Category: Uncategorized

A Gram-negative bacillus is isolated from a midstream urine collection. This organism is oxidase-negative, nitrate-positive, indole-negative, and H2S- positive. What is the most likely identification? Sheep Blood Agar Non-hemolytic, mucoid, swarming. Colony Count: > 100,000 CFU/ml MacConkey Agar Non-lactose fermenting

Evaluating the quality of a sputum specimen sent to the laboratory for bacterial culture is best performed by:

This protozoan is the causative agent of Chagas Disease:

A 64-year old woman presents to the emergency room with a 3-day history of a cough producing blood-tinged sputum and a fever. The Gram stain of the sputum has many WBCs and Gram-positive cocci, observed in pairs and chains.  The predominant organism in culture was alpha hemolytic and gave the following reactions: Catalase negative PYR negative Which is the most likely identification of this organism?

A mordant that is applied after the primary stain to chemically bond the alkaline dye to the bacterial cell wall is:

A throat culture grows 1+ mixed alpha-hemolytic and non-hemolytic flora on the blood agar plate. What is the best interpretation of this information?

A CSF specimen from a neonate grows beta-hemolytic, short, gram positive bacilli. The organism was catalase positive, oxidase negative, and motile. What is the most likely identification?

The term hyaline is used to describe:

Chicken pox is caused by which virus?

A urine is submitted for bacterial culture. The culture shows growth on sheep-blood agar and no growth on MacConkey agar. The colonies on blood agar are white and hemolytic. Select the next best test to perform in the identification of this organism: