In developing countries, shigellosis (bacillary dysentery) is caused by S. flexneri and S. dysenteriae. It is found in human intestinal tract as pathogen. Pathogenesis and Clinical features: Route of infection is fecal-oral route Inoculum dose: 103 organisms Pathogenicity determinant: Toxins: Endotoxin: irritate the bowel wall Exotoxin: Enterotoxin and neurotoxin S.dysenritiae type 1(shiga bacillus) produce heat labile exotoxin-
mediated IP: 1-2 days
It causes shigellosis (bacillary dysentery) characterized by sudden onset of bloody mucoid diarrhea, abdominal cramp, tenesmus, fever, generalized muscle ache and weakness. Complication: Dehydration
Electrolyte and acid-base disturbance High prevalence: Poor sanitation
Poor personal hygiene Polluted water supply Young children are frequently affected. Laboratory diagnosis:
Specimen: Stool,serum Gram reaction: Gram-negative non-motile rods.