, then CLSI recommends doing a phenotypic confirmation test.

False

T/F: In the current syphilis testing algorithm recommended by the CDC, a nontreponemal test (i.e., RPR or VDRL) is ordered first, followed by a treponemal test if the former is reactive.

False

T/F: Inducible chromosomal AmpC enzymes occur in all Enterobacteriaceae.

False

T/F: Ixodes ticks must remain attached for at least 72 hours to effectively transmit spirochetes to their host.

False

T/F: Lactobacillus spp. are gram-positive rods that grow on Rogosa's selective tomato juice agar and are catalase-positive.

False

T/F: Leptospirosis is mainly diagnosed by detection of antibody using serologic tests. The main serologic test used continues to be the microagglutination test (MAT), and a titer of >1:100 in a single serum specimen by the MAT test is presumptive evidence of leptospirosis in a patient with a compatible clinical illness.

False

T/F: M. genitalium can be identified by using a hemadsorption assay using guinea pig erythrocytes.

False

T/F: M. genitalium causes most cases of nongonococcal urethritis in men.

False

T/F: M. penetrans was initially isolated from the urogenital tract of homosexual men with no evidence of HIV infection.

False

T/F: Most members of the B. fragilis group are resistant to penicillins and cephalosporins, but there is no resistance to clindamycin.

False

T/F: Most rapidly growing mycobacteria are susceptible to the primary antituberculous drugs.

False

T/F: Mycoplasma genitalium possesses a species-specific 140 kDa protein called P140 that allows the organism to adhere in the respiratory tract.

False

T/F: Mycoplasmas and ureaplasmas are part of the Mycoplasmatales class.

False

T/F: Mycoplasmas and ureaplasmas require sterols.

False

T/F: Plated media should be regularly inspected under magnification and oblique light to observe the "fried-egg" colonies of Ureaplasma urealyticum or the small dense colonies of Mycoplasma hominis.

False

T/F: Porphyromonas spp. typically produce nonpigmented to pigmented colonies and are bile-resistant.

False

T/F: Prevotella spp. typically produce black-pigmented colonies, and primarily produce acetic, butyric, and succinic acids.

False

T/F: Rat-bite fever is caused worldwide by Streptobacillus moniliformis, a filamentous, gram-negative, nonmotile, and non-acid-fast rod.

False

T/F: Aerobic actinomycetes are widely distributed in nature and can be isolated from soil and marine sediments and the feces of many animals.

TRUE

T/F: Aerobic actinomycetes should be sent to a reference laboratory for complete identification if your laboratory does not have the capacity to perform sequencing or other advanced methods (i.e., MALDI-TOF) for identification.

TRUE

T/F: Clostridium difficile diarrhea is commonly acquired by nosocomial exposure to spores?

TRUE

T/F: Disseminated nocardiosis often seeds the central nervous system.

TRUE

T/F: F. nucleatum and F. necrophorum are the most commonly isolated species of the Fusobacterium genus.

TRUE

T/F: Nocardia contain mycolic acid in their cell wall.

TRUE

T/F: Nocardiae are opportunistic pathogens that most often cause infection in patients who are immunocompromised or have debilitating diseases.

TRUE

T/F: Skin and mucocutaneous nocardiosis is commonly caused by species that are not part of the N. asteroides complex.

TRUE

T/F: Strict obligate anaerobes are not capable of growth on agar surfaces exposed to oxygen levels >0.5%.

TRUE

T/F: The most common mechanism of infection by Nocardia spp. is inhalation of airborne fragments of the bacteria from the environment with development of pneumonia.

TRUE

T/F: Whipple's disease requires a prolonged course of treatment of >1 year with trimethoprim-sulfamethoxazole to prevent relapse.

TRUE

Which factor is most important in the persistence of leptospirosis in the environment?

The propensity of leptospires to colonize the surface of the renal proximal tubular epithelial cells in diseased animals

T/F: Aminoglycoside modifying enzymes catalyze the modification at -OH or -NH2 groups of the 2-deoxystreptamine nucleus or the sugar moieties and are phosphotransferases, acetyltransferases, or nucleotidyltransferases.

True

T/F: An inducible resistance assay called the D-zone test should be done for staphylococci, β-hemolytic streptococci, and Streptococcus pneumoniae before reporting clindamycin results.

True

T/F: Anaerobes isolated from sterile sites, especially bloodstream infections, should have antibiotic susceptibility testing performed in-house or by send-out to a reference laboratory.

True

T/F: Anaerobic conditions can be produced in jar systems with either the disposable hydrogen-carbon dioxide generator or by the gas evacuation/replacement procedure.

True

T/F: Anaerobic transport and culture medium contain reducing agents such as thioglycolate and L-cysteine to maintain a low oxidation-reduction potential (i.e., Eh).

True

T/F: Antibiotic susceptibility reports should include an interpretation for each drug of susceptible (S), intermediate (I), or resistant (R).

True

T/F: Because of the limitations of phenotypic tests and the high diversity of genes encoding carbapenemases, molecular analysis using polymerase chain reaction (PCR) analysis is the best detection method.

True

T/F: Because of the similarity in nucleotide sequences between M. pneumoniae and M. genitalium, specific probes have to be used in molecular assays to prevent false-positive results.

True

T/F: Broth microdilution is the method of choice for susceptibility testing of nontuberculous mycobacteria.

True

T/F: C. perfringens is a common bacterial agent of diarrheal disease and outbreaks caused by ingestion of contaminated food.

True

T/F: Carbapenem resistance has been reported in Bacteroides, Prevotella, and Fusobacterium.

True

T/F: Relapsing fever is diagnosed by performing either an initial IFA or ELISA test that requires cultivated borreliae. Because of the high specificity of these assays, a confirmatory Western immunoblot does not need to be done on reactive samples.

