MCEM Part A Study Guide/Microbiology/Specific Pathogen Groups/Streptococci and Staphylococci

Section 1: Streptococci and Staphylococci

Gram-positive cocci can be divided into two groups using the catalase test. Catalase catalyses the conversion of H₂O₂ to water and oxygen, causing bubbles. Staphylococci produce catalase and are therefore catalase-positive, whereas Streptococci are catalase-negative.

Streptococci

These are facultative anaerobes.

Streptococcus pneumoniae

Streptococcus pneumoniae in spinal fluid. FA stain (digitally colorized).

methods of spread of infection principal clinical features

Streptococcus pyogenes

methods of spread of infection principal clinical features

Staphylococci

Staphylococcus aureus

methods of spread of infection principal clinical features

Staphylococcus epidermidis

methods of spread of infection principal clinical features

Alpha-haemolytic streptococci

endocarditis procedural prophylaxis