Antimicrobial Susceptibility Patterns of Enterococcal Isolates And its Relevance With Biofilms Formation And Β -Lactamase Production

Abstract

Background: Enteroccci are part of the normal intestinal flora of human and animal, but with increasing antimicrobial resistance, enterococci are recognized as serious nosocomial as well as community pathogens. Objectives: To investigate the antimicrobial susceptibility patterns of 44 isolates of enterococci recovered from different pathological specimens from in-and out-patients from Diyala province. Materials and methods: The present study was conducted in Baquba General Hospital and Al-Batool Hospital for Maternity and children during the period from 1st. September/2005 to 30th. September /2006. A total of 343 specimens were collected from 213 inpatients and 130 outpatients. 200 (58.3%) were females and 143 (41.7%) were males. The mean age of patients was (32.8 ± 17.2) years. Specimens include, urine, stool, vaginal swabs, throat swabs, burn swabs, blood for culture, middle ear swabs, wound swabs, sputum and cerebrospinal fluid. Specimens were streaked on blood agar, and other differential and selective media. 44 isolates of enterococci (30 E. faecalis, 10 E. faecium, 3 E. gallinarium, and 1 E. avium) were recovered and identified according to standard bacteriological and biochemical criteria. The susceptibility patterns toward 13 antimicrobial agents were done by disc diffusion method. Data were statistically analysed. Results: The results revealed that the highest susceptibility of enterococcal isolates was toward the Nalidixic acid (79.5%), Ciprofloxacin (61.4%), Amoxacillin+clavilanic acid (61.4%), Rifampicillin (36.4%),Trimethoprim (22.7%), Vancomycin (11.4%). However, all isolates were resistant to Cloxacillin, Cefotaxim, Amoxicillin, Tetracycline, and Erythromycin. The susceptibility of non- β -lactamase producing isolates to penicillin were significantly higher than β - lactamase producing isolates (p<0.001). Furthermore, the sensitivity of non-biofilms former isolates were significantly higher than that of biofilms former isolates (p= 0.002). Conclusion: The overall susceptibility rates of enterococcal isolates recovered from nosocomial as well as community acquired infections to available antimicrobials are low.