False

T/F: Resistance to fluoroquinolones is mainly caused by chromosomal mutations in DNA gyrase and topoisomerase IV, which are enzymes involved in protein synthesis.

False

T/F: Resistance to linezolid has been described in both Staphylococcus aureus and vancomycin-resistant enterococci because of mutation in the 50S ribosomal subunit, which results in decreased antibiotic affinity for its target site.

False

T/F: Resistance to penicillin is increasing worldwide in Streptococcus pyogenes.

False

T/F: Streptococcus pneumoniae isolates recovered from a cerebrospinal fluid in a patient with meningitis should be reported using lower MIC breakpoints as isolates from other sites.

False

T/F: Suspected mycoplasmal colonies from routine agar medium should be subcultured onto a mycoplasmal growth medium such as BCYE differential agar.

False

T/F: The Borrelia burgdorferi complex (B. burgdorferi sensu lato) contains only one human pathogen, B. burgdorferi sensu stricto, whose distribution is restricted to North America.

False

T/F: The Kinyoun stain is preferred for direct detection of mycobacteria in clinical specimens.

False

T/F: The MIC breakpoints for oxacillin in other coagulase-negative staphylococci besides Staphylococcus lugdunensis are higher than S. aureus.

False

T/F: The incubation period for M. pneumoniae infection is a minimum of 3 to 4 weeks.

False

T/F: The minimum inhibitory concentration is the highest concentration of drug that inhibits visible bacterial growth.

False

T/F: Ureaplasma urealyticum and Ureaplasma diversum are the two "T-strain" mycoplasmas that have been isolated from the human genitourinary tract.

False

T/F: When performing antibiotic susceptibility testing, a MAJOR error is defined as reporting a clinical pathogen as susceptible when it is resistant.

False

T/F: Wound care is the main way to prevent tetanus after injury; there is currently no vaccine or antitoxin available.

False

Which statement best describes the characteristics of Bilophila spp.?

Gram-negative rods whose growth is enhanced by bile, catalase-positive

Which statement best describes CLSI grouping of recommended antimicrobial agents for testing and reporting antibiotic susceptibility test results?

Group B should be tested but selectively reported

All of the following are characteristics of the genus Enterococcus EXCEPT:

Growing at 10C but not 40C

Which series of characteristics are consistent with an identification of Burkholderia cepacia?

Grows well on MacConkey, weak oxidase-positive result, colistin resistance

In persons with latent Mycobacterium tuberculosis infection, the greatest risk factor for progressing to active tuberculosis is:

HIV infection

Which statement best describes the life cycle of Ixodes ticks?

Hard-bodied Ixodes ticks are vectors that transmit Lyme disease borreliae to humans.

Anaerobic blood culture bottles may not be collected in which of the following clinical situations?

Healthy patient with a superficial, non-necrotizing cellulitis

A 35-year-old man comes to the physician for a follow-up examination. He has had persistent left upper quadrant abdominal pain for 3 weeks. Upper esophagogastroduodenoscopy shows an active duodenal ulcer. Tests of gastric and duodenal biopsy specimens for urease are positive. Which one of the following is the most likely causal organism?

Helicobacter pylori

Active chronic antral gastritis is now considered to be an infectious disease caused by:

Helicobacter pylori

Bacterial cells of Nocardia spp. cannot be seen in tissue sections using which of the following stains?

Hemotoxylin and eosin (H&E)

Which statement best describes the usual susceptibility pattern of M. pneumoniae?

High-level macrolide resistance has been reported

Which biochemical test is useful for the detection of Legionella pneumophila? (i.e., Legionella pneumophila is usually positive for this test, whereas most other Legionella species are negative.)

Hippurate hydrolysis

The species of Mycobacterium that grows best at 42°C is:

M. xenopi

Which of the following mycobacteria might stain poorly or not at all with auramine/rhodamine?

Mycobacterium abscessus complex

A 16-year-old cystic fibrosis patient develops fever and increasing cough. A sputum is submitted for mycobacterial smear and culture. The smear is positive for acid-fast bacilli. The most likely pathogen is:

Mycobacterium abscessus.

T2H selectively inhibits the growth of:

Mycobacterium bovis

The most common mycobacterial contaminant in the laboratory is:

Mycobacterium gordonae

Which of the following is most commonly associated with disseminated disease in a patient with AIDS?

Mycobacterium intracellulare

Which of the following is a photochromogen?

Mycobacterium marinum

A positive niacin test is characteristic of:

Mycobacterium tuberculosis

An MGIT tube is flagged positive for mycobacterial growth by the instrument. A Kinyoun-stained smear of the broth shows long, serpentine cords. The most likely organism is:

Mycobacterium tuberculosis.

Which species is not part of the Nocardia asteroides complex?

N. brasillensis

Rapid molecular surveillance tests for the direct detection of MRSA are FDA cleared for:

Nares only/nose only

What are characteristics of the genus Legionella?

Narrow (0.3 to 0.9 mm diameter), poorly staining gram-negative bacillus; asaccharolytic

The altered penicillin-binding protein (PBP) that is found in methicillin-resistant isolates of Staphylococcus aureus is called:

PB2a

Which is the most sensitive method for the direct detection of Legionella pneumophila in a clinical respiratory specimen?

PCR

What PCR method is used in strain typing?

PCR-RFLP

Which of the following statements is FALSE pertaining to infection caused by Rhodococcus equi?

R. equi is treated with one or more antifungal agents.

Tube coagulase test uses:

Rabbit plasma with EDTA

Which statement best describes the prediction of Staphylococcus aureus to β-lactams based on penicillin and oxacillin test results?

Resistance to both penicillin and oxacillin predicts resistance for all β-lactams and β-lactam/β-lactamase inhibitor drugs.

Micrococci and related species are:

Resistant to furazolidone

What PCR mod amplifies RNA targets?

