Antibiotic Resistance And Genotyping Of Gram-Positive Bacteria Causing Hospital-Acquired Infection In Patients Referring To Children’s Medical Center

INTRODUCTION: A serious problem affecting human society is the development of bacterial resistance. The purpose of the current study was to evaluate the antibiotic resistance of Gram-positive bacteria (GPB) and genotyping of common GPB causing hospital-acquired infections (HAIs) in patients who were referred to Children’s Medical Center during a 6-month period by random amplified polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus sequence polymerase chain reaction (ERIC-PCR). METHODS: During the 6-month period, antimicrobial resistance profiles of GPB isolates recovered from patients in Children’s Medical Center were determined using the Kirby–Bauer disk diffusion and MIC. Typing of common GPB was performed and the results were analyzed by gel compare software. RESULTS: In this cross-sectional study, 6524 cultures were performed and 138 Ggram-positive bacteria were isolated (2%). Staphylococcus aureus strains showed the highest antibiotic penicillin resistance (96.3%). Twenty-six per cent of the strains were methicillin-resistant S. aureus (MRSA) and no resistance was found against vancomycin. All isolates of Enterococcus faecium were resistant to ciprofloxacin (100%). The resistance to vancomycin was very high (67%) and no resistance was observed to linezolid. The results of genotyping analysis of S. epidermidis strains showed the presence of two clones with a genetic relationship of over 80%. All of the S. aureus strains were in one cluster and half of the E. faecium strains were in a cluster with a genetic predilection of over 80%. CONCLUSION: This study indicated frequent occurrence of antimicrobial resistance, especially in Enterococcus spp. isolates. Rapid spreads of MRSA and VREF from a clonal origin require implementing careful isolation and infection control measures.