the comparative frequency of β-lactamase production and antibiotic susceptibility pattern of bacterial strains isolated from staff hands and hospital surfaces in alzahra hospital–isfahan

background and objectives: hospital surfaces can serve as reservoirs of potential pathogenic bacteria.staff hands are the main source of bacterial transmission in hospital. the prevalence of bacteria harboring β– lactamase enzyme in staff hands and hospital surfaces, leads to spread of β–lactamase producing bacteria and ultimate increase of antibiotic resistance nosocomial infections. the aim of this study was to investigate the frequency of β-lactamase producing bacteria and susceptibility pattern of isolated bacteria from staff hands and high and low contact hospital surfaces of alzahra hospital in isfahan, iran. material and methods: this laboratory-based study was performed in alzahra hospital in isfahan during 2005-2007 years. overally, 274 samples (194 strains from surfaces and 80 strains from staff hands) were screened during the study. environmental samples were collected by using swabs in nutrient broth (nb) and samples from staff hands were collected with finger print method. bacterial identification was performed by conventional biochemical identification tests. for determination of β–lactamase production, acidometric method was used, and antibiotic susceptibility testing was performed by kirby bauer method. results: the 194 isolated strains from hospital surfaces were: staphylococcus spp. 105 (53.7%), bacillus spp. 74 (24%) enterobacteriaceae 21 (10.7%), pseudomonas spp . 9 (4.6%), streptococcus spp. 2 (1%), other gram negative bacilli 10 (5.15%), and the 80 strains isolated from staff hands were: bacillus spp. 48 (60%), staphylococcus spp. 28 (35%), enterobacteriaceae4 (0.5%). the isolated bacteria from both sources were highly resistant to tested antibiotics. according to the results from acidometric test, 125 (61.54%) strains isolated from hospital surfaces and 46 (61.85%) strainsisolated from staff hands, were β-lactamase producers. conclusion: the results show the high frequency of antibiotic resistant and β–lactamase producing bacterial strains on staff hands and hospital surfaces in present study.