Evolution of a 72-kb cointegrant, conjugative multiresistance plasmid from early community-associated methicillin-resistant Staphylococcus aureus isolates.
|Yui Eto, Karina
|Yui Eto, K. and Firth, N. and Davis, A.M. and Kwong, S.M. and Krysiak, M. and Lee, Y.T. and O'Brien, F.G. et al. 2019. Evolution of a 72-kb cointegrant, conjugative multiresistance plasmid from early community-associated methicillin-resistant Staphylococcus aureus isolates. Antimicrobial Agents and Chemotherapy.
Horizontal transfer of plasmids encoding antimicrobial-resistance and virulence determinants has been instrumental in Staphylococcus aureus evolution, including the emergence of community-associated methicillin-resistant S. aureus (CA-MRSA). In the early 1990s the first CA-MRSA isolated in Western Australia (WA), WA-5, encoded cadmium, tetracycline and penicillin-resistance genes on plasmid pWBG753 (∼30 kb). WA-5 and pWBG753 appeared only briefly in WA, however, fusidic-acid-resistance plasmids related to pWBG753 were also present in the first European CA-MRSA at the time. Here we characterized a 72-kb conjugative plasmid pWBG731 present in multiresistant WA-5-like clones from the same period. pWBG731 was a cointegrant formed from pWBG753 and a pWBG749-family conjugative plasmid. pWBG731 carried mupirocin, trimethoprim, cadmium and penicillin-resistance genes. The stepwise evolution of pWBG731 likely occurred through the combined actions of IS257, IS257-dependent miniature inverted-repeat transposable elements (MITEs) and the BinL resolution system of the β-lactamase transposon Tn552 An evolutionary intermediate ∼42-kb non-conjugative plasmid pWBG715, possessed the same resistance genes as pWBG731 but retained an integrated copy of the small tetracycline-resistance plasmid pT181. IS257 likely facilitated replacement of pT181 with conjugation genes on pWBG731, thus enabling autonomous transfer. Like conjugative plasmid pWBG749, pWBG731 also mobilized non-conjugative plasmids carrying oriT mimics. It seems likely that pWBG731 represents the product of multiple recombination events between the WA-5 pWBG753 plasmid and other mobile genetic elements present in indigenous CA-MSSA. The molecular evolution of pWBG731 saliently illustrates how diverse mobile genetic elements can together facilitate rapid accrual and horizontal dissemination of multiresistance in S. aureus CA-MRSA.
|Evolution of a 72-kb cointegrant, conjugative multiresistance plasmid from early community-associated methicillin-resistant Staphylococcus aureus isolates.
|Antimicrobial Agents and Chemotherapy
|School of Pharmacy and Biomedical Sciences
|Faculty of Health Sciences
|Ramsay, Josh [0000-0002-1301-7077]
|Ramsay, Josh