Microbiological and Genetic Study on Non-Hemolytic Streptococcus spp. Isolated from X-Ray exposed Technicians and Subjection Isolates to Laser and Plasma Radiation.

This study included isolation and identification of Streptococcus spp. from X-ray exposed patients and healthy persons. From a total of (144) throat samples, (122) swabs obtained from X-ray exposed patients and (20) swabs from healthy persons. The samples were collected from different hospitals and X-ray clinics in Baghdad during the period from October /2010 to June/2011. Results of identification by the biochemical tests of X-ray exposed patients isolates showed that 44(35.4%) isolates were Streptococus spp., 43(27.4%) Staphylococcus spp., 15(12.2%) Bacillus spp.and 31(35%)isolates were belonged to the other microorganisms .While results of identification isolates from healthy persons showed that 9(45%) isolates were Streptococcus spp.,3(15%) Staphylococcus spp., 2 (10%) Bacillus spp. and 6(30%) isolates were belonged to the other microorganisms. Identification of Streptococcus spp. isolated from patients exposed to x-ray by rapid ID32 system showed that (71.4%) isolates were Streptococcus oralis, (14.2 %) S. viridians and (14.2%) S.salvairus. While results of Identification of Streptococcus spp. isolated from healthy persons by rapid ID32 system showed that (57.1%) isolates were Streptococcus oralis, (28.5%) S. feacalis, and (14.2%) S. mutans. Plasmid profile was determined for all Streptococcus spp. isolates. Results showed that all Streptococcus spp. exposed to X-ray lost their plasmid, while only two isolates of Streptococcus spp. isolated from healthy persons possessed a small size plasmid When the susceptibility of isolates toward 8 of commen antibiotics, was tested, results showed that several isolates of Streptococcus spp. isolated from healthy persons were resistant to most of the antibiotics used. The percentages of resistance were 92.8, 85.7, 50, 28.5 and 14.2% of isolates against ampicillin, cephalothin, bacitracin, erythromycin, tetracycline and gentamycin respectively. However Streptococcus spp. isolates exposed to X-rays patients were more resistant to same antibiotics. The susceptibility to antibiotics of Streptococcus spp. isolates of X-ray exposed patients after exposed to diod laser 890nm was increased only toward bacitracin, While Streptococcus spp isolated from healthy persons were more resistance to cephalothin , cefixime and gentamycin ,despite the suscepibility to bacitracin was increased. The ability of Streptococcus isolates for biofilm production was decreased after exposing to diod laser 890nm. Almost same results in antibiotic susceptibility and biofilm production of Streptococcus spp. were obtained after exposure to Non-Thermal plasma, while biofilm production of X-ray exposured isolates was increased after exposure to Non-Thermal plasma.