Abstract
Presence of methicillin-resistant Staphylococcus aureus (MRSA) strains carrying plasmid-borne multidrug efflux pump-encoding gene, qacA/B, is a serious issue for infection control in hospitals, because they can survive hand hygiene. The qacA/B genes are divided into five subtypes: qacA, qacBI, qacBII, qacBIII, and qacBIV. The aim of this study was to investigate the prevalence and risk factors of hospitalized patients infected by respective qacA/B-positive MRSA strains between 2010 and 2016 in Tokyo, Japan. Of the 600 total MRSA strains observed, the qacA/B-positive strains constituted 19.8% (199 isolates), of which 56.8% (113 isolates), 28.6% (57 isolates), and 14.6% (29 isolates) were classified as qacA, qacBIII, and qacBII-positive strains, respectively. The prevalence of qacA-positive MRSA strains significantly decreased from July 2010 to June 2011 (34.0%) to July 2015 to May 2016 (5.3%) (p < 0.05). When staphylococcal cassette chromosome (SCC)mec types of the respective qacA/B-positive strains were determined, 81.4% of the qacA-positive strains were classified into SCCmec type II, which has recently been decreasing in hospital-acquired MRSA in Japan. Risk factor analysis showed that there were no specific clinical departments associated with the presence of qacA-positive strains. Our findings suggest that change in the MRSA clonal lineages impact to decrease the prevalence of qacA-positive strains in Japanese hospitals.
Get full access to this article
View all access options for this article.
References
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
