Genetic characterization of two vancomycin-resistant isolates in Kerman, Iran.

AIM

The aim of this study was the genetic characterization of two clinical vancomycin-resistant (VRSA) isolates.

MATERIALS AND METHODS

Resistance to vancomycin was determined by phenotypic method. PCR was used for detection of (2")-Ic, (3')-IIIa, , Immune Evasion Cluster [ and ] genes and biofilm operon ABCD. On the other hand, multilocus sequence typing and typing methods were performed for the determination of clonal relationship and operon was detected and sequenced.

RESULTS

Vancomycin-resistant strain 1 (VRSA-1) was positive for (2")-Ic, (3')-IIIa, D genes, belonging to type I; SCC type III; type t030; and ST239. However, the genetic characterization of Vancomycin-resistant strain 2 (VRSA-2) revealed the presence of various types of resistance genes (2")-Ic, (3')-IIIa, , i, relating to type I; SCC type III; type t459; and ST239. The presence of transposon Tn was determined by PCR sequencing.The Basic Local Alignment Search Tool analysis of operon in the VRSA isolates showed 99.6% sequence homology to Tn in vancomycin-resistant enterococci, indicating the operon has an enterococcal origin.

CONCLUSION

In conclusion, the ST239 is one of the most common clones of MRSA isolates which involved the hospital-associated infections, therefore, the emergence of VRSA isolates with ST239 increased the spread of resistance to vancomycin in the hospital settings.