Developmental Regulation of Genes Encoding Universal Stress Proteins in Schistosoma mansoni

The draft nuclear genome sequence of the snail-transmitted, dimorphic, parasitic, platyhelminth Schistosoma mansoni revealed eight genes encoding proteins that contain the Universal Stress Protein (USP) domain. Schistosoma mansoni is a causative agent of human schistosomiasis, a severe and debilitating Neglected Tropical Disease (NTD) of poverty, which is endemic in at least 76 countries. The availability of the genome sequences of Schistosoma species presents opportunities for bioinformatics and genomics analyses of associated gene families that could be targets for understanding schistosomiasis ecology, intervention, prevention and control. Proteins with the USP domain are known to provide bacteria, archaea, fungi, protists and plants with the ability to respond to diverse environmental stresses. In this research investigation, the functional annotations of the USP genes and predicted nucleotide and protein sequences were initially verified. Subsequently, sequence clusters and distinctive features of the sequences were determined. A total of twelve ligand binding sites were predicted based on alignment to the ATP-binding universal stress protein from Methanocaldococcus jannaschii. In addition, six USP sequences showed the presence of ATP-binding motif residues indicating that they may be regulated by ATP. Public domain gene expression data and RT-PCR assays confirmed that all the S. mansoni USP genes were transcribed in at least one of the developmental life cycle stages of the helminth. Six of these genes were up-regulated in the miracidium, a free-swimming stage that is critical for transmission to the snail intermediate host. It is possible that during the intra-snail stages, S. mansoni gene transcripts for universal stress proteins are low abundant and are induced to perform specialized functions triggered by environmental stressors such as oxidative stress due to hydrogen peroxide that is present in the snail hemocytes. This report serves to catalyze the formation of a network of researchers to understand the function and regulation of the universal stress proteins encoded in genomes of schistosomes and their snail intermediate hosts

Original Article The incidence, intensity and host morbidity of human parasitic protozoan infections in gastrointestinal disorder outpatients in Buea Sub Division,

Background: Numerous protozoans inhibit the gastrointestinal tract of humans with the majority being either non-pathogenic commensals or of a type that may result in mild disease. However, some of these organisms can cause severe diseases under certain circumstances while others may become highly virulent and invasive causing potentially lethal systemic disease. This study investigated the prevalence, intensity and host morbidity of human intestinal protozoan infections in individuals living in the Buea Sub-Division, Cameroon. Methodology: Random sampling was used to collect stool samples from 356 patients in a cross-sectional study. All samples were examined by formol-ether concentration and direct smear techniques. Data collected was analyzed and differences in proportions were determined using the Chi square (χ 2) test, Fisher’s exact test, or analysis of variance where appropriate. Results: It was found that 28.1 % (100/356) of the sampled population were infected with protozoans. Females showed a higher infection rate (29.7%; 56/182) than males (26.4%; 46/174) and there was a significantly (P < 0.001) higher prevalence in rural areas (38.7%; 55/142) than in urban areas (21.0%; 45/214). The 6 to 12 years age group had a significantly (P < 0.05) higher infection rate (42.9%; 30/70). The total prevalence of intestinal protozoans was as follows: E. histolytica (24.4%), E. coli (11.2%) and G. lamblia (0.6%). The most prevalent morbidity effects associated with intestinal protozoan infections were abdominal pains, dysentery and body weakness. Conclusions: Since human intestinal parasitic infections are high in the study area, mass treatment of people with intestinal protozoans i