Prevalence of vancomycin resistant Enterococci colonization in gastrointestinal tract of hospitalized patients

Vancomycin-resistant Enterococci (VRE) are the most common nosocomial pathogen worldwide. Colonization with VRE can lead to serious infection, some of which e.g. VRE sepsis can be fatal. Because VRE are dangerous important pathogens, we aimed to determine the prevalence of VRE among patients admitted in infectious, ICU and surgery wards in a referral teaching hospital in Isfahan, Iran.Patients and A total of 100 patients from infectious, ICU and surgery (post- operative patients) wards were selected by simple sampling method. Stool specimens were taken from the patients and cultured in VRE selective media (bile- esculin agar plate with 6 µg/ml of vancomycin) and gram positive cocci from black colonies were inoculated to the tryptase soya broth plus 6.5% NaCl and again gram positive cocci were inoculated to bile-esculin and finally MIC (minimal inhibitory concentration) evaluated by E-Test for detection of VRE. Totally 58 out of 100 patients had positive cultures for enterococci. Among them 16 out of 58 were female (27.6%) and 42 (72.4%) were male. Of 58 positive cultures, 17 (29.3%) were highly resistant to vancomycin. There was significant relation between previous antibiotic therapy especially vancomycin and VRE in this study (P=0.02). Most of the patients (74.1%) with negative cultures for Enterococci had GI surgery. Most of culture positive patients (46%) were from infectious ward. There was no significant relation between VRE and sex, GI surgery and admission ward in this study. Results of this study suggest that previous antibiotic therapy especially vancomycin and B-lactam is a major risk factor for colonization with VRE. Prevalence of VRE in our study was high. This problem is very important in epidemiology of hospital infections. Considering the fact that there is no substitute agent for vancomycin in our country, it is necessary to determine guidelines regarding treatment with antibiotics specially vancomycin.