Investigating a rare methicillin-resistant <em>Staphylococcus aureus</em> strain: first description of genome sequencing and molecular characterization of CC15-MRSA

Abstract

PurposeMethicillin resistant Staphylococcus aureus CC15 strains (CC15-MRSA) have only been sporadically described in literature. This study was carried out to describe the genetic make-up for this rare MRSA strain.MethodsFour CC15-MRSA isolates collected in Riyadh, Saudi Arabia, between 2013 and 2014 were studied. Two isolates were from clinical infection and 2 from retail meat products. Whole genome sequencing was carried out using Illumina HiSeq2500 genome analyzer.ResultsAll the CC15-MRSA isolates had the multilocus sequence typing profile ST1535, 13–13-1–1-81-11-13, which is a single locus variant of ST15. Of the 6 contigs related to the SCC element, one comprised a recombinase gene ccrAA, ccrC-PM1, fusC and a helicase, another one included mvaS, dru, mecA and 1 had yobV and Q4LAG7. The SCC element had 5 transposase genes, namely 3 identical paralogs of tnpIS431 and 2 identical paralogs of tnpIS256. Two identical copies of a tnpIS256-based insertion element flank the aacA-aphD gene. Two copies of this insertion element were present with 1 located in the SCC element and another inserted into the sasC gene. A short 3 kb region, which lacks any bacteriophage structural genes and site-specific DNA integrase, was inserted into the hlb gene. The hsdM and the 5’-part of the hsdS gene are replaced by a copy of the hsdM/hsdS paralogs from νSaβ giving rise to a new chimeric paralog of hsdS in νSaα.ConclusionCC15-MRSA shows a novel SCCmecV/SCCfus composite element. Its variant of hsdM/hsdS probably facilitated uptake of foreign mobile genetic elements that promoted emergence of CC15-MRSA. Close surveillance is needed to monitor spread and emergence of further CC15 MRSA strains.

Livestock-Associated Methicillin-Resistant Staphylococcus aureus (MRSA) in Purulent Subcutaneous Lesions of Farm Rabbits

“…One isolate belonged to CC15 and spa-type t084. CC15 has been widely described in the literature, but this clone is typically linked with MSSA [52]. As for spa t084, it has been described as being associated with this clonal complex [53].…”

Genotyping of Staphylococcus aureus associated with nasal colonization among healthcare workers using DNA microarray

“…Indeed this might explain why CC15-MRSA which has hitherto only been sporadically identified in the literature has been shown with higher occurrence in Saudi Arabia [5,12,13]. It is probable that genetic changes which facilitate the acquisition of mobile genetic elements by CC15-MSSA colonizers is driving the emergence of this rare CC15-MRSA in our setting [14].…”

<p>Emergence of Methicillin-Resistant <em>Staphylococcus aureus</em> Belonging to Clonal Complex 15 (CC15-MRSA) in Kuwait Hospitals</p>

“…Prior to this report, CC15-MRSA-V+SCCfus isolates were isolated sporadically from retail camel meat 12 and human patients in Saudi Arabia. 13,20 The report of 42 CC15-MRSA-V+SCCfus isolates in this study represents the largest collection of CC15-MRSA-V+SCCfus isolates reported in the literature among human patients and represents a significant change in the epidemiology of this clone and its expansion into the human patient population.…”

“…These isolates carried pta 81 instead of pta12 in traditional ST15 isolates. 20 PFGE of the 42 isolates yielded four closely related patterns designated types A-D with the majority of the isolates belonging to PFGE type A and its subtypes ( Figure 1). The t084 isolates were clustered among PFGE type A (N=28) and its subtypes A1 (N=9), type A2 (N=1) and type D (N=1).…”

“…19 Whole genome sequencing of four CC15-MRSA isolates cultured from human patients (N=2), and retail meat (N=2) in Saudi Arabia revealed that all four isolates belonged to the same sequence type, ST1535 (13-13-1-1-81-11-13), which is a single locus variant of ST15 and harbored a novel SCCmec V/SCCfus composite genetic element. 20 Significant changes in the distribution of MRSA clones have been reported in Kuwait public hospitals in recent years. The number of MRSA clones in Kuwait hospitals increased from one dominant clone in 1992 to 30 diverse clones in 2010.…”