Antibiotic resistance pattern of enterococcal isolates from patients with urinary tract infection

Abstract

Background: Enterococci are the most common cause of healthcare associated urinary tract infections. The frequency of isolation of Enterococci from urinary tract of hospitalized patients has risen. Enterococcus is considered as an important nosocomial pathogen because of its intrinsic as well as acquired resistance to antibiotics. The purpose of this study is to determine the emergence of Enterococci as uropathogens and their antimicrobial susceptibility pattern. Materials and methods: This cross sectional study was conducted at the Department of Microbiology, A.C.S Medical College and Hospital. A total of 175 Enterococcus spp were isolated from patients with urinary tract infection. Identification and speciation of the Enterococcal isolates were done using conventional method. The antibiotic susceptibility testing of the Enterococcal isolates was performed by modified Kirby-Bauer disk diffusion method as per Clinical Laboratory Standard Institute (CLSI) guidelines. Results: A total of 175 urine specimens yielding the growth of Enterococci were studied. Enterococcus faecalis (77.7%) was the predominant species isolated followed by E. faecium (20%) and E. durans (2.3%).The sensitivity pattern of the isolates showed an increased resistance to antibiotics like erythromycin (66.3%), ciprofloxacin (56%) and penicillin (49.7%). The HLAR (High Level Aminoglycoside Resistance) to gentamycin was observed in 37.2%, however the susceptibility rate of nitrofurantoin was 86.9%, amoxicillin - clavulanic acid was 81.1% and ampicillin (21.7%). Among the isolated Enterococci, 5.7% were vancomycin resistant. All the Enterococci were found to be sensitive to linezolid. Conclusion: Enterococci have emerged from being harmless commensals to versatile lethal pathogens. In our study, E.faecalis was the most frequently isolated species followed E.faecium . Linezolid, vancomycin, nitrofurantoin and amoxicillin-clavulanic acid were found to be the most effective antimicrobials against Enterococci isolated from patients with UTI. However vancomycin or linezolid therapy should be restricted for use in patients infected with MDR strains only. Although the frequency of isolation of VRE is not very high in our setting, this may be the beginning. Tracking of antimicrobial susceptibility due to increasing resistance rate is very important in treatment of Enterococcal infections.