Species Prevalence And Antimicrobial Resistance Pattern Of Enterococcal Isolates In A Tertiary Health Care Centre
Dept. of microbiology,
Context: Enterococci are one of leading causes of nosocomial and community acquired infections and in recent years, they have become increasingly resistant to a wide range of antimicrobial agents. Aim: The present study was done to determine the species distribution and antimicrobial resistance pattern of enterococcal isolates. Material and Methods: 120 enterococcal isolates from different clinical samples were included in the study. They were identified by the standard microbiological methods and their antimicrobial susceptility was done by the Kirby-Bauer disc diffusion method. Vancomycin resistance was detected by the disc diffusion method and the agar dilution method and MIC testing was done by the macrobroth dilution method. High level aminoglycoside resistance (HLAR) was detected as per the CLSI guidelines. Results: E. faecium was the predominant species (47.50%) which was detected, followed by E.faecalis (44.16%) and others. E. faecium strains displayed a higher degree of drug resistance. The E.gallinarum species expressed low level vancomycin resistance, which was not detected by the disc diffusion method. More than 70% resistance was seen for ampicillin, erythromycin and tetracycline. 9(7.5%) isolates were found to be resistant to vancomycin. 5(4.16%) isolates were resistant to teicoplanin. All the isolates were susceptible to linezolid. HLAR was seen in 73(47.18%) isolates. Conclusion: E.faecium is now emerging as the predominant enterococcal species which causes infections and most of the enterococcal isolates (>77%) are multidrug resistant. Vancomycin resistance and HLAR in enterococci are rising rapidly. This study emphasizes the need for routinely carrying out a detailed speciation and antibiotic susceptibility testing of the enterococcal isolates in the bacteriology laboratory.