Background: Strongyloides stercoralis is prevalent in tropical and subtropical regions of the world. S. stercoralis is the only nematodes with the ability to multiply in its host's body via autoinfection transmission. Larvae detection in faeces is difficult partly because of low egg production and irregular larvae excretion in faeces. Serologic tests (ELISA, IFA) are also diagnostic; however, S. stercoralis antigens are not available as a diagnostic tool. In the present study, we analyzed filariform larva (U) proteins of S. stercoralis by the immuno blot technique.Materials and methods: Stool samples were examined by direct smear, formalin-ether and agar plate method to identify the patients. Sera were stored at 20°C. Filariform larvae were obtained by agar plate culture, which was incubated for 6-7days at 25°C, then frozen at - 70°C. Finally, larvae were suspended at a concentration level of 12000 in 250ml PBS, containing protease inhibitors and then sonicated. Protein level was measured by Bradford method. Proteins of S. stercoralis filari form larvae were separated by SDS-PAGE, blotted onto nitrocellulose paper. Western blot analysis of these antigens was achieved using infected human sera (0.1, 0.01, 0.001 dilution) with strongyloidiasis, toxocariasis, hydatidosis, amoebiasis and normal human serum as control.Results: Four immunodominant proteins (23, 28, 30, 41 kDa) were recognized with strongyloidiasis sera in O.ldiluted serum. None of the proteins reacted to normal human and amebiasis serum, but some showed reaction with serum of hydatidosis and toxocariosis. Having increased the level of serum dilution, only 41 kDa protein was recognized by strongyloidiasis sera. Other sera did not show any reaction to the parasite's proteins. Therefore, the 41 kDa protein presents as most important immunodaminant protein in this study.Conclusion: The identification of immunodominant proteins, which have adapted themselves to the physiological and genetically conditions of the host is an appropriate diagnostic approach. Indeed, recombinant protein, such as 41 kDa, could enhance the sensitivity and specificity of serologic tests.

Salmonella abortus ovis is the main causative agent of sheep abortion in Iran. Study of major antigens among different S.abortus ovis strains seems to be useful for designing the effective vaccine. In this experiment 37 S.abortus ovis strains were studied. Western- blot method has been applied to detect major antigens in S.abortus avis strains. All strains developed 5 and 3 major antigens respectively for SS44 and CH-Bakhtiary strains and Varamin strains. Antigens with 26, 15-20 and less than 9 kD yield more effective reaction with serum antibodies. Band of 26kD was identical among all strains. Different S.abortus avis strains revealed both identical and non identical antigens that not only could be used for further epidemiological studies but also assist designing of more effective vaccines for local and universal applications.

Introduction and Objective: Burkholderia mallei, is the etiologic agent of the glanders disease. Clinical and bacteriological diagnosis of glanders is difficult in the early stages of the disease. Some methods such as Complement fixation test (CFT) due to false positive results and troublesome for veterinary authorities and cause financial losses to animal owners, the other one is Malleination test, which requires appropriate equipment and efficient laboratory personnel. Therefore, in order to quickly and accurately diagnose the disease, especially in areas that cannot be kept animals, new methods should be used to identify the disease. The Western blot is a serological diagnostic test and has been recommended by the World Organization for Animal Health (OIE). The aim of this study was to apply Western blot assay using purified lipopolysaccharide (LPS) containing antigen of Burkholderia mallei was designated. Material and Methods: In this study, a total of 75 sera were collected from different horse populations from several geographical areas of Iran. Specificity and sensitivity of the Complement fixation test, ELISA and a Western blot were compared for serodiagnosis of glanders. ELISA test was based on B. mallei antigens and Western blot by using of a purified LPS-containing B. mallei-antigen. Results: The Western blot and ELISA were more specific than the Complement fixation test. ELISA based on B. mallei antigens had more sensitivity compared to Complement fixation test and Western blot. Finally, sensitivity and specificity were obtained for Complement fixation test (92. 31% and 98. 38%), Western blot (92. 31%, 100%) and (100% and 100%) respectively. Conclusion: Complement fixation test for glanders is still the prescribed serological method for commercial purposes, which is used to confirm the health of animals. However, in order to maintain the biosafety of valuable and expensive horse colonies, it is important to implement a more accurate and intelligent disease control and eradication program. This enhances the laboratory diagnostic capabilities to better understand the cause of the disease and to use and optimize the diagnostic methods of glanders in the country. Therefore, efforts to further improve and optimize ELISA and Western blotting should be continue.

