Micro Quizzes and HW questions

The minimum bactericidal concentration (MBC) of an antimicrobial agent is defined as the lowest concentration of that antimicrobial agent that kills at least _________ of the original inoculum.

99.9%

What organism is found in the San Joaquin Valley region of California? A. Sporothrix schenckii B. Coccidioides immitis C. Penicillium marneffei D. Paracoccidioides brasiliensis

B. Coccidioides immitis

What organism displays Babes-Ernst granules on a Gram stain? A. Rhodococcus equi B. Corynebacterium diphtheriae C. Erysipelothrix rhusiopathiae D. Listeria monocytogenes

B. Corynebacterium diphtheriae

Cycloserine-cefoxitin-fructose agar (CCFA) is used for the recovery of:

C diff

Most bacterial cultures are incubated at this temperature range. A. 25° C to 27° C B. 30° C to 40° C C. 35° C to 37° C D. 40° C to 42° C

C. 35° C to 37° C

If an organism fermented glucose only and utilized peptones, what would the TSI reaction be? A. Acid/acid B. Alkaline/alkaline C. Alkaline/acid D. Acid/alkaline

C. Alkaline/acid

A primary tenet of antimicrobial therapy is to use A. the least toxic agents. B. the most cost-effective agents. C. All of the above D. the most clinically effective agents.

C. All of the above

What is a breakpoint panel? A. An MIC panel that contains nonroutine drugs. B. A standard MIC panel that contains many more dilution wells for each drug tested. C. An MIC panel with only one or a few concentrations of each drug. D. An MIC panel with only three or four drugs tested.

C. An MIC panel with only one or a few concentrations of each drug.

What is the causative agent of glanders? A. Burkholderia cepacia B. B. gladioli C. B. mallei D. Stenotrophomonas maltophilia

C. B. mallei

Which of the following tests can be used to presumptively identify Streptococcus pyogenes? A. Optochin B. Nitrate C. Bacitracin D. Citrate

C. Bacitracin

A young adult goes to the emergency department complaining of headache, dizziness, stiff neck, and purpura with a petechial skin rash. What two tests should the physician immediately perform? A. Urine and blood culture B. Genital and throat culture C. Blood and cerebrospinal fluid (CSF) culture D. Skin scraping and pupil dilation

C. Blood and cerebrospinal fluid (CSF) culture

Although antibodies are generally regarded as part of the adaptive immune system, they can enhance the function of which innate process(es)? A. Phagocytosis (via opsonization) B. Natural killer cell cytotoxicity C. Both phagocytosis (via opsonization) and natural killer cell cytotoxicity D. None are correct

C. Both phagocytosis (via opsonization) and natural killer cell cytotoxicity

A microbiologist is working the miscellaneous bench reading stool cultures. The campy plate from a culture has growth on the plate that was incubated at 42? C. The colonies are nonhemolytic, moist, ?runny looking,? and spreading. The Gram stain shows tiny gram-negative rods with some S-shapes and seagull-wing shapes. What is growing on the plate? A. Aeromonas B. Helicobacter C. Campylobacter D. Acinetobacter

C. Campylobacter

What organism may play a role in Guillain-Barr? syndrome (GBS)? A. Helicobacter B. Aeromonas C. Campylobacter D. Plesiomonas

C. Campylobacter

Which of the following methods is used to determine the presence of growth in mycoplasma broth media? A. Broth turbidity B. Presence of biofilm on surface C. Change in phenol red pH indicator D. Release of radiolabeled CO2

C. Change in phenol red pH indicator

Guidance for the development of a selective-reporting or cascade-reporting protocol for antibiotics is available from the A. Food and Drug Administration (FDA). B. United States Army Medical Research Institute (USAMRIID). C. Clinical Laboratory and Standards Institute (CLSI). D. Centers for Disease Control and Prevention (CDC).

C. Clinical Laboratory and Standards Institute (CLSI).

What is the name of the organism that causes tularemia, which can be contracted from rabbits? A. Brucella tularensis B. B. hareis C. Francisella tularensis D. F. philomiragia

C. Francisella tularensis

The hybrid capture assay is used to detect: A. RSV from sputum specimens B. HCV from bile specimens C. HPV from clinical specimens D. HIV from blood specimens

C. HPV from clinical specimens

A microbiologist is reading plates from a cerebrospinal fluid (CSF) culture. She notices that there is growth on chocolate agar (CHOC), but no growth on sheep blood agar (SBA) or MacConkey (MAC) agar. The Gram stain showed a gram-negative bacillus. What organism should be suspected? A. Streptococcus pneumoniae B. Staphylococcus aureus C. Haemophilus influenzae D. Escherichia coli

C. Haemophilus influenzae

On egg-yolk agar, Clostridium perfringens will demonstrate: A. brown to black colonies with a halo B. bluish-green sheen on surface of colonies C. off-white precipitate around colonies D. All of the above

C. off-white precipitate around colonies

All of the following characteristics describe the genus Plesiomonas except: A. ferments glucose. B. motile. C. oxidase negative. D. facultative anaerobes.

C. oxidase negative.

Aeromonads have been implicated in all of the following diseases except: A. osteomyelitis. B. meningitis. C. pneumonia. D. otitis.

C. pneumonia.

Routine primary plating media include all the following items, except A. broth medium used as a supplement. B. selective and differential medium for enteric gram-negative bacilli for most routine bacterial cultures. C. special biochemical media. D. nonselective agar plate.

C. special biochemical media.

Bacterial species that exhibit phenotypic differences are considered A. biovarieties. B. phagevarieties. C. subspecies. D. serovarieties.

C. subspecies.

As a general guideline, it is suggested that within a particular antimicrobial class, primary (group A) agents should be reported first and secondary (group B) agents should be reported only if A. the FDA has recalled the primary agents. B. the hospital pharmacy no longer stocks the group A agent. C. the patient cannot tolerate the primary agents. D. the physician insists that a secondary agent be reported.

C. the patient cannot tolerate the primary agents.

In situ hybridization, first described in 1969, is where A. protein molecules can be detected in tissue specimens. B. DNA or RNA can be detected directly in tissue with labeled probes. C. a piece of tissue is soaked in a DNA solution, eliciting antinuclear antibodies in the tissue. D. both RNA and DNA molecules can be detected simultaneously.

B. DNA or RNA can be detected directly in tissue with labeled probes.

What type of swab should be used for a Neisseria gonorrhoeae culture? A. Calcium alginate B. Dacron C. Cotton D. Flax

B. Dacron

A young girl is brought to her physician by her mother, who says the child has been very sluggish with a fever of 38 °C (100.5 °F) for a week. The mother noticed that the child's tonsils were red and that yesterday the back of her throat turned a gray color and looked to have a gray membrane on it. What disease should the physician suspect? A. Tonsillitis B. Diphtheria C. Strep throat D. Scarlet fever

B. Diphtheria

What substance produced by the Salmonella spp., which cause gastroenteritis, has been implicated as a significant virulence factor? A. Endotoxin B. Enterotoxin C. Hyaluronidase D. Protease

B. Enterotoxin

How can Nocardia spp. be presumptively identified? A. Medusa head colonies with filamentous, branching organisms present on acid-fast stain B. Filamentous, branching organisms with a carbolfuchsin acid-fast stain with a weak acid decolorizer, but not a Kinyoun acid-fast stain C. Sulfur granules that when crushed and Gram stained reveal filamentous, branching organisms D. Strong staining with Gram stain and the presence of filamentous, branching organisms

B. Filamentous, branching organisms with a carbolfuchsin acid-fast stain with a weak acid decolorizer, but not a Kinyoun acid-fast stain

In the carrier state, where are pathogenic salmonella carried? A. Liver B. Gallbladder C. Intestines D. Stomach

B. Gallbladder

Which antibiotic inhibits folate synthesis, providing the essential precursor molecule, pyridine thymidylate, needed in DNA synthesis? A. Quinolones B. Sulfamethoxazole C. Aminoglycosides D. Vancomycin

B. Sulfamethoxazole

One of the factors that allows Mycoplasma to infect the respiratory tract and the urogenital tract is that A. the body has a hard time detecting their presence, because they have no cell wall. B. they suppress the immune response. C. they adhere to the epithelium of mucosal surfaces and are not eliminated by mucus secretions. D. All of the above.

C. they adhere to the epithelium of mucosal surfaces and are not eliminated by mucus secretions.

Up-to-date tables that list potential antimicrobial agents to include in batteries for testing against particular organisms or organism groups are published by the:

CLSI

A diabetic foot swab from a 82 year old woman with recurrent infections is submitted for culture the Gram stain reveals: many neutrophils, no squamous epithelial cells many Gram negative bacilli many Gram positive cocci in chains The physician request that all pathogens be worked up, In addition to the sheep blood and Mac agar plates routinely used for wound cultures, the technologist might also process:

CNA agar plate

Which of the following media can be used to culture Campylobacter jejuni?

Campy CVA

A moderate growth of a heaped, dry-appearing, white organism is isolated from a patient with "thrush." The colony has tiny projections or "feet" projecting out along the edge of its margin. A presumptive identification of this organism would be

Candida spp

Acquired mechanisms of resistance are those that A. are passed on from one bacteria to the next using pili. B. result from acquisition of DNA by acquisition of extrachromosomal DNA. C. passed on from generation to generation. D. are the result of a frameshift mutation in chromosomal DNA.

B. result from acquisition of DNA by acquisition of extrachromosomal DNA.

Which group of tests best differentiates Helicobacter pylori from C. jejuni?

