Pathogen genetic diversity a challenge for vaccine development: Looking for the pathogen’s Achilles’ heel

Creation of variant forms has serious consequences in diagnostic, treatment strategies and the future vaccine development. Thus, the actual and future roles of the altered or emergent pathogens in the global pandemic of AIDS, Malaria, Flu and Ebola must be monitored in new molecular epidemiological studies. During the last 5 years, we studied the genetic structure of several pathogens such as 1] malaria parasite showing that gene deletion, recombination can occur and lead to false RDT negative and to the creation of new antigens (hybrid parasites); 2] in HIV, our findings indicate a shift in the virus population circulating over time in Mali. Those observations are suggesting that a vaccine development against those pathogens such Plasmodium falciparum parasite and HIV will be a challenge. Our approach that is to target pieces of antigens within a genome which must be well conserved across the specie and immunogenic enough in boosting the immune response. Four steps were identified in that approach which are: 1] Genome mining using computational and experimental tools to identify genes that encode proteins with promising vaccine antigens properties, 2] use of the Immunoinformatics tools to map protein sequences for short, linear putative T-cell epitopes CTL/ T helper, 3] then candidates are synthesized as peptides and evaluated for HLA binding and antigenicity (in vitro evaluation) and then 4] Prototype epitope-based vaccines are evaluated for immunogenicity in human Host (in vivo evaluation). Our laboratory has partnered with the GAIA foundation to test this approach in Mali

Isolation and molecular identification of yeast strains from “Rabilé” a starter of local fermented drink

“Rabilé” is dried yeast harvested from Sorghum beer, used as a traditional starter culture but more especially as ingredient in sauce and food cooking in Burkina Faso. The present study aimed to isolate and identify indigenous yeast flora of “Rabilé”. Standard microbiological process was carried out to value and isolate yeast in different samples of “Rabilé” coming from four localities of Burkina Faso. Phenotypical method and molecular method (PCR and RFLP) were used for yeast  strains characterization and identification. The results showed that yeast counts ranged from 9.49 to 10.35 log cfu/g of “Rabilé”. A total of twenty yeast strains were isolated. Based on phenotypical characters three genera were detected: Candida (40%), Saccharomyces (35%) and Rhodotorula (25%). Molecular identification revealed two specific strains among yeasts isolated as S. cerevisiae with a frequency of 35% and R. mucilaginosa with a frequency of 25%. This data highlights the diversity of indigenous yeast flora of “Rabilé”.Key words: Rabilé, yeast, polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), traditional starter culture

Etude de la Variabilité Morphologique de Saba Senegalensis (A. DC.) Pichon en Casamance (Sénégal)

This study was carried out to better understand the distribution of Saba senegalensis, through an analysis of its morphological variability in different areas of production in Casamance. Leaf and fruit samples were taken from 150 individuals across six (06) sites with high yield. Thirteen (13) morphological descriptors were used. Diembéring, Nyassia and Badiatte individual have a more important foliar development. It is defined by longer leaves (13.69 cm) and longer petioles (1.36 cm) in Diembering and broad leaves (6.26 cm) with short petioles (1.08 cm) inNyassia. InThionk Essyl, SaréBocar and Saré Sara, S. senegalensis individuals are characterized by smaller leaves with 5.77 cm on average. For morphological descriptors related to fruits and seeds, Nyassia and Thionk Essyl show better fruit development. From the results, it appears that the variability of the morphological descriptors studied follows the geographical origin but for some descriptors related to the leaves, their variability is also linked to the genome.Cette étude contribue à une meilleure connaissance de l’espèce Saba senegalensis, à travers une analyse de sa variabilité morphologique selon les zones de production en Casamance. Elle est réalisée dans six (06) sites à fort potentiel de production où des prélèvements de feuilles et de fruits ont été effectués sur 150 individus. Treize (13) descripteurs morphologiques ont été retenus. Les populations de Diembéring et de Nyassia présentent un développent foliaire plus important. Il est défini par des feuilles (13,69 cm) et des pétioles (1,36 cm) plus longs à Diembéring, et des feuilles relativement larges (6,26cm) à Nyassia. Au niveau des sites de Thionk Essyl, Saré Bocar et Saré Sara, l’espèce Saba sengalensis est caractérisée par des feuilles moins larges, avec une moyenne de 5,77 cm. Pour les descripteurs morphologiques relatifs aux fruits et graines, Nyassia et Thionk Essyl présentent un meilleur développement. Il ressort des analyses que, la variabilité des descripteurs morphologiques étudiées suit l’origine géographique mais pour certains descripteurs relatifs aux feuilles, leur variabilité serait liée aussi au génome

