ENTEROTOXIN PRODUCTION AND PLASMID PROFILES IN SALMONELLA-TYPHIMURIUMISOLATED FROM MAN

One hundred twenty-six isolates of Salmonella typhimurium from various clinical sources were tested for enterotoxin production and character ization of plasmid profile. Cell-free culture supernates and polymyxin B extracts of all the strains were assayed by rabbit heal loop and sk in permeability tests. Enterotoxic activity was detected in culture su pernates of 32 strains. Twenty-one strains by both rabbit ileal loop a nd skin permeability tests, nine strains by skin permeability test, an d two strains by rabbit ileal loop test were positive. Live culture of three enterotoxic strains, positive in culture supernates produced il eal secretion. Polymyxin B extracts from 6 hours and 18 hours broth cu ltures of all the strains were devoid of enterotoxicity, Ileal mucosa exposed to culture supernate of enterotoxigenic strains showed swollen and blunted villi with submucosal oedema while those exposed to polym yxin B extracts showed shortening of villi and sloughing of epithelial lining, Plasmid profiles of enterotoxigenic strains were heterogenous and grouped into 20 different profiles. No correlation could be estab lished between plasmid profile, R-pattern, and enterotoxin production.