Prevalence of Vancomycin and Methicillin resistant Staphylococcus aureus isolates from Lancet Laboratories Uganda
Abstract
Methicillin resistant Staphylococcus aureus (MRSA), majorly associated with nosocomial and community infections worldwide, are emerging as resistant strains to many antibiotics narrowing down the efficacy of antimicrobial therapy. This study was conducted at Lancet laboratories in Wandegeya (Uganda) to determine the prevalence of MRSA and VRSA in clinical samples. A total of 353 clinical samples including 51 blood, 64 urines, 186 pus, 35 HVS and 17 sputum received by the laboratory were processed. Isolated S. aureus were further screened for Methicillin resistance by Kirby-Bauer disk diffusion method using cefoxitin (30µg) disk on sterile Mueller Hinton agar. All MRSA were subjected to in-vitro determination of MIC of vancomycin by E-test method as recommended by CLSI guidelines to determine Vancomycin resistance. All the different clinical samples processed were found to contain S. aureus yielding a total of 353 clinical isolates of S. aureus. Of these, 36(36.0%) from pus, 31(31.0%) from blood, 7(7.0%) from HVS, 22(22.0%) from urine and 4(4.0%) from sputum were Methicillin resistant. 1(1%) MRSA isolate from blood was a Vancomycin intermediate S. aureus (VISA). This study showed high prevalence of MRSA, low prevalence (1%) VISA and zero prevalence of VRSA in clinical samples at Lancet Laboratories. Emergence of vancomycin resistant S. aureus would be registered in future. Strict control measures to prevent MRSA spread and a routine surveillance for VRSA should be introduced. More studies with larger sample sizes should be conducted to establish the status of Vancomycin resistance in S. aureus and molecular studies to identify resistance-conferring genes.