Multidrug-resistant Bacillus cereus in retail poultry meat: molecular insights into toxigenicity and antimicrobial...

Bacillus cereus (B. cereus) is a spore-forming foodborne pathogen linked to poultry contamination. This study evaluated its prevalence, groEL phylogeny, toxigenic potential, and antimicrobial resistance in Egyptian retail poultry meat.

A total of 110 retail poultry meat samples were collected from commercial supermarkets in Port Said, Egypt, between April and May 2025. Afterwards, samples underwent bacteriological examination. The isolated samples were subjected to groEL gene sequence analysis, antibiotic sensitivity testing, and PCR detection for toxigenic and resistance genes.

The total prevalence of B. cereus in the food samples examined was 14.5%. The groEL-based phylogeny revealed high genetic similarity between our isolates and human clinical strains, suggesting a potential for zoonotic transmission and highlighting the public health risk. Furthermore, the isolated B. cereus strains exhibited β-hemolytic and lecithinase activities, and PCR analysis demonstrated that the examined B. cereus strains usually harbored hbl complex (hblD: 81.3%, hblA:81.3%, and hblC: 75%), nhe complex genes (nheB: 62.5%, and nheA: 50%), pc-plc (100%), ent-FM (100%), cytK (50%), and ces (31.25%) virulence genes. In addition, all isolates encoded bla1, bla2, and tetA (100% each), and 75% carried ermA. Overall, 62.5% of isolates were multidrug resistant to seven agents from six antimicrobial classes and harbored bla1, bla2, ermA, and tetA.

This study highlights the prevalence of multidrug-resistant B. cereus in poultry meat, underscoring the importance of molecular monitoring of MDR B. cereus strains. These findings indicate that toxigenic B. cereus persists in poultry meat and exhibits evolving resistance profiles, underscoring the need for multiple control strategies to reduce food contamination in poultry production and retail settings and highlighting the significant public health concern posed by this pathogen.