Li Jiyun, Zhou Yuqing, Yang Dawei, Zhang Shan, Sun Zhiliang, Wang Yang, Wang Shaolin, Wu Congming
Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, College of Veterinary Medicine, China Agricultural University, Beijing, China; College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan, China.
Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, College of Veterinary Medicine, China Agricultural University, Beijing, China; Department of Medical Microbiology and Infectious Disease, Division of Infection and Immunity, Cardiff University, Cardiff, UK.
Vet Microbiol. 2020 Nov 24;252:108932. doi: 10.1016/j.vetmic.2020.108932.
The prevalence and antimicrobial susceptibility of Clostridium perfringens (C. perfringens) in chickens and pigs were investigated in Beijing and Shanxi, China. In total, 322 C. perfringens (chicken n = 60 and pig n = 262) were obtained from 620 feces of chickens (n = 256) and pigs (n = 364). Multiplex PCR for toxin typing of C. perfringens revealed that all the isolates belong to type A, with 45.7 % (147/322) isolates carrying beta-2 toxin-encoding gene cpb2. Minimum inhibitory concentrations of 27 antimicrobial agents showed that 91.0 % of the tested C. perfringens isolates were resistant to gentamicin and sulfonamides (sulfisoxazole and trimethoprim-sulfamethoxazole), and little resistance was showed to amoxicillin-clavulanate, ceftiofur, doxycycline, vancomycin and linezolid. Additionally, nosiheptide, avilamycin, virginiamycin and bacitracin exhibited good activity against the tested C. perfringens with low MIC (0.06 to ≤4 μg/mL) and MIC values (0.25-8 μg/mL). Whole genome sequencing (WGS) of 48 representative isolates from each farm indicated that the C. perfringens contained diverse antimicrobial resistance genes [tetA(P), ant(6)-Ib, erm(Q), etc.] and toxin genes (cpb2, colA, cloSI, pfoA, etc.). By comparative analysis, four C. perfringens isolates from three different pig farms harboured cpb2-carrying plasmid p1 with 100 % nucleotide sequence identity, suggesting horizontal gene transfer among these microorganisms. The further phylogenomic reconstruction, based on the core-genome single nucleotide polymorphisms (SNPs) of the representatives, demonstrating that C. perfringens from the same farms and regions were closely related. These findings expanded our knowledge of C. perfringens isolated from animals in China, which provided scientific basis for efficient intervention or prevention measures of antimicrobial resistance in animal husbandry in China.
在中国北京和山西，对鸡和猪中产气荚膜梭菌的流行情况及药敏性进行了调查。共从620份鸡（n = 256）和猪（n = 364）的粪便中分离出322株产气荚膜梭菌（鸡60株，猪262株）。对产气荚膜梭菌进行毒素分型的多重PCR结果显示，所有分离株均属于A型，其中45.7%（147/322）的分离株携带编码β-2毒素的基因cpb2。27种抗菌药物的最低抑菌浓度结果显示，91.0%的受试产气荚膜梭菌分离株对庆大霉素和磺胺类药物（磺胺异恶唑和甲氧苄啶-磺胺甲恶唑）耐药，而对阿莫西林-克拉维酸、头孢噻呋、多西环素、万古霉素和利奈唑胺耐药性较低。此外，诺西肽、阿维拉霉素、维吉尼亚霉素和杆菌肽对受试产气荚膜梭菌表现出良好活性，最低抑菌浓度较低（0.06至≤4 μg/mL），最小抑菌浓度值为（0.25 - 8 μg/mL）。对每个养殖场48株代表性分离株进行全基因组测序（WGS）表明，产气荚膜梭菌含有多种耐药基因[tetA(P)、ant(6)-Ib、erm(Q)等]和毒素基因（cpb2、colA、cloSI、pfoA等）。通过比较分析，来自三个不同猪场的4株产气荚膜梭菌分离株携带cpb2的质粒p1，核苷酸序列同一性为100%，表明这些微生物之间存在水平基因转移。基于代表性菌株核心基因组单核苷酸多态性（SNP）的进一步系统发育重建表明，来自同一养殖场和地区的产气荚膜梭菌密切相关。这些发现扩展了我们对中国动物源产气荚膜梭菌的认识，为中国畜牧业抗菌药物耐药性的有效干预或预防措施提供了科学依据。
