Ameliorative and Disinfection Effects of Ultraviolet-C Radiation on Experimentally Induced and Infected Skin Wounds: A Mice Model Study.

Only ultraviolet-C (UV-C) from UV lights, which are emitted by the sun and absorbed by the atmosphere's ozone layer, does not reach the Earth's surface. UV-C is a powerful disinfection method that is commonly used to sterilize fluids, air, and surfaces. There is a little knowledge of the effects of UV-C radiation on living bodies. The purpose of this study is to examine the ameliorative effect of UV-C on skin lesions in mice that have been experimentally created and infected with Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus sp. In total, 32 mice were used, and 4 mm skin defects were created and lesions infected with bacteria. Half of the mice in each group were treated with 254 nm UV-C twice a day for 4 days before being euthanatized. Blood samples were collected for hematological analysis, while skin samples were collected for microbiological, pathological, and immunohistochemical examinations. In addition, pathological examinations were performed on visceral organ samples. UV-C treatment caused rapid healing and complete or significant disinfection of skin lesions. Moreover, UV-C treatment reduced caspase-3 expressions in lesioned areas, according to immunochemistry. There were no pathological findings in visceral organs as a result of UV-C treatment. This study found that UV-C can be used to treat and disinfect infected skin lesions in short period and repeated doses.

Lancefield classification and antimicrobial resistance of hemolytic streptococci isolated from bovine mastitis.

Streptococcal species are known to be responsible for bovine mastitis. The aim of the present study was to determine antimicrobial drug resistance patterns of hemolytic streptococci distributed according to Lancefield serogrouping. Streptococcus sp. strains were isolated from 124 bovine milk samples from 31 cows with subclinical or clinical mastitis submitted to Mehmet Akif Ersoy University Faculty of Veterinary Medicine, Department of Microbiology Laboratory in Burdur province, Turkey from January 2015 to January 2017. A total of 63 Streptococcus sp. were isolated and the most frequently obtained isolates were classified as Lancefield's serogroup B (84.13%), the remaining isolates as serogroup F (15.87%). Out of 63 isolates, 53 (84.13%) showed beta­hemolytic activity whereas 10 (15.87%) alpha­hemolytic activity. Antimicrobial resistance was assessed by disk diffusion test against the most common antibiotics used in the field. Among the 63 Streptococcus sp. tested, the highest antimicrobial resistance patterns were observed for neomycin (95.24%), trimethoprim sulphamethoxazole (87.30%) and gentamicin (69.84%). None of the isolates showed resistance to amoxicillin­clavulanic acid, except for one serogroup F isolate. The resistance rates for the other antimicrobials ranged from 1.59% to 38.04%. A total of 50 isolates exibited multi­drug resistance to ≥ 3 antimicrobial agents tested. Overall, our results suggested that there is an urgent need to enhance awareness among the dairy farmers in choosing the appropriate drug for treating mastitis.