Multiple introductions of methicillin-resistant Staphylococcus aureus ST612 into Western Australia associated both with human and equine reservoirs

Riley J T Murphy; Joshua P Ramsay; Yung T Lee; Stanley Pang; Mark A O'Dea; Julie C Pearson; Jane E Axon; Edward Raby; Shima M Abdulgader; Andrew Whitelaw; Geoffrey W Coombs

doi:10.1016/j.ijantimicag.2019.08.022

Multiple introductions of methicillin-resistant Staphylococcus aureus ST612 into Western Australia associated both with human and equine reservoirs

Int J Antimicrob Agents. 2019 Dec;54(6):681-685. doi: 10.1016/j.ijantimicag.2019.08.022. Epub 2019 Aug 31.

Authors

Affiliations

¹ Curtin Health Innovation Research Institute (CHIRI) and School of Pharmacy and Biomedical Sciences, Curtin University, Perth, Western Australia, Australia.
² Antimicrobial Resistance and Infectious Disease (AMRID) Research Laboratory, Murdoch University, Murdoch, Western Australia, Australia.
³ Antimicrobial Resistance and Infectious Disease (AMRID) Research Laboratory, Murdoch University, Murdoch, Western Australia, Australia; Department of Microbiology, Fiona Stanley Hospital, PathWest Laboratory Medicine-WA, Murdoch, Western Australia, Australia.
⁴ Department of Microbiology, Fiona Stanley Hospital, PathWest Laboratory Medicine-WA, Murdoch, Western Australia, Australia.
⁵ Clovelly Intensive Care Unit, Scone Equine Hospital, 106 Liverpool Street, Scone, New South Wales, Australia.
⁶ Division of Medical Microbiology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, Western Cape, South Africa.
⁷ Division of Medical Microbiology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, Western Cape, South Africa; Division of Medical Microbiology, Department of Pathology, Stellenbosch University, Stellenbosch, Western Cape, South Africa; National Health Laboratory Service, Tygerberg Hospital, Cape Town, South Africa.
⁸ Antimicrobial Resistance and Infectious Disease (AMRID) Research Laboratory, Murdoch University, Murdoch, Western Australia, Australia; Department of Microbiology, Fiona Stanley Hospital, PathWest Laboratory Medicine-WA, Murdoch, Western Australia, Australia. Electronic address: geoffrey.coombs@health.wa.gov.au.

PMID: 31479739
DOI: 10.1016/j.ijantimicag.2019.08.022

Abstract

Staphylococcus aureus is a serious human and animal pathogen. Multilocus sequence type 612 (ST612) is the dominant methicillin-resistant S. aureus (MRSA) clone in certain South African hospitals and is sporadically isolated from horses and horse-associated veterinarians in Australia. Colonisation and infection by ST612-MRSA is increasing in Western Australia. Whole-genome sequencing was performed for 51 isolates of ST612-MRSA from Western Australian patients and healthcare workers, South African hospital patients, Australian veterinarians and New South Wales horses. Core genome phylogenies suggested that Australian equine and veterinarian-associated ST612-MRSA were monophyletic. Individual Western Australian isolates grouped either with this equine-associated lineage or more diverse lineages related to those in South African hospitals. Bioinformatic analyses of the complete ST612-MRSA reference genome SVH7513 confirmed that ST612-MRSA was closely related to ST8 USA500 MRSA. Common use of rifampicin in South Africa and equine veterinarian practice may favour ST612-MRSA in these settings. Humans and horses colonised with ST612-MRSA are potential reservoirs for MRSA in Australia.

Keywords: Bacteraemia; Equine; MRSA; Methicillin-resistant Staphylococcus aureus; Molecular epidemiology; Zoonosis.

MeSH terms

Animals
Disease Reservoirs / microbiology*
Genome, Bacterial
Horses / microbiology*
Humans
Methicillin-Resistant Staphylococcus aureus / genetics*
Phylogeny
Western Australia