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1.
Emerg Infect Dis ; 28(12): 2463-2471, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36343384

RESUMEN

To determine a demographic overview of orthopoxvirus seroprevalence, we tested blood samples collected during 2003-2019 from France (n = 4,876), Bolivia (n = 601), Laos (n = 657), and Mali (n = 255) for neutralizing antibodies against vaccinia virus. In addition, we tested 4,448 of the 4,876 samples from France for neutralizing antibodies against cowpox virus. We confirmed extensive cross-immunity between the 2 viruses. Seroprevalence of antibodies was <1% in Bolivia, <5% in Laos, and 17.25% in Mali. In France, we found low prevalence of neutralizing antibodies in persons who were unvaccinated and vaccinated for smallpox, suggesting immunosenescence occurred in vaccinated persons, and smallpox vaccination compliance declined before the end of compulsory vaccination. Our results suggest that populations in Europe, Africa, Asia, and South America are susceptible to orthopoxvirus infections, which might have precipitated the emergence of orthopoxvirus infections such as the 2022 spread of monkeypox in Europe.


Asunto(s)
Enfermedades Transmisibles , Orthopoxvirus , Viruela , Humanos , Viruela/prevención & control , Estudios Seroepidemiológicos , Bolivia/epidemiología , Laos/epidemiología , Malí , Anticuerpos Neutralizantes
2.
J Nutr ; 152(7): 1792-1800, 2022 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-35441218

RESUMEN

BACKGROUND: Malnutrition and diarrhea are leading causes of death in children aged <5 y. Rice bran is a nutrient-dense prebiotic available globally. OBJECTIVES: The objective of this secondary analysis was to evaluate the effects of daily rice bran supplementation on environmental enteric dysfunction (EED) markers, total fecal secretory IgA (sIgA), and microbiota in infants at high risk of malnutrition. METHODS: Six-month-old Malian and Nicaraguan infants were randomly assigned to control or daily rice bran supplementation cohorts (1 to 5 g/d). Feces were collected monthly for 6 mo to evaluate fecal sIgA, markers of EED, and microbiota diversity. Statistical methods included linear mixed models, generalized mixed models, Spearman correlation, and Wilcoxon rank-sum tests. RESULTS: Six-month-old Malian infants had significantly elevated sIgA (4.0× higher, P < 0.001), fecal myeloperoxidase (31.6× higher, P < 0.001), fecal α1-antitrypsin (1.8× higher, P = 0.006), and lower fecal neopterin (0.13× higher, P < 0.001) than the age-matched Nicaraguan infants. In the Nicaraguan rice bran cohort from 6 to 12 mo of age, there was a significant decrease in sIgA concentrations (0.4×, P < 0.05) and a correlation between sIgA and the EED marker α1-antitrypsin (0.523, P < 0.0001) at 12 mo of age. In Malian infants, daily rice bran ingestion resulted in decreased EED scores (0.71×, P = 0.02) and a stable sIgA concentration over time. The rice bran group of Malian infants also had correlation between sIgA and the EED marker neopterin (0.544, P < 0.001) at 12 mo of age and a significant (P < 0.05) increase in microbiota α-diversity at a younger age (9 mo with rice bran compared with 10 mo in control group), which supports earlier microbiota maturation. CONCLUSIONS: These results support rice bran as a functional food ingredient targeting gut mucosa in children at high-risk of malnutrition.


Asunto(s)
Desnutrición , Microbiota , Oryza , Biomarcadores , Ingestión de Alimentos , Heces , Humanos , Inmunoglobulina A Secretora , Lactante , Neopterin
3.
Int J Mol Sci ; 23(10)2022 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-35628368

