Excretory-secretory (ES) products of nematodes and other helminths are the first molecules to interact with cell surfaces and soluble proteins within the host. In the present study, ES products of the filarial nematode Onchocerca ochengi were investigated as a model for Onchocerca volvulus, the causative agent of river blindness. These products were collected from adult and larval stages in vitro over a period of 7 days, to compare their immunological recognition in cattle and human sera, infected with species of Onchocerca. From the 156 sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) ES products or extracts, protein bands showed different patterns between female and male products. A comparison of antibody recognition of the different ES products by sera from infected cattle and humans, when analysed by enzyme-linked immunosorbent assay (ELISA), revealed a relatively higher reactivity of the female somatic extract to human and cattle sera compared to ES products of both genders. Nevertheless, similar reactivity of the O. ochengi male and female ES products to human and cattle sera was noticed. As a result, the interaction of ES products with the surface of the host and immune system often led to host responses, including the generation of antibodies. The O. ochengi ES products are therefore good sources of potential immunogenic proteins. The identification of these ES products is in progress, with the aim of developing vaccine candidates against human onchocerciasis.

One of the strategies for developing novel pharmaceutical drugs is to use natural sources such as plants for therapeutic treatment. Plant extracts are a cocktail of compounds which act synergically and can improve treatment effectiveness, reduce therapeutic duration and resistance. The ethanolic extracts of leaves and seeds of Cucurbita pepo ovifera var ovifera from Sudano-Guinean and Sudano-Sahelian zones of Cameroon were evaluated on the cattle parasite nematode Onchocerca ochengi. Worms were incubated with different concentrations of the plant extracts in RPMI-1640 supplemented with streptomycin and gentamicin. Mortality at 37°C was monitored after 24, 48 and 72 h. Ivermectin was used as positive control and DMSO as negative. Plant extracts

Meloidogyne represent a genus of plant-parasitic nematode. This nematode is serious crop pests, including tomatoes and is widespread in almost all regions of the world. Very little attention has been paid to these parasites in Cameroon and none in the agro-ecological zone of the Guinean high savannah. We therefore undertook this study to identify and assess the density of this nematode in this area. For this study, a total of 30 root samples were collected in tomatoes production areas from 4 districts and females Meloidogyne were isolated and counted. Specific identification was done by Polymerase Chain Reaction (PCR) using the markers C2F3/1108 and COX1. The genus Meloidogyne was thus identified in the 30 production basin sites of this zone. High densities of Meloidogyne were observed in 18 sites, with an average density of between 21-50 females per gram of fresh root. In contrast, low densities were noted at 12 sites with values between 6 and 19 females per gram of root. However, this distribution is function of the cropping period, soil texture, pH, organic matter content, soil saturation rate, and cropping practices (host or non-host plants and fallow practice). Electrophoretic profiles of Deoxyribonucleic Acid (DNA) amplified with C2F3/1108 and COX1 primers showed corresponding migrations at 1700 bp, 1100 bp and 421 bp characteristic of the presence of M. incognita/M. javanica, M. arenaria and M. incognita/M. hapla in this agro-ecological zone. In view of these results, which provide information on the distribution of Meloidogyne in this area, it seems necessary for producers to develop management strategies by improving preventive techniques and by piloting technical and cultural itineraries for the control of this plant pest.

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