the prevalence of antibiotic resistance of enterobacteriaceae strains isolated in community- and hospital-acquired infections in teaching hospitals of hamadan, west of iran

background: the prevalence of antimicrobial resistance among enterobacteriaceae is increasing worldwide. identification of pathogens and their resistance to antimicrobials is mandatory for successful empiric antibiotic treatment. the aim of this study was to investigate the prevalence of antimicrobial resistance of enterobacteriaceae isolated from hospital-acquired and community-acquired infections. methods: in a descriptive-comparative study, during 2010, all clinical isolates of enterobacteriaceae and their antibiograms from laboratories of sina and bessat hospitals, hamadan, west of iran were included. hospital-acquired infections were identified by records from infection-control units. a questionnaire containing information about demographic characteristics, source of specimen, kind of enterobacteriaceae and their antimicrobial resistance was filled for each patient. data were analysed using spss. results: a total of 574 samples were collected, out of which the most prevalent pathogens were escherichia coli and klebsiella pneumoniae. almost all isolates of enterobacteriaceae were resistant to ampicillin (98.8%), and the least resistance was to piperacillin (3.7%). in addition, most isolates were resistant to cefazolin, cefixime, and co-trimoxazole. among third generation cephalosporins, the highest resistance to ceftriaxone and the least resistance to ceftizoxime were observed. 19.3% of isolates were resistant to imipenem. in terms of fluroquinolones, nosocomial infections and community acquired infections were resisitant to ciprofloxacin 33% and 4.1% respectively. the rate of resistance in nosocomial infections was higher than that of community-acquired infections. conclusion: the prevalence of multidrug resistant enterobacteriaceae is increasing both in community-acquired and hospital-acquired infections. because of propable increasing resistance to fluoroquinolones and newer betalactams, reassessment of resistance of enterobacteriaceae must continue in future years.