RESUMEN

Xanthomonas oryzae pv. oryzae (Xoo) strains that cause bacterial leaf blight (BLB) limit rice (Oryza sativa) production and require breeding more resistant varieties. Transcription activator-like effectors (TALEs) activate transcription to promote leaf colonization by binding to specific plant host DNA sequences termed effector binding elements (EBEs). Xoo major TALEs universally target susceptibility genes of the SWEET transporter family. TALE-unresponsive alleles of clade III OsSWEET susceptibility gene promoter created with genome editing confer broad resistance on Asian Xoo strains. African Xoo strains rely primarily on the major TALE TalC, which targets OsSWEET14. Although the virulence of a talC mutant strain is severely impaired, abrogating OsSWEET14 induction with genome editing does not confer equivalent resistance on African Xoo. To address this contradiction, we postulated the existence of a TalC target susceptibility gene redundant with OsSWEET14. Bioinformatics analysis identified a rice locus named ATAC composed of the INCREASED LEAF INCLINATION 2 (ILI2) gene and a putative lncRNA that are shown to be bidirectionally upregulated in a TalC-dependent fashion. Gain-of-function approaches with designer TALEs inducing ATAC sequences did not complement the virulence of a Xoo strain defective for SWEET gene activation. While editing the TalC EBE at the ATAC loci compromised TalC-mediated induction, multiplex edited lines with mutations at the OsSWEET14 and ATAC loci remained essentially susceptible to African Xoo strains. Overall, this work indicates that ATAC is a probable TalC off-target locus but nonetheless documents the first example of divergent transcription activation by a native TALE during infection.


Asunto(s)
Oryza , Efectores Tipo Activadores de la Transcripción , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Resistencia a la Enfermedad/genética , Susceptibilidad a Enfermedades , Regulación de la Expresión Génica de las Plantas , Oryza/metabolismo , Fitomejoramiento , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Talco/metabolismo , Efectores Tipo Activadores de la Transcripción/metabolismo , Xanthomonas
4.
Emerg Infect Dis ; 27(7): 1902-1908, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34152946

RESUMEN

The spread of drug resistance to antimalarial treatments poses a serious public health risk globally. To combat this risk, molecular surveillance of drug resistance is imperative. We report the prevalence of mutations in the Plasmodium falciparum kelch 13 propeller domain associated with partial artemisinin resistance, which we determined by using Sanger sequencing samples from patients enrolled in therapeutic efficacy studies from 9 sub-Saharan countries during 2014-2018. Of the 2,865 samples successfully sequenced before treatment (day of enrollment) and on the day of treatment failure, 29 (1.0%) samples contained 11 unique nonsynonymous mutations and 83 (2.9%) samples contained 27 unique synonymous mutations. Two samples from Kenya contained the S522C mutation, which has been associated with delayed parasite clearance; however, no samples contained validated or candidate artemisinin-resistance mutations.


Asunto(s)
Antimaláricos , Malaria Falciparum , Antimaláricos/uso terapéutico , Resistencia a Medicamentos , Humanos , Kenia , Malaria Falciparum/tratamiento farmacológico , Mutación , Plasmodium falciparum , Proteínas Protozoarias/genética
5.
Malar J ; 20(1): 235, 2021 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-34034754

RESUMEN

BACKGROUND: The current first-line treatments for uncomplicated malaria recommended by the National Malaria Control Programme in Mali are artemether-lumefantrine (AL) and artesunate-amodiaquine (ASAQ). From 2015 to 2016, an in vivo study was carried out to assess the clinical and parasitological responses to AL and ASAQ in Sélingué, Mali. METHODS: Children between 6 and 59 months of age with uncomplicated Plasmodium falciparum infection and 2000-200,000 asexual parasites/µL of blood were enrolled, randomly assigned to either AL or ASAQ, and followed up for 42 days. Uncorrected and PCR-corrected efficacy results at days 28 and 42. were calculated. Known markers of resistance in the Pfk13, Pfmdr1, and Pfcrt genes were assessed using Sanger sequencing. RESULTS: A total of 449 patients were enrolled: 225 in the AL group and 224 in the ASAQ group. Uncorrected efficacy at day 28 was 83.4% (95% CI 78.5-88.4%) in the AL arm and 93.1% (95% CI 89.7-96.5%) in the ASAQ arm. The per protocol PCR-corrected efficacy at day 28 was 91.0% (86.0-95.9%) in the AL arm and 97.1% (93.6-100%) in the ASAQ arm. ASAQ was significantly (p < 0.05) better than AL for each of the aforementioned efficacy outcomes. No mutations associated with artemisinin resistance were identified in the Pfk13 gene. Overall, for Pfmdr1, the N86 allele and the NFD haplotype were the most common. The NFD haplotype was significantly more prevalent in the post-treatment than in the pre-treatment isolates in the AL arm (p < 0.01) but not in the ASAQ arm. For Pfcrt, the CVIET haplotype was the most common. CONCLUSIONS: The findings indicate that both AL and ASAQ remain effective for the treatment of uncomplicated malaria in Sélingué, Mali.