Reverse transcriptase PCR

Which of the following best describes the usual susceptibility patterns for aerobic actinomycetes?

Rhodococcus equi is usually resistant to penicillin and cephalosporins.

T/F: Clinical presentation of early congenital syphilis may include prematurity and low birth weight, hepatomegaly and/or splenomegaly, a skin rash that resembles the skin lesions of secondary syphilis, and deformed tibias (saber shins) or teeth (mulberry teeth).

True

T/F: Clostridium difficile is found in one-third of cases of antibiotic-associated diarrhea, which subsides once treatment is stopped.

True

T/F: Enterobacteriaceae that produce carbapenemases are becoming an increasing problem worldwide.

True

T/F: Enterococci are inherently resistant to aminoglycosides.

True

T/F: F. nucleatum is a gram-negative rod that appears "spindle-shaped" and grows as "breadcrumb-like" colonies.

True

T/F: False-positive tests may occur when using an inhibitor-based method to confirm the presence of an AmpC β-lactamase in Enterobacteriaceae when the isolate also has a KPC carbapenemase.

True

T/F: Haemophilus influenzae is commonly ampicillin resistant because of the production of a β-lactamase.

True

T/F: Human mycoplasmas can be divided into three groups on the basis of utilization of three substrates: glucose, arginine, and urea.

True

T/F: If Staphylococcus aureus is resistant to erythromycin but has a negative D-zone test for clindamycin inducible resistance, the organism has an efflux mechanism.

True

T/F: If Streptococcus pyogenes tests resistant to penicillin, then this predicts resistance to all other β-lactam drugs.

True

T/F: If a treponemal test is positive (i.e., EIA) but the nontreponemal test is negative, the patient may have primary or latent syphilis, previously treated or untreated syphilis, or yaws or pinta.

True

T/F: Individuals with M. pneumoniae infection may experience major dermatologic manifestations such as erythema multiforme major (Stevens-Johnson syndrome).

True

T/F: Infant botulism is the most common type of disease reported in the United States.

True

T/F: Infections most commonly associated with rapidly growing mycobacteria involve skin and subcutaneous tissue.

True

T/F: Isolation of Ureaplasma urealyticum from the lower genital tract of pregnant women is associated with the delivery of low-birth-weight infants.

True

T/F: Ixodes scapularis, I. ricinus, and I. persulcatus are the most important vectors of Lyme borreliosis worldwide.

True

T/F: Leptospira may be detected by microscopic examination of blood, CSF, or urine, but spirochetes in blood can only be detected during the early bacteremic phase of the illness.

True

T/F: Lyme disease is the most commonly reported vector-borne infection in both the United States and Europe.

True

T/F: M. pneumoniae can be presumptively isolated from a respiratory tract specimen by growth of glycolytic, spherical colonies that grow on SP-4 agar after 4 to 20 days of incubation.

True

T/F: Molecular approaches for the detection of M. genitalium include real-time PCR assays that amplify the specific adhesin gene (MgPa).

True

T/F: Molecular assays have been developed for detection and specific identification of M. hominis and Ureaplasma urealyticum from clinical samples.

True

T/F: Most Bifidobacterium spp. are susceptible to kanamycin and vancomycin but resistant to colistin.

True

T/F: Most cases of botulism are caused by antigenically distinct, heat-labile protein toxins produced by C. botulinum, most commonly types A, B, E, and F.

True

T/F: Multidrug-resistant bacteria often have multiple mechanisms of resistance operative that confer the final resistance phenotype.

True

T/F: Mycoplasma fermentans, M. penetrans, and M. pirum have been implicated as opportunistic agents or cofactors that contribute to the pathogenesis of HIV-related disease.

True

T/F: Mycoplasma hominis bacteremia and sternal wound infection have occurred following cardiac surgery.

True

T/F: Mycoplasmas and ureaplasmas are organisms that differ from other bacteria because they lack a rigid cell wall.

True

T/F: Nocardia and Tsukamurella will grow in the presence of lysozyme.

True

T/F: Oxacillin disk testing should not be used for testing Staphylococcus aureus.

True

T/F: Phenotypic confirmation of the presence of an extended-spectrum β-lactamase (ESBL) in E. coli relies on the fact that these enzymes are inhibited by clavulanic acid.

True

T/F: Propionibacterium spp. are resistant to metronidazole.

True

T/F: Pseudomonas aeruginosa along with other nonfermenters including Stenotrophomonas maltophilia, Burkholderia cepacia complex, and Acinetobacter spp. is frequently multidrug resistant to three or more antibiotic classes.

True

T/F: Resistance to cefixime and ceftriaxone in Neisseria gonorrhoeae has been increasing worldwide, including the United States, that the Centers for Disease Control and Prevention no longer recommends using oral cephalosporins for treatment.

True

T/F: Resistance to penicillin has been reported in rare isolates of Neisseria meningitidis.

True

T/F: Resistance to β-lactam antibiotics in Pseudomonas aeruginosa occurs because of altered porins and the production of various types of β-lactamases.

True

T/F: Similar MIC breakpoints for oxacillin are recommended by CLSI for Staphylococcus aureus and S. lugdunensis.

True

T/F: Specific Leptospira species cause leptospirosis in humans. Thirteen pathogenic species of Leptospira are recognized, which contain more than 260 serovars.

True

T/F: Staphylococcus aureus strains with a high level of resistance to methicillin and other β-lactam antibiotics carry and express the mecA or mecC genes.

True

T/F: Staphylococcus saccharolyticus is an anaerobic coagulase-negative Staphylococcus species that may cause native and prosthetic valve endocarditis.

True

T/F: Streptococcus pneumoniae becomes resistant to penicillin by alteration of its cell wall and the expression of penicillin-binding proteins with a low affinity for this drug.

