Revisiting the Immune Trypanolysis Test to Optimise Epidemiological Surveillance and Control of Sleeping Sickness in West Africa

Human African trypanosomiasis (HAT) due to Trypanosoma brucei (T.b.) gambiense is usually diagnosed using two sequential steps: first the card agglutination test for trypanosomiasis (CATT) used for serological screening, followed by parasitological methods to confirm the disease. Currently, CATT will continue to be used as a test for mass screening because of its simplicity and high sensitivity; however, its performance as a tool of surveillance in areas where prevalence is low is poor because of its limited specificity. Hence in the context of HAT elimination, there is a crucial need for a better marker of contact with T.b. gambiense in humans. We evaluated here an existing highly specific serological tool, the trypanolysis test (TL). We evaluated TL in active, latent and historical HAT foci in Guinea, Côte d'Ivoire and Burkina Faso. We found that TL was a marker for exposure to T.b. gambiense. We propose that TL should be used as a surveillance tool to monitor HAT elimination

Intrathecal immune response pattern for improved diagnosis of central nervous system involvement in trypanosomiasis

Diagnosis of central nervous system (CNS) involvement in human African trypanosomiasis is crucial in determination of therapy. Cerebrospinal fluid (CSF) and serum immunoglobulin concentrations, blood-CSF barrier dysfunction, pattern of intrathecal immunoglobulin synthesis, trypanosome-specific antibody synthesis, and CSF lactate concentrations were analyzed in 272 patients with Trypanosoma brucei gambiense infection. As part of the 2- or 3-class immune response, the predominant intrathecal IgM synthesis was the most sensitive (95%) marker for inflammation of the brain. We propose to replace the World Health Organization (WHO) criteria (white blood cell count >5 cells/microL and presence of trypanosomes in CSF) with a new approach for stage determination in trypanosomiasis: CNS involvement is diagnosed only in patients with >20 cells/microL or with intrathecal IgM synthesis, independent of the presence of trypanosomes in CSF. Compared with the use of these new criteria, the WHO criteria incorrectly classified 49 of 234 patients in the meningoencephalitic stage and 7 of 38 patients in the hemolymphatic disease stage. We also show that trypanosomiasis-related immunoglobulin patterns are of value in differential diagnosis

Impact of oral and intramuscular administration amoxicillin on the selection of amoxicillin-resistant Enterobacteriaceae in the digestive flora of piglets

Objective: The aim of this study was to evaluate the level of selection of amoxicillin-resistant Enterobacteriaceae in the digestive microbiota of piglets during oral and intramuscular administration of amoxicillin.Methodology and Results: Enumeration of Enterobacteriaceae was carried out on MacConkey agar with and without amoxicillin. E. coli isolates were identified and subjected to antimicrobial susceptibility test. The percentages of amoxicillin-resistant Enterobacteriaceae before treatment were between 10-13% for the three groups of piglets. After starting treatment of amoxicillin, from day 1 to day 4, the percentages of resistant Enterobacteriaceae were between 54 to 81% for the intramuscular treated groups and 58 to 87% for those treated orally. In the control group, percentage was 11%. During days of treatments, the percentage of amoxicillin-resistant E. coli strains to the associated antibiotics evolved during the treatments. In the control piglets, the percentages of E. coli resistant antibiotics did not increase.Conclusion and application of findings: Administration of oral amoxicillin resulted in a greater selection of resistant enterobacteria in the digestive microbiota of piglets than those induced by the intramuscular route. Escherichia coli, an important strain in animal and human pathology, was the target of detection in this selection of these resistant enterobacteria. They constitute a public health risk due to the transfer of resistance genes from pathogenic bacteria of porcine origin to the human digestive flora via the food chain. The results obtained from this study are part of a bacterial resistance monitoring policy that will prevent pig farmers from Côte d’Ivoire, the majority user of these antibiotics.Keywords: Piglets, Enterobacteriaceae, Amoxicillin, Resistance, Digestive microbiot

Genetic Structure Of Quinoa (Chenopodium Quinoa Willd.) From The Bolivian Altiplano As Revealed By Rapd Markers

Quinoa (Chenopodium quinoa Willd.) is a pseudocereal originated from the Andes important for small farmers’ food security as well as for commercial production. Recently, it has been claimed that in Bolivia genetic erosion could result from the marginalization of the crop in the north and from its commercial standardization in the south. The aim of this study was to quantify the hierarchical structure of the genetic variation present in eight quinoa field populations, consisting of cultivated and weedy individuals, representative of the altiplano and interandean valleys of Bolivia. Randomly amplified polymorphic DNA markers show that quinoa has a strong population structure and a high intra-population variation. An effect of geographical structure of the populations was highlighted, due to population isolation, not simply linked to distance but more probably to climatic and orographic barriers present in the studied zone. The population structure is also reinforced by the limited seed exchanges among farmers as revealed by field interviews. This population structure appears related to three major biogeographic zones: the northern and central altiplano, the interandean valley, and the southern Salar. Intrapopulation genetic diversity was higher than that expected for a mainly autogamous species, and higher than that reported in anterior studies based on germplasm collections. These results are commented in view of current knowledge on phylogeny and reproductive biology of the species, and their implications regarding genetic resources management are discussed