Catalase, oxidase, and Gram stain

In the laboratory, the clinical microbiologist is responsible for all the following, except A. identifying microorganisms. B. selecting treatment for patients. C. isolating microorganisms. D. analyzing bacteria that cause disease.

B. selecting treatment for patients.

The Lancefield grouping antigen is a______________________

Cell wall carbohydrate

Corneal scrapings are collected and examined microscopically using a direct fluorescent test to detect inclusion bodies for the diagnosis of infection caused by:

Chlamydia trachomatis

An environmental sampling study of respiratory therapy equipment produced cultures of a yellow, nonfermentative (at 48 hrs), gram neg bacillus from several of the nebulizers, and is associated primarily with meningitis in neonates and a wide variety of infections in immunocompromised patients. would most likely be a species of:

Chryseobacterium

ferment lactose hydrolyze urea slowly opposite of Salmonella (+) H2S

Citrobacter

Multiplex PCR is good for A. detecting PCR products at the lowest levels of any of the PCR tests. B. simultaneously detecting two or more different targets from one PCR tube. C. being the most sensitive method used to detect transfer RNA. D. using more than one DNA polymerase to make three to four times the amount of PCR products than standard PCR.

B. simultaneously detecting two or more different targets from one PCR tube.

The common characteristic of transcription-mediated amplification and reverse-transcriptase polymerase chain reaction is that both: A. use DNA polymerase. B. start with an RNA target. C. generate RNA as the primary product. D. are isothermal processes.

B. start with an RNA target.

The target nucleic acid strand is A. the one that is labeled with a chromogen. B. the DNA or RNA sequence unique to the organism of interest. C. the one to which the extra nucleic acid attaches. D. the strand that is used as the oligonucleotide primer.

B. the DNA or RNA sequence unique to the organism of interest.

In a hybridization reaction, the pH affects A. the probe's nucleic acids so that they do not lose their hydrogen atoms. B. the stability of double-stranded nucleic acid molecules in solution. C. the breakdown of the oligonucleotide pieces. D. the ability of the mismatches between the probe and the target to duplex.

B. the stability of double-stranded nucleic acid molecules in solution.

Which of the following media is used to isolate Francisella tularensis?

Cysteine-blood agar

What McFarland standard provides turbidity comparable to that of a bacterial suspension containing approximately 1.5 × 108 colony-forming units (CFU)/mL? A. 1.0 B. 2.0 C. 1.5 D. 0.5

D. 0.5

Generally, microbiologists observe the colonial morphology of organisms on primary culture after how many hours of incubation? A. 72 hours B. 24 to 48 hours C. 6 to 12 hours D. 18 to 24 hours

D. 18 to 24 hours

Acceptable specimens during the first week of leptospirosis include which of the following: A. Cerebrospinal fluid (CSF) B. Blood C. Urine D. A and B

D. A and B

What is the colony morphology of A. haemolyticum on sheep blood agar (SBA)? A. A wide zone of β-hemolysis and a large, yellow, mucoid colony B. γ-Hemolysis, with pitting around the edges of the colony C. α-Hemolysis, with a central black opaque dot in the colony D. A narrow zone of β-hemolysis and a black opaque dot is seen when the colony is scraped away

D. A narrow zone of β-hemolysis and a black opaque dot is seen when the colony is scraped away

The purified protein derivative reaction to determine exposure to tuberculosis is based on which of the following? A. Formation of antigen-antibody complexes B. A type II hypersensitivity reaction C. An immediate hypersensitivity reaction D. A sensitized T-cell response

D. A sensitized T-cell response

A serological reaction is set up in which the antigen is bound to a large carrier, the antibody is soluble, and the antigen and carrier bind and form an insoluble complex that is detected macroscopically. What type of assay is described? A. Precipitation B. Neutralization C. Flocculation D. Agglutination

D. Agglutination

What evidence indicates the presence of anaerobes in cultures? A. A foul odor upon opening an anaerobic jar or bag B. Growth on the anaerobic plates, but not on the sheep blood agar (SBA) plates incubated in the CO2 incubator C. Colonies on kanamycin-vancomycin laked-blood agar (KVLBA) that fluoresce brick-red under ultraviolet light D. All of the above

D. All of the above

When Mycoplasma hominis invades the upper genitourinary tract, it can cause the following: A. Salpingitis B. Pyelonephritis C. Pelvic inflammatory disease D. All of the above

D. All of the above

When transporting specimens for Mycoplasma culture to the laboratory, extreme care must be taken so that the specimen does not A. dry out. B. become contaminated. C. become overgrown with bacterial normal biota. D. All of the above

D. All of the above

susceptibility testing is warranted include A. the presence of other bacteria and the quality of the specimen from which the organism was grown. B. the host's status. C. the body site from which the organism was isolated. D. All the above

D. All the above

All of the following cells are considered part of natural immunity EXCEPT: A. monocytes. B. eosinophils. C. neutrophils. D. B lymphocytes.

D. B lymphocytes.

What organism causes melioidosis? A. Burkholderia mallei B. B. cepacia C. B. gladioli D. B. pseudomallei

D. B. pseudomallei

What bacterium produces colonies that are nonhemolytic, large, gray, and flat with an irregular margin on sheep blood agar (SBA)? A. Streptococcus pneumoniae B. Nocardia asteroides C. Listeria monocytogenes D. Bacillus anthracis

D. Bacillus anthracis

How are antibiotics chosen for inclusion into laboratory antimicrobial testing protocols? A. The institutional pharmacy and therapeutics committee sets the list of drugs that are used in their facility B. There are no set standards, because physicians demand which drugs they want tested for particular bugs each time an antimicrobial susceptibility test is performed. C. The Clinical and Laboratory Standards Institute (CLSI) recommends the drugs that should be tested and reported for each type of specimen. D. Both B and C.

D. Both B and C.

What organism is associated with pneumonia in patients with cystic fibrosis or chronic granulomatous disease (CGD)? A. Stenotrophomonas maltophilia B. Pseudomonas putida C. Pseudomonas fluorescens D. Burkholderia cepacia

D. Burkholderia cepacia

The laboratory receives a specimen in which the doctor suspects that the infecting organism is Haemophilus influenzae. This organism grows best in an atmosphere that contains 5% to 10% carbon dioxide. It is therefore classified as what type of bacteria? A. Obligate aerobe B. Facultative anaerobe C. Obligate anaerobe D. Capnophilic

D. Capnophilic

An anaerobic culture reveals colonies with a double zone of hemolysis on SBA plate. There was no growth on plates incubated aerobically. The Gram stain of that organism was a boxcar-shaped, gram-positive bacillus. What organism is this? A. Clostridium perfringens B. C. difficile C. C. ramosum D. C. clostridioiforme

A. Clostridium perfringens

A vaginal swab is received for anaerobic culture. How should this request be handled or processed? A. Plate material to anaerobic plates and incubate B. Place swab in culture broth and incubate C. Place swab in sterile saline, vortex, use saline to inoculate anaerobic plates then incubate D. Contact the physician, this is an unacceptable specimen

D. Contact the physician, this is an unacceptable specimen

How are TC cells and natural killer (NK) cells similar? A. Require antibody to be present B. Recognize antigen in association with human leukocyte antigen (HLA) class II markers C. Do not bind to infected cells D. Effective against virally infected cells

D. Effective against virally infected cells

Entamoeba dispar is most easily confused morphologically with: A. Entamoeba coli B. Entamoeba hartmanni C. Dientamoeba fragilis D. Entamoeba histolytica E. Blastocystis hominis

D. Entamoeba histolytica

Which of the following protozoan organisms has been widely implicated in waterborne and foodborne outbreaks in the United States? A. Pentatrichomonas hominis B. Dientamoeba fragilis C. Entamoeba coli D. Giardia duodenalis

D. Giardia duodenalis

After 24 hours, a sheep blood agar (SBA) from a vaginal culture is read. The SBA has alpha-hemolytic, pinpoint, rough colonies all over the plate. A catalase test is performed, and it is negative. What organisms do these characteristics fit? A. Corynebacterium and Arcanobacterium B. Staphylococcus and Listeria C. Diphtheroids and rhodococci D. Lactobacillus and viridans streptococci

D. Lactobacillus and viridans streptococci

A sputum culture from a patient in Texas has colonies that grow buff colored colonies in approximately 4 weeks. After exposure to light, the colonies turn intense yellow. This isolate is most likely: A. M. xenopi. B. M. scrofulaceum. C. M. fortuitum. D. M. kansasii.

D. M. kansasii.

What constituent of Lowenstein-Jensen (LJ) medium is added to suppress the growth of gram-positives? A. Carbolfuchsin B. Gentian purple C. Mercurochrome D. Malachite green

D. Malachite green

The methyl red test detects metabolic by-products from what pathway? A. Citrate pathway B. Butylene glycol pathway C. Clark and Lubs pathway D. Mixed acid fermentation pathway

D. Mixed acid fermentation pathway

In the Kirby-Bauer test, what is used to grow streptococci that do not grow adequately on unsupplemented Mueller-Hinton agar? A. Chocolate agar B. Mueller-Hinton agar with 5% rabbit blood C. PEA agar D. Mueller-Hinton agar with 5% sheep blood

D. Mueller-Hinton agar with 5% sheep blood

A 12-year-old girl is brought to the emergency room with meningitis and a history of swimming in a warm-water spring. Motile amoebae that measure 10 μm in size are seen in CSF and are most likely: A. Iodamoeba bütschlii trophozoites B. Endolimax nana trophozoites C. Dientamoeba fragilis trophozoites D. Naegleria fowleri trophozoites

D. Naegleria fowleri trophozoites

Specimens such as blood, bone marrow, and synovium are mixed with anticoagulants right after collection. Why should this occur? A. It kills off the normal flora and only leaves the pathogens in the specimen. B. Anticoagulants often dissolve part of the bacteria's cell wall and congeal many bacteria into groups. C. It ensures the specimen will work when using an automated spreader device. D. Organisms become bound up in the clotted material and are difficult to isolate.