True

T/F: Tetanus is caused by the actions of two toxins, tetanolysin and tetanospasmin elaborated by C. tetani.

True

T/F: Tetracyclines can be tested but should not be reported on infants and younger children because of potential side effects if prescribed.

True

T/F: The aerotolerance of anaerobes depends on the production of superoxide dismutase, catalase, and possibly peroxidase enzymes.

True

T/F: The four major targets of antibiotic action in bacterial pathogens include inhibition of cell wall synthesis, protein synthesis, DNA replication, and folate coenzyme biosynthesis.

True

T/F: The membrane-associated 169-kDa protein called P1 is the major cytoadhesin that mediates adherence of M. pneumoniae to host cells.

True

T/F: The minimum bactericidal concentration is the lower concentration of an antibiotic that kills 99.9% of the bacterial inoculum.

True

T/F: The optimal incubation temperature for culture of Mycobacterium marinum is 30°C to 32°C.

True

T/F: The peak concentration of an antibiotic in serum is the therapeutic indicator, and the trough level is the toxicity indicator.

True

T/F: The production of a strong catalase reaction and lack of butyric acid production are key characteristics that separate Bilophila wadsworthia from Fusobacterium species.

True

T/F: The role of M. fermentans in HIV pathogenesis, sexually transmitted infections, rheumatoid arthritis, chronic fatigue syndrome, and other conditions has not been definitively delineated.

True

T/F: Ureaplasma urealyticum may be vertically transmitted to the neonates delivered to colonized mothers.

True

T/F: Veillonella parvula is the anaerobic gram-negative coccus, which is most commonly isolated from clinical specimens.

True

T/F: Visualization of a sulfur granule on Gram's stain of a clinical sample may indicate the presence of an anaerobic infection caused by P. propionicum or Actinomyces spp.

True

T/F: When performing antibiotic susceptibility testing, a minor error is reporting a susceptible or resistant result as intermediate or reporting an intermediate result as either susceptible or resistant.

True

What does RNA use instead of thymine?

Uracil

What is the most commonly used non-culture-based method for the diagnosis of legionellosis?

Urinary antigen testing

Which is the optimal method for diagnosing antibiotic-associated colitis caused by toxigenic C. difficile?

Use of a two- or three-step algorithm that includes a combination of tests

Which activity is a risk factor for developing legionellosis?

Using a hot tub/jacuzzi

Members of the Mitis group of viridans streptococci are:

Usually arginine dihydrolase- and esculin hydrolysis-negative and do not ferment mannitol or sorbitol

Early onset disease in the neonate associated with group B streptococci:

Usually presents with bacteremia, pneumonia, and/or meningitis.

In the reference broth microdilution antimicrobial susceptibility testing procedure, which of the following is true of vancomycin-intermediate Staphylococcus aureus (VISA)?

VISA isolates will have vancomycin MICs of 4 to 8 μg/mL.

The newly described species Streptococcus pseudopneumoniae:

Will demonstrate resistance or intermediate susceptibility to optochin when cultures are incubated in 5% CO2.

Rifampin resistance in Mycobacterium tuberculosis is caused by a mutation in which gene?

rpob

The Mycobacterium species that is a scotochromogen at 37°C but a photochromogen at 25°C is:

M. szulgai

Which of the following is NOT a manifestation of pulmonary nocardiosis?

Positive tuberculin skin test

Which of these organisms has been isolated from the human genital tract?

M. hominis

Organism-Feature matching: Features: 1) DNase-positive: 2) Non-motile, oxidase negative: 3) Cause of neonatal meningitis: 4) Pyocyanin production 5) Rapidly urea-positive after 4 hours 6) Colistin (R), lysine decarboxy (+) 7) Cause of meliodiasis 8) No growth at 42C, makes pyoverdine 9) Causes flower rot and pneumoniae in patients with CGD 10) Colonies have wrinkled appearance in agar Organisms: - P. fleurescins - P. aeruginosa - B. bronchoseptica - A. baumannii - B. cepacia - B. gladioli - B. pesudomaillie - E. meningoseptica - P. stutzeri - S. maltophilia

1) DNase positive: Acinetobacter baumannii 2) Non-motile, Oxi negative: Bordetella bronchiseptica 3) Causes neonatal meningitis: Burkholderia cepacia 4) Pyocyanin production: Burkholderia gladioli 5) Rapidly urea-pos after 4 hours: Burkholderia pseudomaillie 6) Colistin (R), Lysine decarboxylase positive: Elizabethkingia meningioseptica 7) Causes meliodiasis: Pseudomonas aeruginosa 8) No growth at 42 C, makes pyoverdine: Pseudomonas fluorescens 9) Causes flower rot and pneumoniae in CGD patients: Pseudomonas stutzeri 10) Wrinkled colonies in agar: Stenotrophomonas maltophilia

Organism-Feature matching #2: Features: 1) Hippurate hydrolysis positive 2) Toxin binds to receptor on intestinal membrane 3) Causes peptic ulcers 4) Hydrolyzes indoxyl acetate 5) Seen in homosexual men (proctitis/proctocolitis) and in "nutritional therapies" 6) Makes green colonies on TCBS 7) Curved rod from external ear wound 8) Seen in liver dysfunction and increased iron deposition issues 9) Considered a member of Enterobacteriaeceae 10) A curved rod that causes diarrhea in humans and is hippurate hydrolysis NEGATIVE Organisms: - A. butzleri - V. cholerae - Campylobacter coli - Campylobacter fetus - Campylobacter jejuni - H. pylori - P. shigelloides - V. paraheaemoliticus - V. alginolyticus

1) Hippurate hydrolysis positive: Arcobacter butzleri 2) Toxin binds to receptor on intestinal membrane: Campylobacter coli 3) Causes peptic ulcers: Campylobacter fetus 4) Hydrolyzes indoxyl acetate: Campylobacter jejuni 5) Seen in homosexual men (proctitis/proctocolitis) and in "nutritional therapies" : Helicobacter pylori 6) Makes green colonies on TCBS: Plesiomonas shigelloides 7) Curved rod from external ear wound: Vibrio alginolyticus 8) Seen in liver dysfunction and increased iron deposition issues: Vibrio cholerae 9) Considered a member of Enterobacteriaeceae: Vibrio parahaemolyticus 10) A curved rod that causes diarrhea in humans and is hippurate hydrolysis NEGATIVE: Vibrio vulnificus

Which is the best method for definitively identifying clinically relevant aerobic actinomycete isolates?

