Virulence factors Pili Attachment to host cells BIOL 533 Lecture 12
BIOL 533 12 Lecture 12 Virulence Factors • Pili – Attachment to host cells
Pathogenesis of escherichia E. coll present in gastrointestinal tract in normal flora Bacterial sepsis(multiplication in blood Primary focus-infection of urinary tract or spread from gastrointestinal tract Death can occur in immunocompromised patients and infections resulting from intestinal perforation BIOL 533 Lecture 12
BIOL 533 13 Lecture 12 Pathogenesis of Escherichia • E. coli present in gastrointestinal tract in normal flora • Bacterial sepsis (multiplication in blood) – Primary focus-infection of urinary tract or spread from gastrointestinal tract – Death can occur in immunocompromised patients and infections resulting from intestinal perforation
Pathogenesis of escherichia Neonatal meningitis E coli and group B streptococci most common 75% E coll possess Capsular Kl antigen Colonization of infants With E coli at delivery is common disease is not BIOL 533 Lecture
BIOL 533 14 Lecture 12 Pathogenesis of Escherichia • Neonatal meningitis – E. coli and group B streptococci most common – 75% E. coli possess Capsular K1 antigen – Colonization of infants with E. coli at delivery is common; disease is not
Pathogenesis of escherichia Urinary tract infections (80% community and most nosocomial) Originate from gastrointestinal tract Important virulence factors Resistance to serum-killing Production of hemolysins Pili-mediated binding(not demonstrated in vivo Production of slime layer that participates in cell adhesion BIOL 533 Lecture 12
BIOL 533 15 Lecture 12 Pathogenesis of Escherichia • Urinary tract infections (80% community and most nosocomial) – Originate from gastrointestinal tract – Important virulence factors • Resistance to serum-killing • Production of hemolysins • Pili-mediated binding (not demonstrated in vivo) • Production of slime layer that participates in cell adhesion
Pathogenesis of escherichia Gastroenteritis (countries with poor hygiene) EnterotoxigenIC (ETEC) Mediated by heat-labile (like cholera) and heat stable exotoxins (activates guanylate cyclase and stimulates secretion of fluid) Both are coded from plasmid-borne genes World-wide both adults and children Incubation 1-2 days, persists 3-4 days Mild symptoms including cramps, nausea, vomiting BIOL 533 watery diarrea 16 Lecture 12
BIOL 533 16 Lecture 12 Pathogenesis of Escherichia • Gastroenteritis (countries with poor hygiene) – Enterotoxigenic (ETEC) • Mediated by heat-labile (like cholera) and heatstable exotoxins (activates guanylate cyclase and stimulates secretion of fluid) – Both are coded from plasmid-borne genes • World-wide:both adults and children – Incubation 1-2 days; persists 3-4 days – Mild symptoms, including cramps, nausea, vomiting, watery diahrrea