Song Yan, Wang Fangkun, Liu Yang, Song Yanying, Zhang Lin, Zhang Fuyou, Gu Xiaoxue, Sun Shuhong
Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Taian, China.
Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Taian, China.
Front Vet Sci. 2020 Aug 5;7:479. doi: 10.3389/fvets.2020.00479. eCollection 2020.
We investigated the prevalence of salmonellosis on 17 poultry breeding farms in nine Chinese provinces (Shandong, Jiangsu, Anhui, Zhejiang, Fujian, Guangdong, Yunnan, Sichuan, and Chongqing). Altogether, 3,508 samples from poultry breeding farms were collected in 2019, including 1,400 from cloaca swabs, 210 from feed, 1,688 from chicken embryos, and 210 from water. All the samples were subjected to bacterial isolation and culture, and bacterial species were identified by polymerase chain reaction. Serotyping, multilocus sequence typing (MLST), and drug-resistance phenotyping were performed on the isolates identified as . Altogether, 126 strains were detected in the 3,508 samples and the positivity rate for the samples was 3.59%. Among all the strains, 95 Salmonella isolates were selected for antimicrobial susceptibility test, resistance gene detection, serotyping, and genotyping. (57/95, 60.00%), (22/95, 23.16%), and (16/95, 16.84%) serotypes were identified. The MLST classification showed that the 95 strains fell into the following five sequence types (STs): ST92 (37/95, 38.95%), ST11 (22/95, 23.16%), ST2151 (19/95, 20.00%), ST13 (16/95, 16.84%), and ST470 (1/95, 1.05%). Apart from ST13, the other four STs shared close genetic relationships, and the genetic direction was ST11-ST470-ST92-ST2151. The resistance rates in the 95 isolates were 100% (95/95) for erythromycin, 68.42% (65/95) for tetracycline, and 53.68% (51/95) for streptomycin and ampicillin, respectively. The isolates were sensitive to polymyxin and sulfamethoxazole. Multi-drug resistance was seen in 70.53% (67/95) of the isolates. β-lactam-, aminoglycoside- and sulfonamide-encoding resistance genes were detected by PCR. The detection rate for and was 100% (95/95), whereas and had rates of 52.63 and 23.16%, respectively. These results indicate that some of the salmonellosis seen in Chinese breeding chicken farms may be caused by infection with , and . They also show that some isolates have multi-drug resistance phenotypes and carry multi-drug resistance genes.
我们对中国9个省份（山东、江苏、安徽、浙江、福建、广东、云南、四川和重庆）的17个家禽养殖场的沙门氏菌病流行情况进行了调查。2019年，共从家禽养殖场采集了3508份样本，其中泄殖腔拭子1400份、饲料210份、鸡胚1688份、水210份。所有样本均进行细菌分离培养，并通过聚合酶链反应鉴定细菌种类。对鉴定为[具体菌名未给出]的分离株进行血清型分型、多位点序列分型（MLST）和耐药表型分析。在3508份样本中共检测到126株[具体菌名未给出]，样本阳性率为3.59%。在所有菌株中，选择95株沙门氏菌分离株进行药敏试验、耐药基因检测、血清型分型和基因分型。鉴定出[具体血清型1未给出]（57/95，60.00%）、[具体血清型2未给出]（22/95，23.16%）和[具体血清型3未给出]（16/95，16.84%）血清型。MLST分类显示，95株[具体菌名未给出]菌株分为以下5种序列型（STs）：ST92（37/95，38.95%）、ST11（22/95，23.16%）、ST2151（19/95，20.00%）、ST13（16/95，16.84%）和ST470（1/95，1.05%）。除ST13外，其他4种STs具有密切的遗传关系，遗传方向为ST11-ST47０-ST92-ST2151。95株分离株中，红霉素耐药率为100%（95/95），四环素耐药率为68.42%（65/95），链霉素和氨苄西林耐药率分别为53.68%（5１/95）。分离株对多粘菌素和磺胺甲恶唑敏感。70.53%（67/95）的分离株表现出多重耐药。通过PCR检测β-内酰胺、氨基糖苷和磺胺类耐药基因。[具体耐药基因1未给出]和[具体耐药基因2未给出]的检测率为100%（95/95），而[具体耐药基因3未给出]和[具体耐药基因4未给出]的检测率分别为52.63%和23.16%。这些结果表明，中国种鸡场中出现的部分沙门氏菌病可能是由[具体菌名1未给出]和[具体菌名2未给出]感染引起 的。它们还表明，一些[具体菌名未给出]分离株具有多重耐药表型并携带多重耐药基因。
