CIRCULATING CLONES OF COMMUNITY-ACQUIRED METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (CA-MRSA) IN WESTERN AUSTRALIA IN THE PAST 11 YEARS (2002-2013)

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most complicated problems in infection control and disease prevention. Imported strains or group of similar strains called clones were introduced from other states within Australia and also from other countries. Western Australia (WA) MRSA clones known to be the most predominant clones circulating in Western Australia (WA). However, MRSA strains originally from other states and countries outside Australia (imported) have increased in number in the last decades. The aim of this study was to examine the epidemiology of CA MRSA clones in Western Australia for the past 11 year’s period (2003-2013). There were 10 predominant clones of CA-MRSA circulating in WA with WA MRSA-1 (32,82%), Queensland (22,67 %) and WA MRSA-2 (22,67 %) clones as the top three predominant clones. The percentage of PVL positive CA-MRSA clones such as Queensland (Qld) clone has been increasing significantly (R²=0,67) from 2,38 % in 2002 to 25,69% in 2013. In contrast, the percentages of two major PVL negative clones, WA MRSA-1 and WA MRSA 2, have been decreasing nearly by half from 52,38 % to 27,71 % and 30,95 % to 16,59 % respectively in the last 11 years. PVL positive clones have been introduced in WA from other states and overseas in the last eleven years. Due to the virulence factor of PVL toxin, the emergence of PVL positive CA-MRSA should be considered as public health concerns.