When cleansing the skin with alcohol and then iodine for the collection of a blood culture, the iodine (or iodophor) should remain intact on the skin for at least:

What is the purpose of adding 0.025%–0.050% sodium polyanetholsulfonate (SPS) to nutrient broth media for the collection of blood cultures

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

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

Select the method of choice for recovery of anaerobic bacteria from a deep abscess.

Select the primary and differential media of choice for recovery of most fecal pathogens

Select the media of choice for recovery of Vibrio cholerae from a stool specimen

Colistin–nalidixic acid agar (CNA) is used primarily for the recovery of:

Chocolate agar and modified Thayer–Martin agar are used for the recovery of:

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

Deoxycholate agar (DCA) is useful for the isolation of:

Specimens for virus culture should be transported in media containing

Cerebrospinal fluid (CSF) should be cultured immediately, but if delayed the specimen should be:

The most sensitive method for the detection of β-lactamase in bacteria is by the use of:

The breakpoint of an antimicrobial drug refers to:

Which of the following variables may change the results of an MIC?

Which class of antibiotics is used for the treatment of serious gram-negative infections as well as infections with Mycobacterium tuberculosis?

A test for the hydrolysis of esculin in the presence of bile is especially useful in identifying species of the genus

The organism associated with a disease characterized by the presence of a pseudomembrane in the throat and the production of an exotoxin that is absorbed into the bloodstream with a lethal effect is

Enterotoxin produced by Staphylococcus aureus is responsible for causing

Streptococcus pyogenes can be presumptively identified using

A gram-positive coccus that is catalase positive, nonmotile, lysostaphin resistant, and modified oxidase positive is best identified as a member of the genus

Staphylococcus saprophyticus, a recognized pathogen, is a cause of

The etiologic agent most commonly associated with septicemia and meningitis of newborns is

Which of the following is the most

commonly isolated species of Bacillus

in opportunistic infections such as

bacteremia, post-traumatic infections

of the eye, and endocarditis

Streptococci obtain all their energy from

the fermentation of sugars to

Streptococci are unable to synthesize the

enzyme

The beta-hemolysis produced by group A Streptococcus seen on the surface of a sheep blood agar plate is primarily the result of streptolysin

An identifying characteristic of Staphylococcus aureus is

Rust-colored sputum in cases of lobar pneumonia is characteristic of which of the following possible etiologic agents?

Which of the following species of Bacillus is nonmotile?

Which of the following is not associated with Staphylococcus aureus?

The pulmonary form of anthrax is known as

Biochemically, the Enterobacteriaceae are gram-negative rods that:

The ortho-nitrophenyl-β-galactopyranoside (ONPG) test is most useful when differentiating

The Voges–Proskauer (VP) test detects which end product of glucose fermentation?

At which pH does the methyl red (MR) test become positive?

A positive Simmons citrate test is seen as a:

In the test for urease production, ammonia reacts to form which product

Which of the following reagents is added to detect the production of indole?

Decarboxylation of the amino acids lysine, ornithine, an

Which genera are positive for phenylalanine deaminase?

Which genera of the Enterobacteriaceae are known to cause diarrhea and are considered enteric pathogens?

Which of the following tests best differentiates Shigella species from E. coli?

Which genera of Enterobacteriaceae are usually nonmotile at 36°C?

Which single test best separates Klebsiella oxytoca from K. pneumoniae?

Which of the following organisms, found in normal fecal flora, may be mistaken biochemically for the genus Yersinia?

Which of the following organisms are generally positive for B-galactosidase?

The Shiga-like toxin (verotoxin) is produced mainly by which Enterobacteriaceae?

Direct spread of pneumonic plague disease occurs by which route?

Which isolates of the Enterobacteriaceae family most commonly produce extended-spectrum B-lactamase (ESBL)?

The most noted differences between P. aeruginosa and Stenotrophomonas maltophilia are:

Which Pseudomonas is usually associated with a lung infection related to cystic fibrosis?

