English

Abstract

Enterococcal UTI is a well-known source of fatal bacteraemia & endocarditis. OBJECTIVE: Identification of different species of Enterococci causing nosocomial urinary tract infection in a tertiary care hospital along with antibiotic susceptibility pattern. METHODS: Admitted patients developing symptoms of UTI atleast after 48 hours of admission were included in this study over a period from January-June 2013.Urine samples collected in appropriate sterile manner were screened for pus cells and bacteria followed by speciation according to Facklam-Collins scheme. Enterococcal isolates were preserved in CTA until tested by VITEK2 (bioMerieux) with AES to confirm the speciation. Antibiogram was performed by disk diffusion method (modified Kirby -Bauer technique) on Muller-Hinton agar and blood agar media. MIC of the tested antibiotics was detected by VITEK 2 with AES which provides accurate fingerprint recognition of bacterial resistance. RESULTS: Out of total 187 urine samples, 34 were culture positive (18%) of which Enterococci were isolated in 9 cases (26.4%); E nterococ cus f aec alis & Enteroc occ us f aec ium four each along with one E nteroc occ us gallinarum strain. Isolated E nterococc us gallinarum and all isolated E nterococc us f aec alis were sensitive to Penicillin group of drugs, although all isolated Enterococcus faecium were resistant to them. None of the Enterococcal isolates produced β- lactamase. In isolated Enterococcus gallinarum and one Enterococcus faecalis isolate, MIC value of Ampicillin was double that of Benzyl-penicillin. Isolated Enterococcus gallinarum was the only Vancomycin resistant Enterococcus strain. According to VITEK2 AEC, it was of vanA type with MIC ≥32μg/ml. All four Enterococcus faecalis isolates were resistant to Quinupristin & Dalfopristin whereas isolated Enterococcus faecium were sensitive to those antimicrobials. All of the isolates were sensitive to Nitrofurantoin except one Enterococcus faecium isolate (MIC value 64μg/ml) and Enterococcus gallinarum isolate (MIC value 64μg/ml), both of which were intermediately susceptible to the drug. CONCLUSION: Four E nterococ cal isolates were susceptible to Ampicillin and Aminoglycosides (high level synergy) suggesting use of combination therapy of Ampicillin and Aminoglycosides for treatment. Vancomycin and Linezolid are the only available drugs for treatment of isolates resistant to both or any one of the drugs Ampicillin and Aminoglycosides (high level synergy). To treat VRE, Linezolid may be prescribed.