Expression, purification and characterization of three overlapping immunodominant recombinant fragments from Bordetella pertussis filamentous hemagglutinin

Filamentous hemagglutinin [FHA] is one of the most important immunoprotective antigens of Bordetella pertussis [B. pertussis] and a major component of the acellular pertussis vaccine. In the present study, three overlapping recombinant fragments from the immunodominant region of FHA were produced and their immunogenicity was investigated. Three overlapping coding sequences of FHA antigen were amplified from B. pertussis genomic DNA by PCR. Amplified fragments were expressed in Escherichia coli [E. coli] BL21[DE3] strain and purified through His-tag using Nickel-based chromatography. Purified fragments were characterized by SDS-PAGE and Western blotting techniques. In vitro peripheral blood mononuclear cells [PBMC] proliferation and IFN- gamma production were assessed in a limited number of healthy adults vaccinated with a commercial acellular pertussis vaccine in response to all purified FHA fragments by H3-Thymidine incorporation and ELISA, respectively. Recombinant FHA segments were successfully cloned and produced at high levels in E. coli BL21[DE3]. SDS-PAGE and Western blot analyses confirmed their purity and reactivity. All three recombinant fragments together with a commercial native FHA were able to induce in vitro PBMC proliferation and IFN- gamma production. Our preliminary results suggest that these overlapping recombinant FHA fragments are immunogenic and may prove to be immunoprotective

Leptospirosis in flat area of Guilan province, Iran, in 2005

Leptospirosis is a widespread zoonosis in the world and is more prevalent in tropical and temperate regions. Flat area of Guilan province is the only endemic area of human leptospirosis in Iran. In 2005, a study was done to investigate the incidence of leptospirosis in the area. We collected blood samples from patients who attended three big general hospitals in the region with clinical presentation consistent with leptospirosis. All sera were examined by a quantitative Igm-Elisa and also by the Microscopic Agglutination Test [MAT] by using 18 standard strains. Sera which were positive in quantitative 19m-Elisa and had titers =160 against at least one pathogenic serovar in mat, were regarded as positive cases [170 from 482]. Analysis of demographic and epidemiological data of positive cases showed that leptospirosis is a disease of predominantly males [62.50%], occurring in high incidence in villagers [89.50%], mainly during the warm season [100%] and notably in September [42.90%]. In addition it is an occupational disease affecting mainly rice field workers [about 90%]