<![CDATA[The present research aimed to study the effect of dietary chitosan supplementation against murineexperimentally infection by Listeria monocytogenes.forty mice were divided equally into 4 groups. The 1st and 2nd groups fed on diet supplement with chitosan(1mg/kg diet) and (1.5mg /kg diet) for (4) weeks respectively, While 3rd and 4th groups considered as controlpositive and negative groups. At (4) weeks the first three groups were inoculated intraperitoneally i/P with(0.2) ml (1×109) CFU/ml, while the 4th group (control negative) inoculated with (0.2) sterile normal saline.At (7) days post infection, the result revealed diet one of mice in each control positive and treated group at(24hrs.) post infection with heavy bacterial isolation from brain, spleen and liver of infected positive groupand mild to absent bacterial isolation in the 1st and 2nd group respectively.Grossly presence of severe congestion in the internal organs with necrotic foci seen on the splenic surface ofinfected positive control while the characteristic feature in the treated infected group was hepatosplenomegaly.Sever pathological changes were noticed in the infected positive control group characterized by suppurativeinflammation with necrosis accompanied with lymphoid depletion and amyloid like substance depositionwhile the main lesion in treated infected groups showed granulomatous lesion, lymphoid hyperplasia andmononuclear cells infiltration with heavy bacterial isolation from brain, spleen and liver of infected positivegroup and mild to absent bacterial isolation in the first and second group respectively, We concluded thatchitosan stimulated and improve the immune responses in mice against Listeria monocytogenes infection.]]>
