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?

The term hyaline is used to describe:

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?

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:

Which virus causes childhood gastroenteritis?

An adult patient has recently returned from a missionary trip to Haiti where she lived in a rural village and tended to livestock.  Upon her return she developed several skin lesions and required surgical intervention to drain.  The direct gram stain showed Gram-positive bacilli and white blood cells. The organism grew catalase positive, non-hemolytic, flat spreading colonies on 5% sheep blood agar.  Which pathogen needs to be considered given the patient history?

The examination of spinal fluid may reveal this parasitic agent of primary amoebic meningoencephalitis: