Survey role and important of surfaces structureand β-lactamase of Bacillus cereus in drug resistance

Abstract

Background: S-layer is a outer protein in bacteria and archaea which intensifies bacterial pathogenicity due to inhibiting antibiotic's entrance to cells. Because staffs and hospital surfaces have a major role in nosocomial infections,contaminating this source with S-layer and ␤-lactamase positive strains of B. cereus can lead to spread the antibiotic resistant nosocomial infections. In this study, in addition to determine the frequency of S-layer and ␤-lactamase positive strains in hospital environment, their function in inhibition of antibiotic's entrance has been surveyed.Methods: The descriptive research was performed on 274 samples isolated from Azzahra hospital and Isfahan University during 2005/2007. In order to preparation of samples, 16 hours bacterial culture in TSA (Tryptone Soya Agar) were used and then electrophoresis with 10X SDS-PAGE were performed. Antibiogram were performed with Kirby Bauer method and ␤-lactamase Results: From 247 isolated bacteria, frequency of B. cereus strains was %9.49. Eleven sample (84/6%) from 13 isolated B. cereus of staff hand and 1 sample (7/7%) from 13 isolated B.cereus from hospital surfaces produce S-layer nanostructure. According to antibiogram result, non producer S-layer strains, in comparative S-layer producer strains, were more sensitive to antibiotics and all Slayer producer B.cereus strains, produce ␤-lactamase.Conclusion: This study show high prevalence S-layer and ␤lactamase producer B. cereus strains in hospital, that lead to increase antibiotic resistance nosocomial infection and is necessary go on to reduce transfer virulence agent and antibiotic resistant in pathogen bacteria. http://dx.