Since an oligomannose-coated liposome (OML) vaccine strategy has been shown to induce a T helper-type 1 (Th1) immune response, it might be a suitable method to control the early stage of African trypanosomosis. In order to
evaluate the adjuvant effect of OML, the present study was conducted to investigate the effect of bovine serum
albumin (BSA)-encapsulating OML (BSA + OML) on host immunity and the Trypanosoma brucei gambiense infection in mice. Immunization with the BSA + OML induced strong ex vivo proliferation
of lymphocytes, and the cultured cells notably produced interleukin (IL)-2, interferon (IFN)-γ, tumor necrosis factor (TNF）-α,IL-6, IL-10, IL-4, and IL-5. The sera from the mice immunized with BSA + OML displayed
the similar cytokines profile, but, in addition, they contained IL-12p70. Following T. b. gambiense infection, the
BSA + OML group exhibited a significantly reduced number of the parasites, slightly delayed survivals, and the
reduction of IL-10 in the sera as compared to the other groups, possibly due to a skewed Th1 immune response. Therefore, the OML-based vaccine described here could provide a platform to apply for various protozoan diseases susceptible to Th1-immunity as a vaccine adjuvant.
Trypanosoma evansi from buffalo, cattle and horse isolates were purified by Diethylaminoethyl cellulose
column chromatography. The purified trypanosomes from each sources were used separately for preparation
of whole cell lysate antigens. A comparative study on polypeptide pattern of whole cell lysate antigens of
these three isolates of T. evansi was studied. It showed a total of 11 dominant polypeptide bands with relative
molecular weight ranging from 95 to 13 kDa, when resolved in 10% sodium dodecyl sulphate
polyacrylamide gel electrophoresis and stained with Coomassie brilliant blue. Except some minor differences
between the relative molecular weight of isolates in a particular region, the polypeptide profiles of these
three isolates did not resolve any significant differences between them. Seven major polypeptides of relative
molecular weight ranges between 86-87, 74-75, 61-62, 51-53, 39, 34-35, 13 kDa and four minor
polypeptides ranges 93-95, 46-47, 28-29, 25-26 kDa appeared as common to all T. evansi of different hosts
origin and these were shared by all the isolates. A doublet band of relative molecular weight ranging between
86-87 kDa and 74-75 kDa appeared in the area between 66 and 97 kDa and a doublet band of relative
molecular weight 39 kDa and ranges 34-35 kDa also appeared in the area between 43 and 29 kDa in these
three isolates. It is opined from the result that antigenic variation due to change in VSG of T. evansi is not a
constant phenomenon. It is relative, depending on some intrinsic factors related to the physiological
environment of host and parasite.
Surveillance of the presence of larval mosquitoes was performed in the suburban municipality of Sta. Ignacia, Tarlac Province, Philippines, with approximately 94.0% of the land area still devoted to agriculture. Five districts were covered, namely: Macageuing, San Francisco, San Vicente, Sta. Ines Centro, and Sta. Ines East. The standard dipping method was used to collect mosquito larvae from rice fields, ponds, creeks, streams and used tires and larvae were identified at the genus level. Culex sp. was the most abundant with a calculated mean breeding index of 22 larvae per dip. Anopheles sp. and Aedes sp. were likewise identified with mean breeding indices of five and two larvae per dip, respectively. In two samplings, Culex sp. had the highest mean larval breeding index (MLBI) of 9 larvae/dip in Sta. Ines Centro (West); while Sta. Vicente registered higher MLBI of Anopheles sp. and Aedes sp. relative to sites in other districts. Considering the endemicity of malaria, lymphatic filariasis and dengue in the country, present findings are valuable in the formulation of control measures specifically targeting presently identified breeding sites that revealed considerable mosquito population. To arrive at a comprehensive picture, we highly recommend a validation of current data in similar sampling sites in the other districts of Sta. Ignacia, concurrent with a species-specific surveillance of culicidae mosquitoes.
Serological survey of Toxoplasma gondii infection was carried out in 68 urban (Manila) and 72 suburban (Dasmariñas, Cavite) residents, comprising 69 females and 71 males, age 16-56 years old. Using a survey questionnaire, the name and address, gender, age, weight, height, civil status, cat exposure, and additional information like history of pregnancy and current reproductive status of females were obtained. The presence of anti-T.gondii antibodies was confirmed using the Toxocell latex agglutination test. The pooled population revealed 38 (27.1%) seropositive (sero+) cases, with higher infection rate among the suburban (30.6%) and female (32.0%) respondents. Differences in percent infection between the study groups, sexes and respondents with normal, overweight and underweight body mass index were insignificant. Of the 22 sero+ females, 21 were in their reproductive age, including five cases in pregnant (23.81%) volunteers. Infection was appreciable among those who had apparent association with cats (32.3%), reinforcing the feline’s primary role in the transmission of T. gondii to humans. Considering the dearth of baseline data on toxoplasmosis in the country, similar studies in other communities are highly recommended.
The morphometric characteristics of three Venezuelan isolates of Trypanosoma evansi, and the basic hematological features as well as host’s body weight were registered throughout experimental murine infections. The phenomena, trypomastigote morphometry dynamics, mouse hematological change and mice body variation, are related in statistical terms. In addition, the changeable morphometric characteristics of the hemoflagellate, and the host’s mutable hematological attributes, and the variable host’s body eight produced three different mathematical models generated by Multiple Linear Regressions that could explain the heterogeneous behavior of this eclectic parasite. Even more, supplementary mathematical models provided by Correspondence Analysis emphasize this reasoning. The results herein presented suggest that the association between trypomastigote morphometry, and host hematology, as well as body eight could be a feasible starting point to understand the heterogeneity of the T. evansi isolates.