D. Organisms become bound up in the clotted material and are difficult to isolate.

This test is useful in the initial differentiation of Proteus, Morganella, and Providencia species from the rest of the Enterobacteriaceae. A. Methyl red B. Oxidation-fermentation C. Amino acid decarboxylase D. Phenylalanine deaminase

D. Phenylalanine deaminase

motile (+) simmon citrate (-) MR (+) VP (+) ornithine decarboxylase

Enterobacter

A sputum specimen from an 89-year-old male patient with suspected bacterial pneumonia grew a predominance of gram-positive cocci displaying alpha-hemolysis on 5% sheep blood agar. The colonies appeared donut shaped and mucoidy and tested negative for catalase. The most appropriate tests for a final identification are:

Optochin, bile solubility, PYR

A specimen from a female complaining of vaginitis emitted a "fishy odor" when mixed with 10% KOH. A stained prep showed some white cells and epithelial cells covered with small Gram variable rods. The most likely organism is:

Gardnerella vaginalis

Which of the following isolates obtained from a vaginal swab from a pregnant woman would trigger a course of antibiotic treatment?

Group B streptococci

How has the treatment of mycobacterial disease changed in light of the multidrug-resistant strains of mycobacteria that are being isolated? A. Combinations of three or four drugs are used instead of a single drug. B. Antibiotic therapy is started sooner in the course of the disease. C. Patients are hospitalized for the duration of their disease. D. More powerful antibiotics are used to treat mycobacterial disease.

A. Combinations of three or four drugs are used instead of a single drug.

The reagents used for the Gram stain are A. Crystal violet, Gram iodine, alcohol-acetone, safranin. B. Carbol fuchsin, acid-alcohol, methylene blue C. Crystal violet, methylene blue. D. Methylene blue, Giemsa stain.

A. Crystal violet, Gram iodine, alcohol-acetone, safranin.

What type of medium is used in the motility test? A. Semi-solid B. Peptone gel C. Cornmeal D. Sabouraud dextrose

A. Semi-solid

A DNase-positive member of the family Enterobacteriaceae is suggestive of A. Serratia. B. Escherichia. C. Enterobacter. D. Proteus.

A. Serratia.

What is the most common causative agent of pyoderma? A. Staphylococcus aureus B. Clostridium perfringens C. Haemophilus influenzae D. Neisseria gonorrhoeae

A. Staphylococcus aureus

A patient comes to the emergency department with a productive cough, shortness of breath, and a fever of 102° F. The patient is diagnosed with pneumonia. What organism commonly encountered in the microbiology laboratory can cause this disease? A. Streptococcus pneumoniae B. Staphylococcus aureus C. Escherichia coli D. Haemophilus influenzae

A. Streptococcus pneumoniae

While swimming in a lake near his home, a young boy cut his foot, and an infection developed. The culture grew a nonfastidious gram negative , oxidase positive, beta-hemolytic, motile bacilli that produced deoxyribonuclease. The most likely identification is:

Aeromonas hydrophilia

Anaerobic gram-negative rods were recovered from the blood of a patient after gallbladder surgery. The bacteria grew well on agar containing 20% bile, but were resistant to kanamycin and vancomycin. What is the most likely identification?

Prevotella spp

What is the most important modifiable risk factor for enteric colonization with vancomycin resistant Enterococcus faecium (VREF)? Please select the single best answer

Prior antibiotic exposure

(+) PAD (+) indole (+) MR (-) VP (+) Simmon Citrate (-) urease negative

Providencia

Flat colonies, fruity smell, oxidase positive, Gram negative rods

Pseudomonas aeruginosa

Which of the following two media are appropriate for Bordetella pertussis:

Regan-Lowe charcoal agar and Bordet-Gengou media

most common anticoagulant

SPS

Which of the following tests is most appropriate for the presumptive identification of Peptostreptocococcus anaerobious?

SPS disk

Edwardsiella tarda is occasionally isolated in stool specimens and can biochemically be confused with:

Salmonella

non lactose fermenter (-) indole, VP, PAD, urease (+) H2S motile (+) lysine decarboxylase

Salmonella

delayed lactose fermenter positive for ONPG test capable of producing DNase, lipase, gelatinase (-) MR (+) VP

Serratia

non motile (-) urease, (-) H2S, (-)lysine decarboxylase and PAD

Shigella

The spot test that is helpful in separating Enterococcus species from the viridans streptococci and S. pneumoniae (both negative) is:

Spot PYR

Gram positive cocci, beta hemolytic, catalase -, Taxo A resistant

Strep agalactiae

Alpha-hemolysis Taxo P sensitive

Strep pneumo

A gram positive coccus isolated from blood culture has the following characteristics optochin susceptibility: negative bacitracin (0.04 U): negative bile esculin hydrolysis: negative hippurate hydrolysis: positive catalase: negative

Streptococcus agalactiae

A flexible calcium alginate nasopharyngeal swab is the collection device of choice for recovery of which organism from the nasopharynx?

Streptococcus pneumoniae

Ethyhydrocupreine HCl susceptability is a presumptive test for the identification of:

Streptococcus pneumoniae

Detection of antibody against cardiolipin is useful for the diagnosis of which of the following diseases?

Syphilis

Why are Mycoplasma resistant to antibiotics such as penicillin and cephalosporins?

Their lack of a cell wall make them resistant

Organize the specimens from highest to lowest priority; bone fragment, urine, amniotic fluid, preserved stool

amniotic fluid, bone fragment, urine, preserved stool

Chlamydophila (Chlamydia) psittaci infections in humans most commonly result after exposure to infected:

avians

Collect by needle aspiration and place in sterile, screw-cap tube or anaerobic transporter / ≥1 mL

body fluid or CSF

Cytocentrifugation is an excellent method for which of the following type of samples?

heavily contaminated.

The chemotherapeutic agents structurally similar to the vitamin p-aminobenzoic acid that inhibits bacteria via inhibition of folic acid synthesis are:

sulfonamides

good for upper respiratory tract specimen collection

swabs

The porphyrin test was devised to detect strains of Haemophilus capable of:

synthesis of hemin

A positive VDRL test for syphilis was reported on a young woman known to have hepatitis. When questioned by her physician, she denied sexual contact with any partner symptomatic for a sexually transmitted disease. Which of the following would be appropriate next step for her physician?

test her serum using a fluorescent treponemal antibody-absorbed assay

clean catch midstream ; pass- 3 secs; container - 2-3 ml

urine collection

The procedure that assures the most accurate detection of MecA-mediated oxacillin resistance in routine broth microdilution susceptibility testing against S. aureus is:

use of cefoxitin for testing

CLSI Methods for Antimicrobial Susceptibility Testing of Anaerobic Bacteria (Approved Standard, M11-A8) states that susceptibility testing is always performed in all except:

wound abscesses

All of the following staphylococci are coagulase-positive, except A. S. saprophyticus. B. Staphylococcus aureus. C. S. intermedius. D. S. delphini.

A. S. saprophyticus.

When a request is submitted to examine a blood sample for malaria, which of the following procedures should be performed? A. A Giemsa thick blood smear preparation for maximum detection and a thin smear for speciation B. A formalin-ethyl acetate concentration for detection and a thin smear for speciation C. A thick smear for maximum detection and to determine morphology D. A PVA trichrome-stained blood smear

A. A Giemsa thick blood smear preparation for maximum detection and a thin smear for speciation

The purified protein derivative reaction to determine exposure to tuberculosis is based on which of the following? A. A sensitized T-cell response B. Formation of antigen-antibody complexes C. An immediate hypersensitivity reaction D. A type II hypersensitivity reaction

A. A sensitized T-cell response

All of the following species of Arcanobacterium are clinically significant except: A. A. urealyticum. B. A. pyogenes. C. Arcanobacterium haemolyticum. D. A. bernardiae.

A. A. urealyticum.

If a bacterium utilizes lactose or sucrose and produces H2S, what will the TSI reaction look like? A. Acid/acid, black butt B. Acid/alkaline, black butt C. Alkaline/alkaline, black slant D. Alkaline/acid, black slant

A. Acid/acid, black butt

What media does Corynebacterium diphtheriae grow on? A. All are correct B. Cystine-tellurite blood C. Sheep blood agar (SBA) D. Loeffler

A. All are correct

These antibiotics are cationic carbohydrate-containing molecules, and their positive charge provides the basis for their interaction with the 30S ribosomal subunit. What class of antibiotic are these? A. Aminoglycosides B. Peptidoglycans C. Trimethoprim D. Sulfamethoxazole

A. Aminoglycosides

What Bacillus sp. is a relatively common cause of food poisoning and opportunistic infection in susceptible hosts? A. Bacillus cereus B. B. anthracis C. B. pneumoniae D. B. asteroids

A. Bacillus cereus

What is the single most important piece of equipment in a mycobacterial laboratory? A. Biological safety cabinet B. Ultraviolet lights C. CO2 incubator D. Covered centrifuge

A. Biological safety cabinet

What organism causes relapsing fever? A. Borrelia recurrentis B. B. burgdorferi C. Leptospira interrogans D. C. psittaci

A. Borrelia recurrentis

Which of the following agars is not selective for Enterobacteriaceae? A. Buffered charcoal yeast extract B. Xylose-lysine deoxycholate C. MacConkey (MAC) D. Hektoen enteric

A. Buffered charcoal yeast extract

What nonfermenter may produce a weak, slow, positive oxidase reaction? A. Burkholderia cepacia B. Pseudomonas putida C. Stenotrophomonas maltophilia D. P. stutzeri

A. Burkholderia cepacia

Which of the following tests can be used to identify Group B streptococci? A. CAMP B. Optochin C. Lancefield D. Bacitracin

A. CAMP

What organisms often are involved in septicemia in the granulocytopenic patient? A. Capnocytophaga spp. B. Eikenella corrodens C. Kingella spp. D. Fusobacterium spp.

