The human skin encompasses a vast diversity of microbial normal flora including Coagulase-Negative Staphylococci (CNS). CNS comprise the gram positive bacterium of Staphylococcus epidermidis as the most common colonizer of the human body which involves armpits, inner surfaces of nares. The predominant strains of S.epidermidis support health of the skin against pathogenic bacteria like Staphylococcus aureus. However, some opportunistic pathogenic strains of S.epidermidis are recognized as device-related bacterial infectious agents. Besides, a wave of Methicillin-Resistant S.epidermidis (MRSE) has been distinguised among nosocomial infectious isolates (1-6).
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In the next step, the total genomic DNA of the four samples including control and irradiated colonies were extracted by DNP kit through following company’s protocol (50T, CinnaGen Inc.) (4, 8)
In the following step, the harvested DNA molecules relating to each studied group were running on agarose gel electrophoresis comprising ethidium bromide 1%. Furthermore, a DNA weight marker III (size marker) produced by CinnaGen Company was applied to compare and analyze the created bands. The density of RNA molecules was ignorable and not significant. In the final stage, the created DNA molecules bands belonging to control and UVB-exposed S.epidermidis bacterial cells were assessed for probable DNA laddering bands as a symbol pattern of programmed cell death (4, 7-12) (Figure 1).
A complete evaluation on macroscopic and microscopic properties pertaining to control and UVB-irradiated bacterial colonies of S.epidermidis was achieved for detecting presumable variations. The outcome of observations devoted neither macroscopic nor microscopic differences in control and UVB-exposed colonies.
Also, the control and UVB-irradiated samples were investigated from molecular charactersitcs. No dissimilarity and alternation including smear, DNA laddering bands or any deformities was recognized in DNA patterns pertaining to 10-minute-UVB-exposed and control samples (Figure 1). The practice was repeated two times.
The high rating of resistance to different antibiotics such as aminoglycosides, macrolides, methicillin, tetracyclines and vancomycin among S.epidermidis strains isolated from patients with nosocomial infections encourages physicians and clinicians to use the strategy of therapeutic photomedicine approaches for treating skin infectious diseases caused by drug-resistant strains of S.epidermidis (5, 13-16).
Ultraviolet or the beam of beyond violet is a limited spectrum (200-400 nm) including UVC, UVB and UVA which is located between visible and X-ray wavelenghths. UV radiation (UVR) has apoptotic, carcinogenic and mutagenic (DNA damage) side effects in both eukaryotic and prokaryotic cells. However, a beneficial reaction of vitamin D sythesis is detected when the epidermis layer of the human skin is exposed to UVB light (2, 4, 7-12, 17).
UVB beams are more powerful and much more erythemagenic than UVA rays. However, UVA beams are able to penetrate deeper than UVB rays into...