16S nucleic acid sequencing using a reference database

What is the incubation period for Legionnaire's disease (i.e., legionellosis)?

2 to 10 days

Define Multiplex PCR

A PCR reaction that employs a primer set common to a large taxonomic group of organisms

Define broad range PCR

A PCR reaction that employs a primer set common to a large taxonomic group of organisms

Which of the following best describes the methods used for definitive identification of clinically relevant anaerobes?

A combination of methods + 16S sequencing

Which of the following measures is not important when troubleshooting broth microdilution assays?

A denser inoculum should be used if the MICs are lower than expected

Which of these organisms has NOT been associated with human disease?

M. lipophilum

Which of the following organisms is included in the Acinetobacter calcoaceticus-baumannii (ACB) complex?

A. nosocomialis

A glucose nonfermenting gram-negative rod is recovered from a positive blood culture. Further testing reveals that the organism produces acid in OF glucose and OF xylose. It is strongly oxidase-positive and acetamide-positive, grows at 42oC, and is arginine decarboxylase-negative. What is the most likely identification of this isolate?

Achromobacter xylosoxidans

A glucose nonfermenting bacterium was isolated from the tracheostomy site of an ICU patient. The organism grew on both blood and MacConkey agars and was oxidase-negative. In response to an inquiry from the attending physician about the clinical significance of the isolate, the director of microbiology reported that the organism has low virulence potential but that it has been reported to cause both community- and hospital-acquired infections. It has been recovered from numerous human sources and is found to colonize 45% of inpatient tracheostomy sites. It is also the most common gram-negative bacteria carried on the skin of hospital personnel. What is the identity of the organism referred to in this case?

Acinetobacter baumannii

Which mechanism is responsible for the characteristic "rice water" stools caused by Vibrio cholerae O1 serotypes?

Activation of the adenyl cyclase system by an enterotoxin, causing intracellular rise in cyclic 3', 5'-adenosine monophosphate (cAMP)

Which statement best describes serologic tests for M. pneumoniae?

Acute and convalescent antibody titers should be measured.

A gram-positive coccus is isolated from a urine culture in colony counts of >105 cfu/mL. The isolate is a-hemolytic on sheep blood, is LAP-positive, is PYR-negative, and does not grow on bile esculin media but does grow in 6.5% NaCl. What is the identity of this urinary tract pathogen?

Aerococcus urinae

Which statement best describes the use of media for primary isolation of anaerobes from clinical specimens?

Anaerobic laked kanamycin-vancomycin (KV) is used for selective isolation from mixed polymicrobial infections.

Which of the following things does NOT cause MICs that are too large or zone sizes that are too small?

Agar depth too thin

A gram-negative glucose nonfermenting rod is isolated from a mixed culture of a patient with a diabetic foot ulcer. The organism is asaccharolytic and oxidase-positive, and reduces nitrite but not nitrate. The technologist also notices a characteristic fruity odor on the BAP. What is the likely identification of this organism?

Alcaligenes faecalis

Which of the following statements best describes the phenotypic characteristics of M. pneumoniae?

All strains belong to one serovar and have a similar rRNA composition.

Penicillin resistance in Streptococcus pneumoniae is caused by:

Alteration in porin molecules associated with transport of antimicrobial agents.

Legionellae have a commensal relationship with which type of other organism?

Amebae

Which statement best describes the antibody response to Treponema pallidum infection?

Antitreponemal IgG antibodies persist for years after the time of infection, regardless of treatment.

Aeromonads are fermentative gram-negative rods that may be differentiated from members of the family Enterobacteriaceae because they:

Are oxidase positive when tested

Community-acquired MRSA (CA-MRSA) infections:

Are soft-tissue infections or necrotizing pneumonia

What is the best method to prevent contact with Lyme disease borreliae?

Avoiding exposure to the arthropod vectors (Ixodes ticks) that cause Lyme disease

Give an example of nucleic acid amplification

B-DNA/Branched chain DNA

Which of the following statements best describes the role of efflux pumps in antibiotic resistance?

Bacteria use efflux pumps to actively excrete a solute out of the cell

Which of these genera is most commonly isolated from human clinical specimens?

Bacteroides

Which of these genera is part of the anaerobic non-spore-forming gram-positive bacilli?

Bifodobacterium

A technologist who works with rabbits in an animal research facility develops a respiratory illness. The rabbits are reported to be ill with snuffles, a term used to describe the symptoms of runny eyes, runny nose, and sneezing in rabbits. A sputum culture from the lab worker grows a gram-negative nonfermenting rod that is oxidase-positive, is asaccharolytic, reduces nitrate but not nitrite, and, if rapid, is urease-positive. What is the most likely identification of this isolate?

Bordetella bronchiseptica

Which statement is false?

Borrelia recurrentis causes tick-borne relapsing fever.

Which of these specimens should be cultured for anaerobes?

Brain abscess pus

Which is the standard media used to culture Legionella?

Buffered charcoal yeast

A 58-year-old male presented with pulmonary symptoms. His only significant history was having spent 1 year as a GI in Vietnam. Sputum cultures yielded growth of a gram-negative rod that grew well on blood agar and MacConkey agar. The organism was oxidase-positive and did not ferment glucose. Which of the following organisms is the most likely bacterial pathogen in this patient?

