The characteristics of population structure and antimicrobial resistance of Streptococcus suis serotype 8, a non‐negligible pathotype
The characteristics of population structure and antimicrobial resistance of Streptococcus suis serotype 8, a non‐negligible pathotype
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不可忽视的致病型猪链球菌血清型8的种群结构和耐药性特征
DOI：
10.1111/tbed.14592
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发表时间：
2022
影响因子：
4.3
通讯作者：
Zongfu Wu
中科院分区：
文献类型：
--
作者：
Zhaoying Liu;Qiuhua Xu;Pujun Liang;Zeren Peng;Huochun Yao;Han Zheng;Zongfu Wu
猪链球菌是猪链球菌病的主要病原体，被认为是人类严重的人畜共患和食源性病原体。猪链球菌的种群结构和致病性特征因血清型而异。作为引起猪临床疾病的主要致病血清型之一，关于猪链球菌血清型8（SS8）的致病性、种群结构和耐药性知之甚少。在这项研究中，对从健康猪和患病猪中分离出的 26 个 SS8 菌株的基因组进行了测序。结合 NCBI 的 38 个序列，我们发现 SS8 群体被聚类为 12 个序列类型 (ST) 和 4 个最小核心基因组 (MCG) 组，这与地理分布相关。值得注意的是，有 10 种菌株属于 MCG 第 1 组，在我们之前的研究中，该组被定义为具有引起全球爆发的能力。我们发现 75% (9/12) 的代表性 SS8 菌株对小鼠和斑马鱼具有毒性，包括所有 ST1241 菌株。主要在致病血清型 2 菌株中鉴定出的 67 个假定毒力相关基因未鉴定出毒力指标。相反，我们发现其中一些基因的基因型与其进化相关。通过药敏试验，所有 26 株分离株均被归类为多重耐药菌株。 tetO和ermB的高携带率主要通过整合可动员元件传播，导致对大环内酯类、林可酰胺类和四环素类药物的普遍耐药表型。这些发现表明SS8的致病潜力不容忽视，为SS8监测提供了有价值的信息。
Streptococcus suis, the leading causative agent of swine streptococcosis, is considered as a severe zoonotic and foodborne pathogen for humans. Characteristics of population structure and pathogenicity of S. suis vary significantly by serotypes. As one of the main pathogenic serotypes causing clinical disease in pigs, very little is known about the pathogenicity, population structure, and antimicrobial resistance of S. suis serotype 8 (SS8). In this study, the genome of 26 SS8 strains isolated from healthy and diseased pigs was sequenced. Together with 38 sequences from NCBI, we found that SS8 population was clustered into 12 sequence types (ST) and 4 minimum core genome (MCG) groups, linked to the geographical distribution. Noteworthily, 10 strains belonged to MCG group 1 which was defined to possess the capacity to cause global outbreaks in our previous study. We found that 75% (9/12) of representative SS8 strains were virulent in mice and zebrafish, including all ST1241 strains. No virulence indicators were identified from 67 putative virulence-associated genes mainly identified among pathogenic serotype 2 strains. Instead, we found that the genotype of some of these genes was correlated to their evolution. All 26 isolates were classified as multidrug-resistant strains by antimicrobial susceptibility testing. The high carrying rate of tetO and ermB, mainly disseminated by integrative mobilizable elements, contributed to the prevalent resistance phenotypes to macrolides, lincosamides and tetracyclines. These findings indicated that the pathogenic potential of SS8 cannot be ignored and provided valuable information for SS8 surveillance.