Abstract

In 2008, nine clinical isolates of vancomycin-resistant Staphylococcus aureus containing Tn1546 were recovered in Sulaimani, Iraq. The genetic diversity in Tn1546-like elements has been documented previously. The differences described thus far have included the integration of insertion sequence (IS) elements IS1216V and IS1251. With polymerase chain reaction (PCR) and deoxyribonucleic acid (DNA) sequence analysis of Tn1546, the distribution of ISs among 9 vanA-containing S. aureus isolates were investigated. Only one VRSA element was identical to the prototype Tn1546 element. Structural analyses of the van gene detected IS1216 and IS1251 in the genomes of 8 isolates. In addition, IS19 was detected in thevanS-vanH region of one of the 8 isolates. Two of the 8 vancomycin-resistant Staphylococcus aureus (VRSA) elements showed a deletion, which eliminated the orf1 region, and IS1216inserted in place of it and also another copy of IS1216 inserted into the vanSH region. The distribution of ISs associated with Tn1546-like elements among the Sulaimani isolates was found to be different from that of American vancomycin-resistant Staphylococci population. From this study, it was concluded that identification and analysis of the IS within the vanA gene could be a useful tool in epidemiological investigations.

Key words: Vancomycin-resistant Staphylococcus aureus (VRSA), insertion sequence (IS), Tn1546, Sulaimani, Kurdistan.