Abstract
Despite the wealth of knowledge available on the diversity of
methicillin resistant Staphylococcus aureus (MRSA) strains that belonged
to different clones, there have been no reports that analyzed such
diversity on isolates belonging to the same clone. This study aimed to
determine the diversity of ST239-MRSA strains, the predominant MRSA
clone in worldwide, and to illustrate the correlation between the toxin
genes, antimicrobial resistances and the genetic background of these
strains. The molecular epidemiology of ST239-MRSA clone was analyzed by
phenotypic antibiotyping, various genotypic assays. We found that
coa-RFLP showed the highest discriminatory power in opposition to agr
typing that had the lowest discriminatory power. The majority of our
isolates (80%) were MDR, belonged to SCCmec III, agr I, coa genotype I
and harbored sea and pvl genes. Our study demonstrated an overall
negative correlation between the antimicrobial resistance and the toxin
gene profiles. Meanwhile, there was no significant correlation between
the toxin profiles and genetic background. The high diversity of
ST239-MRSA strains might be among the contributors to the reported
difficulties in control and prevention of MRSA infection in Egypt. With
such diversity, it is assumed that these strains may have undergone
different evolutionary processes.