PROTEASE ACTIVITY OF CLOSTRIDIUM PERFRINGENS STRAIS ISOLATED IN SAN LUIS

CORIGLIANO M; STAGNITTA P; GUZMÁN AMS

Potrero de los Funes, San Luis.

Congreso; XXIV Annual Scientific Meeting. Cuyo Biology Society. Potrero de los Funes. San Luis.; 2006

Sociedad de Biología de Cuyo

The enterotoxin produced by Clostridium perfringens is the etiological agent of C. perfringens food poisoning in humans. Protease formation has been correlated with food spoilage and pathogenicity in a number of clostridia. The production of proteolytic enzymes by 10 Clostridium isolated of varying toxigenicity and origin was studied to determine if all isolated secreted proteases. The strains were isolated from meat foods, condiments and spices and dehydrated soups consumed in San Luis. Five of the strains were enterotoxigenic and five no enterotoxigenic. The bacteria were grown in thioglycolated broth at 37ºC for 6 h. Cell-free supernatans were obteined from cultures by centrifugation to 10,000 x g, 10 min and assayed for proteolytic activity by using two methods: Brock method modified using 0,2% azocasein and the absorbance determination at 450 nm; and the Dominguez and Cejudo method modified using 1% azocasein and the absorbance determination at 366 nm. All C. perfringens strains analyzed produced extracellular protease. The enterotoxigenic strains showed bigger activity that the no enterotoxigenic strains. Comparing the two methods, the Dominguez and Cejudo method modified was the method of but easy application and where the biggest activities were shown. The protease activities of the 10 strains examinated indicate a quantitative difference that could be related with the biggest pathogenicity of the enterotoxigenic strains.