Speciation and Antimicrobial Susceptibility pattern of Enterococci from a Tertiary Health Care Center in North India. 385-389
Dr Varsha Gupta, Professor, Deptt. Of Microbiology, Govt. Medical College & Hospital. Email: email@example.com
Introduction: In recent years, Enterococci have become important nosocomial pathogens. Therefore, it is important for a hospital setting to continuously monitor such infections, and to determine their species and antimicrobial susceptibility pattern from time to time. Keeping these objectives in mind, the present study was conducted in our tertiary health care center in North India.
Methods: A total of 100 enterococcal strains isolated from urine and blood samples were speciated as per the scheme of Facklam and Collins. Antibiotic susceptibility was determined for Amoxycillin, Penicillin, Cephalexin, Erythromycin, Cotrimoxazole, Gentamicin, Vancomycin, Teicoplanin, Linezolid, Imipenem, Piperacillin, Ampicillin- sulbactam, and Nitrofurantoin by the Kirby Bauer disc diffusion method. MIC detection was done by the agar dilution method for penicillin and vancomycin. HLAR detection was done by the agar dilution method for gentamicin and streptomycin, by supplementing the Mueller Hinton agar with 500μg/ml and 2000 μg/ml of the antibiotics, respectively.
Results: 96 of the strains were of Enterococcus faecalis, and 4 were of Enterococcus faecium. Antibiotic susceptibility tests showed a high level of resistance to cephalexin (100%), gentamicin(96.42%), cotrimoxazole (87.03%), erythromycin (77.19%), and penicillin (61.17%). However, only two strains were found to be resistant to vancomycin and teicoplanin. All the strains were sensitive to linezolid. HLAR was seen in 75% of the strains for gentamicin, and in 69% strains for streptomycin. In case of penicillin, MIC values were found to be >16 μg/ml for 14 strains (14%). 6 strains had MIC values of upto 4μg/ml for vancomycin. Out of these, one E. faecalis strain turned out to be Vancomycin resistant enterococci (VRE) showing an MIC value as high as 512 μg/ml.
Conclusion: We conclude that enterococcal strains with high rate of resistance to penicillin and aminoglycosides are prevalent in our nosocomial setting, and emergence of the VRE strain has further worsened this situation. There is an urgent need for more rational and restricted use of antimicrobials in order to minimize the selection and spread of such strains.