The multidrug-resistant Pseudomonas fluorescens strain: a hidden threat in boar semen preservation

Zhixuan Xiong; Ziqiang Hong; Xinxin Li; Dongyang Gao; Linkang Wang; Shudan Liu; Junna Zhao; Xiangmin Li; Ping Qian

doi:10.3389/fmicb.2023.1279630

The multidrug-resistant Pseudomonas fluorescens strain: a hidden threat in boar semen preservation

Front Microbiol. 2023 Oct 6:14:1279630. doi: 10.3389/fmicb.2023.1279630. eCollection 2023.

Authors

Zhixuan Xiong^{1

2

3}, Ziqiang Hong^{1

2

3}, Xinxin Li^{1

2

3}, Dongyang Gao^{1

2

3}, Linkang Wang^{1

2

3}, Shudan Liu^{1

2

3}, Junna Zhao^{1

2

3}, Xiangmin Li^{1

2

3}, Ping Qian^{1

2

3}

Affiliations

¹ National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, Hubei, China.
² College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China.
³ Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China.

Abstract

Although the bacterial composition of boar ejaculate has been extensively studied, the bacterial composition of extended boar semen is often overlooked, despite the potential risks these microorganisms may pose to the long-term preservation of extended boar semen at 15-17°C. In this study, we characterized the bacterial community composition of extended semen and discovered that Pseudomonas spp. was the dominant flora. The dominant strains were further isolated and identified as a potential new species in the Pseudomonas fluorescens group and named GXZC strain, which had adverse effects on sperm quality and was better adapted to growth at 17°C. Antimicrobial susceptibility testing showed that the GXZC strain was resistant to all commonly used veterinary antibiotics. Whole-genome sequencing (WGS) and genome annotation revealed the large genetic structure and function [7,253,751 base pairs and 6,790 coding sequences (CDSs)]. Comparative genomic analysis with the closest type strains showed that the GXZC strain predicted more diversity of intrinsic and acquired resistance genes to multi-antimicrobial agents. Taken together, our study highlights a problem associated with the long-term storage of extended boar semen caused by a P. fluorescens group strain with unique biological characteristics. It is essential to develop a new antibacterial solution for the long-term preservation of boar semen.

Keywords: Pseudomonas fluorescens; antibiotic resistance island; boar semen preservation; microbial resistance; whole-genome sequencing.

Grants and funding

This study was supported by grants from the Yingzi Tech and Huazhong Agricultural University Intelligent Research Institute of Food Health [Nos. IRIFH202302 and IRIFH202209] and the Fundamental Research Funds for the Central Universities [2662016PY004].