Prevalence of Multidrug Resistance in Enterococcus faecium Isolated from Patients and Environment of Hospitals in Lorestan Province, (Iran)

With increasing use of vancomycin antibiotic, vancomycin-resistant Enterococcus (VRE), is considered as a major cause of nosocomial infections. In this study, the pattern of antibiotic resistance and prevalence of vancomycin resistant enterococcus faecium, were investigated.
In this descriptive study, after isolation and identification of 690 strains of Enterococcus from clinical and environmental specimens in different wards of Lorestan hospitals, the pattern of antibiotic resistance of these strains to common antibiotics, were investigated using dick diffusion and agar dilution methods. The antibiotic resistance genes (vanA, vanB, pbp5, pbpZ, and blaZ), were detected by PCR technique.
Among 690 studied Enterococcus isolates, 439 isolates (64%), were Enterococcous feacalis, 228 isolates (33%) Enterococcous faecium, and 23 isolates (3%), were other Enterococci. Based on the antibiogram test by disk diffusion method, the highest resistance was to penicillin with 446 isolates (67%) and the lowest resistance was to linezolid with 0 isolate (0%). In the evaluation of resistance using minimum inhibitory concentration (MIC), the antibiotic resistance rate was obtained to be 58% for ampicillin, 59% for penicillin, and 23% for vancomycin. Resistance genes, including vanA, vanB, pbp5, pbpZ, and blaZ, were detected in 84 (72%), 26 (22%), 87 (74%), 63 (53%), and 0 (0%) of the isolates.
Based on the results of this study, resistance to vancomycin in Enterococcus strains is also found in Lorestan province like other parts of the world. Therefore, application of control and preventive measures are necessary. Furthermore, to prescribe appropriate antibiotic, it is recommended to perform antibiogram test for each patient before the treatment.