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ORIGINAL RESEARCH article

Front. Microbiol.
Sec. Antimicrobials, Resistance and Chemotherapy
Volume 15 - 2024 | doi: 10.3389/fmicb.2024.1453801

Identification of novel Tet(X6)-Tet(X2) recombinant variant in Elizabethkingia meningoseptica from a bullfrog farm and downstream river in China

Provisionally accepted
Haobo Jin Haobo Jin 1Qing Jia Qing Jia 1Jin Xi Jin Xi 2Xinglong Zhu Xinglong Zhu 1Min-Ge Wang Min-Ge Wang 3Ruan-yang Sun Ruan-yang Sun 4Chaoyue Cui Chaoyue Cui 1*
  • 1 Wenzhou Medical University, Wenzhou, China
  • 2 Department of Clinical Laboratory, the Second Affiliated Hospital of Wenzhou Medica University, Wenzhou, China
  • 3 Liaocheng University, Liaocheng, Shandong Province, China
  • 4 South China Agricultural University, Guangzhou, Guangdong Province, China

The final, formatted version of the article will be published soon.

    The dissemination of strains producing tetracyclines monooxygenase Tet(X) from breeding farms to the natural environment poses a potential threat to public health. The aim of this study is to investigate the prevalence and distribution characteristics of tigecycline-resistant strains in typical bullfrog farming in China. Three tet(X)-producing Elizabethkingia meningoseptica strains were isolated from bullfrog breeding ponds, the sewage outlet, and downstream river in Zhejiang Province, China. These three strains exhibit a multidrug-resistant phenotype, displaying high level resistance to all 13 tested antibiotics, with sensitivity only to rifampicin. They carry a novel Tet(X) variant, differing from Tet(X6) by seven residues, and possess the ability to degrade tetracyclines.Interestingly, the novel Tet(X) is a recombinant variant formed by homologous recombination of Tet(X6) and the C-terminal of Tet(X2). Further analysis revealed that Tet(X6) formed several Tet(X) variants, including Tet(X5), through homologous recombination. The novel tet(X) gene is located on a circularizable integrative and conjugative element (ICEEmeChn3), with ISwz1 participating in the recombination of its multidrug resistance region, potentially facilitating the mobilization and recombination of tet(X) in early hosts. Moreover, these strains were clonally transmitted and shared a close genetic relationship (SNP< 62) with a clinically-sourced strain isolated from the same province. To our knowledge, this is the first report of homologous recombination between Tet(X) variants with differing activities. These clonal strains provide evidence of the transmission of tet(X)positive strains from aquaculture sewage to the natural environment, highlighting the need to strengthen the monitoring and management of this emerging farming model.

    Keywords: tet(X), Recombinant variant, Elizabethkingia meningoseptica, Ice, tigecycline

    Received: 24 Jun 2024; Accepted: 19 Jul 2024.

    Copyright: © 2024 Jin, Jia, Xi, Zhu, Wang, Sun and Cui. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Chaoyue Cui, Wenzhou Medical University, Wenzhou, China

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