AUTHOR=Zhou Haibo , Lu Zhaoxin , Liu Xinmei , Bie Xiaomei , Cui Xinping , Wang Zuwei , Sun Xiaojie , Yang Jun 

TITLE=Characterization and transmission of plasmid-mediated multidrug resistance in foodborne Vibrio parahaemolyticus

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1437660

DOI=10.3389/fmicb.2024.1437660

ISSN=1664-302X

ABSTRACT=<sec><title>Objectives</title><p>The purpose of this study was to determine the structural features and transferability of the multidrug-resistance (MDR) plasmid, and resistance phenotypes for the tested antimicrobials in foodborne <italic>Vibrio parahaemolyticus</italic>.</p></sec><sec><title>Methods</title><p>Plasmids were isolated from a <italic>V. parahaemolyticus</italic> strain of seafood origin, then sequenced using the Illumina NovaSeq 6000 and PacBio Sequel II sequencing platforms to obtain the complete genome data. Characterization of the MDR plasmid pVP52-1, including determination of antimicrobial resistance genes (ARGs), plasmid incompatibility groups, and transferability, was carried out.</p></sec><sec><title>Results</title><p><italic>V. parahaemolyticus</italic> strain NJIFDCVp52 contained two circular chromosomes and two circular plasmids (pVP52-1 and pVP52-2). Plasmid typing indicated that pVP52-1 belonged to the incompatibility group IncA/C<sub>2</sub> and the sequence type pST3. pVP52-1 carried 12 different ARGs, an IS110-composite transposon consisting of <italic>aac(6′)-Ib</italic>-cr, <italic>qnrVC1</italic>, <italic>aac(6′)-Ib</italic>, <italic>dfrA14</italic>, and the IS26-<italic>mphA</italic>-IS6100 unit flanked by inverted sequences of IS5075 and IS4321. pVP52-2 carried no ARGs. A plasmid elimination assay showed that only pVP52-1 and its ARGs were lost, the loss of resistance to several antimicrobials, causing a change from the ampicillin-ampicillin/sulbactam-cefazolin-cefoxitin-ceftazidime-cefotaxime-imipenem-trimethoprim/sulfamethoxazole resistance pattern to the ampicillin resistance pattern. In accordance, a conjugation transfer assay showed that only pVP52-1 and its ARGs were horizontally transferred, leading to increased antimicrobial resistance in <italic>Escherichia coli</italic> strain EC600, causing a change from the ampicillin-nalidixic acid resistance pattern to the ampicillin-ampicillin/sulbactam-cefazolin-cefoxitin-ceftazidime-cefotaxime-imipenem-nalidixic acid-chloramphenicol-tetracycline-trimethoprim/sulfamethoxazole-azithromycin resistance pattern. Further transferability experiments revealed that pVP52-1 could be transferred to other enterobacterial strains of <italic>E. coli</italic> and <italic>Salmonella</italic>.</p></sec><sec><title>Discussion</title><p>This study emphasizes the urgent need for continued surveillance of resistance plasmids and changes in antimicrobial resistance profiles among the <italic>V. parahaemolyticus</italic> population.</p></sec>