A. Capnocytophaga spp.

What test differentiates staphylococci from streptococci? A. Catalase B. Coagulase C. β-Hemolysis D. All of the above

A. Catalase

What are the confirmatory tests performed at a state laboratory for Bacillus anthracis? A. Cell wall polysaccharide and a capsule antigen B. Endospore stain and a capsule antigen C. Cell wall polysaccharide and an endospore stain D. Flagellar antigen and mannitol fermentation

A. Cell wall polysaccharide and a capsule antigen

An Entamoeba histolytica trophozoite has which characteristics? A. Central karyosome in the nucleus and clear pseudopodia B. Ingested RBCs, clear pseudopodia, and uneven chromatin on the nuclear membrane C. Ingested RBCs, clear pseudopodia, and large glycogen vacuoles in the cytoplasm D. Uneven karyosome, no peripheral chromatin, granularpseudopods

A. Central karyosome in the nucleus and clear pseudopodia

What is the principle of restriction enzyme analysis of chromosomal DNA? A. DNA is extracted and isolated, and digested with a restriction enzyme. The resulting RFLP pattern is analyzed by agarose gel electrophoresis and transferred to a membrane. B. The serum specimen is electrophoresed, transferred to a membrane, digested, and then reacted with a probe to identify the target. C. Plasmids are cut into small pieces with restriction enzymes. The resulting restriction fragment length polymorphism (RFLP) pattern is analyzed by agarose gel electrophoresis; there is transfer to a membrane, then use of a probe to identify specific sequences. D. The chromosomal DNA is denatured, then annealed. The resulting hybrids are electrophoresed, transferred to a membrane, and then analyzed for a specific sequence.

A. DNA is extracted and isolated, and digested with a restriction enzyme. The resulting RFLP pattern is analyzed by agarose gel electrophoresis and transferred to a membrane.

The Southern blot test separates A. DNA. B. proteins. C. RNA. D. Lipids.

A. DNA.

A microbiologist is reading stool culture plates. She sees an organism that has a dry, pink colony with a surrounding "halo" of pink on MAC. What is a good presumptive identification of this organism? A. Escherichia/Citrobacter-like organism B. Enteric pathogen C. Klebsiella/Enterobacter-like organism D. Haemophilus influenzae

A. Escherichia/Citrobacter-like organism

T helper cells recognize which of the following? A. Exogenous peptide bound to class II MHC B. Endogenous peptides bound to class I MHC C. Native extracellular viral proteins D. Microbe-specific structures

A. Exogenous peptide bound to class II MHC

What are the primary antigens used in serologic grouping of salmonellae? A. Flagellar H antigen and somatic O antigen B. Somatic A antigen and flagellar O antigens C. Flagellar H antigen and capsular A antigen D. Capsular A antigen and somatic O antigen

A. Flagellar H antigen and somatic O antigen

Preformed mediators that are released during the activation phase of a type I hypersensitivity response include which of the following? A. Histamine B. Cyclooxygenase C. Prostaglandin D. Leukotriene

A. Histamine

The antibody mediator associated with a Type I Hypersensitivity reaction is? A. IgE B. IgM C. IgD D. IgG

A. IgE

To perform a quality laboratory analysis, the laboratory needs specific information regarding the patient and the specimen. What can be a critical weak link in the specimen management process? A. Incomplete information on the requisition B. Poor-quality laboratory information system C. Poor specimen collection techniques D. Poor-quality hospital information system

A. Incomplete information on the requisition

After 24-hour incubation, an SBA from a vaginal culture reveals heavy growth of α-hemolytic, pinpoint, rough colonies. A catalase test is performed, and it is negative. What organism should you suspect? A. Lactobacillus B. Diphtheroids C. Listeria D. Arcanobacterium

A. Lactobacillus

What type of an atmosphere do campylobacters require for growth? A. Microaerophilic and capnophilic B. Anaerobic and moist C. Capnophilic and halophilic D. Microaerophilic and high nitrogen content

A. Microaerophilic and capnophilic

Which white cell in the peripheral blood migrates into tissue to become a macrophage? A. Monocyte B. Neutrophil C. Eosinophil D. Basophil

A. Monocyte

What two biochemical tests help distinguish Aeromonas spp. from other enterics? A. Oxidase and indole B. Oxidase and Simmon's citrate C. Simmon's citrate and indole D. Voges-Proskauer (VP) and indole

A. Oxidase and indole

What is the most frequently isolated Pasteurella species? A. P. multocida B. P. septica C. P. gallicida D. P. canis

A. P. multocida

How should a specimen for Neisseria gonorrhoeae culture be transported to the laboratory? A. Placed in Amies with charcoal transport system and transported to the laboratory immediately B. Placed in a bacterial transport and transported to the laboratory at the end of the day C. Placed in a tube of broth and transported to the laboratory immediately D. Placed in the paper swab cover and transported to the laboratory at the end of the day

A. Placed in Amies with charcoal transport system and transported to the laboratory immediately

Which cell is capable of producing antibody? A. Plasma cell B. Macrophage C. Neutrophil D. CD4+ T cell

A. Plasma cell

A 33-year-old female presents with eyes that have been red and irritated for the past month. Discharge from the eyes is not apparent. She also has a recurrent low-grade fever and a rash on her chest and legs. Her joints have been achy for the past few months, and her mouth has been so dry it is often difficult to swallow food. Antinuclear antibody testing is performed, and a speckled pattern is observed on HEp-2 cells. Which follow-up test result would you expect for this patient? A. Presence of anti-SS-A or anti-SS-B B. Presence of antibody to dsDNA C. Positive ANCA D. Decreased rheumatoid factor

A. Presence of anti-SS-A or anti-SS-B

What organism in the genus Providencia is incriminated in nosocomial outbreaks in burn units and has been isolated from urine cultures? A. Providencia stuartii B. P. alcalifaciens C. P. rustigianii D. P. heimbachae

A. Providencia stuartii

What nonfermenter is the leading cause of nosocomial pneumonia and bacteremia? A. Pseudomonas aeruginosa B. P. fluorescens C. P. putida D. P. mendocina

A. Pseudomonas aeruginosa

Once infected with Borrelia recurrentis, a 2- to 15-day incubation period follows where high numbers of organisms are found in the blood. The infected individual experiences high fever, rigors, severe headache, muscle pains, and weakness. This febrile period lasts for about 3 to 7 days, but ends quickly with the induction of an immune response. However, a similar but less severe course of symptoms recurs several days to weeks later. What causes this relapse? A. The organism systematically changes its surface antigens during the course of a single infection. B. The organism produces extracellular toxins that cause the symptoms. C. This organism survives inside infected cells and once the cell dies, the organism is released into the blood, causing this relapse. D. This relapse occurs as the host is trying to mount the secondary antibody response.

A. The organism systematically changes its surface antigens during the course of a single infection.

Why are aminoglycosides not an effective treatment for meningitis? A. They do not cross the blood-brain barrier. B. They are not effective against Neisseria, Streptococcus, or Haemophilus. C. They are nephrotoxic and will harm the patient's kidneys. D. They are ototoxic and will harm the patient's ears.

A. They do not cross the blood-brain barrier.

Why should antimicrobial susceptibility testing of normal flora isolates or isolates likely to represent contamination or colonization not be performed? A. This may encourage a physician to treat a normal condition. B. The amount of antibiotic needed to kill all of the normal flora in a site can cause toxic effects to the patient. C. Antimicrobial susceptibility testing should be performed on all bacteria isolated from the patient. D. This will expose normal flora to various antibiotics and cause resistance to develop.

A. This may encourage a physician to treat a normal condition.

The incorrect match between the organism and one method of acquiring the infection is: A. Trypanosoma brucei rhodesiense—bite of sand fleas B. Giardia lamblia (G. intestinalis, G. duodenalis)—ingestion of water contaminated with cysts C. Hookworm—skin penetration of larvae from soil D. Toxoplasma gondii—ingestion of infected raw or rare meats

A. Trypanosoma brucei rhodesiense—bite of sand fleas

What enables the microbiologist to select the correct media for primary culture and optimize the chance of isolating a pathogenic organism? A. Understanding the growth requirements of potential pathogens at specific body site B. Determining staining characteristics C. Understanding the cell structure and biochemical pathways of an organism D. Knowing the differences in cell walls of particular bacteria

A. Understanding the growth requirements of potential pathogens at specific body site

Which of the following is a curved, gram-negative rod that grows on TCBS agar? A. Vibrio B. Campylobacter C. Clostridium D. Fusobacterium

A. Vibrio

Serum proteins that increase in concentration within 24 to 48 hours of the onset of infection or injury are called: A. acute-phase proteins. B. immunoglobulins. C. complement proteins. D. reagins.

