Prevalence of antibiotic resistance genes among Enterococcus strains isolated from the clinical specimens

Abstract

BackgroundEnterococci are one of the most common causes of hospital-acquired infections, including urinary tract infections, surgical wound infections, and endocarditis. A combination of aminoglycoside and a cell wall-effective antibiotic such as ampicillin or vancomycin is used to treat serious infections caused by Enterococcus species. Therefore, the resistance of Enterococcus strains to these antibiotics will raise concerns in the treatment of infections caused by these bacteria. MethodsIn this study, Enterococci strains isolated from clinical specimens were identified by biochemical and microbiological methods. PCR technique was used to evaluate the presence of resistance genes to various antibiotics. ResultsA total of 52 Enterococcus strains were identified from clinical specimens and the presence of resistance genes was studied in them. The vanA gene was identified in 11.5% of enterococcal isolates. Both vanA and vanB genes were identified in 3.8% of the isolates, but no vanB and vanC genes were found. The blaZ gene was detected in 9.6% of enterococcal isolates. GyrA and parC fluoroquinolone resistance genes were identified in 86.5% and 88.4% of enterococcal isolates, respectively. The aac (6′)-Ie-aph (2″)-I gene for aminoglycoside acetyltransferase was detected in 30 (57.6%) isolates. ConclusionIn this study, the prevalence of fluoroquinolone resistance genes and aminoglycoside resistance genes were high, so these antibiotics must be prescribed based on antibiogram results. Due to the low prevalence of vancomycin resistance genes and blaZ genes, these antibiotics can be used in the treatment of Enterococcus strains infections.