Burkholderia pseudomaillie

Which statement best describes characteristics that are useful for the identification of Clostridium spp.?

C. ramosum and other species produce terminal spores.

A healthy 18-month-old has been experiencing diarrhea almost every hour for past 36 hours with no vomiting or fever. Infant stays with maternal grandmother during the day who is also reported to have diarrhea. There have been no recent contacts with well water or travelers. Stool contains mucus and streaks of blood, and has been sent to the microbiology laboratory for culture. Examination of MacConkey and Hektoen agar plates after 24 hours reveals only lactose-positive colonies. However, a blood agar plate incubated in an atmosphere of 5% oxygen and 10% CO2 reveals growth of curved, gram-negative bacilli that show "gull wing" and "S-shape" morphology. Further testing would likely lead to the identification of which of the following organisms?

Campylobacter jejuni

Which one of the following organism is reported to be associated with the development of Guillain-Barré syndrome in a subset of infected patients 1 to 3 weeks after the patients develop onset of diarrheal symptoms?

Campylobacter jejuni

What is true of third-generation binding dyes?

Can detect single-nucleic acid polymorphisms

Exfoliative toxins produced by Staphylococcus aureus:

Cause dissolution of the mucopolysaccharide matrix of the epidermal stratum granulosum in the scalded skin syndrome.

Which technology, in addition to PCR and DNA sequencing, has been used to identify cultivated Legionella species?

Cellular fatty acid analysis

Aeromonas is most frequently associated with which of the following conditions?

Cellulitis/wound infection from water or soil

Which of the following is a major complication of placental mycoplasma or ureaplasma infection?

Chorioamnionitis with premature rupture of membranes

Which statement is not true about the horizontal transfer of resistance determinants in bacteria?

Clinical pathogens constitutively express antibiotic resistance genes with or without exposure to a stimulus.

Which of these genera is part of the anaerobic spore-forming gram-positive bacilli?

Clostridium

A gram-negative rod grows as a colorless colony on a MacConkey agar plate. When inoculated to a Kligler's iron agar tube, an alkaline slant/alkaline butt reaction is observed. The organism is oxidase-positive, produces a sweet grape-like odor, and grows at 42oC. Which of the following clinical infections is most likely to be caused by this organism?

Ear-infection after swimming in a fresh-water lake

Which one of the following is NOT associated with infections caused by Pseudomonas aeruginosa?

Eating rare/undercooked hamburger

A nonfermenting gram-negative rod was isolated from the spinal fluid of an infant with meningitis. The same organism was subsequently isolated from a respirator located in the hospital nursery. The organism exhibited a yellow pigment when grown on sheep blood agar but failed to grow on MacConkey agar and was indole-positive. This organism is most likely:

Elizabethkingia meningoseptica

Isolates of vancomycin-resistant enterococci usually belong to which species?

Enterococcus faecium

Viral load testing is common for this specimen in the clinical lab

Epstein-Barr virus

***WRITTEN QUESTION/TYPE-IN**** List the primary antituberculous drugs.

Ethambutol (ETB), rifampin (RMP), isoniazid (INH) and pyrazinamide (PZA)

**WRITTEN QUESTION/TYPE IN ANSWER*** Testing an isolate of Mycobacterium tuberculosis for susceptibility to second-line drugs should be done when primary testing shows resistance to which one of the primary agents?

Ethambutol and isoniazid are the two most common primary agents of testing but rifampin and pyrazinamide have also been used

Which of the following is a characteristic of all bacteria belonging to the group of nonfermenting gram-negative bacteria?

Found in nature, food, soil, water, and vegetation

Which statement(s) best describe the interaction of HIV and syphilis?

Genital ulceration caused by a primary syphilitic chancre facilitates acquisition of HIV.

What is unique concerning next-generation sequencing?

Huge amounts of parallel nucleic acid sequencing is possible

What is an example of signal amplification?

Hybrid capture

The peptide nucleic acids (PNAs) used in the PNA FISH and QuickFISH assays identify organisms by:

Hybridized with species specific RNA sequences

The Biolog System for identification of staphylococci:

IDs these organisms on the basis of differential oxidation of a variety of chemical substrates.

Which of the following statements is not a recommendation for cumulative antibiogram reporting?

Include carefully collected surveillance isolates, not clinical isolates.

Which statement is FALSE pertaining to the pathogenesis of premature labor induced by Ureaplasma urealyticum?

Increased urea production by this organism is toxic to the fetus.

Which statement best describes the prevalence of syphilis in the United States?

Increasing rates since 2001

Recovery of Campylobacter jejuni from stool requires which of the following combination of culture and incubation conditions?

Incubation at 42°C, selective medium containing cephalothin, atmosphere containing 5% O2, 10% CO2

Which of the following countries has the highest number of tuberculosis cases?

India

A 60-year-old Hispanic male presents to the emergency room with medical history of hypertension, coronary artery disease, hypercholesterolemia, and coronary artery bypass graft. Three days prior to admission (PTA), patient ate chicken grilled for 10 minutes and rice. Two days PTA, patient developed intermittent periumbilical pain and diarrhea characterized as brown to watery stools with a frequency of 8 to 10x/day. One day PTA, he developed fever of 102°F accompanied by chills. Considering the above information, what culture considerations should be followed in attempting to recover the etiologic agent of this man's diarrhea?

Inoculate a blood agar plate containing a cephalosporin type of antibiotic and incubate in microaerophilic conditions

Which of these types of infections commonly involves anaerobes?

Intra-abdominal abscesses

The major virulence factor responsible for the ability of Staphylococcus epidermidis to colonize and form biofilms on IV catheters is:

Intracellular adhesins made of polysaccharides

How is real-time PCR different from traditional PCR?