A. acute-phase proteins.

The most effective phagocytic and antigen-presenting cell is the: A. dendritic cell. B. macrophage. C. neutrophil. D. monocyte.

A. dendritic cell.

All of the following are normal inhabitants of the human oral cavity except Capnocytophaga: A. fusofurium. B. gingivalis. C. ochracea. D. haemolyticus.

A. fusofurium.

.The only cells in the body capable of specifically recognizing and distinguishing different antigenic determinants are: A. lymphocytes. B. macrophages. C. dendritic cells. D. neutrophils.

A. lymphocytes.

In Maldi-Tof biomolecules irradiated by a laser are separated by their: A. mass to charge ratio B. ionization field C. molecuar weight D. shape to mass

A. mass to charge ratio

All of the following symptoms are characteristic of Weil disease, except A. pneumonia B. renal failure. C. hepatic failure. D. intravascular disease.

A. pneumonia.

Two types of specimens can use preservatives to maintain them until they can be delivered to the laboratory. They are A. urine, stool. B. stool, throat cultures. C. urine, vaginal secretions. D. pus from a wound, vaginal secretions.

A. urine, stool.

This test determines if an organism is a delayed lactose fermenter. Nitrate A. o-nitrophenyl-β-D-galactopyranoside B. (ONPG) test C. Dihydroxylase D. β-Galactosidase

B. (ONPG) test

Which factor is added to media to provide cholesterol for mycoplasma-like organisms? A. Trypticase soy digest B. 20% fetal calf serum C. X and V factor supplement D. 5% sheep blood

B. 20% fetal calf serum

What mechanism allows strict anaerobes to grow in the crevices and areas between the teeth when plaque is present? A. The bacteria secrete sugar to nourish the strict anaerobes. B. A low oxidation-reduction potential occurs at the tooth surface under the plaque. C. The normal flora secrete antibiotics to kill all the other bacteria and allow the strict anaerobes to thrive. D. The plaque-causing bacteria secrete an alkaline fluid and change the pH around the tooth.

B. A low oxidation-reduction potential occurs at the tooth surface under the plaque.

All of the following statements are true regarding the significance of performing direct microscopic examinations of specimens for culture, EXCEPT: A. May serve as a guide for selecting appropriate culture media based on microorganisms observed. B. Allows the microbiologist to discard the sample and cancel testing if no organisms are observed. C. It can provide the physician with a rapid presumptive diagnosis. D. Provide a quality control comparison to the culture for actual isolates recovered.

B. Allows the microbiologist to discard the sample and cancel testing if no organisms are observed.

Material from an intestinal abscess produces gray colonies with a brown color in the area around the colonies on a BBE plate incubated anaerobically. There is also a dark precipitate in the medium in the areas of heavy growth. A Gram stain of the colonies reveals gram-negative coccobacilli. What is the presumptive identification of this organism? A. Bacteroides vulgatus B. B. fragilis C. B. pneumoniae D. B. denticola

B. B. fragilis

What medium is used to isolate Legionella? A. MacConkey B. BCYE C. Chocolate D. Bordet-Gengou

B. BCYE

Which two tests are often used in the identification of the non-β-hemolytic, catalase-negative, gram-positive cocci? A. Hippurate hydrolysis and optochin B. Bile esculin and salt tolerance C. Nitrate and CAMP D. Bacitracin and CAMP

B. Bile esculin and salt tolerance

What agar is used to isolate the Bordetella species? A. BCYE B. Bordet-Gengou C. Chocolate D. Martin-Lewis

B. Bordet-Gengou

How do the β-lactamase inhibitors work? A. By structurally rearranging the β-lactamase molecule so that it loses specificity for the β-lactam antibiotic B. By acting as substrates for the β-lactamase and reducing their effect on the antibiotic C. By competing with the antibiotic for porin sites on the outer membrane D. By acting as transport molecules to transport the antibiotic into the bacterial cell

B. By acting as substrates for the β-lactamase and reducing their effect on the antibiotic

What Corynebacterium infects mostly immunocompromised patients? A. C. pseudotuberculosis B. C. jeikeium C. C. ulcerans D. C. striatum

B. C. jeikeium

A 4-day-old infant shows symptoms of conjunctivitis. A Giemsa stain of the conjunctival scraping shows perinuclear cytoplasmic inclusions. This organism is most likely A. C. trachomatis serovars A, B, Ba, C. B. C. trachomatis serovars D-K. C. C. trachomatis serovars L1, L2, L3. D. C. pneumoniae.

B. C. trachomatis serovars D-K.

VA microbiologist is reading stool culture plates. She is looking for enteric pathogens on the MAC plate. What do they look like? A. Large, bright pink colonies B. Clear, colorless colonies C. Small, mucoid, green colonies D. Small, orange colonies

B. Clear, colorless colonies

Although a patient is strongly suspected of having giardiasis and is still symptomatic, three routine stool examinations (O&P examination) have been performed correctly and reported as negative. Biopsy confirmed the patient had giardiasis. Reasons for these findings may include: A. The patient was coinfected with several bacterial species B. Giardia lamblia (G. intestinalis, G. duodenalis) tends to adhere to the mucosal surface and more than three stool examinations may be required to confirm a suspected infection C. The organisms present did not stain with trichrome stain, and therefore the morphology is very atypical D. Special diagnostic procedures, such as the Knott concentration and nutrient-free agar cultures, should have been used

B. Giardia lamblia (G. intestinalis, G. duodenalis) tends to adhere to the mucosal surface and more than three stool examinations may be required to confirm a suspected infection

Organisms that should be considered in a nursery school outbreak of diarrhea include: A. Endolimax nana, Giardia lamblia (G. intestinalis, G. duodenalis), and Entamoeba coli B. Giardia lamblia (G. intestinalis, G. duodenalis), Dientamoeba fragilis, and Cryptosporidium parvum C. Cryptosporidium spp., Trichomonas vaginalis, and Entamoeba coli D. Trichomonas hominis, Dientamoeba fragilis, and Endolimax nana

B. Giardia lamblia (G. intestinalis, G. duodenalis), Dientamoeba fragilis, and Cryptosporidium parvum

What are two tests presumptively used to identify Group B streptococci? A. PYR and hippurate hydrolysis B. Hippurate hydrolysis and CAMP C. Bacitracin and PYR D. Optochin and PYR

B. Hippurate hydrolysis and CAMP

What form of anthrax is found among animal workers and has been dubbed woolsorter's disease? A. Gastrointestinal B. Inhalation C. Optical D. Cutaneous

B. Inhalation

A microbiologist is reading a stool culture and notices a mucoid pink colony on MAC agar. What is the most likely organism? A. Yersinia enterocolitica B. Klebsiella pneumoniae C. Proteus vulgaris D. Escherichia coli

B. Klebsiella pneumoniae

What is the name of the bacteria that plays an important role in the health of the female vaginal tract, protecting it against pathogens? A. Diphtheroids B. Lactobacillus C. Erysipelothrix rhusiopathiae D. Gardnerella vaginalis

B. Lactobacillus

The initial screening of gram-negative rods is done by testing for the use of this carbohydrate. A. Sucrose B. Lactose C. Glucose D. Mannitol

B. Lactose

An animal attendant at the zoo developed symptoms that included fever, chills, headache, severe myalgia, and malaise. His urinalysis revealed the presence of protein and blood. A couple of weeks earlier, the attendant was handling the chimpanzees, and one of the chimps urinated on him. What is the most likely cause of illness? A. Borrelia B. Leptospira C. Treponema D. Helicobacter

B. Leptospira

These two classes of antibiotics allow initiation and mRNA translation to begin, but they act by inhibiting peptide elongation. A. Macrolides and quinolones B. Macrolides and tetracyclines C. Aminoglycosides and quinolones D. Aminoglycosides and glycopeptidians

B. Macrolides and tetracyclines

What is the preferred technique to rapidly detect Chlamydia trachomatis in clinical specimens? A. Enzyme immunoassay (EIA) B. Nucleic acid amplification test (NAAT) C. Cell culture D. Cytologic methods

B. Nucleic acid amplification test (NAAT)

A microbiologist is reading the plates from a sputum culture. On the sheep blood agar (SBA), the microbiologist sees flat spreading colonies with a metallic sheen. On cetrimide agar, a fluorescent green color is seen in the media with clear colonies. On MacConkey, medium clear colonies are seen that have a fruity or grapelike odor. What is the most likely organism? A. Pseudomonas fluorescens B. P. aeruginosa C. P. putida D. P. stutzeri

B. P. aeruginosa

What test presumptively differentiates β-hemolytic Group A streptococci and nonhemolytic Group D enterococci from other streptococcal species? A. Bacitracin B. PYR C. Hippurate hydrolysis D. Optochin

B. PYR

In a patient with diarrhea, occasionally Entamoeba histolytica/E. dispar (four nucleated cysts, no chromatoidal bars) are identified as being present; however, these cells, which are misdiagnosed as protozoa, are really: A. Macrophages B. Polymorphonuclear leukocytes (PMNs) C. Epithelial cells D. Eosinophils

B. Polymorphonuclear leukocytes (PMNs)

The two species of coagulase-negative staphylococci most often isolated in clinical laboratories are A. S. capitus and S. lugdunensis. B. S. epidermidis and S. saprophyticus. C. Staphylococcus aureus and S. epidermidis. D. S. saccharolyticus and S. epidermidis.

