First report of two foodborne Salmonella enterica subsp. enterica serovar Bovismorbificans isolates carrying a novel mega-plasmid harboring blaDHA-1 and qnrB4 genes

Lili Li; Rikke Heidemann Olsen; Chong Wang; Anhua Song; Jian Xiao; Hecheng Meng; Troels Ronco; Lei Shi

doi:10.1016/j.ijfoodmicro.2021.109439

First report of two foodborne Salmonella enterica subsp. enterica serovar Bovismorbificans isolates carrying a novel mega-plasmid harboring bla_DHA-1 and qnrB4 genes

Int J Food Microbiol. 2021 Dec 16:360:109439. doi: 10.1016/j.ijfoodmicro.2021.109439. Epub 2021 Oct 16.

Authors

Lili Li¹, Rikke Heidemann Olsen², Chong Wang³, Anhua Song⁴, Jian Xiao⁴, Hecheng Meng⁵, Troels Ronco², Lei Shi⁶

Affiliations

¹ Institute of Food Safety and Nutrition, Jinan University, Guangzhou, Guangdong, China; School of Food Science and Engineering, South China University of Technology, Guangzhou, Guangdong, China.
² Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
³ Shandong New Hope Liuhe Group Ltd., Qingdao, China.
⁴ Guangzhou Food Inspection Institute, Guangdong, China.
⁵ School of Food Science and Engineering, South China University of Technology, Guangzhou, Guangdong, China. Electronic address: femenghc@scut.edu.cn.
⁶ Institute of Food Safety and Nutrition, Jinan University, Guangzhou, Guangdong, China; State Key Laboratory of Food Safety Technology for Meat Products, Xiamen 361100, China.

PMID: 34688125
DOI: 10.1016/j.ijfoodmicro.2021.109439

Abstract

Salmonella enterica displaying resistance to extended-spectrum cephalosporins and fluoroquinolone (FQs) has been deemed a high-priority pathogen by the World Health Organization (WHO). While CTX-M type acquired β-lactamases have been detected in S. enterica serovar Bovismorbificans, DHA enzymes have been rarely reported in S. Bovismorbificans. In this study, we here report for the first time the isolation of two multi-drug resistant (MDR) S. Bovismorbificans strains co-harboring plasmid-encoded AmpC (pAmpC) β-lactamase gene (bla_DHA-1) and qnrB gene, 16Sal017 isolated from a chicken meat sample and 16Sal018 from a grass carp fish sample, collected from retail markets in Guangzhou, China. The bla_DHA-1 and qnrB genes in these two strains were both located on the same novel 217,773 bp IncHI2 plasmid belonged to ST2. The plasmid contained 16 additional acquired antimicrobial resistance genes encoding resistance to eight antibiotic classes and quaternary ammonium compound. Besides, 16Sal017 contained an additional 10,124 bp Col (pHAD28)-like plasmid harboring qnrS1. The bla_DHA-1 and qnrB4 genes were located in an 18,198 bp region, sul1-qacEΔ1-ampR-bla_DHA-1-pspABCDF-qnrB4-sapABC-IS91-sul1-qacEΔ1, which has been identified in various bacteria species, indicating the high transfer ability of bla_DHA-1 and qnrB4 genes within this gene cluster. The IncHI2 plasmid was found to be transferable to Escherichia coli J53 by conjugation and resulted in the acquiring of multiple resistance in the transconjugants. Genome sequence comparisons by cgMLST and MAUVE alignment indicated 16Sal017 and 16Sal018 are highly similar and are not epidemiologically linked with strains from other sources and countries. Our findings suggest S. Bovismorbificans as a new host for conjugative mega-plasmid harboring bla_DHA-1 and qnrB4 genes, and highlight the potential transmission opportunity of these S. Bovismorbificans clones through the food chain, which need continuous investigation.

Keywords: Food products; S. Bovismorbificans; bla(DHA-1); qnrB4.

MeSH terms

Animals
Anti-Bacterial Agents / pharmacology
Drug Resistance, Multiple, Bacterial / genetics
Microbial Sensitivity Tests
Plasmids / genetics
Salmonella enterica* / genetics
Salmonella*
Serogroup
beta-Lactamases / genetics

Substances

Anti-Bacterial Agents
beta-Lactamases

Supplementary concepts

Salmonella enterica subsp. enterica