BACILLUS CEREUS IN SOME INDIAN FOODS, INCIDENCE AND ANTIBIOTIC, HEAT AND RADIATION RESISTANCE

Abstract

Samples of 124 different foods purchased from local markets were examined to determine the incidence of Bacillus cereus. The foods examined were pulses, rice and rice products, oils, fish, meat, spices, milk and milk products and ice creams. Isolations were made on mannitol‐egg yolk‐polymyxin B agar medium and confirmed by morphological and biochemical tests. B. cereus was present in 28.5% of rice and rice products (100% of boiled rice), 40% of fish, 80% of chicken and meat products, 30% of spices and 87% of ice creams. Pasteurized milk and milk products and protein‐rich food powders containing milk or cocoa were also contaminated with B. cereus. The average count of B. cereus varied from 2 × 102 to 5 × 105/g. The response of cells and spores from 6 randomly selected isolates of B. cereus to antibiotics and to heat treatment was identical. However, both vegetative and spore forms of these isolates exhibited subtle differences in radiation resistance. Pathogenicity of all isolates was determined by their ability to lyse human erythrocytes. Five of the six isolates selected produced a strong nonhemolytic toxin which is lethal to mice.

Bacillus cereus food poisoning: international and Indian perspective

“…Raimundo and Robbs (1988) observed that out of 30 samples of milk and milk products, procured from supermarkets in Rio de Janeiro City, Brazil B. cereus was present in 66.6 % of pasteurized milk samples, 80.0 % of full-fat dried milk and 13.3 % of dairy cream samples. Kamat et al (1989) analyzed pasteurized milk and milk products and protein-rich food powders containing milk or cocoa with average B. cereus count from 2×10 2 to 5×10 5 /g. Homleid (1993) examined a number of samples of skim, low-fat and whole milk, whipping cream and 20 % fat cream from Norwegian dairies at the KIM (Milk Products Control Institute) immediately after production and after 10 days storage and reported that B. cereus was present in about 8-10 % of samples of each product type, except 20 %-fat cream.…”

“…Contamination of B. cereus is also reported Yadava 2004, from variety of foods from India viz. fish (40 %), chicken and meat products (80 %) (Kamat et al 1989) fried rice (24 %) and chow Mein (23 %). Anamika and Kalimuddin (2004) found that a total of 81 samples out of 120 samples of khoa, paneer and mushroom obtained from local and standard shops in Ranchi, Jharkhand, India, were contaminated with B. cereus.…”

Biofilm Formation and Cell Surface Properties among Pathogenic and Nonpathogenic Strains of the Bacillus cereus Group

“…This persistence is due to spores, which may survive pasteurization, heating, and gamma-ray irradiation (9,13), and to biofilms, which have been shown to be highly resistant to cleaning procedures (18). Biofilms are also suspected to be involved in bacterial pathogenicity, as they may form on host epithelia (15).…”

Inactivation of Bacillus cereus Spores during Rice Cooking

“…Noamal B. ce/1eus spore loads in raw rice has been reported to be in the range of < 10 to a maximum of 105 CFUlg (Lee & Chang, 1980;Chung & Sun, 1986;Kamat et a!., 1989;Lee et a/., 1995). Even with a maximum spore load of 105 CFU/g, cooking times of ~25 min would be adequate to attain a spore level of I Oo CFUlg using D The theamal resistance l oo'*c ' data of B. cereus spores in rice broth generated in this phase of the study were used in the proceeding mathematical calculation of the cooking schedule for ordinary rice cooked by boiling.…”