Crystalline layer is the outermost protein in bacteria and archiae, and it inhibits antibiotics introduction due to increase of pathogenicity in bacteria. According to the role of health care workers and hospital surfaces in nosocomial infections, contamination of this source with Bacillus cereus strains produce crystalline layer and beta lactamase as a result of the spread of antibiotic resistance of nosocomial infections. The aim of this study is to survey the frequency of nano structure of crystalline layer and beta lactamase nano enzyme, and the role of crystalline layer in antibiotics inhibition in B. cereus strains isolated from health care workers and hospital surfaces. The research was performed with laboratory method in Azzahra hospital and Isfahan University. 274 samples were used for the preparation samples, which include culture bacteria in TSA (tryptone soya agar), separated surface proteins and specimen's electrophoresis with 10X SDS-PAGE. Samples antibiogram were performed with Kirby Bauer method, and beta lactamase production was detected with acidimetric method. Based on the result of SDS-PAGE, 46.20% of the studied. B cereus strains were able to produce crystalline layer and 53.8% were unable to produce crystalline layer. According to the antibiogram result, the nonproducer strain of crystalline layer, when compared with the producer strain was sensitive to antibiotics and to all the strains that produced crystalline layer and beta lactamase. The result showed high prevalence of B. cereus strains that produced crystalline layer and beta lactamase in the hospital sensitive environment, due to increase of the antibiotic resistance of nosocomial infection. As such, it is necessary to reduce the transfer of virulence agent and antibiotic resistance in pathogen bacteria.

No abstract

The most common surface structures bacteria are monomolecular crystalline arrays of proteinaceous subunits termed surface layers or S-layers. Since S-layer-carrying organisms are ubiquitous in the biosphere and because S-layers represent one of the most abundant cellular proteins, it is now obvious that these metabolically expensive products must provide the organisms with an advantage of selection in very different habitats. S-layers have been associated with a number of possible functions that relate to pathogenicity. S-layers can function as adhesins, enabling the bacterium to adhere to host cell membranes and tissue surfaces in order to colonize and protect bacteria from harmful enzymes and antimicrobial agents or changes in pH. Bacillus cereus is one of nosocomial infections bacteria. B. cereus produces several potential virulence factors such as S-layer. A total of 274 strains were isolated from staff hand and hospital surfaces of Azzahra-hospital during 2005 to 2007 years. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of S-layer proteins extracted from B. cereus strains by using Tris-HCl (pH 8) showed that the S-layer proteins of different strains isolate of staff hands and hospital surfaces had subunit molecular weight of 97-kDa. Antibiotic susceptibility was performed according to antibiotic susceptibility standard disc diffusion agar. All the statistical analyses carried out using SPSS version 14. Chi-square and fisher test used for determination of significance of association. The p≤ 0.05 was considered significant. From 247 bacteria, frequency of B. cereus strains was 9.49%. From 13 isolated B. cereus of, staff hand 11 strain (84/6%) and from 13 isolated B. cereus from hospital surfaces, 1 strain (7/7%) production S-layer. According to the antibiogram result, S-layer non producer strains, in comparison with S-layer producer strains, were more sensitive to antibiotics. The result showed high prevalence of S-layer producer of B. cereus strains in hospital; and this point is due to the increased antibiotic resistance of nosocomial infections.

Health care workers and hospital surfaces have important role in nosocomial infection, if resistance strain transfer to hospitalized patients, led to spread of antibiotic nosocomial infections. The research was laboratory and performed during 2005/2007 years in Azzahrahospital in Isfahan. According to statistical formula study on147 Staphylococcus species isolated from clinical samples, skin hands of health care workersandhospital surfaces. Bacterial identification, were performed with microbiological methods and bet lactamase product was performed with Acidometric method. According to Acidometric result 100% and 50% of S. aureus and S. epidermidis isolated from clinical samples and 75% and 66.6% of S. aureus and S. epidermidis isolated from skin hands of health care worker and 84.6%, 70.45% and 75% of S. aureus, S. epidermidis and S. saprophyticus isolated from hospital surfaces can produce beta lactamase Nano enzyme. Result demonstrate high prevalence of resistance antibiotics Staphylococcusspp. isolated from clinical, biotic and abiotic conditions in hospital. One of reason creative antibiotic resistant in bacteria is increase contact of sensitive bacteria with resistance strains.

Nursing staff have important roles to play in nosocomial infections. Antibiotic resistance is the ability of a microorganism to withstand the effects of an antibiotic; it evolves naturally via natural selection through random mutation, but it could also be engineered. The purpose of this study was to survey the relative frequency of antibiotic resistant strains in isolated bacteria from nursing staff. The present study was performed at one of the tertiary care hospitals in Isfahan, Iran, during a 24 month period (2007 to 2009). Eighty bacterial isolates from nursing staff were studied. Samples were collected with finger print method. Standard microbiological methods were performed for the detection of bacterial species. Bacterial antibiogram pattern according to Clinical and Laboratory Standards Institute (CLSI) 2010, were used by disk diffusion method. The result showed that Staphylococcus spp. 28 (53%), Bacillus spp. 48 (60%) and Enterobacteriaceae 4 (5%) were constituents of the isolated bacteria from nursing staff. According to the antibiogram pattern, 17.