Asunto(s)
Amodiaquina/uso terapéutico , Antimaláricos/uso terapéutico , Combinación Arteméter y Lumefantrina/uso terapéutico , Artemisininas/uso terapéutico , Malaria Falciparum/prevención & control , Preescolar , Combinación de Medicamentos , Femenino , Humanos , Lactante , Masculino , Malí
6.
Phytopathology ; 111(8): 1428-1437, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33386066

RESUMEN

Rice blast, caused by the filamentous ascomycete Pyricularia oryzae, is one of the most devastating diseases of rice. Four genetic clusters were previously identified, and three have a large geographic distribution. Asia is the center of diversity and the origin of most migrations to other continents, and sexual reproduction persisted only in the South China-Laos-North Thailand region, which was identified as the putative center of origin of all P. oryzae populations on rice. Despite the importance of rice blast disease, little is known about the diversity and the population structure of the pathogen in Africa (including Madagascar). The present study was intended to describe the structure of African populations of P. oryzae and identify the relationship between African and worldwide genetic clusters. A set of 2,057 strains (937 African and 1,120 Madagascan strains) were genotyped with 12 simple sequence repeat markers to assess the diversity and the population structure of P. oryzae. Four genetic clusters were identified in Africa and Madagascar. All four clusters previously identified are present in Africa. Populations from West Africa, East Africa, and Madagascar are highly differentiated. The geographic structure is consistent with limited dispersion and with some migration events between neighboring countries. The two mating types are present in Africa with a dominance of Mat1.2, but no female-fertile strain was detected, supporting the absence of sexual reproduction on this continent. This study showed an unsuspected high level of genetic diversity of P. oryzae in Africa and suggested several independent introductions.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Asunto(s)
Ascomicetos , Magnaporthe , Oryza , Ascomicetos/genética , Variación Genética , Magnaporthe/genética , Enfermedades de las Plantas
7.
Plant Biotechnol J ; 2018 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-29406604

RESUMEN

Quantitative trait loci (QTL) that confer broad-spectrum resistance (BSR), or resistance that is effective against multiple and diverse plant pathogens, have been elusive targets of crop breeding programmes. Multiparent advanced generation intercross (MAGIC) populations, with their diverse genetic composition and high levels of recombination, are potential resources for the identification of QTL for BSR. In this study, a rice MAGIC population was used to map QTL conferring BSR to two major rice diseases, bacterial leaf streak (BLS) and bacterial blight (BB), caused by Xanthomonas oryzae pathovars (pv.) oryzicola (Xoc) and oryzae (Xoo), respectively. Controlling these diseases is particularly important in sub-Saharan Africa, where no sources of BSR are currently available in deployed varieties. The MAGIC founders and lines were genotyped by sequencing and phenotyped in the greenhouse and field by inoculation with multiple strains of Xoc and Xoo. A combination of genomewide association studies (GWAS) and interval mapping analyses revealed 11 BSR QTL, effective against both diseases, and three pathovar-specific QTL. The most promising BSR QTL (qXO-2-1, qXO-4-1 and qXO-11-2) conferred resistance to more than nine Xoc and Xoo strains. GWAS detected 369 significant SNP markers with distinguishable phenotypic effects, allowing the identification of alleles conferring disease resistance and susceptibility. The BSR and susceptibility QTL will improve our understanding of the mechanisms of both resistance and susceptibility in the long term and will be immediately useful resources for rice breeding programmes.

8.
Emerg Infect Dis ; 23(13)2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-29155671

RESUMEN

Antimalarial drug resistance is an evolving global health security threat to malaria control. Early detection of Plasmodium falciparum resistance through therapeutic efficacy studies and associated genetic analyses may facilitate timely implementation of intervention strategies. The US President's Malaria Initiative-supported Antimalarial Resistance Monitoring in Africa Network has assisted numerous laboratories in partner countries in acquiring the knowledge and capability to independently monitor for molecular markers of antimalarial drug resistance.


