Relationship between the resistance genes to quaternary ammonium compounds and antibiotic resistance in staphylococci isolated from surgical site infections.

BACKGROUND

We aimed to investigate the prevalence of disinfectant resistance genes (qacA/qacB,qacC) and the aminoglycosides resistance genes [(aac(6')aph(2''),aph(3')-IIIa,ant(4')-Ia)] in both S. aureus and coagulase-negative staphylococcal strains (CoNS) isolated from surgical site infections.

MATERIAL AND

METHODS

Totally, 130 staphylococcal strains isolated from surgical site infections between January 2012 and February 2013 were included in the study. The PCR technique was employed to verify any presence of methicillin resistance gene (mecA), aminoglycoside resistance genes [(aac(6')/aph (2''), aph(3)-III a ant (4')-1a)], and disinfectant resistance genes (qacA/qacB,qacC) in staphylococci.

RESULTS

MecA gene was determined in 58 (44.6%) of 130 staphylococcal isolates. A total of 28 (73.7%) of 38 S. aureus isolates were found to be positive for the mecA gene, and 4 (12.9%) of 31 isolates sensitive to amikacin were sensitive to methicillin. Eighteen (47.4%) of 38 amikacin-resistant S. aureus isolates were found to be positive for qacA/qacB genes and 11 (8.9%) of them were positive for qacC gene. Both mecA and qacA/qacB genes were found to be positive at the same time in 19 amikacin-resistant S. aureus strains. Seven (18.4%) S. aureus isolates were determined to be positive for qacA/qacB and qacC genes. Frequency of qacA/B genes was found to be 47.4% among amikacin-resistant S. aureus strains, while qacC gene was found to be 28.9% (p<0.05). The ratio of qacA/B and qacC genes in CoNS was found to be 37.9% and 20.7%, respectively (p<0.05).

CONCLUSIONS

Quaternary ammonium resistance genes were found to be positive at a remarkable ratio in the staphylococcal isolates from surgical wounds. Especially, the high rates of aminoglycosides and methicillin-resistance gene was remarkable in S. aureus isolates. Quaternary ammonium resistance genes were found to be positive.