Staphylococci Important human pathogen Causes both relatively minor and serious diseases One of the hardiest of the non sporeforming bacteria Can exist on dry surfaces for a long period Relatively heat-resistant; temperature range of18°-40°C BIOL 533 Lecture 10
BIOL 533 2 Lecture 10 Staphylococci • Important human pathogen – Causes both relatively minor and serious diseases • One of the hardiest of the nonsporeforming bacteria – Can exist on dry surfaces for a long period – Relatively heat-resistant; temperature range of 18° - 40° C
Staphylococci Morphology Gram+ grape-like cluster, but in clinical specimens, can be a single cocci or diplococci General physiological characteristics Nonmotile Facultatively anaerobic Catalase Grows in media containing 10% Nacl BIOL 533 Lecture 10
BIOL 533 3 Lecture 10 Staphylococci • Morphology – Gram+ grape-like cluster, but in clinical specimens, can be a single cocci or diplococci • General physiological characteristics – Nonmotile – Facultatively anaerobic – Catalase + – Grows in media containing 10% NaCl
Staphylococci Relationship to disease (only 3 important s, aureus- causes a number of diseases -S. epidermidis-present in normal flora (normally benign, except when introduced via catheters, etc.) S. saprophyticus-causes uninary tract infections BIOL 533 Lecture 10
BIOL 533 4 Lecture 10 Staphylococci • Relationship to disease (only 3 important) – S. aureus—causes a number of diseases – S. epidermidis—present in normal flora (normally benign, except when introduced via catheters, etc.) – S. saprophyticus—causes uninary tract infections
Staphylococci Microbial physiology and structure Capsule may not be found growing on media, but it is usually present in vivo Teichoic acids are phosphate containing polysaccharides bound to both peptidoglycan and cytoplasmic membrane Species specific Poor immunogens but when bound to peptidoglycan, get an antibody response BIOL 533 Lecture 10
BIOL 533 5 Lecture 10 Staphylococci • Microbial physiology and structure – Capsule may not be found growing on media, but it is usually present in vivo – Teichoic acids are phosphate containing polysaccharides bound to both peptidoglycan and cytoplasmic membrane • Species specific • Poor immunogens, but when bound to peptidoglycan, get an antibody response
Pathogenesis of s aureus Features typical of staphylococci infections Initial lesion is normally mild and localized Results in a boil-normally, it is self-limiting Can result in systemic infection BIOL 533 Lecture 10
BIOL 533 6 Lecture 10 Pathogenesis of S. aureus • Features typical of staphylococci infections: – Initial lesion is normally mild and localized – Results in a boil—normally, it is self-limiting – Can result in systemic infection