Reference no: EM132687636

1. A blood culture grows an organism with the following characteristics:

GPC in clusters Catalase positive

Creamy-white colony, non-hemolytic on sheep's blood agar

Staph latex negative

If you suspect this is a contaminant, what is the most likely identification?

2. A culture from a rapidly progressing, very serious wound grows an organism with the following characteristics:

GPC in chains and pairs

Catalase negative

Lancefield group A antisera test is grainy

What type of hemolysis (alpha, beta,or gamma) would you expect to see on a blood agar plate, including large or small zone size?

3. A newborn baby is diagnosed with sepsis and meningitis. The baby's cerebrospinal fluid grows an organism that is a GPC in chains and pairs, has a small zone of beta-hemolysis on blood agar, and is catalase negative. What test would you perform next?

4. A sputum specimen from a patient with community-acquired pneumonia grows a 3+ quantity of an alpha-hemolytic GPC, mostly in pairs. What result would you expect from a catalase test on this organism?

5. A patient on a ventilator develops a nosocomial pneumonia and sepsis. A blood culture grows a GPC in pairs and chains that is slightly alpha hemolytic on blood agar and resistant to many antibiotics, including vancomycin. The catalase test, performed from the blood agar plate is difficult to interpret, showing a few bubbles, but not very many. What is the most likely identification of this organism?