Comparison of Tn1546 element of vancomycin resistant Staphylococcus aureus isolated from burned patients in Sulaimani hospital

Abstract

little is known about vancomycin-resistant Staphylococci in Iraq. Staphylococcus aureus, a major cause of potentially life-threatening infections acquired in health care settings and in the community, has developed resistance to most classes of antimicrobial agents soon after their introduction into clinical use. In many health care institutions around the world, glycopeptides such as vancomycin provide effective therapy against most strains of multidrug-resistant S. aureus, including MRSA. In 2008, the first nine clinical isolates of vancomycin-resistant Staphylococcus aureus (VRSA) containing vanA gene with variable vancomycin MICs were recovered in Sulaimani Emergency hospital for war victims/Sulaimani/ Kurdistan region of Iraq. With PCR and DNA sequence analysis, the Tn1546 elements, a mobile genetic element that encodes vancomycin resistance proteins in enterococci and staphylococci, amplified and the sequences of which was compared to the prototype Tn1546 element from enterococci and also to the previously sequenced Tn1546 of VRSA recorded in gene bank/ NCBI, the Sulaimani VRSA Tn1546 element was different by distinct modifications in nucleotide sequences and showed partial homology with an enterococcal transposone Tn1546-like element. These differences in the Tn1546 elements explain various expression level of VanA gene which indicated by vancomycin MICs. This is believed to be the first Iraqi molecular study on S. aureus isolate that has been shown to be vancomycin-resistant, due to a Tn1546 transposone analogue..