Asunto(s)
Resistencia a Medicamentos , Programas de Gobierno , Malaria/epidemiología , Malaria/prevención & control , Vigilancia en Salud Pública , África/epidemiología , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Salud Global , Humanos , Malaria/tratamiento farmacológico , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/epidemiología , Malaria Falciparum/prevención & control , Estados Unidos
9.
Malar J ; 16(1): 250, 2017 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-28615016

RESUMEN

BACKGROUND: The monitoring of Plasmodium falciparum sensitivity to anti-malarial drugs is a necessity for effective case management of malaria. This species is characterized by a strong resistance to anti-malarial drugs. In Senegal, the first cases of chloroquine resistance were reported in the Dakar region in 1988 with nearly 7% population prevalence, reaching 47% by 1990. It is in this context that sulfadoxine-pyrimethamine temporarily replaced chloroquine as first line treatment in 2003, pending the introduction of artemisinin-based combination therapy in 2006. The purpose of this study is to assess the ex vivo sensitivity to different anti-malarial drugs of the P. falciparum population from Pikine. METHODS: Fifty-four samples were collected from patients with non-complicated malaria and aged between 2 and 20 years in the Deggo health centre in Pikine in 2014. An assay in which parasites are stained with 4', 6-di-amidino-2-phenylindole (DAPI), was used to study the ex vivo sensitivity of isolates to chloroquine, amodiaquine, piperaquine, pyrimethamine, and dihydroartemisinin. High resolution melting was used for genotyping of pfdhps, pfdhfr, pfmdr1, and pfcrt genes. RESULTS: The mean IC50s of chloroquine, amodiaquine, piperaquine, dihydroartemisinin, and pyrimethamine were, respectively, 39.44, 54.02, 15.28, 2.23, and 64.70 nM. Resistance mutations in pfdhfr gene, in codon 437 of pfdhps gene, and an absence of mutation at position 540 of pfdhps were observed. Mutations in codons K76T of pfcrt and N86Y of pfmdr1 were observed at 51 and 11% population prevalence, respectively. A relationship was found between the K76T and N86Y mutations and ex vivo resistance to chloroquine. CONCLUSION: An increase in sensitivity of isolates to chloroquine was observed. A high sensitivity to dihydroartemisinin was observed; whereas, a decrease in sensitivity to pyrimethamine was observed in the parasite population from Pikine.


Asunto(s)
Antimaláricos/farmacología , Malaria/parasitología , Plasmodium falciparum/efectos de los fármacos , Adolescente , Amodiaquina/farmacología , Artemisininas/farmacología , Niño , Preescolar , Cloroquina/farmacología , ADN Protozoario/química , ADN Protozoario/aislamiento & purificación , Resistencia a Medicamentos/genética , Colorantes Fluorescentes , Genotipo , Técnicas de Genotipaje , Humanos , Indoles , Concentración 50 Inhibidora , Mutación , Pruebas de Sensibilidad Parasitaria , Plasmodium falciparum/clasificación , Plasmodium falciparum/genética , Polimorfismo de Nucleótido Simple , Pirimetamina/farmacología , Quinolinas/farmacología , Senegal , Adulto Joven
10.
J Infect Dis ; 214(suppl 3): S164-S168, 2016 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-27707892

RESUMEN

Aware of the rapid spread of Ebola virus (EBOV) during the current West African epidemic, Mali took several proactive steps to rapidly identify cases within its borders. Under the Mali International Center for Excellence in Research program, a collaboration between the National Institute of Allergy and Infectious Diseases and the Malian Ministry of Higher Education and Scientific Research established a national EBOV diagnostic site at the University of Sciences, Techniques and Technologies of Bamako in the SEREFO Laboratory. Two separate introductions of EBOV occurred in Mali from neighboring Guinea, but both chains of transmission were quickly halted, and Mali was declared "Ebola free" on 18 January 2015 and has remained so since. The SEREFO Laboratory was instrumental in the success of Mali's Ebola response by providing timely and accurate diagnostics. As of today, the SEREFO Laboratory has tested 103 samples from 88 suspected cases, 10 of which were EBOV positive, since the Ebola diagnostics unit started in April 2014. The establishment of Ebola diagnostics in the SEREFO Laboratory, safety precautions, and diagnostics are described.


