Gram-Positive Cocci Overview

These flashcards cover key concepts regarding Gram-positive cocci, focusing on Staphylococcus and Streptococcus, including their characteristics, diseases, and virulence factors.

What are the general characteristics of Staphylococci?

They are gram-positive cocci, catalase-positive, aerobic or facultatively anaerobic, nonmotile, and non-spore-forming.

What is the primary reservoir for Staphylococcus aureus?

Human nares, with colonization in the axillae, vagina, pharynx, and skin.

What are the virulence factors of Staphylococcus aureus?

Enterotoxins, Toxic Shock Syndrome Toxin-1 (TSST-1), and Exfoliative Toxin.

What type of infections does Staphylococcus aureus cause?

A spectrum of infections including skin and wound infections, toxic shock syndrome, and food poisoning.

How is Streptococcus distinguished from Staphylococcus?

By being catalase-negative and generally forming pairs or chains.

What is the primary mode of transmission for Streptococcus pyogenes?

Person-to-person transmission via respiratory droplets or direct contact with skin lesions.

What diseases are associated with Streptococcus pneumoniae?

Pneumonia, meningitis, and otitis media.

What antibiotics resistance is concerning with Enterococcus species?

Vancomycin-resistant Enterococcus (VRE) is a major public health concern.

What is the main virulence factor of Streptococcus pneumoniae?

The polysaccharide capsule.

What is the Lancefield classification used for?

Classifying streptococci based on group-specific carbohydrate antigens in their cell wall.