Whole genome analysis of a schistosomiasis-transmitting freshwater snail

Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of Biomphalaria glabrata, a lophotrochozoan protostome, and provide timely and important information on snail biology. We describe aspects of phero-perception, stress responses, immune function and regulation of gene expression that support the persistence of B. glabrata in the field and may define this species as a suitable snail host for S. mansoni. We identify several potential targets for developing novel control measures aimed at reducing snail-mediated transmission of schistosomiasis

<i>Leishmania donovani<i/>-derived lipophosphoglycan plus BCG induces a Th1 type immune response but does not protect Syrian golden hamsters (<i>Mesocricetus auratus<i/>) and BALB/c mice against <i>Leishmania donovani<i/>

The efficacy of Leishmania donovani-derived lipophosphoglycan (LPG) plus Mycobacterium bovis Bacille Calmette-Guérin (BCG) as a vaccine candidate against visceral leishmaniosis in susceptible BALB/c mouse and Syrian golden hamster (Mesocricetus auratus) models was investigated. Following a triple vaccination with a total dose of 150 µl BCG plus 60 µg or 30 µg of LPG for hamsters and BALB/c mice respectively, there were no noticeable side effects both locally and systemically; implying that the molecule was safe at this dosage level. Vaccinated animals demonstrated an activation of both the humoral as well as cell-mediated responses to LPG, which correlated with resistance against the disease. Protection by LPG plus BCG, was however, poor as the remaining immunized animals showed disease progression leading to severity of the disease as illustrated by emaciation, mass loss and heavy splenic parasitaemia in hamsters. These data nevertheless suggest that it may be rewarding to further evaluate the potential of LPG as a vaccine candidate in leishmaniosis using other adjuvants, which may enhance its immunogenicity

Microsatellite typing reveals strong genetic structure of Schistosoma mansoni from localities in Kenya

Genetic diversity and population structure of seven populations of Schistosoma mansoni sampled in Kenya were assessed using five microsatellite markers. The mean number of alleles per locus, expected heterozygosity in Hardy-Weinberg equilibrium and pairwise FST values ranged from 5.2 to 10.7, 0.5-0.8 and 3.6-27.3%, respectively. These data reveal that S. mansoni populations in Kenyan have relatively high levels of genetic diversity and is significantly differentiated. Our data combined with information on biogeography support the hypothesis that the strong genetic structure in Kenyan schistosomes is as a result of limited gene flow and large population sizes. Resistance to anthelminthics has not been reported among the Kenyan schistosomes, we hypothesize that this is probably due to the very little gene flow among populations, thereby limiting opportunities for the spread of rare alleles that might confer resistance to the drugs

Anaemia and organomegaly associated with parasitic infections among schoolchildren in Sengerema District, north-western Tanzania

Anaemia and organomegaly are among the health problems affecting schoolchildren in Tanzania and their causes are multifactorial. The objective of this study was to determine the prevalence of anaemia and organomegaly and their relationship with single and multiple parasitic infections among schoolchildren in Sengerema District in north-west Tanzania. This cross sectional study involved 400 schoolchildren. Anaemia and organomegaly were determined using HemoCue photometer and clinical palpation, respectively. A Kato-Katz technique was employed to screen faecal samples for Schistosoma mansoni and other intestinal helminths. Giemsa stained thick and thin blood smears were examined for malaria parasites. The prevalence of anaemia was 19.5% (<11g/dl) and majority of the children had mild (22.8%) to moderate (36.6%) anaemia. Organomegaly (palpable spleen and liver) was detected in 41% of the children and hepatomegaly was the most common (53.7%). The prevalence of S. mansoni, hookworm and P. falciparum were 64.3%, 38% and 13.5% respectively. No significant relationship was observed between single and multiple parasitic infections with anaemia and organomegaly. Logistic regression analysis revealed that increased infections intensity of S. mansoni was significantly associated with an increased likelihood of hookworm concomitant infections (P<0.002). In conclusion, the data confirm that malaria, intestinal schistosomiasis and hookworm are common among school children but are not associated with anaemia and organomegaly. Further longitudinal studies are recommended to establish any such association. The prevalence of parasitic co-infections among schoolchildren calls for an integrated control approach to reduce the burden of these infections

Leishmania donovani-derived lipophosphoglycan plus BCG induces a Th1 type immune response but does not protect Syrian golden hamsters (Mesocricetus auratus) and BALB/c mice against Leishmania donovani

The efficacy of Leishmania donovani-derived lipophosphoglycan (LPG) plus Mycobacterium bovis Bacille Calmette-Guerin (BCG) as a vaccine candidate against visceral leishmaniosis in susceptible BALB/c mouse and Syrian golden hamster (Mesocricetus auratus) models was investigated. Following a triple vaccination with a total dose of 150 µI BCG plus 60 µg or 30 µg of LPG for hamsters and BALB/c mice respectively, there were no noticeable side effects both locally and systemically; implying that the molecule was safe at this dosage level. Vaccinated animals demonstrated an activation of both the humoral as well as cell-mediated responses to LPG, which correlated with resistance against the disease. Protection by LPG plus BCG, was however, poor as the remaining immunized animals showed disease progression leading to severity of the disease as illustrated by emaciation, mass loss and heavy splenic parasitaemia in hamsters. These data nevertheless suggest that it may be rewarding to further evaluate the potential of LPG as a vaccine candidate in leishmaniosis using other adjuvants, which may enhance its immunogenicity.The articles have been scanned with a HP Scanjet 8300; 600dpi, saved in TIFF format. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Intemational Society for Infectious diseases (lSID). Intemational Atomic Agency (IAEA). Kenya Medical Research Institute.mn201