Identification of Three Novel PmGRI1 Genomic Resistance Islands and One Multidrug Resistant Hybrid Structure of Tn7-like Transposon and PmGRI1 in Proteus mirabilis.

Boheng Ma,Hongning Wang,Xuechun Wang,Juan He,Yizhi Tang,Yu Zhang,Changwei Lei,Yufeng Gao

doi:10.3390/antibiotics10101268

Boheng Ma, Hongning Wang + Show 6 more

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https://doi.org/10.3390/antibiotics10101268

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Journal: Antibiotics (Basel, Switzerland)	Publication Date: Oct 18, 2021
Citations: 6	License type: CC BY 4.0

Affiliation: Sichuan University

Abstract

The widespread use of antibiotics in large-scale livestock production has led to serious antibiotic resistance. Proteus mirabilis is an important pathogenic bacterium on large-scale farms. Chromosomally localized mobilizable genetic elements (genomic islands) and mobile genetic elements (Tn7-like transposons) play an important role in the acquisition and transmission of resistance genes by P. mirabilis. To study the prevalence and resistance characteristics of antibiotic-resistant genomic islands in P. mirabilis of animal origin in China, we performed whole genome sequencing of P. mirabilis isolated from large-scale pig and chicken farms. Three new variants of PmGRI1 (HN31, YN8, and YN9), and a hybrid structure (HN2p) formed by the multidrug-resistant Tn7-like-HN2p transposon and a genomic island PmGRI1-HN2p, were identified from P. mirabilis. All variants underwent homologous recombination mediated by insertion sequence IS26. A genomic rearrangement in the chromosome between the Tn7-like-HN2p transposon and PmGRI1-HN2p occurred in HN2p. The heterozygous structure contained various antimicrobial resistance genes, including three copies of fluoroquinolone resistance gene qnrA1 and 16S rRNA methylase gene rmtB, which are rarely found in P. mirabilis. Our results highlight the structural genetic diversity of genomic islands by characterizing the novel variants of PmGRI1 and enrich the research base of multidrug resistance genomic islands.

Highlights

Proteus mirabilis belongs to the Enterobacteriaceae family and is widely distributed in the environment and the intestinal tract of living organisms
Our results highlight that PmGRI1 and the hybrid structure of Tn7-like and PmGRI1 can carry numerous antibiotic resistance genes, which may be one of the important reasons for the acquisition and spread of antibiotic resistance genes in P. mirabilis
Our study showed that IS26-mediated homologous recombination of the observed on both ends of the inserted fragment, which may be associated with the inserbackbone region and multidrug resistance region promoted the diversity of PmGRI1-like tion island of a large fragment in this region

Summary

Introduction

Proteus mirabilis belongs to the Enterobacteriaceae family and is widely distributed in the environment and the intestinal tract of living organisms. Mobilizable genetic elements (genomic islands (GIs) and Tn7-like transposons) play important roles in the capture and transmission of multidrug resistance genes in P. mirabilis [7,8,9,10]. GIs, such as integrative and conjugative elements and integrative and mobilizable elements, can integrate gene fragments or single-stranded DNA into bacterial chromosomes via horizontal gene transfer and often contain various genes that confer novel traits to their hosts, such as antibiotic resistance, virulence, and enhanced adaptation of bacteria to their environment [11,12,13]. Multidrug-resistant GIs carrying the macrolide resistance gene erm(B) have been reported in Campylobacter of animal origin, and erm(B) was found to be prevalent and significantly increased in Campylobacter in Guangdong Province, China.

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