Abstract
This study which included (45) diabetic patients at age groups (11-71) years, fifteen male and thirty females compared with normal control, 5 male and 10 females showed a significant decrease in the bactericidal activity of the serum using diabetic sera containing high glucose concentration while those containing low glucose concentration showed a clear bactericidal activity. The results also showed a significant a decrease in the phagocytic activity of neutrophiles among the diabetic patients compared with the control group. The isolates of Alcaligenes showed sensitivity toward non-immunized human serum, A. faecalis showed high sensitivity toward the serum while the subsp A. Xylosoxidans. denitrificans and A, Xylosoxidans xylosoxidans are showed different sensitivity toward non -immune serum after (3) hours of incubation.