Meat and meat products as potential sources of emerging MDR Bacillus cereus: groEL gene sequencing, toxigenic and antimicrobial resistance

Background Bacillus cereus is implicated in severe foodborne infection in humans.

This study intended to assess the occurrence, gro EL gene sequencing, biofilm production, and resistance profiles of emerged multidrug resistant (MDR) B. cereus in meat and meat product samples.

Moreover, this work highlights the virulence and toxigenic genes ( hbl ABCD complex, nhe ABC complex, cyt K, ces , and pc-plc ) and antimicrobial resistance genes ( bla 1, tet A, bla 2, tet B, and erm A).

Methods Consequently, 200 samples (sausage, minced meat, luncheon, beef meat, and liver; n  = 40 for each) were indiscriminately collected from commercial supermarkets in Port Said Province, Egypt, from March to May 2021.

Subsequently, food samples were bacteriologically examined.

The obtained isolates were tested for gro EL gene sequence analysis, antibiotic susceptibility, biofilm production, and PCR screening of toxigenic and resistance genes.

Results The overall prevalence of B. cereus among the inspected food samples was 21%, where the highest predominance was detected in minced meat (42.5%), followed by beef meat (30%).

The phylogenetic analysis of the gro EL gene exposed that the examined B. cereus strain disclosed a notable genetic identity with other strains from the USA and China.

Moreover, the obtained B. cereus strains revealed β-hemolytic activity, and 88.1% of the recovered strains tested positive for biofilm production.

PCR evidenced that the obtained B. cereus strains usually inherited the nhe complex genes ( nhe A and nhe C: 100%, and nhe B: 83.3%), followed by cyt K (76.2%), hbl complex ( hbl C and hbl D: 59.5%, hbl B: 16.6%, and hbl A: 11.9%), ces (54.7%), and pc-plc (30.9%) virulence genes.

Likewise, 42.9% of the examined B. cereus strains were MDR to six antimicrobial classes and encoded bla 1, bla 2, erm A, and tet A genes.

Conclusion In summary, this study highlights the presence of MDR B. cereus in meat and meat products, posing a significant public health risk.

The contamination by B. cereus is common in minced meat and beef meat.

The molecular assay is a reliable fundamental tool for screening emerging MDR B. cereus strains in meat and meat products.