Asunto(s)
Servicios de Laboratorio Clínico/organización & administración , Brotes de Enfermedades , Ebolavirus/aislamiento & purificación , Fiebre Hemorrágica Ebola/diagnóstico , Ebolavirus/genética , Guinea , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/virología , Humanos , Malí/epidemiología , Manejo de Especímenes
11.
Malar J ; 15(1): 433, 2016 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-27562216

RESUMEN

BACKGROUND: The use of artemisinin as a monotherapy resulted in the emergence of artemisinin resistance in 2005 in Southeast Asia. Monitoring of artemisinin combination therapy (ACT) is critical in order to detect and prevent the spread of resistance in endemic areas. Ex vivo studies and genotyping of molecular markers of resistance can be used as part of this routine monitoring strategy. One gene that has been associated in some ACT partner drug resistance is the Plasmodium falciparum multidrug resistance protein 1 (pfmdr1) gene. The purpose of this study was to assess the drug susceptibility of P. falciparum populations from Thiès, Senegal by ex vivo assay and typing molecular markers of resistance to drug components of ACT currently used for treatment. METHODS: The ex vivo susceptibility of 170 P. falciparum isolates to chloroquine, amodiaquine, lumefantrine, artesunate, and artemether was determined using the DAPI ex vivo assay. The high resolution melting technique was used to genotype the pfmdr1 gene at codons 86, 184 and 1246. RESULTS: A significant decrease in IC50 values was observed between 2012 and 2013: from 13.84 to 6.484 for amodiaquine, 173.4 to 113.2 for lumefantrine, and 39.72 to 18.29 for chloroquine, respectively. Increase of the wild haplotype NYD and the decrease of the mutant haplotype NFD (79 and 62.26 %) was also observed. A correlation was observed between the wild type allele Y184 in pfmdr1 and higher IC50 for all drugs, except amodiaquine. CONCLUSION: This study has shown an increase in sensitivity over the span of two transmission seasons, marked by an increase in the WT alleles at pfmdr1. Continuous the monitoring of the ACT used for treatment of uncomplicated malaria will be helpful.


Asunto(s)
Antimaláricos/farmacología , Artemisininas/farmacología , Etanolaminas/farmacología , Fluorenos/farmacología , Frecuencia de los Genes , Haplotipos , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Plasmodium falciparum/efectos de los fármacos , Selección Genética , Adolescente , Antimaláricos/uso terapéutico , Combinación Arteméter y Lumefantrina , Artemisininas/uso terapéutico , Niño , Preescolar , Combinación de Medicamentos , Etanolaminas/uso terapéutico , Femenino , Fluorenos/uso terapéutico , Genética de Población , Técnicas de Genotipaje , Humanos , Malaria Falciparum/parasitología , Masculino , Plasmodium falciparum/clasificación , Plasmodium falciparum/genética , Senegal , Adulto Joven
12.
Malar J ; 14: 415, 2015 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-26492968

RESUMEN

BACKGROUND: Although the epidemiology of malaria has been based primarily on microscopy and rapid diagnostic tests, molecular methods are necessary to understand the complexity of natural infection in regions where transmission is intense and simultaneous infection with multiple parasite genotypes is common such as sub-Saharan Africa. METHODS: To compare microscopic and molecular estimates of the incidence and clearance of Plasmodium falciparum infection, we followed 80 children monthly for 1 year in the village of Bancoumana in Mali. RESULTS AND DISCUSSION: Similar seasonal patterns were observed with both methods (rainy season peak, dry season nadir), although molecular methods detected more infections than microscopy (571 vs 331 in 906 specimens), more new infections (311 vs 104 during 829 person-months) and spontaneous clearance events (317 vs 116) and found higher incidence (0.38 vs 0.13 new genotypes/person/month, p < 0.001) and spontaneous clearance rates (0.38 vs 0.14 genotypes cleared/person/month, p < 0.001). These differences were greatest for persistently-infected subjects in whom neither new infections nor the clearance of old infections could be detected by microscopy (0.71 new infections and 0.73 cleared infections per month using molecular methods vs 0.000 by microscopy, p < 0.001). CONCLUSIONS: Molecular methods provide information about genetic diversity, the intensity of transmission and spontaneous clearance in the absence of drug treatment that cannot be obtained by microscopy. They will be necessary to evaluate the efficacy of vaccines, drugs and other control strategies for diseases such as malaria in which simultaneous infection with more than one organism (genotype) is common.


