Key Laboratory of Zoonosis of Ministry of Agricultural and Rural Affairs, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, Guangzhou, Guangdong 510642, China.
State Key Laboratory for Animal Disease Control and Prevention, Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Zoonosis of Ministry of Agricultural and Rural Affairs, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, Guangzhou, Guangdong 510642, China.
Food Res Int. 2024 Feb;178:113952. doi: 10.1016/j.foodres.2024.113952. Epub 2024 Jan 12.
The spread of antimicrobial-resistant microbes and genes in various foods poses a significant threat to public health. Of particular global concern is the plasmid-mediated tigecycline resistance gene tet(X4), which, while identified in various sources, has not hitherto been reported in aquatic products. This study aimed to investigate the occurrence and characterization of tigecycline-resistant strains from aquatic products. A total of 73 nonrepetitive seafood samples were purchased from 26 farmers' markets to detect tigecycline-resistant strains. Of these, nine Escherichia coli strains (comprising two ST58, one ST195, ST10, ST48, ST88, ST877, ST1244, ST14462) and one Citrobacter meridianamericanus, recovered from nine (12.33 %, 9/73) seafood samples (fish, n = 7; shrimp, clam and crab, n = 1 respectively), were positive for the tet(X4). Notably, phylogenetic analysis showed that E. coli ST195, a common ST carrying tet(X4), has a close phylogenetic relationship (23∼48 SNPs) with 32 tet(X4)-harboring E. coli ST195 isolates (isolated from pigs, animal foods, vegetable, and humans) deposited in NCBI database. Additionally, E. coli ST58 was closely (2 SNPs) related to one tet(X4)-positive E. coli strain from retail vegetables documented in the NCBI database. Whole genome sequencing and bioinformatic analysis revealed that tet(X4) genes were located on IncX1 (7 E. coli) or hybrid plasmid IncFIA(HI1)/IncHI1B(R27)/IncHI1A (2 E.coli and one C. meridianamericanus). These plasmids displayed high homology with those of plasmids from other sources deposited in GenBank database. These findings underscore the role of epidemic clones and plasmids in driving the dissemination of tet(X4) gene within Enterobacterales of aquatic products origin. To the best of our knowledge, this is the first report of tet(X4)-positive Enterobacterales from aquatic products. The pervasive propagation of tet(X4) gene facilitated by epidemic plasmids and clones across food animals, food products, humans, and the environment presents a serious threat to public health.
各种食品中抗微生物药物耐药微生物和基因的传播对公共健康构成重大威胁。特别引起全球关注的是质粒介导的替加环素耐药基因 tet(X4)，虽然已在各种来源中发现，但尚未在水产品中报道。本研究旨在调查水产品中替加环素耐药菌株的发生和特征。从 26 个农贸市场购买了 73 个非重复海产品样本，以检测替加环素耐药菌株。其中，从 9 个海产品样本（鱼类，n = 7；虾、蛤和蟹，n = 1）中分离出 9 株大肠埃希菌（包括 2 株 ST58、1 株 ST195、ST10、ST48、ST88、ST877、ST1244、ST14462）和 1 株柠檬酸杆菌，这些菌株均携带 tet(X4)。值得注意的是，系统进化分析显示，携带 tet(X4)的常见 ST 型大肠杆菌 ST195 与 32 株携带 tet(X4)的大肠杆菌 ST195 菌株（从猪、动物食品、蔬菜和人类中分离）具有密切的系统进化关系（23∼48 个 SNP）。此外，大肠杆菌 ST58 与 NCBI 数据库中记录的零售蔬菜中一株 tet(X4)阳性大肠杆菌菌株密切相关（2 个 SNP）。全基因组测序和生物信息学分析表明，tet(X4)基因位于 IncX1（7 株大肠杆菌）或杂合质粒 IncFIA(HI1)/IncHI1B(R27)/IncHI1A（2 株大肠杆菌和 1 株柠檬酸杆菌）上。这些质粒与 GenBank 数据库中其他来源的质粒高度同源。这些发现强调了流行克隆和质粒在推动水产来源肠杆菌科中 tet(X4)基因传播中的作用。据我们所知，这是首次从水产品中报告 tet(X4)阳性肠杆菌科。通过流行质粒和克隆在食用动物、食品、人类和环境中传播 tet(X4)基因，对公共健康构成严重威胁。
