ABSTRACT
Toxoplasmosis, a zoonotic parasitic disease, is a huge challenge for which there is no effective vaccine up till now. In this study, chitosan nanospheres encapsulated with Toxoplasma lysate vaccine was evaluated for its ability to protect mice against both acute and chronic toxoplasmosis models of infection. Results showed that chitosan nanospheres were equally effective to Freund's incomplete adjuvant (FIA) in enhancing the efficacy of Toxoplasma lysate vaccine. The effectiveness was demonstrated by the delayed death of vaccinated mice following challenge either with virulent RH or avirulent Me49 strains, the significant decrease in parasite density in different organs, significant increase in the humoral and cellular immune response (IgG and IFN γ) with a marked reduction of pathological changes in the different organs. However chitosan nanospheres were superior to FIA due to their cost effective preparation and much less necrotic changes induced in the studied organs. The success of chitosan polymer as an alternative to commonly used adjuvants paves the way for the use of other newly developed polymers to be used in the field of vaccine development.
ABSTRACT
The restriction fragment length polymorphism (PCR-RFLP) of 18S rDNA amplified fragments, was conducted to recognize between an unidentified Leishmania isolated from Egyptian patient infected in Saudi Arabia and two L. major reference strains causing cutaneous lesions. The strains were maintained both in vivo & in vitro. Additional requirement as morphological characterization on basis of the light microscope & scanning electron microscopy and behaviour in experimental Swiss albino mice regarding development of lesions were performed. The results showed that, PCR-RFLP analysis of the 18S rDNA amplified PCR fragments was highly successful to put the unidentified Leishmania strain in the category of L. major. There was no significant differences regarding the cutaneous lesions development. In spite of the significant variations of the morphometric measurements of the three strains were observed.
Subject(s)
Leishmania major/classification , Leishmania major/genetics , Polymerase Chain Reaction/methods , Polymorphism, Restriction Fragment Length , Adult , Animals , Genotype , Humans , Leishmania major/growth & development , Leishmania major/isolation & purification , Leishmaniasis, Cutaneous/parasitology , Leishmaniasis, Cutaneous/pathology , Male , Mice , RNA, Ribosomal, 18S/analysis , RNA, Ribosomal, 18S/geneticsABSTRACT
Antigenicity of the tegumental extract, excretory-secretory products and the whole somatic extract of Fasciola gigantica were evaluated to detect the most sensitive and specific antigen out of them that could be used as an immuno-diagnostic tool. Scanning electron microscopic study was carried out to have a full picture about the tegumental structure. The immunohistochemical staining technique was done using the indirect immunoperoxidase method on F. gigantica sections before and after removal of the tegument to recognize the most antigenic parts by using patients sera. Counter immunoelectrophoresis was carried out by using sera from patients with fascioliasis (positive control), patients with schistosomiasis and healthy individuals (control group). In addition, antibody response against the three types of antigens was detected as ELISA absorbance readings. The results revealed that antigens of F. gigantica that cause antibody formation in hosts are those generated and released mainly from the tegument. They were the most sensitive and specific.
