Evaluation of Clinically Important Gram Positive Isolates and Their Susceptibility Pattern in Tertiary Care Hospitals: 3-Year Prospective Study

Abstract

AIM1. To analyse clinically important Gram-Positive isolates (Staphylococcus aureus, Enterococcus Species and Streptococcal Species) and their susceptibility pattern in tertiary care Hospitals. 2. To study the epidemiology of the isolates and sensitivity pattern of Gram Positive isolates in South Tamilnadu. METHODSSamples collected from different wards were subjected to culture, isolation and identification of Gram Positive isolates and Antibacterial Susceptibility testing by Kirby Bauer method. This study was carried out in the Institute of Microbiology, Madurai Medical College, Madurai. RESULTS6900 non-repetitive isolates from 29,275 patients were collected. They were from urine, sputum, blood, pus and respiratory samples. Total number of Gram Positive isolates processed was 1022. Staphylococcus aureus was the most common organism isolated in our study followed by Enterococcus Species and Streptococcal Species. Staphylococcus aureus isolates showed high sensitivity to Glycopeptides, Clindamycin, Doxycycline, Cefazolin, Erythromycin and Amoxicillin-Clavulanic acid. This isolates showed low sensitivity to Penicillin, Trimethoprim/Sulphonamides and Ciprofloxacin. Enterococcus isolates showed high sensitivity to Glycopeptides. These isolates showed low sensitivity to Penicillin, Amoxicillin-Clavulanic acid, Ampicillin, Nitrofurantoin, Levofloxacillin, High Level Gentamicin and High Level Streptomycin. Streptococcus isolates showed high sensitivity to Penicillin, Clindamycin, Doxycycline, Erythromycin, Ofloxacillin and Ceftriaxone. Methicillin Resistant Staphylococcus aureus showed resistance from 5% to 4.20%. Vancomycin Resistant Enterococci showed resistance from 0.50% to 0%. CONCLUSIONIn this 3-year study, Staphylococcus aureus was the most common organism isolated from clinical specimens. Staphylococcus aureus isolates showed high sensitivity to Glycopeptides Clindamycin, Doxycycline, Cefazolin, Erythromycin and AmoxicillinClavulanic acid. Enterococcus isolates showed high sensitivity to Glycopeptides. Methicillin Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci exhibit lesser resistance rates in the 3-year study period. This study will help both clinicians and infection controlling practitioners to treat the patients. This single center study can give important information regarding emerging resistance patterns.