Cross-conservation of T-cell epitopes: Now even more relevant to (H7N9) influenza vaccine design

A novel avian-origin H7N9 influenza strain emerged in China in April 2013. Since its re-emergence in October–November 2013, the number of reported cases has accelerated; more than 220 laboratory-confirmed cases and 112 deaths (case fatality rate of 20–30%) have been reported. The resurgence of H7N9 has re-emphasized the importance of making faster and more effective influenza vaccines than those that are currently available. Recombinant H7 hemagglutinin (H7-HA) vaccines have been produced, addressing the first problem. Unfortunately, these recombinant subunit vaccine products appear to have failed to address the second problem, influenza vaccine efficacy. Reported unadjuvanted H7N9 vaccine seroconversion rates were between 6% and 16%, nearly 10-fold lower than rates for unadjuvanted vaccine seroconversion to standard H1N1 monovalent (recombinant) vaccine (89% to pandemic H1N1). Could this state of affairs have been predicted? As it turns out, yes, and it was. In that previous analysis of available H7-HA sequences, we found fewer T-cell epitopes per protein than expected, and predicted that H7-HA-based vaccines would be much less antigenic than recent seasonal vaccines. Novel approaches to developing a more immunogenic HA were offered for consideration at the time, and now, as the low immunogenicity of H7N9 vaccines appears to indicate, they appear to be even more relevant. More effective H7N9 influenza vaccines can be produced, provided that the role of T-cell epitopes is carefully considered, and accumulated knowledge about the importance of cross-conserved epitopes between viral subtypes is applied to the design of those vaccines

Relationship between soil water content and crop yield under sahelian climate conditions: case study of Tougou experimental site in Burkina Faso

This study aims at assessing the relationship between soil water stock and the yield of agricultural practices in Tougou catchment located in northern Burkina Faso. It is a region that has experienced a significant and continuous degradation of its natural resources, especially soils, due to the climate variability and the rapid increase of the population. Areas allocated to subsistence agriculture are increasing at the expense of pastoral land. This degradation causes a change in processes and mechanisms that control ecological systems. In order to provide solutions to this issue, some agricultural practices have been implemented to improve crop yield. This is particularly the case of traditional techniques:za, stony line and half-moon, which can significantly improve the soil infiltration capacity and yield. Daily monitoring of soil moisture and pressure in experimental plots based on these agricultural practices show that half-moon and Za¯ provided good yield with 2180kg / ha and 1070 kg / ha respectively compared to that of the control plot with about 480 kg/ha. These important yields are due in large part to the improvement of the retention capacity of these soils, thus giving to crops the necessary water need for their development even in drought period

Нефтяное загрязнение берегов Севастополя

Приводятся результаты изучения загрязнения береговых структур при низких уровнях нефтяных углеводородов в морской воде. В прибрежных водах и берегах на границе с морем нефтяные углеводороды в концентрациях, не достигающих поражающего уровня для морской биоты вступают в сложные взаимодействия с гидробионтами. Первым этапом этого процесса является накопление или поверхностное загрязнение морских организмов-обрастателей. Такие данные являются составной частью мониторинга прибрежных акваторий и первым этапом изучения роли биопотоков нефтяных углеводородов в общем потоке нефтяного загрязнения у морских берегов.Наводяться результати вивчення забруднення берегових структур при низьких рівнях нафтових вуглеводнів в морській воді. У прибережних водах і берегах на кордоні з морем нафтові вуглеводні в концентраціях, що не досягають вражаючого рівня для морської біоти вступають в складні взаємодії з гідробіонтами. Першим етапом цього процесу є накопичення або поверхневе забруднення морських організмів-обрастателей. Такі дані є складовою частиною моніторингу прибережних акваторій і першим етапом вивчення ролі біопотоков нафтових вуглеводнів в загальному потоці нафтового забруднення морських берегів.The results of the study of coastal structures pollution at low levels of oil hydrocarbons in the sea water are given. Oil hydrocarbons at concentrations that do not reach damaging levels for marine biota enter into complex interactions with marine life in coastal waters and sea shores. The first step of this process is the accumulation or surface contamination of marine fouling organisms. These data are a part of the monitoring of coastal waters and the first step in studying the role of oil hydrocarbons bioflows in the general flow of the oil pollution at sea coast

