Characterization of NDM-1-Producing Carbapenemase in Proteus mirabilis among Broilers in China.

Xiaolin Zhu,Yaru Zhang,Li Zhao,Lining Xia,Jinquan Wang,Ke Wang,Wenhui Wang,Zhihui Hao,Zhangqi Shen,Zhihai Liu

doi:10.3390/microorganisms9122443

Abstract

Carbapenem-resistant pathogens mediated by metallo-beta-lactamases (MBLs) have spread worldwide, where NDM-1 is a typical and key MBL. Here, we firstly discussed the distribution characterization of NDM-1, which produces multidrug-resistant Proteus mirabilis among broilers in China. From January to April 2019, 40 (18.1%, 40/221) blaNDM-1-carrying P. mirabilis strains were recovered from commercial broilers in slaughterhouse B in China. All the isolates were resistant to imipenem, meropenem and other β-lactams. These isolates belong to five clusters identified via pulsed field gel electrophoresis (PFGE). Further studies on twenty representative strains revealed that seven blaNDM-1 genes were located on plasmids with sizes of 104.5–138.9 kb. Notably, only three strains (PB72, PB96 and PB109) were successfully transferred to Escherichia coli J53, while the other four isolates were located in nontransferable plasmids. The rest were harbored in chromosomes. Ulteriorly, based on whole genome sequencing (WGS), these twenty isolates showed four typical phylogenetic clades according to single nucleotide polymorphisms (SNPs) of a core genome and presented four main genomic backbone profiles, in which type II/III strains shared a similar genetic context. All of the above is evidence of blaNDM-1 transmission and evolution in P. mirabilis, suggesting that the prevalence may be more diverse in broiler farms. Accordingly, as intestinal and environmental symbiotic pathogens, blaNDM-1-positive P. mirabilis will pose greater threats to the environment and public health.

Highlights

Introduction iationsProteus mirabilis is an opportunistic pathogen belonging to the Enterobacteriaceae family, widely distributed in the natural environment and the intestines of humans and animals.Clinically, it can cause diarrhea, sepsis, respiratory issues and urinary tract infections, with a potential risk of zoonosis [1–3]
polymerase chain reaction (PCR) and DNA sequence analysis indicated that all the CRP isolates produced blaNDM-1
The livestock animals used as food sources and their environment have the dominant reservoir of carbapenem-resistant Enterobacteriaceae (CRE)-producing New Delhi metallo-β-lactamase (NDM), an important NDM

Summary

Introduction

Proteus mirabilis is an opportunistic pathogen belonging to the Enterobacteriaceae family, widely distributed in the natural environment and the intestines of humans and animals. It can cause diarrhea, sepsis, respiratory issues and urinary tract infections, with a potential risk of zoonosis [1–3]. Along with Escherichia coli, Salmonella and methicillinresistant Staphylococcus aureus (MRSA), it is considered to be an important cause of infections in humans and animals [4,5]. The reports of carbapenem resistant bacteria in livestock, wild animals, food products and the environment have increased [8–11], which has gradually aroused high levels of attention globally in Licensee MDPI, Basel, Switzerland

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