Systematic Veterinary Bacteriology and Mycology

SHIGELLA

• Four species (S. boydii, S. dysenteriae, S. flexneri and S. sonnei) are etiological agents of diarrhoea and dysentery in man and subhuman primates.
• They are Gram –ve, non-motile, rod shaped organisms found in the intestinal flora of animals.
• Shigella are facultatively anaerobic and grows on blood agar and MacConkey agar at 37^oC without haemolysis.
• Shigella produces an enterotoxin which acts on the epithelial lining of the terminal illeum and large intestine, producing bloody mucus stained stool.