Characterization of methicillin resistant staphylococcal aureus [MRSA] isolates from mansoura university hospitals

ABSTRACT

Hospital-acquired infections due to MRSA are associated with considerable morbidity, mortality, and excess costs. Our work aimed to study the prevalence, risk factors and genotypic characteristics of MRSA isolates from patients admitted at Mansoura University Hospitals [muhs]. A total 184 of Staphylococcal aureus [SA] clinical specimens were collected from our in-patients between June 2009 to June 2010. Isolated colonies were identified in a systematic manner for selection of MRSA. Oxacillin and cefoxitin resistance tests identified MRSA that were subjected to antibiogram and resistogram. MRSA amplified genes, visualized by agarose gel electrophoresis, were analyzed by Sanger sequencing. Only 49 isolates out of the isolated strains of SA were identified as MRSA strains by cefoxitin disc diffusion test. All strains are resistant to cefoxitin, ceftriaxon, cloxacillin and ampicillin while most strains were susceptible to vancomycin. Sanger sequencing of meca gene showed 3 monographs. MRSA isolates were more from blood samples [F< 0.001] of patients above 60 years [P< 0.001], of low socioeconomic status [P< 0.001], and of >2wks duration hospital stay [P< 0.05], in icus [P< 0.001], with a previous history of hospital admission within the past year [P< 0.001] and a positive history of antibiotic use in the last 6 months [P< 0.001]. Positive family history of chronic disease [P< 0.001] or hospitalization within the last year [P< 0.05] and the presence of family member working in a clinic or a hospital [P< 0.05] were noted in MRSA-positive patients. Our data revealed an increased prevalence of multi-drug resistant MRSA isolates where PCR was of the best choice for their rapid and accurate detection. An effective infection control program should be implemented for appropriate MRSA management