Abstract
Bacillus cereus sensu lato is widespread and causes significant food spoilage that alters
the flavour and structure of milk. The present study investigated the prevalence, enterotoxigenic
genes, and resistant profiles of B. cereus strains isolated from raw milk of Bos
taurus in South Africa (the Eastern Cape Province). One thousand four hundred samples
were obtained from commercial dairy farms and were evaluated for the presence of B.
cereus using B. cereus selective agar, and genomic DNA was isolated from B. cereus colonies
with specific characteristics. PCR was used to evaluate the presence of enterotoxigenic
genes, and antibacterial susceptibility was carried out using the Kirby-Bauer Disc diffusion
method. The result revealed that B. cereus was detected in 250 raw milk samples. In addition,
67.2% of the isolates grew when incubated at 4 ◦C. Among the enterotoxigenic genes
studied, ces showed the highest occurrence (88.8%), but hblABC (0%) did not demonstrate
amplification from any isolate. Our analysis found two significant patterns (III and V):
nheABC-entFM (27.2% and 24.4%) and the ces gene. Total (100%) sensitivity was observed
for six of the twelve antibiotics tested, while organisms showed complete resistance to
penicillin and rifampicin. This study marks the initial documentation of B. cereus and
its enterotoxigenic genes in Bos taurus raw milk sourced from the Eastern Cape Province,
South Africa. Enterotoxin FM should be considered the second most crucial enterotoxin,
after non-hemolytic enterotoxin, and should be included in the molecular approach used
to classify pathogenic B. cereus in nutrimental products. These findings underscore the
urgent need for public health awareness, particularly in rural communities where raw
milk consumption is prevalent. The high prevalence of antibiotic resistance and toxigenic
strains of B. cereus calls for improved milk pasteurization practices to mitigate the risk of
foodborne illness.