Microbiological and Genetic Study on NonHemolytic 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.