DETECTION OF BACILLUS-CEREUS DIARRHEAL ENTEROTOXIN IN RAW AND PASTEURIZED MILK

Raw and pasteurized milk samples submitted for routine quality analysi s were screened for the presence of Bacillus cereus diarrheal enteroto xin (BDE) using the TECRA BDE Visual Immunoassay (VIA) kit. BDE was no t detected in 298 raw milk samples tested by the TECRA VIA. B. cereus was isolated from 2 of 298 (0.7%) raw milk samples cultured. Culture s upernatants from these isolates were positive for BDE in the TECRA VIA but negative in the Reverse Passive Latex Agglutination (RPLA) test f or BDE. Forty-three of 112 (38.4%) pasteurized milk samples incubated at 10 degrees C until their expiry dates were positive for BDE by the TECRA VIA. The same number of samples incubated at 4 degrees C had no detectable levels of enterotoxin. B. cereus in the range of 10(3) to 1 0(6) CFU/ml was isolated from all BDE-positive pasteurized milk sample s. BDE was detected in the culture supernatants of all the 43 isolates by TECRA VIA and in 30 of these isolates by RPLA. These results demon strate that moderate temperature abuse of pasteurized milk may allow t he growth of B. cereus and BDE production.