Characterization of immunoreactive proteins of Setaria cervi isolated by preparative polyacrylamide gel electrophoresis.

Filarial parasites are complex mixtures of antigenic proteins and characterization of these antigenic molecules is essential to identify the diagnostically important filaria-specific antigens. In the present study, we have fractionated the somatic extracts from adults of Setaria cervi (bovine filarial parasite) on preparative SDS-polyacrylamide gel electrophoresis and tested the immunoreactivity of the separated gel fractions with polyclonal antibodies against filarial excretory-secretory antigens as well as filarial patients sera. The SDS-PAGE analysis of gel eluted fractions revealed 1 protein band in F-1 fraction, 2 protein bands in F-2 fraction and 2-3 protein bands in all other fractions (F3- F11). Seven gel eluted fractions (F1, F2, F3, F4, F5, F6 and F11) showed high ELISA reactivity with the polyclonal antibody (against excretory-secretory antigen) and four of these fractions (F-1, F-2, F3 and F6) exhibited high ELISA reactivity with antibodies present in filarial patient sera. The reactivities of the gel fractions (F1 and F2), recognized by filarial patients sera, were also tested with the monoclonal antibody (detecting the filarial circulating antigen). The F1 and F2 gel eluted fractions were found to have the target antigen of monoclonal antibody as evident by high reactivity with the monoclonal antibody in ELISA and immunoblotting. The S. cervi gel eluted F1 fraction (containing single antigen) could detect antibodies in filarial patients sera and not in non-filarial sera thereby suggesting its usefulness for specific serodiagnosis of human filariasis.

Setaria equina: in vivo effect of diethylcarbamazine citrate on microfilariae in albino rats.

Although diethylcarbamazine citrate (DEC) is successful drug in eliminating human filariasis, yet, its mode of action is still debatable. Herein, the effect of DEC to treat albino rats infected with the animal filarial parasite Setaria equina was tested. Microfilarial (mf) counts and sections from liver, lung, kidney as well as spleen were investigated at different time points after treatment by light microscopy. After 45 and 300min of treatment, a significant decrease in blood mf was observed accompanied by adherence of degenerated mf to both kupffer cells and leukocyte in liver sections. In lung sections, loss of sheath was observed at 45min, while degeneration was observed at later time points. In kidney sections, more mf counts and less matrix were observed in the glomeruli at all time points after treatment. Degenerated mf were observed in spleen sections only at, late time point, 480min after treatment. In conclusion, one of the possible mechanisms by which DEC reduces blood microfilarial count is trapping larvae in organs and killing them through cellular adherence.

Incidental isolation of Setaria equina microfilariae in preparations of equine peripheral blood mononuclear cells.

In the course of a vaccine experiment on horses, microfilariae were observed in cultures of peripheral blood mononuclear cells (PBMCs) isolated from eleven of fifteen study horses. The microfilariae were clearly viable as evidenced by their vigorous movements in the cultures, thus indicating that they had survived the Ficoll gradient purification and the cryopreservation method used for retaining the PBMCs. The microfilariae were identified as Setaria equina, which is a vector-borne filarial nematode that causes a relatively benign infection of equids in which the adult worms reside in the peritoneal cavity. Although it is not possible to definitely state where the infections were acquired, the horses originated from Saskatchewan, Canada and spent a relatively short period of time in the United States prior to blood sampling. Therefore, it is likely that the infections occurred in Canada. Interestingly, assays conducted to determine levels of cytokine mRNA transcripts in the isolated PBMCs seemed to be largely unaltered by the presence of the microfilariae in the cell cultures. These findings demonstrate that a standard method used to purify and cryopreserve PBMCs from blood can result in the unintended co-isolation of worms from microfilaremic animals. Furthermore, the presence of the microfilariae did not appear to alter significantly the results of our immunologic assays, suggesting either that the nematode antigens were not recognized or that immunological tolerance may have developed in these horses. Although notable effects on the assays were not observed in this study, it seems possible that microfilarial contamination could represent a confounding variable for experiments examining cellular immunity.

[Increase of infection of European bison by nematodes Setaria labiatopapillosa in Bialowie a Forest]. / Wzrost zarazenia zubrów w Puszczy Bialowieskiej nicieniami Setaria labiatopapillosa.

BACKGROUND: The aim of these studies was to determine the level of infection of European bison by nematodes belonging to the genus Setaria. MATERIAL AND METHODS: From February 2006 to February 2007 21 bisons from 6 months to 20 years old shot in Bialowieza Forest have been examined. During the necropsy pleural and peritoneal cavities were macroscopically examined for the presence of nematodes. The parasites were removed from tissues and fixed in 70% ethanol with 5% addition of glycerol and then identified to the species. Samples of blood were taken from shot bison and after centrifugation in microhaematocrit tubes directly examined to confirm the infection. RESULTS: Nematodes Setaria labiatopapillosa were found in 71% of examined bisons. They usually laid freely in peritoneal cavity and sometimes also in pleural one. Accidentally single nematodes were observed in omentum on the surface of omasus and on the surface of liver surrounded by connective tissue. Intensity of bison infection by S. labiatopapillosa varied from 1 up to 24 specimens. Both young and old animals were infected with these nematodes. Observed after 3 years period over 30% rise of prevalence of nematodes S. labiatopapillosa, occurrence of these nematodes in all age groups of this host, and high intensity of infection are alarming. Although these nematodes in their typical localization and low level of infection do not evoke visible symptoms, the pathogenity of this species of nematode is not yet sufficiently recognized, and it is the reason, that monitoring of this infection in bison is necessary.

Setaria equina infection of Turkish equines: estimates of prevalence based on necropsy and the detection of microfilaraemia.

Necropsies on 43 horses, 35 donkeys and two mules slaughtered in Ankara, Turkey, revealed that 12 (15%) of the equines harboured adult Setaria equina. When blood samples were checked for microfilariae, using Knott's method and a combination of membrane filtration followed by histochemical staining for acid phosphatase (AP), only three (4%) of the animals were found to be microfilaraemic. When stained for AP, the S. equina microfilariae exhibited diffuse red staining over the entire body, including the sheath, with brighter staining around the anal and excretory pores. Application of Knott's method revealed only two of the three microfilaraemias detected using the combination of filtration and AP staining. The combination may represent a useful technique for the detection of equine microfilaraemia.

Prevalence of microfilariae in cattle at slaughter in Zaria, Nigeria.

Skin snips and blood taken from 372 randomly selected slaughtered cattle in Zaria, Nigeria were examined for microfilariae. A total of 293 (78.8%) skin snips and 218 (58.6%) blood samples were positive for microfilariae. Two types of microfilariae, identified as Onchocerca armillata, with a percentage prevalence of 64%, and O. gutturosa with a prevalence of 40% were isolated from the skin. The blood microfilariae were identified as those of Setaria labiatopapillosa.

Serum protein changes and their correlation with antibody production in rabbits following induced Setaria cervi infection.

The sera obtained from normal control and Setaria cervi infected rabbits were analysed weekly both qualitatively and quantitatively. Electrophoretic studies as well as biochemical estimation reveal an increase in total protein and globulin and a decrease in albumin level. The changes were more marked in the third week, followed by a declining phase reaching an almost normal level by the sixth week. The increased globulin level analysed electrophoretically also coincided with the appearance of 2 precipitin arcs in immunoelectrophoretic analysis indicating a correlation between antibody production and hyperglobulinaemia.