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A 65-year-old male has developed an abdominal abscess following surgery for a bowel resection.  The specimen is sent to the laboratory and the gram stain shows many pleomorphic gram negative bacilli.  Based on this information, which of the following are possible genera?

Rickettsia and Ehrlichia species all:

A first morning sputum is received for culture of mycobacteria. It is digested and concentrated by the NALC method. Two Lowenstein Jensen slants are incubated in the dark at 35 degrees C with 5-10% CO2. the smears reveal acid fast bacilli and after 7 days, no growth appears on the slants. The best explanation is:

A positive string test is used to identify:

A gram-negative diplococcus that grows on Thayer Martin agar can be further confirmed as N. meningitidis if it is:

Which of the following agars is used for selective isolation of C. difficile?

Although the culture of organisms in the family Spirochaetaceae is not generally recommended, Kelly’s medium has been useful in cultivating species of:

In concentration methods for acid fast bacilli, the sputum must be:

A patient with a nosocomial pneumonia has a sputum gram stain that shows many WBCs and numerous small gram negative coccobacilli.  The organism grew in 24 hours as a mucoid hemolytic colony on SBA and a colorless colony on MAC.  The organism has the following characteristics: catalase positive, oxidase negative, arginine negative, lysine negative, nitrate negative, and ONPG negative.  The organism is:

The reverse CAMP test, lecithinase production, double zone hemolysis, and gram stain morphology are all useful criteria in the identification of: