Characterization of a Novel Conjugative Plasmid in Edwardsiella piscicida Strain MS-18-199

Frontiers in Cellular and Infection Microbiology

Mark L. Lawrence¹  Hossam Abdelhamed¹  Reshma Ramachandran¹  Ozan Ozdemir¹  Geoffrey Waldbieser² 

[1] College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States;Warmwater Aquaculture Research Unit, Thad Cochran National Warmwater Aquaculture Center (USDA-ARS), Stoneville, MS, United States;

关键词: antimicrobial resistance;    mobile genetic element;    Edwardsiella;    aquaculture;    genome sequence;   

DOI  :  10.3389/fcimb.2019.00404

来源: DOAJ

【 摘 要 】

Edwardsiella piscicida is a pathogenic bacterium responsible for significant losses in important wild and cultured fish species. E. piscicida strain MS-18-199 recovered from a diseased hybrid catfish from East Mississippi and showed resistance to florfenicol, chloramphenicol, oxytetracycline, doxycycline, erythromycin, tetracycline, azitromycin, spectinomycin, sulfonamide, and bacitracin. To explore the mechanisms of resistance in E. piscicida strain MS-18-199, genomic DNA was extracted and subjected to whole genome sequencing (WGS) using a combination of long (Oxford Nanopore) and short (Illumina) reads. The genome of strain MS-18-199 revealed a novel plasmid named pEPMS-18199. The 117,448 bp plasmid contains several antimicrobial resistance (AMR) elements/genes, including florfenicol efflux pump (floR), tetracycline efflux pump (tetA), tetracycline repressor protein (tetR), sulfonamide resistance (sul2), aminoglycoside O-phosphotransferase aph(6)-Id (strB), and aminoglycoside O-phosphotransferase aph(3)-Ib (strA). Two genes, arsA and arsD, that encode protein components related to transport/resistance to arsenic were also found in pEPMS-18199. In addition, pEPMS-18199 carried twelve conjugative transfer genes (tra), eight transposases and insertion elements, two plasmid stability proteins, two replication proteins, and three partitioning proteins (par system). Results from mobilization and stability experiments revealed that pEPMS-18199 is highly stable in the host cell and could be transferred to Escherichia coli and Edwardsiella ictaluri by conjugation. To our knowledge, this is the first detection of a multidrug resistance (MDR) conjugative plasmid in E. piscicida in the United States. Careful tracking of this plasmid in the aquaculture system is warranted. Knowledge regarding the molecular mechanisms of AMR in aquaculture is important for antimicrobial stewardship.

【 授权许可】

Unknown