Asunto(s)
Malaria Falciparum/diagnóstico , Malaria Falciparum/epidemiología , Microscopía/métodos , Técnicas de Diagnóstico Molecular/métodos , Plasmodium falciparum/aislamiento & purificación , Niño , Preescolar , Femenino , Humanos , Incidencia , Lactante , Masculino , Malí/epidemiología , Epidemiología Molecular , Plasmodium falciparum/genética , Estudios Prospectivos
13.
Antonie Van Leeuwenhoek ; 107(4): 869-81, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25588569

RESUMEN

Four bacterial strains, designated M89, M92, M97(T), and M106, were isolated in a previous study from surface-sterilized leaves of rice (Oryza sativa) or murainagrass (Ischaemum rugosum) at three sites in Mali, Africa. Here they were examined by a polyphasic taxonomic approach and analysis of a whole-genome sequence. Phylogenetic analyses based on 16S rRNA sequence and multilocus sequence analysis of seven genes showed that these four strains formed a distinct lineage representing a novel species within the genus Xanthomonas. This was supported by whole-genome average nucleotide identity values calculated from comparisons of strain M97(T) with established Xanthomonas species. The strains can be differentiated from the known Xanthomonas species on the basis of their fatty acid and carbohydrate utilization profiles. Population growth studies on rice confirmed that these bacteria multiply in rice leaves without causing symptoms. Identification of this novel species can be accomplished by using diagnostic primer sets or by gyrB gene sequence analysis. We propose to classify these rice- and grass-associated bacteria as Xanthomonas maliensis sp. nov. with strain M97(T) = CFBP7942(T) = LMG27592(T) as the type strain.


Asunto(s)
Oryza/microbiología , Hojas de la Planta/microbiología , Xanthomonas/clasificación , Xanthomonas/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Análisis por Conglomerados , Citosol/química , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Ácidos Grasos/análisis , Genoma Bacteriano , Malí , Tipificación de Secuencias Multilocus , Filogenia , ARN Ribosómico 16S/genética , Xanthomonas/genética
15.
Virus Evol ; 10(1): veae011, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38435712

RESUMEN

Avian influenza viruses (AIVs) of the H9N2 subtype have become widespread in Western Africa since their first detection in 2017 in Burkina Faso. However, the genetic characteristics and diffusion patterns of the H9N2 virus remain poorly understood in Western Africa, mainly due to limited surveillance activities. In addition, Mali, a country considered to play an important role in the epidemiology of AIVs in the region, lacks more comprehensive data on the genetic characteristics of these viruses, especially the H9N2 subtype. To better understand the genetic characteristics and spatio-temporal dynamics of H9N2 virus within this region, we carried out a comprehensive genetic characterization of H9N2 viruses collected through active surveillance in live bird markets in Mali between 2021 and 2022. We also performed a continuous phylogeographic analysis to unravel the dispersal history of H9N2 lineages between Northern and Western Africa. The identified Malian H9N2 virus belonged to the G1 lineage, similar to viruses circulating in both Western and Northern Africa, and possessed multiple molecular markers associated with an increased potential for zoonotic transmission and virulence. Notably, some Malian strains carried the R-S-N-R motif at their cleavage site, mainly observed in H9N2 strains in Asia. Our continuous phylogeographic analysis revealed a single and significant long-distance lineage dispersal event of the H9N2 virus to Western Africa, likely to have originated from Morocco in 2015, shaping the westward diffusion of the H9N2 virus. Our study highlights the need for long-term surveillance of H9N2 viruses in poultry populations in Western Africa, which is crucial for a better understanding of virus evolution and effective management against potential zoonotic AIV strain emergence.

