College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China.
Food and Pharmaceutical Engineering Institute, Guiyang University, Guiyang 550005, China.
J Dairy Sci. 2020 May;103(5):3994-4001. doi: 10.3168/jds.2019-17541. Epub 2020 Feb 26.
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, trimethoprim-sulfamethoxazole, 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.
本研究旨在揭示从包括婴幼儿配方粉、生牛乳、巴氏奶、超高温奶和奶酪在内的乳制品中分离出的蜡样芽胞杆菌的流行情况、分子特征和抗生素敏感性。在总实验中，分析了从中国 5 个省采集的 500 个样本。分析了分离株的多位点序列分型、毒素基因分布和抗生素敏感性。共检出 54 株蜡样芽胞杆菌，其中生牛乳 13 株（26%）、巴氏奶 12 株（12%）、奶酪 10 株（10%）、超高温奶 12 株（8%）、婴幼儿配方粉 7 株（7%）。这些分离株被分为 24 个序列型（ST）；其中，ST24、ST26、ST82、ST142、ST377、ST857 和 ST1046 是主要的优势 ST。毒素基因（hblA、hblC、hblD、nheA、nheB、nheC、cytK、entFM、bceT、hlyII 和 cesB）检测结果显示，94.4%的分离株携带 nheABC 基因，而仅有 11.1%的分离株含有 hblACD 基因簇。此外，cytK、bceT、entFM、hlyII 和 cesB 基因的检出率分别为 75.9%、77.8%、85.2%、53.7%和 11.1%。抗生素敏感性试验表明，大多数蜡样芽胞杆菌分离株对氨苄西林、青霉素、头孢吡肟、头孢噻吩和头孢唑林耐药，对庆大霉素、氯霉素、亚胺培南、四环素、环丙沙星、复方磺胺甲噁唑、红霉素、卡那霉素和头孢替坦敏感。因此，本研究揭示了中国乳制品中蜡样芽胞杆菌的流行情况和特征，表明了该病原菌的潜在风险，并有助于对该病原体的有效预防和控制。
