The Prevalence, Molecular Characterization and Antimicrobial Susceptibility of S. aureus Isolated from Impetigo Cases in Duhok, Iraq

Staphylococcus aureus is one of the most important opportunistic pathogens. Impetigo is the common contagious bacterial infection of the skin caused by S. aureus.

Samples were taken from 204 patients with impetigo disease. S. aureus isolates were tested for their antimicrobial susceptibility. Genomic DNA of S. aureus was used to transform E. coli HB101 strain and expression capability of S. aureus plasmids in transformed E. coli was investigated. 68.62% (140/204) of the specimens were nonbullous impetigo and 31.38% (64/204) were bullous impetigo. S. aureus strains were isolated from 41.66% (85/204) of impetigo cases (82.35% from nonbullous and 17.65% from the bullous impetigo). There was an inverse relationship between the incidence of S. aureus isolated and age.

Three biotypes of S. aureus were identified based on their fermentation of different sugars. All isolates were resistant to penicillin and most isolates were resistant to ampicillin (95.3%), amoxicillin, (94.11%) and cephalexin (90.95%). Most isolates were sensitive against vancomycin and rifampicin (98.83%). 5.88% (5/85) of S. aureus isolates were identified as MRSA. A maximum of 5 markers from S. aureus isolates were capable to be expressed in transformed E. coli HB101 strains. The incidence of impetigo caused by S. aureus is comparable with reports from elsewhere. S. aureus isolates showed multidrug resistance against antibiotics.

Plasmids of S. aureus are capable to show its expression in E. coli HB101. Molecular study is needed to investigate the role of plasmids in different patterns of multi drug resistance.