Which organism is associated with immunodeficiency syndromes and melioidosis (a glanders-like disease in Southeast Asia and northern Australia)

A yellow pigment–producing organism that is oxidase positive, nonmotile, and does not grow on MacConkey agar is:

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

Which of the following products is responsible for satellite growth of Haemophilus spp. around colonies of Staphylococcus and Neisseria spp. on sheep blood agar

The majority of Haemophilus influenzae infections are caused by which of the following capsular serotypes?

Which Haemophilus species is difficult to isolate and recover from genital ulcers and swollen lymph nodes?

Which Haemophilus species is generally associated with endocarditis?

The test used most often to separate the Micrococcaceae family from the Streptococcaceae family is:

Micrococcus and Staphylococcus species are differentiated by which test(s)?

Lysostaphin is used to differentiate Staphylococcus from which other genus?

Which of the following tests is used routinely to identify Staphylococcus aureus?

Which of the following enzymes contribute to the virulence of S. aureus?

Toxic shock syndrome is attributed to infection with:

Which Staphylococcus species, in addition to S. aureus, also produces coagulase?

Streptococcus species exhibit which of the following properties?

Which group of streptococci is associated with erythrogenic toxin production?

A fourfold rise in titer of which antibody is the best indicator of a recent infection with group A β-hemolytic streptococci?

Which test is used to differentiate the viridans streptococci from the group D streptococci and enterococci?

S. pneumoniae and the viridans streptococci can be differentiated by which test?

The salt tolerance test (6.5% salt broth) is used to presumptively identify:

The quellung test is used to identify which Streptococcus species?

Variation in colony types seen with fresh isolates of Neisseria gonorrhoeae and sometimes with Neisseria meningitidis are the result of:

Large gram-positive spore-forming rods growing on blood agar as large, raised, β-hemolytic colonies that spread and appear as frosted green-gray glass are most likely:

Bacillus anthracis and Bacillus cereus can best be differentiated by which tests?

Which is the specimen of choice for proof of food poisoning by Bacillus cereus?

A non–spore-forming, slender gram-positive rod forming palisades and chains was recovered from a vaginal culture and grew well on tomato juice agar

A Corynebacterium species recovered from a throat culture is considered a pathogen when it produces:

A gram-positive branching filamentous organism recovered from a sputum specimen was found to be positive with a modified acid-fast stain method. be positive with a modified acid-fast stain method. What is the most likely presumptive identification?

Routine laboratory testing for Treponema pallidum involves:

Spirochetes often detected in the hematology laboratory, even before the physician suspects the infection, are:

Which of the following organisms is the cause of Lyme disease?

The diagnostic method most commonly used for the identification of Lyme disease is

Primary atypical pneumonia is caused by

Which organism typically produces “fried-egg” colonies on agar within 1–5 days of culture from a genital specimen?

The manganous chloride–urea test is used for the identification of which organism?

A direct smear from a nasopharyngeal swab stained with Loeffler methylene blue stain showed various letter shapes and deep blue, metachromatic granules. The most likely identification is:

Which of the following organisms are transmitted to animals and humans after a tick bite?

Obligate anaerobes, facultative anaerobes, and microaerophiles are terms referring to bacteria

that require:

Which broth is used for the cultivation of anaerobic bacteria in order to detect volatile fatty acids an aid to identification?

A gram-positive spore-forming bacillus growing on sheep-blood agar anaerobically produces a double zone of β-hemolysis and is positive for lecithinase. What is the presumptive identification?

Egg yolk agar is used to detect which enzyme produced by Clostridium species?

Which Clostridium spp. causes pseudomembranous colitis or antibiotic-associated colitis?

Which gram-negative bacilli produce black pigment and brick red fluorescence when exposed to an ultraviolet light source?

All of the following genera are anaerobic cocci that

stain gram positive except:

The gram-positive non–spore-forming anaerobic rods most frequently recovered from blood cultures as a contaminant are:

Which Clostridium species is most often recovered from a wound infection with gas gangrene

The best specimen for recovery of the mycobacteria from a sputum sample is:

Which is the most appropriate nonselective medium for recovery of mycobacteria from a heavily contaminated specimen?

Which organism, associated with tuberculosis in cattle, causes tuberculosis in humans, especially in regions where dairy farming is prevalent?

