Fifty eight isolates of Streptococcus agalactiae were obtained from wound and urine specimens among one hundred thirty six from patients with diabetes mellitus and identified through cultural, morphological, and biochemical examinations in addition to VITEK 2 Compact System. All of the isolates were tested regarding their sensitivity to 18 antibiotics and the results showed that all of the isolates were resist to clindamycin, and sensitive to teicoplanin. The current study was carried out to use two methods (ie microtiter biofilm and Congo red agar) so as to provide and extend insight into bacterial colonization and biofilm formation among diabetic patients. The two methods were compared and the results revealed that microtiter was the best method for biofilm detection, and two chemical materials (ie silver oxide, and iron oxide) were used as anti-biofilms for all isolates, one of the best concentration and kind of chemical materials was Iron oxide at 75 mg/ml for reducing biofilm formation. PCR system was employed in order to detect the virulence genes (ie lmb gene), the results that 30 (51.72%) were positive for lmb genes.