Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China; State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbiology Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou 510070, China.
Department of Food Science &Technology, Jinan University, Guangzhou, China.
Int J Food Microbiol. 2020 May 16;321:108549. doi: 10.1016/j.ijfoodmicro.2020.108549. Epub 2020 Feb 4.
Cronobacter spp. are important foodborne pathogens that infections occur in all age groups, especially cause serious life-threatening diseases in infants. This study aimed to acquire data on Cronobacter spp. contamination of meat and meat products (n = 588) in China during 2011 to 2016, and investigated the use of CRISPR typing technology as an approach for characterizing the genetics of Cronobacter spp. The overall contamination rate for Cronobacter spp. was determined to be 9.18% (54/588). Of the positive samples, 90.74% (49/54) had <10 MPN/g, with duck samples had a relatively high contamination rate (15.69%, 8/51) and highest contamination level (28.90 MPN/g). Four species and nine serotypes were identified among 69 isolates, of which C. sakazakii was the major species (n = 50) and C. sakazakii serogroup O1 and O2 (n = 17) were the primary serotypes. The majority of Cronobacter spp. strains were found to be susceptible to most antibiotics except exhibited high resistance to cephalothin (76.81%, 53/69), and total two multi-drug resistant C. sakazakii strains were isolated from duck. The genetic diversity of Cronobacter spp. was remarkably high, as evidenced by the identification of 40 sequence types (STs) and 60 CRISPR types (CTs). C. sakazakii ST64 (n = 7) was the predominant genotype and was further divided into two sub-lineages based on CRISPR diversity, showing different antibiotic resistance profile. These results demonstrate that CRISPR typing results have a good correspondence with bacterial phenotypes, and it will be a tremendously useful approach for elucidating inter-subtyping during molecular epidemiological investigations while interpreting the divergent evolution of Cronobacter. The presence of Cronobacter spp. in meat and meat product is a potential threat to human public health.
克罗诺杆菌属是重要的食源性致病菌，可感染所有年龄段人群，尤其是对婴儿可引起严重的危及生命的疾病。本研究旨在获取 2011 年至 2016 年中国肉及肉制品中克罗诺杆菌属污染的数据，并研究 CRISPR 分型技术作为克罗诺杆菌属基因特征分析的一种方法。结果表明，克罗诺杆菌属污染率总体为 9.18%（54/588）。阳性样品中，<10 MPN/g 的占 90.74%（49/54），其中鸭样品污染率较高（15.69%，8/51），污染水平最高（28.90 MPN/g）。69 株分离株中鉴定出 4 个种和 9 个血清型，其中阪崎克罗诺杆菌为主要种（n=50），O1 和 O2 血清群（n=17）为主要血清型。大多数克罗诺杆菌属菌株对大多数抗生素敏感，除对头孢噻吩表现出高耐药性（76.81%，53/69）外，还从鸭中分离出 2 株多药耐药的阪崎克罗诺杆菌。克罗诺杆菌属的遗传多样性非常高，共鉴定出 40 个序列型（ST）和 60 个 CRISPR 型（CT）。阪崎克罗诺杆菌 ST64（n=7）为主要基因型，根据 CRISPR 多样性进一步分为两个亚系，表现出不同的抗生素耐药谱。这些结果表明，CRISPR 分型结果与细菌表型具有良好的对应关系，这将是一种非常有用的方法，可在分子流行病学研究中阐明种内分型，同时解释克罗诺杆菌属的分化进化。肉及肉制品中存在克罗诺杆菌属对人类公共健康是一个潜在威胁。