Background: Visceral leishmaniasis (VL) is endemic in the northwest and south of Iran. Untreated cases of VL could cause death. The aim of the present study was to evaluate the diagnostic performance of western blotting to detect a specific immunodominant proteins pattern for Leishmania infantum infection using human sera infected with VL. Methods: We studied a panel of 122 cryopreserved human serum samples from the leishmaniasis Research Laboratory, Tehran University of Medical Sciences, Tehran, Iran from 2010 to 2017. Serum samples were collected from visceral (Group I, n: 43) and cutaneous leishmaniasis (CL) (Group II, n: 8) patients, healthy individuals from endemic (Group III, n: 13) and non-endemic (Group IV, n: 16) areas for VL, and patients with other infectious diseases (Group V, n: 42). Total antigens were prepared from the Iranian strain of L. infantum promastigote form. Results: In western blotting method, 34 protein bands of 14 to 163 kDa were recognized using the sera of VL patients. The polypeptide fractions with the highest frequency including 29, 51, and 62 kDa fractions were detected using 81. 4%, 79%, and 81. 4% of the sera, respectively. These bands were not detected using the sera of the negative control. Moreover, 19-23, 27, 31-35, 143-163, and 109 kDa fractions were detected specifically using the sera of the patients with VL. Conclusion: This technique could be a primary step for further exploration of VL immunodominant antigens for cloning (or any technique) further investigations for future planning.

Background and Aims: HIV is spreading rapidly among people word wide. Infection with this virus leads to immune suppression and finally acquired immune deficiency syndrome (AIDS).Early HIV detection is depended on antibody screening against virus by Enzyme Linked Immunosorbent Assay (ELISA).Some confirmatory tests such as, Western Blot and Recombinant Immunobloting Assay (RIBA), are used to verify viral infection. Many of confirmatory tests results are indeterminate. The aim of this study is comparing the frequency and patterns of indeterminate results in two groups, blood donors and patients with high risk behaviors, in northeast of Iran.Materials and Methods: From October 2009 to March 2014 total number of 1055 serum samples with previous positive HIV ELISA test history, were tested in our laboratory. Some by RIBA and some by western blot method.Results: Most of indeterminate results belonged to blood donors that were tested by Western Blot analysis and were positive. The most reacting band was P24 in both methods and groups.Conclusion: RIBA assay is more sensitive and reliable than western Blot, but it’s necessary to use other supplementary tests with less indistinctive results.

In Leishmania (L.) major-infected BALB/c mice Th2-type cells results in disease progression, whereas C57BL/6- infected mice mount a Th1-type response, which leads to control of the infection. Th2 response correlates with IgG1 whereas, Th1 response supports switching to IgG2a subclasses. Since IgG isotype-dominated response depends on different CD4+T cell subsets, we studied the antigenic profile of L. major promastigotes that induce IgG1, IgG2a and IgG2b isotypes in BALB/c and C57BL/6 mice to provide insight into Th1 and Th2 inducing antigens. Humoral immune responses were studied in sera from L. major-infected BALB/c and C57BL/6 mice by ELISA and immunoblot analysis. These techniques were used to detect IgG, IgG1, IgG2a, and IgG2b antibodies against crude promastigote antigens. BALB/c mice showed higher IgG, IgG1 and IgG2a antibody levels compared to C57BL/6 mice (p<0.01). The IgG2a/IgG1 ratio was higher in C57BL/6 mice. There was no significant difference in IgG2b level between susceptible (BALB/c) and resistant (C57BL/6) mice. Western blot analysis revealed that 27, 32, 117, 125 and 153 kDa bands reacted only with IgG1 from both mice strains. The 41, 45, 47, 52 and 55 kDa bands reacted only with IgG2a from C57BL/6. A very similar pattern of immunostaining was observed for IgG2a and IgG2b in each mouse strain. The results from both mouse strains indicate that some antigens react exclusively with IgG1, the antibody, which may be involved in generation of a predominant Th2 response. The antigens that reacted strongly with IgG2a in C57BL/6 are potential candidates for eliciting protective Th1 response.

Ticks are important ectoparasites which are a considerable threat to human beings and to animals all over the world. Enormous economic losses annually occur in livestock production around the world as a result of their existance. One of the ways to control ticks and tick-borne diseases is to introduce resistance to these ectoparasites through immunization. For identification of the putative protective antigens, screening of large number of parasite antigens and their fractions are necessary. In this study, midguts of fed adult female Hyalomma anatolicum anatolicum were used to prepare antigen and to identify the midgut profile. Polypeptide profile was analysed by SDS-PAGE with 12.5% concentration under denaturated conditions and discontinuous buffer system. Humoral immunity and antigenic pattern were evaluated by Western blot. A total of 4 fractions were observed in the polypeptide profile. The molecular weight of the fractions was 97, 84, 66 and 55 kDa. The band with molecular weight of 66 kDa was dominant. Positive reaction with 84, 66 and 55 kDa bands were observed in immuno-blot of the midgut antigens.