A Study of Antimicrobial Resistance in Clinical Isolates of Enterococci.

ABSTRACT

Introduction: Recent years have witnessed a resurgence of interest in enterococci due to increasing resistance to antibiotics in term of both multiplicity of resistance and level of resistance to particular drugs. Methodology: This is a hospital based study, conducted in R.D. Gardi Medical College and C.R.G.Hospital Ujjain (M.P.). All clinical samples such as urine, blood, pus, sputum, ascitic fluid, stool etc. were collected from patients visiting OPD and admitted in CRGH in the study period of 1 and 1/2 year (January 2011-June 2012). Bacterial colonies suggestive of enterococci were further identified and antibiotic susceptibility testing done for each enterococcal isolates by DDT of Kirby Bauer on Muller Hinton Agar according to CLSI guideline.3,5,6 MIC was also determine for ampicillin, gentamicin, streptomycin and vancomycin by Agar dilution.6 Result and Observation Only 2 enterococcal species isolated they were E.faecalis (86.62%) and E.faecium (15.18%). In pathogenic E.faecalis, 90.28% isolates showed resistance to penicillin, 65.28% to ampicillin, 62.5% to high level gentamicin (HLG) and 51.39% to high level streptomycin (HLS). One E.faecalis was resistant to vancomycin (VRE). All E.faecalis were sensitive to linezolid. In pathogenic E.faecium 84.61% isolates showed resistance to penicillin, 23.08 % to ampicillin, 53.85% to HLG and 69.23% to HLS. All E.faecium were sensitive to vancomycin and linezolid. In colonizing enterococci resistance is very low as compared with pathogenic. Multiple drug resistance (penicillinG, ampicillin, HLG, HLS) was more common (32.94%) in isolates of enterococci. Discussion: Study from Sevagram and Nagpur also isolated two species of Enterococci. Very high penicillin-G resistance was also observed in study from Nagpur.15 In this study resistance to ampicillin in E.faecalis was 65.28% and in E.faecium 23.08%. A study done in Mumbai also find similar finding.16 A study done by Rahangdale et al, which showed 49.59% high level resistance to gentamicin.15 In this study HLSR in E.faecalis was 51.39% and in E.faecium 69.23%. Observation close to our study was reported from Nagpur.15 Vancomycin resistance was not detected in E.faecium. Resistance to vancomycin is widely variable. Agrarwal et al, Titze-de-Almeida et al, Rahangdale et al, did not get any VRE in their study. 14,15,17 Conclusion: Multidrug resistances are the common problem. Although, at present, VRE is not a problem in our set up, its routine monitoring is essential, since it appears to be an emerging pathogen in India.