Staphylococci Overview

Question 1

Staphylococcus spp. gram stain

Answer 1

GPC in clusters

Question 2

Staphylococcus spp. key characteristics

Answer 2

Catalase pos. Fermentative, Resistant to bacitracin

Question 3

S. aureus gram stain

Answer 3

GPC in clusters

Question 4

S. aureus key characteristics

Answer 4

Coagulase pos., Ferments mannitol (yellow colonies on mannitol salt agar). Usually DNase & ther- monuclease pos.

Question 5

S. aureus pathogenicity

Answer 5

Causes suppurative cutaneous infec- tions, toxic shock syndrome, food poisoning

Question 6

Coagulase-negative staphylococci (CNS) gram stain

Answer 6

GPC in clusters

Question 7

Coagulase-negative staphylococci (CNS) key characteristics

Answer 7

Coagulase neg. Grow on mannitol salt agar but don’t ferment mannitol. Sensitive to novobiocin.

Question 8

Coagulase-negative staphylococci (CNS) pathogenicity

Answer 8

Common cause of hospital- acquired UTI

Question 9

S. saprophyticus gram stain

Answer 9

GPC in clusters

Question 10

S. saprophyticus key characteristics

Answer 10

Coagulase neg. Resistant to novobiocin. May ferment mannitol.

Question 11

S. saprophyticus PATHOGENICITY

Answer 11

UTI in young sexually active females, urethritis & prostatitis in males

Question 12

Micrococcus gram stain

Answer 12

Large GPC in pairs, tetrads (predominant arrangement), clusters

Question 13

Micrococcus key characteristics

Answer 13

Catalase pos. Coagulase neg. Oxidase pos. Susceptible to bacitracin. Resistant to furazolidone & lysostaphin.

Question 14

Micrococcus pathogenicity

Answer 14

Usually nonpathgenic. Found in environment & on skin, mucous membranes, oropharynx