Determination of antibiotic resistance genes, immune evasion cluster and agr types among Staphylococcus aureus strains isolated from children with adenoiditis

Abstract

Adenoiditis is the most common infection in childhood and different microorganism such as viruses and bacteria cause this infection. Staphylococcus aureus (S. aureus) is the main Gram-positive bacterium that can involve in adenoiditis. The aim of this study was to determination of antibiotic resistance, immune evasion cluster genes and agr types among S. aureus isolates were collected from children with adenoiditis. Totally 36 clinical isolates of S. aureus were obtained from 112 children suffering from adenoiditis. Susceptibility of the isolates to different antimicrobial agents were determined using standard disk diffusion method. PCR technique was used for detection of resistance and virulence genes. SCCmec and agr typing were used for molecular typing of the isolates. All isolates were sensitive to vancomycin and 47.2% of isolates were resistant to penicillin. Twenty-two present of isolates were considered as MRSA and SCCmec type IV was detected in 5 MRSA isolates. Only, agr types I and II were identified among the isolates. ermC was the predominant macrolide resistance gene and ant(4′)-Ia was the most common aminoglycoside resistance gene. Virulence genes including sak, chp and sea were identified in 47.2% (n = 17), 30.5% (n = 11) and 13.8% (n = 5). This study was the first report in Iran, Kerman, about determination of antibiotic resistance, virulence genes, agr groups and SCCmec types among the clinical S. aureus isolates were collected from children with adenoiditis. Also, our results can be helpful in empirical therapy and increase our knowledge about genetic characteristics of S. aureus isolates are involved to adenoiditis.