Document Type : Original Article(s)
Authors
1
MSc of Microbiology, Department of Food Industrial,Islamic Azad University of Shahraza Branch, Membership of Young Researcher Club. Isfahan
2
Professor, Department of Biology, Faculty of Basic Sciences, University of Alzahra(Tehran), Tehran
3
Professor, Department of Biology, Faculty of Sciences, University of Tehran, Tehran
4
Associate Professor, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan
Abstract
Background: Over the past 3 decades of research, it has become apparent that one of the most common surface structures on the archaea and bacteria are monomolecular crystalline arrays of proteinaceous subunits, termed surface layer or S-layer. S-layer protects bacteria to the phagocytosis and prohibits the entry of some biomolecules and adhesion molecules to the matrix proteins which increase the stability of infection and antibiotic resistance in virulence agents. Therefore the spread of bacteria which have S-layer in the hospitals should be avoided. Surfaces can serve as reservoirs of potential pathogen and is important in the chain of infection. Surfaces bacteria have low potential to spread, but staff hands have many contacts with hospital surfaces, especially with high contact surfaces. Therefore it could be a potential source of bacteria transmission from surfaces.
Methods: This research was performed between 2005 to 2007, in the Alzahra hospital of Isfahan university of medical sciences. 274 samples were randomly selected (194 sample from surface and 80 sample from staff hand). Environmental samples collected, from high and low contact surface with swab in NB and staff hand. Samples were collected through finger print method and identification of bacteria, were performed with microbiological methods: staining, chemical test, use of differential and selective media. Isolated Bacillus cereus strains, performed with Bacillus cereus Selective Agar, for preparation samples, in first culture Bacteria in TSA, for 16h, then separated surface proteins and finally, specimen's electrophoresis proximally molecular weight marker. S-layer in Bacillus cereus has 97KD molecular weight.
Findings: According to the results, the prevalence of Bacillus cereus strains was %9.49. The prevalence of Bacillus cereus strains in environmental and staff hands were respectively %6.7 and %16.25, and of 13 isolated Bacillus cereus from, staff hand 11 strain (84/6%) and from 13 isolated Bacillus cereus from environmental samples 1 strain (7/7%) production S-layer.
Conclusion:Result show, high prevalence Bacillus cereus in staff hands and hospital surfaces and frequency surface layer in Bacillus cereus isolated of staff hands into hospital surfaces.
Key words: Surface layer, Bacillus cereus, Staff Hands, Hospital Surfaces, Nosocomial Infections.
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