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Introduction: Methicillin resistant Staphylococcus aureus (MRSA), the most common cause of nosocomial infection has been a major cause of morbidity and mortality around the world. They are normally resistant to most of the antibiotics used in clinical practice. This study has been carried out to find out the resistance pattern among S. aureus., Methods: During November 2007 to June 2008, clinical samples from patients with nosocomial infection were processed for culture and sensitivity following standard methodology in microbiology laboratory, Tribhuvan University teaching hospital, Kathmandu, Nepal., Results: Among 149 Staphylococcus aureus isolates, highest resistance was observed against Penicillin (91.94%) followed by Fluoroquinolone (61.74%), Erythromycin (52.94%), Gentamicin (46.98%), Cotrimoxazole (42.95%), Tetracycline (40.94%) and others, whereas susceptibility was observed maximum against Chloramphenicol (94.85%) followed by Rifampicin (92.61%), Tetracycline (59.06%), Cotrimoxazole (57.04%), and others. None of the isolates were resistant to Vancomycin and Teicoplanin. Of these isolates 44.96 % of the isolates were Methicillin resistant S. aureus (MRSA). Resistance to Penicillin, Fluoroquinolone, Erythromycin, Gentamicin, Co-trimoxazole and Tetracycline were associated significantly with MRSA isolates (chi2= 8.779, p<0.05, chi2= 74.233, p<0.05, chi2= 84.2842, p<0.05, chi2= 108.2032, p<0.05, chi2= 88.1512, p<0.05 and chi2= 79.1876, p<0.05 respectively). Although most of the Methicillin sensitive S. aureus (MSSA) isolates were susceptible to both Rifampicin and Chloramphenicol, only Rifampicin susceptibility was significantly associated with them (chi2= 10.1299, p<0.05). Among three Biochemical tests for the detection of beta lactamase detection namely chromogenic, iodometric and acidimetric test, chromogenic test method had highest sensitivity and specificity., Conclusions: Since MRSA comprised a greater part of S. aureus isolates and were multi-resistant, patients infected by such strains should be identified and kept in isolation for hospital infection control and treated with second line of drug like vancomycin.

To find out the prevalence of Staphylococcus aureus nosocomial infection and methicillin resistant S. aureus (MRSA), clinical samples from nosocomially infected patients were processed by following standard methodology in microbiology laboratory, Tribhuvan University Teaching Hospital, Kathmandu, Nepal. Of 149 S. aureus isolates, skin infection isolates contributed a major part 72.5% making nosocomial infection by S. aureus most prevalent in skin infection followed by lower respiratory tract infection 11.41% and urinary tract infection 8.7%. Overall MRSA prevalence was 45.0%. MRSA prevalence was 42.6% in skin infection, 82.3% in lower respiratory tract infection and 30.8% in urinary tract infection. MRSA infection was found associated with lower respiratory tract infection only. Highest occurrence of nosocomial infection was observed in female surgical ward, surgical out patient department, orthopedic ward, male surgical ward and maternity ward. MRSA isolation was high from lower respiratory tract of patients admitted in intensive care unit, coronary care unit, Sub-acute intensive care unit, intermediate coronary care unit, neurology ward and post-operative ward. Whereas methicillin sensitive S. aureus (MSSA) occurrence was higher in patients admitted in orthopedic, Surgical out patient department, and female surgical ward. The occurrence of MRSA did not differ with age but MRSA was found associated with male patients and MSSA was associated with female patients. Since MRSA prevalence was high, regular surveillance of MRSA and nosocomial infections should be done and universal precautions to control nosocomial infections should be followed.

Nosocomial infection is a major problem in the world today. Methicillin-resistant Staphylococcus aureus (MRSA) strains, usually resistant to several antibiotics, shows a particular ability to spread in hospitals and is now present in most of the countries. The aim of the present study was to determine the prevalence of MRSA infections and their antimicrobial susceptibility pattern in our hospital located in eastern Nepal. Identification of Staphylococcus aureus was confirmed by standard methods and the antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion method. Interpretation criteria were those of the national committee for clinical laboratory standards. During a period of one year, out of a total of 750 Staphylococcus aureus strains isolated from various clinical samples, 196 (26.14%) were found to be Methicillin-resistant. Seventy percent isolates of MRSA were from inpatient departments and amongst them only 10% of the isolates were from intensive care units (ICU). More than 65% of MRSA were found to be resistant to Penicillin, Cephalosporins, Ciprofloxacin, Gentamicin Erythromycin and Tetracycline, while 47.96% of them were resistant to Amikacin. Many MRSA strains were multidrug-resistant. However, no strains were resistant to Vancomycin. To reduce the prevalence of MRSA, the regular surveillance of hospital acquired infection, isolation nursing of patients who carry MRSA, monitoring of antimicrobial susceptibility pattern and formulation of a definite antibiotic policy may be helpful.

Life threatening infections caused by enterococcus species with multidrug resistance has emerged as a threat to medical care in the present era. This study was conducted to characterize enterococcus species isolated from different clinical samples and to detect the pattern of susceptibility to some of the commonly used antibiotics in B.P Koirala Institute of Health Sciences (BPKIHS), a tertiary care hospital in eastern Nepal. Clinical samples submitted to the microbiology unit of Central Laboratory Service (CLS) for culture and sensitivity during March 2002 - February 2003 was analyzed. Enterococcus species were identified by colony characteristics, gram staining and relevant biochemical tests. Antibiotic susceptibility test was done by the Kirby Bauer disc diffusion technique. Of 50 Enterococcus species isolated, E. faecalis was the predominant isolate (48.0%) followed by E. faecium (32.0%) and E. avium (20.0%). Eighty-eight percent of E. faecalis showed sensitivity to cephotaxime and 87.0% to vancomycin. Multiple drug resistance was observed most commonly in E. faecium. Seventeen percent of E. faecium were resistant to vancomycin and 63.0% to ciprofloxacin and 44.0% to ampicillin. On the contrary E. avium rarely showed resistance to the antimicrobials tested including vancomycin. Enterococcal infections are common nowadays specially in hospitalized patients. Inappropriate use of antibiotics in clinical practice and poultry should be discouraged to prevent the emergence of multidrug resistant species.