Zhang Zhenbiao, Zhang Liu, Dai Hegen, Zhang Haixia, Song Yu, An Qi, Wang Jianzhong, Xia Zhaofei
College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, China.
College of Veterinary Medicine, China Agricultural University, Beijing, China.
Front Vet Sci. 2022 Mar 10;9:816415. doi: 10.3389/fvets.2022.816415. eCollection 2022.
complex is an increasingly important bacterial pathogen that is capable of causing severe organs and life-threatening disease. This study aimed to investigate the multidrug resistance, phylogroups, molecular characterization, and hypervirulence-associated determinants of the complex, which were isolated from clinical diseased dogs and cats. A total of 35 complex (2.3%; 95% confidence interval, 1.6-3.2) isolates were identified from 1,500 samples, all of which were collected randomly from veterinary hospitals in the 12 regions across China. Antimicrobial susceptibility testing showed that isolates were extremely resistant to amoxicillin-clavulanate (82.9%) and trimethoprim-sulfamethoxazole (77.1%). The rate of multidrug-resistant reached an astonishing 82.9% and found a carbapenemase-producing strain carrying IncX3- derived a cat from Zhejiang. The prevalence rates of extended-spectrum β-lactamase gene and plasmid-mediated quinolone resistance gene were 51.4% and 45.7%, respectively. The resistance gene of isolates from cats was more significantly ( < 0.05) prevalent than that from dogs. Likewise, complex harbored hypervirulence-associated genes (11.4%), (5.7%), and (2.9%). Three (8.6%) of the 35 isolates were determined as hypermucoviscous by the string test. Lipopolysaccharide serotype O1v2 had the highest percentage of 25.7%, but capsular serotypes presented diversity distribution among the isolates. The core-genome phylogenetic tree demonstrated most of the isolates belonged to the phylogroup (91.4%). Multilocus sequence typing analysis identified 25 different STs; ST15 and ST37 were the most abundant accounting for isolates, followed by ST307, ST656, ST1408, and ST4566. In addition, the prevalence of IncFIB-type plasmid for cat isolates was significantly higher ( < 0.05) than that for dogs. Sequences of IncX3 in -positive strain contained regions showing >99% nucleotide sequence identity to the reference plasmid pNDM-MGR194 from the human.
某复合体是一种日益重要的细菌病原体，能够引发严重器官病变及危及生命的疾病。本研究旨在调查从临床患病犬猫中分离出的该复合体的多重耐药性、系统发育群、分子特征以及与高毒力相关的决定因素。从中国12个地区的兽医医院随机采集的1500份样本中，共鉴定出35株该复合体菌株（2.3%；95%置信区间，1.6 - 3.2）。药敏试验表明，分离株对阿莫西林 - 克拉维酸（82.9%）和甲氧苄啶 - 磺胺甲恶唑（77.1%）具有极高耐药性。多重耐药率达到惊人的82.9%，并发现一株产碳青霉烯酶菌株携带来自浙江的IncX3衍生的a型碳青霉烯酶基因。超广谱β - 内酰胺酶基因和质粒介导的喹诺酮耐药基因的流行率分别为51.4%和45.7%。猫分离株的耐药基因流行率显著高于犬分离株（P < 0.05）。同样，该复合体携带与高毒力相关的基因（11.4%）、（5.7%）和（2.9%）。35株分离株中有3株（8.6%）通过拉丝试验被判定为高黏液性。脂多糖血清型O1v2的比例最高，为25.7%，但荚膜血清型在分离株中呈现出多样化分布。核心基因组系统发育树显示，大多数分离株属于该系统发育群（91.4%）。多位点序列分型分析鉴定出25种不同的序列类型；ST15和ST37最为常见，占分离株的比例最高，其次是ST307、ST656、ST1408和ST4566。此外，猫分离株中IncFIB型质粒的流行率显著高于犬分离株（P < 0.05）。该阳性菌株中IncX3的序列包含与来自人类的参考质粒pNDM - MGR194核苷酸序列同一性>99%的区域。
