Controlling spread of resistance genes from wastewater to aquatic systems requires more knowledge on how resistance genes are acquired and transmitted. Whole genomic sequences from sewageassociated staphylococcus isolates (20 S. aureus, 2 Staphylococcus warneri, and 2 Staphylococcus delphini) were analyzed for the presence of antibiotic resistance genes (ARGs) and metal resistance genes (MRGs). Plasmid sequences were identified in each isolate to investigate co-carriage of ARGs and MRGs within. BLASTN analysis showed that 67% of the isolates carried more than one ARG. The carriage of multiple plasmids was observed more in CC5 than CC8 S. aureus strains. Plasmid exchange was observed in all staphylococcus species except the two S. delphini isolates that carried multiple MRGs, no ARGs, and no plasmids. 85% of S. aureus isolates carried the blaZ gene, 76% co-carried blaZ with cadD and cadX, with 62% of these isolates carrying blaZ, cadD, and cadX on the same plasmid. The co-carriage of ARGs and MRGs in S. warneri isolates, and carriage of MRGs in S. delphini, without plasmids suggests non-conjugative transmission routes for gene acquisition. More studies are required that focus on the transduction and transformation routes of transmission to prevent interspecies exchange of ARGs and MRGs in sewage-associated systems.
|State||Published - Oct 2021|
Bibliographical noteFunding Information:
The work was supported by the Kentucky Water Resource Research Institute for FY2018–2019 via the USGS Student Research Enhancement Grant. Also, the initial part of this study as supported by the National Science Foundation grant #1547080. These sources were supplemented by funds from the University of Kentucky College of Engineering, Civil Engineering Department.
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Antibiotic resistance genes
- Gene content
- Gene transfer
- Metal resistance genes
- Staphylococcus aureus
ASJC Scopus subject areas