Speaker
Description
This study investigated the genetic basis of macrolide resistance and further antimicrobial resistance (AMR) properties in Mannheimia haemolytica and Pasteurella multocida from diseased cattle and pigs. Seventeen macrolide-resistant isolates from respiratory diseases included in GERM-Vet (M. haemolytica, cattle, 2008-2020, n=13/780; P. multocida, pigs, 2008-2021, n=4/1115) and eight bovine P. multocida from sporadic cases of mastitis (2021-2023) were investigated. Antimicrobial susceptibility testing was done according to CLSI recommendations. Closed whole genome sequences were generated via hybrid assembly of Illumina MiSeq and Oxford Nanopore MinION reads. Among the 25 isolates tested, resistance to several of the antimicrobial agents, including aminoglycosides, phenicols, penicillins, tetracyclines, macrolides and sulfonamides, was detected. In 19 isolates (respiratory disease n=12, mastitis n=7), integrative and conjugative elements (ICEs) were identified that conferred multidrug resistance. These ICEs, some of them novel, harbored the AMR genes erm(T), lnu(H), estT, mef(C), mph(G), floR, catA3, aadA31, aad(3")(9), aph(3')-Ia, aac(3)-IIa, strA, strB, tet(H), tet(Y), and sul2 in varying combinations. Four M. haemolytica also carried a 4,613-bp plasmid with the β-lactamase gene blaROB-1. Resistance-mediating ICEs or plasmids, as found here, can promote the rapid spread of AMR via horizontal gene transfer and co-selection events.
Keywords
Pasteurella multocida, Mannheimia haemolytica, cattle, pigs, respiratoy infection, mastitis, resistance monitoring, whole-genome sequencing, mobile genetic elements
| Registration ID | ECVM25-119 |
|---|---|
| Professional Status of the submitter, who is also the speaker | Postdoc |
Authors
Co-authors
External references
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