Assistant Lecturer Fathaa Abdulaah Mahmoud

The present study aimed to investigate the effect of cryptococcal sonicated antigen and chitosan on the infection with this fungus which isolated from human skin lesions.

In order to achieve  this goal, usage of  Cryptococcusneoformansisolate which was isolated from human skin lesion in order to prepare the sonicated antigen also  60 white mice from  both sexes, at average age 8-10 weeks were getted and divided randomly into 4 groups equally and treated as following:

fifteen (15) mice were immunized with 0.5ml of WSC Ags (protein concentration14mg/ml )S/C two doses ,one week interval.

fifteen (15) mice were fed  diet supplemented with chitosan 1g/kg diet for 6 weeks.

fifteen (15) mice were immunized as 1st group and at the same time fed diet supplemented with chitosan as 2nd group.

fifteen (15) mice, which seted as control positive group.

At day 28-30 post-immunization. skin and  indirect  passive haemagglutination  tests  were done ,then 1st  ,2nd ,3rd ,and 4th groups were inoculated intraperitoneal with  0.3 ml of fungal suspention containing 1X10⁷fungal cells, all animals were sacrificed at day 30 post-infection.

The study shows that the immunized animals with WSCAgs expressed high values ofdelayed type hypersensitivityand high levels of Abs titer as well as the chitosan stimulate the immune system, whileall animals of control positive  were died at the first week post-infection.

There are  no clear lesions in the kidney and brain and the lesions in the spleen and lung aremarked  proliferation of  lymphocytic cells in the periarteriolar sheath and  proliferation of  mononuclear cells  around sinuses form cord like appearance  , the liver  showed  mature granulomatous lesion consisting of aggregation of active macrophages in the liver parenchyma ,in  other animals ,The liver showed multiple granulomatous lesions in portal area consisting of aggregation of epithelioid cells, macrophages ,lymphocytes around few degenerative  yeast cells and surrounded  by fibrous connective tissue ,the fibrosis infiltrated with  large  number of mononuclear cells extended to capsular region. infected animals   were died during the first  2 weeks post-infection with severe fungal cells isolated from internal organs  and severe  suppurative  inflammatory reaction in the examined organs during early stage  of infection  with granulomatous lesions appear at day 14 post-infection .while no mortality  rate was seen in animal fed diet supplement with chitosan  with or without immunization  moderate fungal isolation and granulomatous lesions were recorded in the examined organs of animals sacrificed at day 30 post-infection

It concluded that cryptococcal sonicated antigen  and  chitosan play important role in protective immunity against C.neoformansinfection.

Full article is published on the Iraqi Journal Veterinary Medicine.