Zhang Peng, Wu Xiaofang, Ji Lei, Yan Wei, Chen Liping, Lu Zhonghao, Xu Deshun, Zha Yunfeng, Xu Dafang, Dong Fenfen
Huzhou Center for Disease Control and Prevention, 999 Changxing Road, Huzhou, Zhejiang Province, 313000, People's Republic of China.
The First People's Hospital of Huzhou, No.158, Guangchang Hou Road, Huzhou, Zhejiang Province, 313000, People's Republic of China.
BMC Genomics. 2024 Dec 5;25(1):1187. doi: 10.1186/s12864-024-11106-3.
Vibrio parahaemolyticus has emerged as the leading cause of seafood-associated infections worldwide. Previous studies have shown that V. parahaemolyticus can be detected in both environmental and clinical samples. However, the molecular characteristics of V. parahaemolyticus isolated from these sources remain unknown.
This study examined 128 strains of V. parahaemolyticus isolated from clinical and environmental samples collected between 2020 and 2023 in Huzhou, China. We identified 73 serotypes; O10:K4, O3:K6, and O4:KUT were the dominant serotypes among clinical isolates. We examined the proliferation and motility of major epidemic strains from environmental and clinical samples. Genetic diversity and evolution were assessed by average nucleotide identity (ANI), phylogenetic tree construction, and multilocus sequence typing (MLST). Furthermore, we identified 13 novel sequence types (STs) among the environmental isolates, indicating that V. parahaemolyticus strains are widely distributed and evolve rapidly in the environment in Huzhou, China. We found 206 virulence genes among these isolates, indicating that environmental isolates possess numerous virulence genes. Additionally, we detected 4 strains carrying the tdh or trh gene, which may increase their pathogenicity. The prediction results of antibiotic resistance genes shown that environmental isolates may carry up to 104 resistance genes, compared to 30 in clinical isolates.
We observed that the environmental serotypes of V. parahaemolyticus exhibit greater diversity compared to clinical isolates, which are predominantly concentrated in three major serotypes. Furthermore, a considerable genetic distance was found between most clinical and environmental isolates. Notably, some clinical isolates show a closer genetic proximity to environmental isolates. Additionally, the distribution of virulence genes, specifically T3SS and tdh, significantly differs among isolates from these two distinct sources. The prediction results for antibiotic resistance genes suggest that environmental isolates may harbor a broader spectrum of resistance genes. The findings of this study provide new insights into the phylogenetic relationships between V. parahaemolyticus strains from clinical and environmental sources, and they enhance the MLST database.
副溶血性弧菌已成为全球海鲜相关感染的主要病因。先前的研究表明，副溶血性弧菌可在环境样本和临床样本中检测到。然而，从这些来源分离出的副溶血性弧菌的分子特征仍不清楚。
本研究检测了2020年至2023年期间在中国湖州采集的临床和环境样本中分离出的128株副溶血性弧菌。我们鉴定出73种血清型；O10:K4、O3:K6和O4:KUT是临床分离株中的优势血清型。我们检测了来自环境和临床样本的主要流行菌株的增殖和运动能力。通过平均核苷酸同一性（ANI）、系统发育树构建和多位点序列分型（MLST）评估遗传多样性和进化。此外，我们在环境分离株中鉴定出13种新的序列类型（STs），表明副溶血性弧菌菌株在中国湖州的环境中广泛分布且进化迅速。我们在这些分离株中发现了206个毒力基因，表明环境分离株拥有众多毒力基因。此外，我们检测到4株携带tdh或trh基因的菌株，这可能会增加它们的致病性。抗生素抗性基因的预测结果表明，环境分离株可能携带多达104个抗性基因，而临床分离株中为30个。
我们观察到，与主要集中在三种主要血清型的临床分离株相比，副溶血性弧菌的环境血清型表现出更大的多样性。此外，大多数临床和环境分离株之间存在相当大的遗传距离。值得注意的是，一些临床分离株与环境分离株显示出更近的遗传亲缘关系。此外，毒力基因的分布，特别是III型分泌系统（T3SS）和tdh，在这两种不同来源的分离株中存在显著差异。抗生素抗性基因的预测结果表明，环境分离株可能含有更广泛的抗性基因。本研究结果为临床和环境来源的副溶血性弧菌菌株之间的系统发育关系提供了新的见解，并扩充了MLST数据库。
