Prevalence, molecular characterization, and antibiotic susceptibility of Bacillus cereus isolated from dairy products in China

Abstract

This study was conducted to reveal the prevalence, molecular characterization, and antibiotic susceptibility of Bacillus cereus isolated from dairy products including powdered infant formula, raw milk, pasteurized milk, ultra-high-temperature milk, and cheese. Five hundred samples collected from 5 provinces in China were analyzed in overall experiments. Multilocus sequence typing, distribution of toxin genes, and antibiotic susceptibility of the isolates were analyzed. Fifty-four B. cereus strains were detected; of these, 13 isolates (26%) were from raw milk, 12 isolates (12%) from pasteurized milk, 10 isolates (10%) from cheese, 12 isolates (8%) from ultra-high-temperature milk, and 7 isolates (7%) from powdered infant formula. These isolates were divided into 24 sequence types (ST); among them, ST24, ST26, ST82, ST142, ST377, ST857, and ST1046 were the main dominant ST. The results of detection of toxin genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK, entFM, bceT, hlyII, and cesB) showed that 94.4% isolates carried nheABC genes, whereas only 11.1% of the isolates contained the hblACD gene cluster. In addition, detection rates of cytK, bceT, entFM, hlyII, and cesB genes were 75.9, 77.8, 85.2, 53.7, and 11.1%, respectively. The antibiotic susceptibility test indicated that most of B. cereus isolates were resistant to ampicillin, penicillin, cefepime, cephalothin, and oxacillin, and were susceptible to gentamicin, chloramphenicol, imipenem, tetracycline, ciprofloxacin, trimethoprimsulfamethoxazole, erythromycin, kanamycin, and cefotetan. Therefore, this study revealed the prevalence and characteristics of B. cereus isolated from dairy products in China, indicating the potential risk and contributing to the effective prevention and control of this pathogen.

Structural Modeling of Cell Wall Peptidase CwpFM (EntFM) Reveals Distinct Intrinsically Disordered Extensions Specific to Pathogenic Bacillus cereus Strains

“…Presence of the gene is now routinely assessed in combination with other diarrheal toxins-encoded genes such as ces, nhe and hbl to determine the potential pathogenicity of a strain. Data show that cwpFM is widely distributed (detection rate of 68-98%) in B. cereus isolated from diverse food matrices [53][54][55][56][57]. cwpFM is also detected in strains associated with food-borne illnesses [33,58] and is even present in emetic strains [59].…”

Characterization of Bacillus cereus in Dairy Products in China

“…Consequently, the sale volume of milk in China will gradually augment, and the market prospect is considerable [ 55 , 56 ]. In view of the high demand for dairy products and the outbreaks of bacterial contamination in liquid milk and milk powder in China, it is urgent to carry out effective analytical tests, especially the detection of microbes during manufacturing, selling and importing of milk [ 12 , 57 , 58 , 59 ]. In addition, the uncertain microbial growth rate and toxicity of microbial metabolites all threaten food safety [ 60 , 61 , 62 , 63 ].…”

“…As an opportunistic pathogen, B. cereus has long-term emerged as a health threat to humans and animals, involving both domestic and wild animals [ 8 , 9 , 10 , 11 ]. Foodborne outbreaks involving B. cereus in China usually occurred through dairy products [ 12 , 13 , 14 , 15 ]. Major symptoms of food-poisoning caused by B. cereus are divided into either diarrhea or emesis [ 5 , 16 ].…”

Antibacterial Use of Macroalgae Compounds against Foodborne Pathogens

“…From these habitats, it is easily spread to foods, where it may cause an emetic or a diarrheal type of food-associated illness that is becoming progressively more prevalent in the food industry [ 144 , 145 ]. An extensive study on the prevalence of B. cereus isolated from dairy products in China was performed [ 146 ]. B. cereus strains were isolated from 500 dairy product samples and a contamination rate of 11% was achieved.…”

“…B. cereus strains were isolated from 500 dairy product samples and a contamination rate of 11% was achieved. Raw milk presented the highest B. cereus contamination rate (26%) followed by pasteurized milk samples (12%), cheese samples (10%), ultra-pasteurized milk samples (8%) and powder infant formula samples (7%) [ 146 ]. In another survey, approximately three hundred B. cereus strains were isolated from vegetables in different cities in China and were detected in 50% of the 419 samples [ 147 ].…”