[Virulence genes and antimicrobial resistance of Bacillus cereus in prepackaged pastries sold in Taizhou from 2020 to 2022].

Objective: To investigate the virulence genes and antimicrobial resistance of Bacillus cereus from the pre-packaged pastries in Taizhou city.

Methods: 500 pre-packaged patries were collected in taizhou city market. 97 Bacillus cereus strains were detected from them by GB 4789.14-2014 method and identified with 4 houseking genes, then 13 virulence genes were detected by polymerase chain reaction(PCR)method and the antimicrobial resistance of Bacillus cereus to 19 antibiotics was detected by paper diffusion method.

Results: The result showed that the contamination rate of Bacillus cereus was 19.4% in 500 pre-packaged pastries. The detection rate of four housekeeping genes groEL, gyr B, rpoB and Vrr were 100%, 94.8%, 97.9% and 96.9%, respectively, and 89.7% at the same time. The virulence gene test result showed that the detection rate of nheABC, entFM, bceT, cytK and hblABCD were 91.8%, 88.7%, 61.9%, 51.6% and 25.8%, emetic virulence genes had the lowest detection rate, ces and EMl were 4.1%, cer was 5.2%. 97 Bacillus cereus strains show different degrees of drug resistance to 14 antimicrobials, the resistance rates to penicillin, ampicillin, cefotaxime and cotrimoxazole were higher than 95%, but they were completely sensitive to streptomycin, vancomycin and chloramphenicol.

Conclusion: There is a risk of contamination by diarrhea-type Bacillus cereus and vomiting-type Bacillus cereus in prepackaged pastries in Taizhou. The isolated and identified Bacillus cereus has multiple-drug resistance.