Current Trends in Antibiotic Susceptibility of Staphylococcus aureus in Clinical Isolates from a Tertiary Care Hospital

The importance of Staphylococcus aureus as a persistent nosocomial and community acquired pathogen has become a global health concern and showed capability of evolving different mechanisms of resistance to most antimicrobial agents leading to constraints in treatment. This scenario is even a greater challenge for developing countries. The present study was carried out to establish the frequency of S. aureus in clinical specimens and trends of antibiotic sensitivity patterns. Samples of pus, blood, urine, body fluids and catheter tips submitted for culture in Microbiology department between August to September 2012, from outdoor and indoor patients of Pakistan Institute of Medical Sciences Islamabad, yielding growth of S. aureus were included in the study. After identification by standard methods, Antibiotic susceptibility of all the isolates was performed by Kirby Baeur disc diffusion method on Muller Hinton agar. It was a retrospective descriptive observational study. Total 106 S. aureus were isolated. 63.2% of the samples were obtained from pus and the next was blood with 18.9%. 45.3% were MRSA most of them from hospitalized patients and which were 100% sensitive to vancomycin and 87.5% to chloramphenicol. To rest of the non -betalactam drugs resistance of 80% or more was present. Staphylococcus is a common clinical isolate from patients in this region of Pakistan and significant number out of them are MRSA especially causing infections in hospitalized patients. The treatment option is limited to expensive carbapenems i.e. vancomycin.