A Study on Prevalence and Characterization of Bacillus cereus in Ready-to-Eat Foods in China

Abstract

Bacillus cereus is widely distributed in different food products and can cause a variety of symptoms associated with food poisoning. Since ready-to-eat (RTE) foods are not commonly sterilized by heat treatment before consumption, B. cereus contamination may cause severe food safety problems. In this study, we investigated the prevalence of B. cereus in RTE food samples from different regions of China and evaluated the levels of bacterial contamination, antibiotic resistance, virulence gene distribution, and genetic polymorphisms of these isolates. Of the tested retail RTE foods, 35% were positive for B. cereus, with 39 and 83% of the isolated strains harboring the enterotoxin-encoding hblACD and nheABC gene clusters, respectively. The entFM gene was detected in all B. cereus strains. The cytK gene was present in 68% of isolates, but only 7% harbored the emetic toxin-encoding gene cesB. Antimicrobial susceptibility testing revealed that the majority of the isolates were resistant not only to most β-lactam antibiotics, but also to rifamycin. Multilocus sequence typing (MLST) revealed that the 368 isolates belonged to 192 different sequence types (STs) including 93 new STs, the most prevalent of which was ST26. Collectively, our study indicates the prevalence, bacterial contamination levels, and biological characteristics of B. cereus isolated from RTE foods in China and demonstrates the potential hazards of B. cereus in RTE foods.

The Bacillus cereus Food Infection as Multifactorial Process

“…However, it must be pointed out that in several studies the ces gene cluster (encoding cereulide synthetase) is not investigated or not mentioned [119][120][121], and that several studies do not distinguish between emetic and enteropathogenic B. cereus at all [122,123]. If the emetic toxin genes are investigated, their occurrence is rather rare compared to the enterotoxin genes ( Table 2 and [124][125][126][127][128][129]). Other studies challenge the tight association of emetic B. cereus with starchy foodstuffs and suggest a rather heterogeneous distribution.…”

Activities of Macrolides in Combination with Vitamin D against Bacillus cereus Isolated from Soil of a Lanfill Site in Nsukka South East Nigeria

“…However, containment strategies are continually being thought of and evaluated. Beyond food poisoning, B. cereus is also associated with nongastrointestinal infections and antibiotic susceptibility testing can provide a reference for the clinical treatment of food poisoning [20,21]. Supplements like Vitamin D, are now used in combination with some antibiotics as alternative clinical option for treating these diseases [22].…”

Resistance Mechanisms to Antimicrobial Peptides in Gram-Positive Bacteria

“…anthracis is the causative agent of anthrax and can manifest in four ways, namely: cutaneous, inhalation, gastrointestinal or injectable (Hagan et al, 2018;Chen et al, 2020). B. cereus causes foodborne diseases, such as gastrointestinal, diarrhea and emesis (Yu et al, 2019;Huang et al, 2020). In 2016, the European Union (EU) reported about 413 food-borne outbreaks caused by Bacillus toxins that affected 6657 people, ranking it the second most common cause of food-borne outbreaks in that year (Fiedler et al, 2019).…”