It can detect amplicon without opening the tube

Which is a requirement for Legionella cultivation?

L-cysteine

Which of the following best illustrates the principles of optimal recovery of anaerobes from clinical specimens?

Laboratory rejection criteria must be published and adhered to.

Which of these organisms is NOT part of bacterial overgrowth in the vagina during bacterial vaginosis?

Lactobacillus

Which of the following requires special media for culture (i.e., does not grow on chocolate agar)?

Legionella

Which Legionella species is acid-fast?

Legionella micdadei

Which Legionella species is the most common cause of human infections?

Legionella pneumophilia

What significant outbreak occurred in the summer of 1976 in Philadelphia?

Legionellosis

Two genera of Streptococcus-like bacteria are intrinsically resistant to vancomycin. These two genera are:

Leuconostoc and Pediococcus.

Which of the following classes/subclasses of antimicrobial agents does not inhibit cell wall synthesis?

Lincosamides

Which statement does not describe the clinical outcomes from rapid reporting of antimicrobial susceptibility results?

Longer ICU stays

Which statement is not true regarding the characteristics of relapsing fever?

Louse-borne relapsing fever is caused by transmission of Borrelia hermsii from an infected louse to humans.

The major virulence factor of group A b-hemolytic streptococci is:

M Protein

Purulent material aspirated from an enlarged cervical lymph node of a child is cultured for mycobacteria. After incubation for 14 days, buff-colored colonies appear on chocolate agar, but there is no growth on 7H10 plates or in MGIT broth. A smear of a colony is positive for acid-fast bacilli. The most likely organism is:

M. haemophilium

Which of the following rapid-cycle PCR probes has a hairpin loop configuration?

Molecular beacon

Identify the one method below that is NOT used to routinely prevent and control the spread of syphilis.

Molecular subtyping of Treponema pallidum to detect transmission clusters

Which statement best describes the signs and symptoms of early Lyme disease?

Most patients (>90%) will have an outwardly spreading "bull's-eye" rash.

A β-lactamase test should be performed for which clinical pathogen?

Moxarella catarrhalis

Which of the following antimicrobial agents inhibits DNA synthesis?

Moxifloxacin

Members of the genus Abiotrophia and genus Granulicatella were formerly called:

Nutritionally variant, nutritionally deficient, or "satelliting" streptococci.

Which of the following statements best describes troubleshooting of the reading of disk diffusion tests?

Overlapping zones may occur when disks are not correctly placed on the agar.

A gram-negative rod was isolated from an infected foot of a patient with extensive burns of the lower extremities. The organism grew well on both blood and MacConkey agars and gave off a sweet odor. On the Mueller-Hinton agar plate used for susceptibility testing, the organisms gave a blue-green appearance. Further testing of this isolate would show it to be:

Oxidase positive, lactose negative, resistant to most antibiotics

Which statement about the antibody response to Borrelia burgdorferi infection is not true?

Patients with Lyme disease do not mount a reliable immune response to any B. burgdorferi antigens, which makes selection of specific antigens for diagnostic serology difficult.

Infections with the emerging streptococcal pathogen Streptococcus iniae are acquired by:

Penetrating injuries from fish spines during processing and cleaning.

The drug of choice for the treatment of group A streptococcal pharyngitis is:

Penicillin

Which of these genera is part of the anaerobic gram-POSITIVE cocci?

Peptostreptococcus

A pneumococcal isolate displays a zone of 12 mm around an optochin disk. What is to be done next?

Perform bile solubility

Which of the following tests is commonly used to confirm identification of M. pneumoniae?

Polymerase chain reaction or test for epifluorescence

Serologic studies have demonstrated that Legionella pneumophila was the cause of an outbreak of a febrile illness without pneumonia in which city?

Pontiac, MI

Which of the following genera is commonly resistant to antimicrobial agents?

Prevotella-Porphyromonas group

Which statement accurately describes the clinical stages of syphilis?

Primary syphilis manifests by chancre formation at the site of inoculation approximately 6 weeks after exposure.

Which of the following is a characteristic of all bacteria belonging to the genus Vibrio?

Produces acid in Klinger's iron and TSI slants

Propionibacterium acnes is an important opportunistic pathogen in which type of infection?

Prosthetic medical devices

A 23-year-old male with a diagnosis of cystic fibrosis is admitted to the hospital because of a pulmonary exacerbation related to his underlying disease. A sputum culture is ordered and grows a glucose nonfermenting gram-negative bacillus that is oxidase-positive and has a characteristic appearance on MacConkey agar. What is the organism?

Pseudomonas aeruginosa

Which one of the following organisms is not included in the Pseudomonas fluorescent group?

Pseudomonas stutzeri

The most discriminatory method for strain typing of Staphylococcus epidermidis and other coagulase-negative staphylococci is:

Pulse-field gel electrophoresis (PFGE)

Which of the following compounds is NOT used to treat nocardiosis?

Pyrazinamide

How does pyrosequencing differ from Sanger sequencing?

Pyrosequencing makes light, Sanger doesn't

Which of the following things is not required in a quality control program for antibiotic susceptibility testing?

QC is required only when the physician complains about a result.

Which of the following classes/subclasses of antimicrobial agents does not inhibit protein synthesis?

Quinolones

Which of the following genera is not part of the nocardioforms placed taxonomically in suborder Corynebacterineae?

Streptomyces

Former members of the genus Stomatococcus are now classified in the genus:

Rothia

A gram-positive coccus is isolated from a catheter tip culture. The organism is weakly catalase-positive and is coagulase-negative. The colonies are noted to be gray-white and very "sticky" when touched with an inoculating loop. What is the likely identity of this organism?

Rothia mucilaginosa

The former name of Streptococcus gallolyticus subspecies gallolyticus is:

S. bovis I

Which is the most common route of transmission for Treponema pallidum to infect humans?

