Prevalence and Distribution of Enterotoxin Genes among Bacillus Cereus Isolated from Meat and Meat Products in Egypt

Abstract

This study determined the incidence and distribution of two enterotoxin genes in Bacillus cereus isolates originating from meat and meat products. A total of 100 samples of meat, including minced meat, luncheon, sausage and pastrami (25 each), were randomly collected from different supermarkets at Gharbia Governorate, Egypt. The samples were cultured individually on mannitol-egg yolk-polymyxin (MYP) agar plates and sheep blood agar plates. Biochemical identification of presumptive colonies was performed. The cytotoxin K (cytK) and hemolysin BL (hblC) genes were detected in B. cereus strains (n=12) from minced meat and meat products by multiplex PCR. B. cereus was identified in 45% of the collected samples. A higher prevalence of B. cereus was detected in minced meat samples (76%) followed by luncheon (44%) and sausage (32%), while the lowest prevalence was observed in pastrami samples (28%). Pairwise comparisons showed significant differences in the distribution of B. cereus isolates between minced meat and pastrami samples (P=0.004), and minced meat and sausages(P=0.01). The co-occurrence of both cytK and hblC (66.7%) was dominant among enterotoxin genes, followed by cytK (25%) and hblC (8.3%). A higher incidence rate of B. cereus in minced meat indicates cross-contamination during processing and transportation, and therefore, represents a significant public health hazard for consumers.