Detection, spread and phylogeny of meticillin-resistant Staphylococcus aureus sequence type 45 in Taiwan

Abstract

Meticillin-resistant Staphylococcus aureus (MRSA) sequence type (ST) 45 was reported in the literature to have been first identified in 2006 in Taiwan. The present study was carried out to explore and trace the emergence, transmission and evolutional dynamics of MRSA ST45 in Taiwan. We identified MRSA ST45 isolates retrospectively from two collections of MRSA isolates, namely TSAR (Taiwan Surveillance of Antimicrobial Resistance) surveys and the CGMH (Chang Gung Memorial Hospital)-based laboratory collection. Representative ST45 isolates were selected for whole-genome sequencing (WGS) analysis. A total of 9554 MRSA isolates was included in this study. Among the 3766 MRSA isolates biennially collected from TSAR surveys between 1998 and 2014, ST45 accounted for 133 (3.53 %) MRSA isolates, was first identified in 2004, and the prevalence rate peaked in 2010 (up to 10.77 %). Among the 5788 MRSA isolates collected between 1995 and 2017 by the CGMH-based laboratory, 257 isolates (4.44 %) were characterized as ST45, with most identified from nursing homes since 2012. Of the 75 isolates randomly selected for WGS, two clades were identified. The major clade, clade II, comprised 63 isolates and was phylogenetically relatively close to those isolates identified from Singapore. All but one of the isolates in clade I, the minor clade, were identified from non-Taiwanese people, mostly from newly recruited foreign workers in 2017, and were phylogenetically relatively close to one isolate from the USA (CA-347). Conclusively, the emergence of MRSA ST45 strain in Taiwan can be traced back to 2004 and the strain is connected to South-East Asian countries. Since its emergence, transmission and spread of MRSA ST45 has occurred in Taiwan.

Nasal Methicillin-Resistant Staphylococcus aureus Colonization in Patients with Type 1 Diabetes in Taiwan

“…ST508, which is a single-locus variation of ST45 and was classified as CC45, was previously reported more commonly in methicillin-susceptible S. aureus [54]. Nevertheless, the emergence of ST508 in MRSA has been noted in Taiwan in recent years [34], and ST45 was also increasingly reported in MRSA isolates [55]. In the present study, one novel strain was discovered (pulsotype AK/ST 6587/SCCmec IV/Spa type 19766/PVL negative).…”

Phylogenetic Analysis and Virulence Characteristics of Methicillin-Resistant Staphylococcus aureus ST45 in China: a Hyper-Virulent Clone Associated with Bloodstream Infections

“…This clone exhibited high survival rates in blood and was thereby closely associated with bacteremia and increased patient mortality ( 18 – 20 ). ST45-MRSA-IV (well-known as Berlin-IV clone), initially observed in Berlin in 1993 ( 21 ) and then predominant in Europe ( 22 ), was clonally related to USA600 ( 19 ). ST45-SCC mec IV was able to cause high mortality in bloodstream infections and had a large global spread capacity ( 23 ).…”

“…In order to predict whether the ST45-MRSA clone will spread across the country, we analyzed past reports and conducted a new epidemiological investigation throughout China. In retrospect, MRSA ST45 has successfully established itself in the general population in Hong Kong ( 9 , 12 , 25 , 26 ) and Taiwan ( 21 , 27 ) and even accounted for an important proportion of clinical MRSA isolates. Recently, the detection of an MRSA ST45 strain has occurred in southern provinces of China ( 10 , 11 , 13 – 15 , 28 ).…”

Staphylococcus aureus Keratitis in Taiwan: Genotyping, Antibiotic Susceptibility, and Clinical Features

“…In Taiwan, most CA-MRSA isolates share common molecular characteristics and belong to one of two major clones characterized by ST59/PFGE type C/SCC mec IV/PVL (−) (designated as Asian-Pacific clone) and ST59/PFGE type D/SCC mec V T /PVL (+) (designated as Taiwan clone) [ 26 , 27 ]. Recently, the ST45 strain has been identified in increasing frequency both in community and health-care settings in Taiwan [ 28 ]. which was also indicated in the current study.…”