Sexually transmitted disease

Campylobacter jejuni can be distinguished from other species of pathogenic campylobacters by:

Sodium hippurate hydrolysis

Which statement(s) best describe the spirochetes?

Spirochetes can be broadly differentiated by the number of axial filaments and insertion discs.

A coagulase-negative Staphylococcus is isolated from a patient with endocarditis. Rapid tests indicate that the isolate is PYR-positive and ornithine decarboxylase-positive. What can be suspected is the identity of this organism?

Staphyloccocus lugdunesis

The coagulase-negative staphylococcal species that is most frequently isolated from human clinical specimens is:

Staphylococcus epidermidis

Resistance to novobiocin is used for the presumptive identification of:

Staphylococcus saprophyticus

Which of the following staphylococcal species may be clumping factor-positive?

Staphylococcus schleiferi spp. schleiferi

A gram-negative organism isolated from sputum grew on MacConkey agar as a lactose-negative colony. The TSI was alkaline/no change, no gas, and no H2S. The organism was oxidase-negative, DNAse-positive, lysine-positive, ONPG-positive, and motile and oxidized maltose more than glucose. What is the most likely identification?

Stentrophomonas maltophilia

Most human isolates of group C b-hemolytic streptococci belong to which species/subspecies?

Streptococcus dysgalactiae subspecies equisimilis

Which of these organisms commonly causes typical lobar pneumonia?

Streptococcus pneumoniae

The zoonotic agent that is a leading cause of bacteremia and meningitis in Asia is:

Streptococcus suis

What are the three basic components of a nucleic acid?

Sugar-phosphate-base

Which of the following statements best describes the corrective action for antibiotic susceptibility tests that are out of control?

Suppress reporting of any antibiotics that are out of control until the problem is resolved.

Which of the following statements best describes the development of antibiotic resistance?

The genes encoding for resistance may be located either on the bacterial chromosome or on an extrachromosomal element or plasmid.

Which of the following things is not important in standardization of antibiotic susceptibility testing methods?

The inoculum can be prepared the night before and can be at any concentration.

Which statement best describes the signs and symptoms of tick-borne relapsing fever?

The patient will present with abrupt onset of fever, chills, delirium, myalgias, and arthralgias with jaundice and hepatosplenomegaly

MALDI-TOF works by:

The separation of proteins based on the mass-to-charge ratio through time-of-flight analysis

Which statement best describes the aerobic actinomycetes?

Their cell walls contain muramic acid, diaminopimelic acid (DAP), or lysine

Which statement best describes the usual susceptibility pattern of M. genitalium?

Therapeutic failures have occurred with tetracycline treatment.

All of the following are characteristics of the Anginosus group of viridans streptococci except that:

These organisms form large colonies on blood agar after 24 hours of incubation.

Which description best characterizes cultivation of human mycoplasmas?

They differ in their optimal pH for growth and atmospheric conditions.

Which statement best describes the recovery of mycoplasmas and ureaplasmas?

They have been recovered from humans, animals, insects, birds, and plants.

T/F: A sodium polyanethol sulfonate (SPS) disk test is a useful test for the identification of P. anaerobius.

True

T/F: All Mycoplasma species produce adenosine triphosphate (ATP) by substrate-level phosphorylation.

True

T/F: All laboratories, even those with limited capability, should be able to isolate anaerobes in pure culture and to evaluate their morphology.

True

What are the typical staining characteristics of Legionella pneumophila in the Gram's stain of a respiratory specimen of an infected patient?

They often DO NOT STAIN

Which statement best describes the usual susceptibility pattern of M. hominis?

This organism has intrinsic and induced resistance to macrolides.

Which statement best describes M. penetrans?

This organism readily adheres to and invades mammalian cells.

Which statement best describes M. genitalium?

This organism shares several characteristics with M. pneumoniae.

Which statement is true?

Treponema are slender organisms with tight coils (6 to 10 axial filaments attached by a single insertion disc).

Which of the following antimicrobial agents is a folate pathway inhibitor?

Trimethoprim-sulfamethoxazole

T/F: A Western immunoblot should be done to detect the borrelial antigens that both IgM and IgG antibodies are developed against in patients with Lyme disease to improve the specificity of serologic tests.

True

T/F: A highly sensitive EIA, or less commonly an IFA, should be used as the initial test for Lyme disease, followed by a standardized Western immunoblot for confirmation.

True

Which of these genera is part of the anaerobic gram-NEGATIVE cocci?

Veillonella

Which organism causing human disease can be characterized by (a) growth stimulated by Na+, (b) infected patients experiencing 12 to 14 L of fluid loss per day, and (c) growth of causative agent on thiosulfate citrate bile salts sucrose (TCBS) agar?

Vibrio cholarae

During summer months, geographic areas in which there is a high incidence of shellfish consumption should routinely screen for which one of the following organisms?

Vibrio parahaemolyticus

A patient with chronic cirrhosis develops septicemia following consumption of raw oysters. An organism is recovered from the blood that is described as a curved gram-negative rod. The organism grows on blood and MacConkey agars and is oxidase-positive. Upon further testing, the organism is found to be a lactose fermenter. What is the most likely identification of this organism?

Vibrio vulnificus

All of the following are manual systems for identification of staphylococci except

Vitek 2 gram-positive ID cards

Which of the following histochemical stains is recommended for the visualization of legionellae in histologic sections?

Warthin-Starry

What environmental niche is associated with Legionella?

Water

When does SYBR green generate signal after exposed to an appropriate excitation wavelength?

When it binds to DOUBLE-STRANDED DNA

Which of the following measures is not important when troubleshooting the reading of Etest assays?

Zone of inhibition should include pinpoint colonies and hazy growth

An isolate of Mycobacterium avium complex from blood should always be tested for susceptibility to:

clarithromycin.