The Effect of Two Antigen Preparations From Group A Streptococcus on Phagocytosis and Cellular Counts of Neutrophils and Monocytes in Albino Mice

Abstract

The phagocytic activity of peritoneal and blood cells counts with neutrophils and monocytes were evaluated in albino mice treated wtth two antigen preparations (A and B) from group A streptococci (GAS). Antigen A included water bathed bacteria at 70 °C for 60 minutes, while in Antigen B the bacteria was autoclaved at 121° C for 15 minutes. The animals were treated with 12 intraperitoneal doses of the antigens with intervals of three days (36 days). The 12th dose was a challenge dose (live bacteria). The first three doses of Antigen A increased the phagocytic index (PI) to a range of 76.46-78.69%, then a gradual decreased percentage was observed, especially at the challenge dose (PI=6.42%). The count of neutrophils and monocytes followed a similar behavior. Treating the animals with Antigen B also elevated the PI, especially at the first three doses (range: 73.86-77.17%). The rest of doses showed a gradual decreasing even at the challenge dose, but the PI values were still higher than the corresponding one in the control (PI=18.66%). Similarly, Antigen B shared the effect of Antigen A in effecting the count of neutrophils and monocytes with some dose fluctuation.