Which of the following Mycobacterium spp. is best differentiated by the rapid hydrolysis of Tween 80?

Which nonpathogenic Mycobacterium specie is isolated most often from clinical specimens and is called the “tapwater bacillus”?

All of the following are examples of appropriate specimens for the recovery of fungi except

For which clinical specimens is the KOH direct mount technique for examination of fungal elements used?

The India ink stain is used as a presumptive test for the presence of which organism?

Cutaneous disease involving skin, hair, and nails usually indicates an infection with a:

What is the first step to be performed in the identification of an unknown yeast isolate?

Which of the following yeasts is characteristically positive for germ tube production?

The urease test, niger seed agar test, and the germ tube test are all used for the presumptive identification of:

Ascospores are formed by which yeast isolate?

Tinea versicolor is a skin infection caused by:

Which of the following structures is invaded by the genus Trichophyton?

The Hair Baiting Test is used to differentiate which two species of Trichophyton that produce red colonies on Sabouraud agar plates?

Which Aspergillus species, recovered from sputum or bronchial mucus, is the most common cause of pulmonary aspergillosis?

What is the specimen of choice for the initial diagnosis of Pneumocystis jirovecii (carinii) in an immunocompromised patient, such as someone with AIDS?

A transplant patient is suspected of having invasive aspergillosis on the basis of clinical and radiological findings. Which specimen is best for the initial identification of aspergillosis by soluble antigen testing?

Classification of viruses is made by:

Which virus is the most common etiological agent of viral respiratory diseases in infants and children?

The most common viral syndrome of pericarditis, myocarditis, and pleurodynia (pain upon breathing) is caused by:

The most common causes of viral pneumonia in adults are

Which virus belonging to the Reoviridae group causes gastroenteritis in infants and young children but an asymptomatic infection in adults?

A very small, single-stranded DNA virus that causes a febrile illness with a rash and is called the fifth childhood disease after rubeola, rubella, varicella, and roseola is:

Which virus has been implicated in adult gastroenteritis resulting from ingestion of contaminated food (especially shellfish) and water?

Which virus is associated with venereal and respiratory tract warts and produces lesions of skin and mucous membranes?

Which technique is used for the confirmation of infection with human immunodeficiency virus (HIV-1)?

The organs of a 65-year-old male were donated soon after a fatal auto accident. Three recipients of his corneas and kidneys died within weeks after receiving his organs. Which of the following viruses most likely caused the death of these recipients?

An immunocompromised patient was admitted to the hospital with a diagnosis of hemorrhagic cystitis. Which combination of virus and specimen would be most appropriate to diagnose a viral cause of this disorder?

The incorrect match between organism and the appropriate diagnostic procedure is:

Parasitic organisms that are most often transmitted sexually include:

The incorrect match between the organism and one method of acquiring the infection is:

Upon examination of stool material for Cystoisospora belli, one would expect to see:

Which specimen is the least likely to provide recovery of Trichomonas vaginalis?

Which of the following is the best technique to identify Dientamoeba fragilis in stool?

A 12-year-old girl is brought to the emergency department with meningitis and a history of swimming in a warm-water spring. Motile amoebae that measure 10 μ in size are seen in the CSF and are most likely:

Characteristics of the rhabditiform (noninfective) larvae of Strongyloides stercoralis include a:

Visceral larva migrans is associated with which of the following organisms?

The examination of sputum may be necessary to diagnose infection with:

The adult tapeworm of Echinococcus granulosus is found in the intestine of:

In infections with Taenia solium, humans can serve as the:

Which microfilariae are usually not found circulating in the peripheral blood?

Organisms that should be considered in a nursery school outbreak of diarrhea include:

The incorrect match between disease and symptoms is:

The term internal autoinfection can be associated with the following parasites:

Ingestion of which of the following eggs will result in infection?

The most prevalent helminth to infect humans is:

Patients with severe diarrhea should use “enteric precautions” to prevent nosocomial infections with:

When humans have hydatid disease, the causative agent and host classification are:

Which parasite causes eosinophilic meningoencephalitis, a form of larva migrans causing fever, headache, stiff neck, and increased cells in the spinal fluid?