The authors describe the ST239 variants detected in this study as follows:

"...The third most common strain was ST239-like MRSA-III (“Vienna/Hungarian/Brazilian Clone”, 22 isolates)....These isolates harboured, beside SCCmec III markers such as ccrA/B3, also ccrC but lacked a mercury resistance element that is common in ST239-like MRSA-III..."

As noted in reference #14 (Chen et al), our study of isolates from the Transylvanian city of Brasov uncovered 2 dominant ST239 variants with several unique features, including the shared presence of a novel transposon (Tn6072) located upstream of the origin of replication. This transposon shared significant homology to the mercury resistance element described by the authors, including the possession of ccrC, but not mer (Moreover, there were 2 distinct ST239 variants, including one with a significant/novel SCCmec deletion which included the ccrA3/B3 genes (see Figure 1, http://aac.asm.org/conten...).

Given the high prevalence of these ST239 variants in Brasov, and the near-absence of classical ST239, it seems likely they are also present among the ST239 isolates from Iasi. Haplotype analysis revealed the presence of Tn6072 in an sublineage of ST239 isolates from Eastern Europe and Turkey (see Figure 3, http://aac.asm.org/conten...). The prototype of this lineage appears to be the "Czech" clone (H2K) described originally by deLencastre and colleagues (http://www.ncbi.nlm.nih.g...).

It would be of interest to the molecular epidemiology of S. aureus in Romania if the authors' microarray data could determine whether the ST239 isolates from Iasi also belong to the aforementioned lineage, and whether their SCCmec elements resemble either of those described in reference #14.