MCCLUNG TOABE AGAR BASE

Clostridium perfringens food poisoning is one of the most common types of human foodborne illness. The foods usually involved are cooked meat or poultry products containing large number of viable cells. A heat-labile enterotoxin produced only by sporulating cells induces the major symptoms of diarrhea in perfringens poisoning. Although the enterotoxin is not performed in the food, the foods in which conditions are favourable for sporulation may contain enterotoxin. Therefore, enumeration of these microorganisms in food plays a significant role in investigation of food borne illness.
McClung and Toabe formulated a medium for isolating and differentiating Clostridium species from foods on the basis of their lecithinase and lipase activity. With the addition of 50% egg yolk emulsion, C. perfringens and a few other Clostridium species show the lecithinase reaction. Lecithinase enzyme lyses egg yolk lecithin, producing an opaque zone of precipitation surrounding the slightly raised colonies.
Add 25 grams of food sample to be tested in two tubes containing 25 ml Fluid Thioglycollate Medium with inverted Durhams tube. Incubation is carried out at 46?C for 4-6 hours. Observe for growth and gas production. Streak the presumptive C. perfringens on McClung Toabe Agar plates and incubate at 35-37?C for 18-24 hours.

for detection and isolation of Clostridium perfringens in foods