B. S. epidermidis and S. saprophyticus.

Why would normal flora isolating from immunosuppressed patients undergo antimicrobial susceptibility testing? A. Cultures from immunosuppressed patients only grow pathogenic organisms that must undergo antimicrobial susceptibility testing. B. Species usually viewed as normal flora may be responsible for an infection in an immunosuppressed patient. C. These are not normal flora; they are other potential pathogens that have the same colonial morphology as normal flora. D. All bacteria isolated from immunosuppressed patients must have antimicrobial susceptibility tests performed.

B. Species usually viewed as normal flora may be responsible for an infection in an immunosuppressed patient.

How is culture media selected for specimen plating? A. Determine the supplemental agar needed, as well as the broth media. B. The selection of media to inoculate is based on the type of specimen submitted for culture and the organisms likely to be involved in the infectious process. C. Always include nonselective media and differential media to help save a day of reading the culture on the bench. D. Use only broth for the initial inoculation and subculture to plates after 24 hours of incubation.

B. The selection of media to inoculate is based on the type of specimen submitted for culture and the organisms likely to be involved in the infectious process.

What is the primary goal in the transportation of specimens to the laboratory? A. To allow the specimen to sit, as long as it is delivered to the laboratory within 2 to 3 days after collection B. To maintain the specimen as near its original state as possible with minimal deterioration C. To get the specimen to the laboratory by the end of the day D. To place the specimen in formalin and then transport it to the laboratory

B. To maintain the specimen as near its original state as possible with minimal deterioration

Which of the following is the best technique for identifying Dientamoeba fragilis in stool? A. Formalin concentrate B. Trichrome-stained smear C. Modifi ed acid-fast-stained smear D. Giemsa stain

B. Trichrome-stained smear

The specimen of choice for detecting gastrointestinal pathogens is A. a urine specimen. B. a stool specimen. C. a swab of the anal area with no feces on it. D. vomit.

B. a stool specimen.

The strength of binding of one Fab on an immunoglobulin to one epitope on an antigen is referred to as: A. avidity B. affinity C. diapedesis D. inflammation

B. affinity

A safe method of transporting aspirated wound material would be in A. a plastic container. B. an anaerobic transport system. C. a tube of broth. D. a leakproof bag.

B. an anaerobic transport system.

Homogeneous staining of the nucleus in an antinuclear antibody test indicates: A. anti-RNA antibody. B. antibody to DNA-histone complexes. C. antibody to extractable nuclear antigens. D. anticentromere antibody.

B. antibody to DNA-histone complexes.

Oxidative/fermentative (O/F) basal medium is a medium that will test the oxidative and fermentative capabilities of a microbe. The pH indicator is _____. A. bromocresol green B. bromothymol blue C. phenolphthalein D. Sudan IV

B. bromothymol blue

Nucleic acid hybridization is A. attaching an RNA to an mRNA unit. B. coupling of complementary single-stranded nucleic acid molecules. C. making RNA from a DNA template. D. mixing different pieces of DNA together and making a hybrid molecule.

B. coupling of complementary single-stranded nucleic acid molecules.

The virulence factors for Neisseria spp. include all the following, except A. capsule. B. exotoxin. C. pili. D. endotoxin.

B. exotoxin.

Elizabethkingae (Chryseobacterium) meningosepticum causes all the following diseases except:' A. pneumonia. B. gastroenteritis. C. endocarditis. D. meningitis.

B. gastroenteritis.

All the following are biochemical features of Salmonella, except A. VP negative. B. lactose positive. C. hydrogen sulfide positive. D. indole negative

B. lactose positive.

The Escherichia coli serotype O157:H7 is associated with all the following, except A. hemorrhagic diarrhea. B. liver damage. C. hemolytic-uremic syndrome (HUS). D. colitis.

B. liver damage.

RT- PCR (reverse transcriptase- PCR) detects what product: A. Ag-Ab complexes B. mRNA products C. dsDNA D. DNA:RNA hybrids

B. mRNA products

All of the following occur during the process of inflammation EXCEPT: A. increased capillary permeability. B. migration of basophils away from tissue. C. increase in blood flow. D. swelling and pain.

B. migration of basophils away from tissue.

The variables that affect the outcome of a given hybridization reaction include all of the following, except A. pH. B. organic acid concentration. C. temperature. D. salt strength.

B. organic acid concentration.

Eosinophils are involved in the immune response against: A. viruses. B. parasites that cannot be phagocytized. C. intracellular bacteria. D. extracellular bacteria.

B. parasites that cannot be phagocytized.

A 10-year-old girl visits her physician's office because she has been complaining about being thirsty and having to go to the bathroom all the time. She has lost 15 pounds over the past 6 months and has been more irritable than usual, especially after meals. The girl's fasting blood glucose is 575 mg/dL (reference range, < 100 mg/dL), her C-peptide is 0.5 ng/mL (reference range, 0.8-3.1 ng/mL), and she has autoantibodies against glutamic acid decarboxylase and insulin. On the basis of these findings, a likely diagnosis for this girl is: A. acute glomerulonephritis. B. type 1 diabetes. C. progressive systemic sclerosis. D. Hashimoto's thyroiditis.

B. type 1 diabetes.

All of the following are characteristics of Shigella spp., except A. lysine decarboxylase negative. B. urea positive. C. hydrogen sulfide negative. D. nonmotile.

B. urea positive.

The decarboxylase tests determine A. to see if α-naphthol can be broken down into its constituent parts: acetoin and diacetyl KOH. B. whether the bacteria possess enzymes capable of removing the carboxyl group of specific amino acids in the test medium. C. if bacteria can maintain an acid pH if only sucrose is present in the media. D. whether the bacteria can further metabolize the acids formed during fermentation to 2,3 butanediol.

B. whether the bacteria possess enzymes capable of removing the carboxyl group of specific amino acids in the test medium.

In addition to CO2 requirements and biochemical characteristics, Brucella melitensis and Brucella abortus are differentiated by growth on media containing which two dyes?

Basic fuchsin and thionin

Several people from a picnic came down with a gastrointestinal disturbance, and public health officials suspected a case of food poisoning. The food, especially hot dogs, were cultured and after 24 hours of growth on sheep blood agar (SBA), there was a small, round, smooth, translucent colony surrounded by a narrow zone of beta-hemolysis. A Gram stain showed gram-positive coccobacilli. Motility medium was inoculated and an umbrella pattern of motility was observed at room temperature. What organism was isolated as the cause of the illness? A. Rothia dentocariosa B. Rhodococcus equi C. Listeria monocytogenes D. Corynebacterium diphtheriae

C. Listeria monocytogenes

What does a lysine iron agar (LIA) slant contain? A. Arginine, lactose, ferric chloride, sodium hydroxide, and urea B. Acetoin, pyruvic acid, nitrate, and sulfanilic acid C. Lysine, glucose, ferric ammonium citrate, and sodium thiosulfate D. Ornithine, glucose, ferric ammonium chloride, and urea

C. Lysine, glucose, ferric ammonium citrate, and sodium thiosulfate

What media are recommended for routine culturing of specimens for the recovery of acid-fast bacilli? A. Middlebrook 7H10 and cooked meat broth B. Sabouraud dextrose and LIM broth C. Löwenstein-Jensen and liquid-based media D. Thiosulfate-citrate-bile salts-sucrose (TCBS) and thioglycollate broth

C. Löwenstein-Jensen and liquid-based media

A patient with Hodgkins disease is feeling bad, so he pays a visit to his physician. The physician's clinical examination reveals submandibular lymphadenitis, subcutaneous nodules, painful swellings, ulcers progressing to abscesses, and draining fistulas. What organism is probably producing these symptoms? A. Mycobacterium tuberculosis B. M. avium C. M. haemophilum D. M. gordonae

C. M. haemophilum

A cell that can recall previous contact with a particular antigen so that subsequent exposure leads to a more rapid and more effective immune response than the first encounter is which type of cell? A. Effector lymphocyte B. Plasma cell C. Memory lymphocyte D. Stem cell

C. Memory lymphocyte

If a newborn has symptoms of meningitis but the cerebrospinal fluid (CSF) is negative for both Gram stain and a routine culture, what organisms should be suspected? A. Neisseria gonorrhea and Chlamydia trachomatis B. Treponema pallidum and Borrelia burgdorferi C. Mycoplasma hominis and Ureaplasma urealyticum D. M. pneumoniae and C. trachomatis

C. Mycoplasma hominis and Ureaplasma urealyticum

An oxidase-positive, gram-negative diplococcus produces bubbles in 30% hydrogen peroxide. What is the organism? A. N. sicca B. N. lactamica C. N. gonorrhoeae D. Neisseria meningitidis

C. N. gonorrhoeae

Nonpathogenic commensal Neisseria spp. include all the following, except A. Neisseria lactamica. B. N. polysaccharea. C. N. meningitidis. D. N. mucosa.

C. N. meningitidis.

In what single setting does Stenotrophomonas maltophilia produce all its disease? A. Community B. Military barracks C. Nosocomial D. College dorms

C. Nosocomial

What two species of Pseudomonas have been linked to transfusion-associated septicemia? A. Pseudomonas aeruginosa and P. stutzeri B. fluorescens and P. aeruginosa C. P. putida and P. fluorescens D. P. putida and P. mendocina

C. P. putida and P. fluorescens

This is a leukocidin that is lethal to leukocytes and produced by staphylococci. A. Hemolysin B. Lancefield C. Panton-Valentine D. Adhesins

C. Panton-Valentine

What disease does Chlamydophila psittaci cause in humans? A. Conjunctivitis B. Endocarditis C. Parrot fever D. Bird flu

C. Parrot fever

Chromoblastomycosis is caused by all the following organisms, except A. Phialophora verrucosa. B. Fonsecaea compacta. C. Penicillium marneffei. D. Fonsecaea pedrosoi.

