Lesson 8b: Escherichia coli Flashcards
usually motile with peritrichous flagella and is often fimbriae
E. coli
E. coli
its cell wall lipopolysaccharide are used as antigens in serotyping E. coli
Serotyping E. coli
✓ Somatic (O)
✓ flagellar (H)
✓ Capsular (K)
antigens that are protein in nature
Flagellar (H)
antigens that composed of polysaccharides
Capsular (K)
are present in many strains and act as adhesins facilitating attachment to mucosal surfaces
Proteinaceous fimbrial (F) antigens
Predisposing factors that permit colonization and render animals susceptible to the development of clinical disease include;
age, immune status, nature of diet and heavy exposure to pathogenic strains
Virulence factors of pathogenic strains of E. coli
capsules, endotoxin, enterotoxin, structure responsible for adherence and colonization
interfere with phagocytosis and with the antibacterial effectiveness of the complement system
Capsule
it released upon lysis or death of the bacteria, produce pyrogenic activity, endothelial damage leading to disseminated intravascular coagulation
endotoxin
are significant events in septicaemia
endotoxic shock
allow attachment to mucosal surfaces and facilitates colonization by diminishing the expulsive effects of peristalsis and the flushing effect of urine
Fimbrial adhesins
Fimbrial adhesins have been identified namely;
K88 (F4, K99 (F5), 987 (F6), F18 and F41
the most common adhesin present in strains of E. coli infecting pigs is?
K88
adhesins occurs in calves
F41
adhesins occurs in calves and lambs
K99