HSS 1100 Lecture Notes - Lecture 4: Petechia, Streptococcus Pneumoniae, Quinolone

• School: University of Ottawa
• Department: Health Sciences
• Course: HSS 1100
• Professor: William Yan

Document Summary

Gram positive cocci circular cell, stain purple. Gram-positive cocci (1 um diameter) growing in grape-like clusters. Species particularly important for humans include: i. ii. iii. Staphylococcus aureus pathogenic; often found as normal flora. Staphylococcus epidermidis normal flora of skin and mucosae; occasionally pathogenic. Staphylococcus saprophyticus in the environment and on skin; can cause urinary infections: staphylococcus aureus (true pathogen) Grows well on simple media (agar, blood-agar) producing 2-3 mm colonies in 24 h (37 c) Cytotoxins ( , , , , p-v leukocidin); toxic to many cells: leukocytes, erythrocytes, macrophages, platelets and fibroblasts. Haemolysins enzyme/toxin that can lyse (break open) red blood cell; dermonecrotic, lethal. Enterotoxin (a-e, g-i) toxins that affect gut (food poisoning) most commonly dairy (creaming); superantigens, important cause of food poisoning (nausea, vomiting, cramps, diarrhoeas) Exfoliative toxins (eta, etb) scalded skin syndrome in infants. Toxic shock syndrome toxin 1 (used to be pyrogenic exotoxin c and enterotoxin f) cause of toxic shock syndrome.