C. Penicillium marneffei.

You have isolated a bacterium from a stool culture that produces clear colonies on sorbitol MacConkey (SMAC) agar. Which of the following would be the most appropriate test to perform next? A. Rapid urease B. Oxidase C. Rapid methylumbelliferyl-b-D-glucuronide (MUG) D. Gram stain

C. Rapid methylumbelliferyl-b-D-glucuronide (MUG)

An example of a fluorescent stain used to stain mycobacterium is: A. Acridine orange B. Calcofluour white C. Rhodamine-auramine D. Fluorescein isothiocyanate

C. Rhodamine-auramine

What disk is used to presumptively identify Peptostreptococcus anaerobius? A. Bile B. Nitrate C. Sodium polyanethol sulfonate (SPS) D. Indole

C. Sodium polyanethol sulfonate (SPS)

What is unique about the Sphingobacterium spp.? A. Sphingomyelin in the cell wall B. Cholesterol in the cell wall C. Sphingophospholipids in the cell wall D. Collagen in the cell wall

C. Sphingophospholipids in the cell wall

What is the mechanism of action of the glycopeptides (vancomycin and teicoplanin)? A. The glycopeptides inhibit folate synthesis and prevent the bacteria from using this as an energy source. B. The glycopeptides interfere with DNA replication and disrupt the protein synthesis operation. C. The glycopeptides bind to the substrate of the transpeptidation enzyme and disrupt the cell membrane construction. D. The glycopeptides interfere with transfer RNA production and disrupt the protein synthesis operation.

C. The glycopeptides bind to the substrate of the transpeptidation enzyme and disrupt the cell membrane construction.

If a test is not considered appropriate for the specimen, the following should happen: A. Discipline the nurse for ordering the wrong test. B. Hold a training session to teach hospital staff about correctly ordering tests. C. The laboratory needs to communicate with the physician to determine exactly what needs to be done. D. Discipline the ward clerk for ordering the wrong test.

C. The laboratory needs to communicate with the physician to determine exactly what needs to be done.

Which of the following is NOT a component or characteristic of natural (innate) immunity? A. The response involves acute-phase reactants. B. The response involves phagocytosis. C. The response involves antibodies. D. Repeated exposure to a pathogen does not change the response.

C. The response involves antibodies.

All of the following are examples of suboptimal specimens that must be rejected, except: A. The specimen container is leaking when received in the laboratory. B. The specimen is received in a fixative solution such as formalin. C. The specimen is for a Neisseria gonorrhoeae (GC) culture and submitted in a JEMBEC system. D. The information on the requisition does not match the information on the specimen label.

C. The specimen is for a Neisseria gonorrhoeae (GC) culture and submitted in a JEMBEC system.

What is the mechanism by which toxic shock syndrome toxin-1 (TSST-1) causes TSS? A. All of the above B. The bacteria release the toxin into the gastrointestinal system where phagocytes engulf the bacteria, leaving a pseudomembrane that irritates the colon. C. The toxin is a superantigen that stimulates T-cell proliferation with production of large amounts of cytokines. D. The bacteria release the toxin into the blood and it goes to the hypothalamus to produce an extremely high fever.

C. The toxin is a superantigen that stimulates T-cell proliferation with production of large amounts of cytokines.

What is the function of protein A in the cell wall of Staphylococcus aureus? A. To block the activation of the complement cascade B. To keep the structural integrity of the cell wall and keep out antimicrobial agents C. To bind IgG and prevent phagocytosis D. To bind IgM and inactivate natural killer cells

C. To bind IgG and prevent phagocytosis

Coombs reagent is used for what purpose? A. To cause a precipitation reaction with small amounts of antibody B. To enhance agglutination with IgM-coated red blood cells C. To enhance agglutination with IgG-coated red blood cells D. To link small antigens on patient red cells

C. To enhance agglutination with IgG-coated red blood cells

How does Clostridium difficile produce pseudomembranous colitis and antibiotic-associated diarrhea? A. Endotoxin B. Hyaluronidase C. Toxin A and toxin B (exotoxins) D. Protease

C. Toxin A and toxin B (exotoxins)

Cutaneous mycoses which affect skin, hair, and nails may be caused by the following organisms: A. Sportothrix schenckii B. Histoplasma, Coccidioides, Blastomyces C. Trichophyton, Epidermophyton, Microsporum D. Mucor, Rhizopus, Absidia

C. Trichophyton, Epidermophyton, Microsporum

Eye infections with Acanthamoeba spp. have most commonly been traced to: A. Use of soft contact lenses B. Use of hard contact lenses C. Use of contaminated lens care solutions D. Failure to remove lenses while swimming

C. Use of contaminated lens care solutions

Common uses of probes include all of the following, except A. chromosomal translocations. B. microbial pathogen detection. C. abnormal white blood cell (WBC) detection. D. gene expression analysis.

C. abnormal white blood cell (WBC) detection.

Antibiotic mechanisms of action target all the following, except A. RNA transcription. B. DNA replication. C. blocking the Embden-Meyerhof pathway. D. bacterial cell wall synthesis.

C. blocking the Embden-Meyerhof pathway.

The best method for detecting multiple genotypes of the same virus is: A. pyrosequencing. B. ligase chain reaction. C. branched DNA amplification. D. strand displacement amplification.

C. branched DNA amplification.

All of the following are part of the process of phagocytosis EXCEPT: A. formation of a phagosome. B. fusion of lysosome with phagosome. C. diapedesis. D. creation of hypochlorite radicals.

C. diapedesis.

Common schemes to classify streptococci include all the following, except A. physiologic characteristics. B. biochemical characteristics. C. flagellar antigens. D. serologic grouping or typing of C carbohydrate.

C. flagellar antigens.

All of the following are characteristics of nonfermenters except: A. thin gram-negative bacilli or coccobacilli. B. oxidase positive. C. indole positive. D. resistance to a variety of antimicrobials, such as aminoglycosides, third-generation cephalosporins, penicillins, and fluoroquinolones.

C. indole positive.

Extended β-lactamases target all the following antibiotics, except A. cephalosporins. B. monobactams. C. macrolides. D. penicillins.

C. macrolides.

Erysipelothrix rhusiopathiae produces all the following diseases except: A. septicemia. B. endocarditis. C. meningitis. D. erysipeloid.

C. meningitis.

A night technician is working in microbiology when a cerebrospinal fluid (CSF) specimen comes in. Almost simultaneously, the technician is called to the emergency department to draw blood on seriously injured car crash victims. How would the technician store the CSF until time permits to work on the CSF specimen? A. Pour the specimen into a tube of broth. B. Leave the specimen on the shelf where it is good for 6 hours at room temperature. C. Put the specimen in the refrigerator where it is good for 4 hours at 4° C. D. Place the specimen in a 35° C incubator where it is good for up to 6 hours.

D. Place the specimen in a 35° C incubator where it is good for up to 6 hours.

A microbiologist is reading the plates from a sputum culture. The culture is from a patient with cystic fibrosis. One organism dominates the blood agar, chocolate, and MacConkey plates. The MacConkey plate shows an organism with a green pigment and a metallic sheen. The probable identification for this organism is: A. Chromobacterium violaceum. B. Serratia marcescens. C. Prevotella melaninogenica. D. Pseudomonas aeruginosa.

D. Pseudomonas aeruginosa.

This antibiotic affects the DNA replication by targeting topoisomerases II and IV, enzymes considered important in controlling DNA replication. A. Trimethoprim B. Glycopeptide C. Sulfamethoxazole D. Quinolone

D. Quinolone

Later in the evening, after attending a family reunion, several family members went to the emergency department after experiencing nausea, vomiting, abdominal pain, and severe cramping. The menu included fried chicken, hot dogs, hamburgers, potato salad, deviled eggs, éclairs, and cheesecake. The symptoms appeared about 4 hours after eating. What is the most probable explanation for these symptoms? A. Scalded skin syndrome B. TSS C. Toxic epidermal necrolysis D. Staphylococcal food poisoning

D. Staphylococcal food poisoning

What does the oxidase test determine? A. If the bacteria have oxidase, which will allow for the oxidation of carbohydrates B. If the bacteria can hydrolyze urea to ammonia and carbon dioxide C. If the bacteria have the enzyme, oxidase, to reduce oxygen to carbon dioxide D. The presence of the cytochrome oxidase system that oxidizes reduced cytochrome with molecular oxygen

D. The presence of the cytochrome oxidase system that oxidizes reduced cytochrome with molecular oxygen

Which two organs are considered the primary lymphoid organs in which immunocompetent cells originate and mature? A. Spleen and mucosal-associated lymphoid tissue (MALT) B. Thyroid and Peyer patches C. Lymph nodes and thoracic duct D. Thymus and bone marrow

D. Thymus and bone marrow

What is the purpose of the digestion-decontamination processing of specimens submitted for mycobacterial culture? A. To liquefy the outer cell wall of the mycobacteria so that they will grow faster B. To make the specimen easier to plate C. To release all bacteria in the sample D. To allow chemical decontaminants to kill nonmycobacterial organisms

D. To allow chemical decontaminants to kill nonmycobacterial organisms

Which of the following is characteristic of Moraxella catarrhalis? A. Acid from glucose and maltose only B. No growth on nutrient agar C. Acid from glucose only D. Tributyrin positive

D. Tributyrin positive

A 35-year-old man travels on a multidestination vacation over a 2 month period, including lengthy stops in tropical Africa and Southeast Asia. Six weeks after returning come home to the United States, he develops a productive cough, fatigue, weight loss, low-grade fever, and night sweats. What disease should the physician consider as a result of his travel history? A. Primary atypical pneumonia B. Pneumonia caused by gram-negative rods C. Streptococcal pneumonia D. Tuberculosis (TB)

D. Tuberculosis (TB)

What is a major category of proteins identified from bacteria by MALDI-TOF? A. Structural Proteins B. Enzymatic proteins C. Ribosomal proteins D. Two are correct

D. Two are correct - ribosomal and structural

Cytotoxic T cells are the primary immune response against which type of pathogen? A. Parasites B. Fungi C. Bacteria D. Viruses

D. Viruses

A technician is reading the biochemical tests for identifying a particular gram-negative rod. The organism has produced acid, indicated by a color change, in the closed tube only. This indicates that the organism is A. a reducer. B. both an oxidizer and a fermenter. C. an oxidizer. D. a fermenter.

