The occurrence of enterotoxigenic isolates of B. cereus in foodstuffs

Abstract

Enterotoxigenic Bacillus cereus was detected in a variety of meat stuffs (36), ready-to-cook products (5), and swabs (7). The bacterial colonies isolated from PEMBA agar were identified as B. cereus. The 85 isolates were examined for the enterotoxin production using both TECRA-VIA and BCET-RPLA kits (ELISA - 47, RPLA - 38). Thirty two isolates (66%) were positive for enterotoxin using the ELISA test while only 15 isolates (39%) gave positive results in the RPLA test system. In total, 178 (91.8%) and 164 (84%) of the strains isolated in our laboratory (from various foods) were enterotoxigenic as determined using TECRA-VIA and BCET-RPLA, respectively. Parallel enterotoxin positive results obtained using both tests were demonstrated in only 9 isolates from 19 assessed (47.4%). Coincidental negative results from both kits were established for 3 isolates (15.8%) only. The isolates of B.cereus from meat were resistant to cephalothin (57%), clindamycin (14%), oxytetracycline (14%), and erythromycin (7%). The isolates from swabs were resistant to cephalothin (83%), erythromycin (16%), clindamycin (16%) and enrofloxacin (16%).

Keywords

• bacillus cereus
• enterotoxin
• bacterial resistance
• foodstuffs
• elisa
• rpla