A Cross-Sectional Study to Assess HPV Knowledge and HPV Vaccine Acceptability in Mali

Despite a high prevalence of oncogenic human papilloma virus (HPV) infection and cervical cancer mortality, HPV vaccination is not currently available in Mali. Knowledge of HPV and cervical cancer in Mali, and thereby vaccine readiness, may be limited. Research staff visited homes in a radial pattern from a central location to recruit adolescent females and males aged 12–17 years and men and women aged ≥18 years (N = 51) in a peri-urban village of Bamako, Mali. Participants took part in structured interviews assessing knowledge, attitudes, and practices related to HPV, cervical cancer, and HPV vaccination. We found low levels of HPV and cervical cancer knowledge. While only 2.0% of respondents knew that HPV is a sexually transmitted infection (STI), 100% said they would be willing to receive HPV vaccination and would like the HPV vaccine to be available in Mali. Moreover, 74.5% said they would vaccinate their child(ren) against HPV. Men were found to have significantly greater autonomy in the decision to vaccinate themselves than women and adolescents (p = 0.005), a potential barrier to be addressed by immunization campaigns. HPV vaccination would be highly acceptable if the vaccine became widely available in Bamako, Mali. This study demonstrates the need for a significant investment in health education if truly informed consent is to be obtained for HPV vaccination. Potential HPV vaccination campaigns should provide more information about HPV and the vaccine. Barriers to vaccination, including the significantly lower ability of the majority of the target population to autonomously decide to get vaccinated, must also be addressed in future HPV vaccine campaigns

Protocol for a parallel group, two-arm, superiority cluster randomised trial to evaluate a community-level complementary-food safety and hygiene and nutrition intervention in Mali:the MaaCiwara study (version 1.3; 10 November 2022)

BACKGROUND: Diarrhoeal disease remains a significant cause of morbidity and mortality among the under-fives in many low- and middle-income countries. Changes to food safety practices and feeding methods around the weaning period, alongside improved nutrition, may significantly reduce the risk of disease and improve development for infants. We describe a protocol for a cluster randomised trial to evaluate the effectiveness of a multi-faceted community-based educational intervention that aims to improve food safety and hygiene behaviours and enhance child nutrition. METHODS: We describe a mixed-methods, parallel group, two-arm, superiority cluster randomised controlled trial with baseline measures. One hundred twenty clusters comprising small urban and rural communities will be recruited in equal numbers and randomly allocated in a 1:1 ratio to either treatment or control arms. The community intervention will be focussed around an ideal mother concept involving all community members during campaign days with dramatic arts and pledging, and follow-up home visits. Participants will be mother–child dyads (27 per cluster period) with children aged 6 to 36 months. Data collection will comprise a day of observation and interviews with each participating mother–child pair and will take place at baseline and 4 and 15 months post-intervention. The primary analysis will estimate the effectiveness of the intervention on changes to complementary-food safety and preparation behaviours, food and water contamination, and diarrhoea. Secondary outcomes include maternal autonomy, enteric infection, nutrition, child anthropometry, and development scores. A additional structural equation analysis will be conducted to examine the causal relationships between the different outcomes. Qualitative and health economic analyses including process evaluation will be done. CONCLUSIONS: The trial will provide evidence on the effectiveness of community-based behavioural change interventions designed to reduce the burden of diarrhoeal disease in the under-fives and how effectiveness varies across different contexts. TRIAL REGISTRATION: ISRCTN14390796. Registration date December 13, 2021 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-022-06984-5