D. a fermenter.

All of these stains are commonly used to visualize mycobacteria on a smear except: A. auramine. B. Kinyoun. C. Ziehl-Neelsen. D. acridine orange.

D. acridine orange.

Mechanisms that mediate intrinsic antibiotic resistance include all the following, except: A. expression of genes mediating inactivating enzymes. B. biofilm formation. C. cell wall impermeability. D. alternate biosynthetic pathways.

D. alternate biosynthetic pathways.

In a polymerase chain reaction, the threshold cycle represents: A. the degree of complementarity between the primers and the target. B. the maximum number of cycles that can be carried out before the amplicons saturate the solution. C. the minimum amount of target that can be amplified. D. an indication of the original amount of target in the sample.

D. an indication of the original amount of target in the sample.

Diabetics may sometimes be infected with their own resident flora. This type of infection is called A. symbiosis. B. a carrier state. C. a parasitic infection. D. an opportunistic infection.

D. an opportunistic infection.

(-) urease negative (+) lysine decarboxylation (+) H2S (+) indole (-) Simmon's citrate delayed lactose fermenter

Edwardsiella

When microbiologists encounter a sputum specimen, they know that the upper respiratory tract contains many indigenous organisms and to identify every organism in the culture would be a time-consuming, cost-prohibitive, and insurmountable task. So microbiologists must: A. be able to ascertain whether the results generated by a commercial or automated system correlate with the suspected organism. B. work quickly with commercially available kits to identify all organisms present in a sputum specimen for the best quality patient care available. C. work up only the gram-negative rods present in the culture. D. differentiate the potential pathogens from the "usual" inhabitants of the upper respiratory tract and direct the diagnostic workup only to potential pathogens.

D. differentiate the potential pathogens from the "usual" inhabitants of the upper respiratory tract and direct the diagnostic workup only to potential pathogens.

The purpose of negative selection of B cells is to: A. direct more B cells to become plasma cells. B. eliminate B cells that don't express mu. C. prevent activation of B cells in the bone marrow. D. eliminate B cells that are specific for self-antigens.

D. eliminate B cells that are specific for self-antigens.

Early-onset congenital syphilis is characterized by all the following symptoms, except A. osteochondritis. B. anemia. C. hepatosplenomegaly. D. encephalitis.

D. encephalitis.

All of the following are approaches to treating anaerobic infections, except A. surgical therapy. B. hyperbaric oxygen. C. antitoxins. D. enzyme inactivators.

D. enzyme inactivators.

Middlebrook 7H10 and 7H11 media are enriched with all of the following except: A. beef catalase. B. oleic acid. C. bovine albumin. D. heme.

D. heme.

Oxacillin-resistant Staphylococcus aureus is called A. penicillinase-resistant S. aureus. B. penicillin-resistant S. aureus. C. oxacillin-resistant S. aureus. D. methicillin-resistant S. aureus (MRSA).

D. methicillin-resistant S. aureus (MRSA).

All of the following are β-lactam antibiotics, except A. carbapenems. B. monobactams. C. penems. D. monoterpenes.

D. monoterpenes.

The measurement of light scattered at an angle by the antigen-antibody complexes in a solution is called: A. turbidimetry. B. equivalency. C. agglutination. D. nephelometry.

D. nephelometry.

All of the following are biochemical characteristics of Vibrio spp. except: A. ferments glucose. B. reduces nitrate to nitrite. C. halophilic. D. oxidase negative.

D. oxidase negative.

If transport of the specimen is delayed, the specimen can be maintained by all of the following, except A. preservatives. B. anticoagulants. C. transport or holding medium. D. oxygen.

D. oxygen.

Chlamydia trachomatis is the infectious agent in all the following conditions in humans, except A. trachoma. B. urogenital infections. C. lymphogranuloma venereum (LGV). D. pharyngitis.

D. pharyngitis.

The most common bacterial characteristic that allows for evasion of phagocytosis by the host is called A. extracellular enzyme production. B. exotoxin production. C. pili. D. polysaccharide capsule.

D. polysaccharide capsule.

Systemic lupus erythematosus is characterized by: A. increase in cells lining the synovial membrane. B. HLA-DR antigens expressed on thyroid epithelial cells. C. absence of immune complexes. D. presence of dsDNA antibodies

D. presence of dsDNA antibodies

Systemic lupus erythematosus can be characterized by all of the following EXCEPT: A. butterfly rash B. joint pain C. presence of circulating immune complexes D. presence of reagin antibody

D. presence of reagin antibody

A 56-year-old woman presents to her physician complaining of weight gain and joint problems. She is increasingly having difficulty walking up stairs and manipulating her fingers. Fingers in both hands as well as knees on both legs are equally painful and stiff. The symptoms have been getting progressively worse over the past 6 months. Rheumatoid factor is elevated, and antinuclear antibodies are not detected. Complement levels in her joints are decreased. This woman most likely has: A. Wegener's granulomatosis. B. Hashimoto's thyroiditis. C. systemic lupus erythematosus. D. rheumatoid arthritis

D. rheumatoid arthritis

If a serum sample does not cause agglutination when mixed with a particular antigen, then you should: A. decrease the viscosity of the sample. B. report that the patient does not have antibody against that antigen. C. increase the particle surface charge by altering the pH. D. test a more diluted sample to overcome possible prozone effects.

D. test a more diluted sample to overcome possible prozone effects.

A 12-year-old girl goes to the doctor complaining of a sore throat, fever, headache, and general malaise. The doctor does a quick strep test that is positive for group A β-hemolytic Streptococcus. No antibiotic testing is needed because Streptococcus is A. not treated in throat cultures. B. universally susceptible to erythromycin. C. not considered a pathogen in the throat. D. universally susceptible to penicillin.

D. universally susceptible to penicillin.

The probe is A. immobilized on a solid support mechanism. B. the strand that is used as the oligonucleotide primer. C. the RNA portion that will act as the DNA replicase and allow replication to occur. D. used to detect the target nucleic acid molecule.

D. used to detect the target nucleic acid molecule.

Notations from the macroscopic (gross) examination of a specimen should include all the following, except A. blood or mucus present. B. stool consistency. C. swab or aspirate. D. what type of container the specimen was collected in.

D. what type of container the specimen was collected in.

Penicillins, cephalosporins, monobactams, and carbapenems all have this ring in their structure that is responsible for inhibiting the transpeptidation reaction, resulting in bacterial lysis and cell death. A. α-Lactam B. Cephems C. Benzene D. β-Lactam

D. β-Lactam

Type of swab that is recommended for STD specimen collection

Dacron and polyester

ferment glucose, lactose (+) indole (+) methyl red (-)voges-proskauer test does not produce H2S, DNase, urease or PAD cannot use citrate

E. coli

In the TSI agar, obligate aerobic bacteria which oxidize glucose but not lactose or sucrose would most like produce the following outcome:

K/NC (alkaline slant, no change ***********)

Mucoid colonies, Gram negative, Oxidase negative

Kleb pneumo

(+) Simmons citrate (-) H2S (-) methyl red (+) Voges -Proskauer test (-) indole non motile

Klebsiella

During the summer break, several middle-aged elementary school teachers from the same school district attended a 3-day seminar in Chicago.Upon returning home, three female teachers from the group were hospitalized with pneumonia, flulike symptoms, and a nonproductive cough.Routine testing of sputum samples revealed normal flora. Further testing using buffered CYE agar with L-cysteine and α-ketoglutarate in 5% CO2 produced growth of opaque colonies that stained faintly, showing thin gram-negative rods. What is the most likely identification?

Legionella pneumophila

Catalase positive, beta hemolysis, Gram + rods

Listeria monocytogenes

Semisolid transport media such as Amies, Stuart, or Cary-Blair are suitable for the transport of swabs for culture of most pathogens except:

Neisseria gonorrhoeae

Acid-fast positive bacilli were recovered from the sputum of a 79-year-old man who had been treated for pneumonia. Which of the following test reactions after 3 weeks of incubation on Löwenstein-Jensen agar are consistent with Mycobacterium tuberculosis?

Niacin = + pos; Nitrate reduction =+ pos Photochromogenic = Neg