16.
PLoS One ; 19(5): e0304550, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38809933

RESUMEN

BACKGROUND: Ae. aegypti is the vector of important µ arboviruses, including dengue, Zika, chikungunya and yellow fever. Despite not being specifically targeted by insecticide-based control programs in West Africa, resistance to insecticides in Ae. aegypti has been reported in countries within this region. In this study, we investigated the status and mechanisms of Ae. aegypti resistance in Niamey, the capital of Niger. This research aims to provide baseline data necessary for arbovirus outbreak prevention and preparedness in the country. METHODS: Ovitraps were used to collect Ae. aegypti eggs, which were subsequently hatched in the insectary for bioassay tests. The hatched larvae were then reared to 3-5-day-old adults for WHO tube and CDC bottle bioassays, including synergist tests. The kdr mutations F1534C, V1016I, and V410L were genotyped using allele-specific PCR and TaqMan qPCR methods. RESULTS: Ae. aegypti from Niamey exhibited moderate resistance to pyrethroids but susceptibility to organophosphates and carbamates. The kdr mutations, F1534C, V1016I and V410L were detected with the resistant tri-locus haplotype 1534C+1016L+410L associated with both permethrin and deltamethrin resistance. Whereas the homozygote tri-locus resistant genotype 1534CC+1016LL+410LL was linked only to permethrin resistance. The involvement of oxidase and esterase enzymes in resistance mechanisms was suggested by partial restoration of mosquitoes' susceptibility to pyrethroids in synergist bioassays. CONCLUSION: This study is the first report of Ae. aegypti resistance to pyrethroid insecticides in Niamey. The resistance is underpinned by target site mutations and potentially involves metabolic enzymes. The observed resistance to pyrethroids coupled with susceptibility to other insecticides, provides data to support evidence-based decision-making for Ae. aegypti control in Niger.


Asunto(s)
Aedes , Resistencia a los Insecticidas , Insecticidas , Mutación , Piretrinas , Animales , Aedes/genética , Aedes/efectos de los fármacos , Resistencia a los Insecticidas/genética , Piretrinas/farmacología , Niger , Insecticidas/farmacología , Mosquitos Vectores/genética , Mosquitos Vectores/efectos de los fármacos , Genotipo , Larva/efectos de los fármacos , Larva/genética , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo
17.
Trials ; 24(1): 68, 2023 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-36717923

RESUMEN

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.


Asunto(s)
Inocuidad de los Alimentos , Madres , Lactante , Femenino , Humanos , Malí , Higiene , Diarrea/prevención & control , Ensayos Clínicos Controlados Aleatorios como Asunto
18.
Artículo en Inglés | MEDLINE | ID: mdl-35010869

RESUMEN

Personal exposure to particulate matter (PM) from anthropogenic activities is a major concern in African countries, including Mali. However, knowledge of particulates is scant. This study was undertaken to characterize personal exposure to PM2.5 microns or less in diameter (PM2.5) in the city of Bamako in Mali. The exposure to PM2.5, through daily activities was observed from September 2020 to February 2021. Participants wore palm-sized optical PM2.5 sensors on their chest during their daily activities. The exposure levels in four different groups of residents were investigated in relation to their daily activities. The variation in PM2.5 concentration was measured during different activities in different microenvironments, and the main sources of exposure were identified. The highest average 10 min concentrations were observed at home and in bedrooms, while the participants were using specific products typically used in Africa, Asia, and South America that included insecticides (IST; 999 µg/m3) and incense (ICS; 145 µg/m3), followed by traffic (216 µg/m3) and cooking (150 µg/m3). The lowest average 10 min concentrations were also observed in the same microenvironment lacking IST or ICS (≤14 µg/m3). With no use of specific products, office workers and students were the least exposed, and drivers and cooks were the most exposed. The concentrations are up to 7.5 and 3 times higher than the World Health Organization's yearly and daily recommended exposure levels, respectively, indicating the need to promptly elaborate and apply effective mitigation strategies to improve air quality and protect public health. This study highlights the importance of indoor air pollution sources related to culture and confirms previous studies on urban outdoor air pollution sources, especially in developing countries. The findings could be applied to cities other than Bamako, as similar practices and lifestyles are common in different cultures.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire Interior , Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Efectos Antropogénicos , Ciudades , Exposición a Riesgos Ambientales/análisis , Monitoreo del Ambiente , Humanos , Malí , Tamaño de la Partícula , Material Particulado/análisis
19.
Nutrients ; 14(3)2022 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-35276967

RESUMEN

Rice bran contains essential nutrients, antioxidants, and bioactives with anti-inflammatory and diarrheal protective properties important for infants. This 6-month randomized controlled trial investigated the effects of heat-stabilized rice bran supplementation during Malian infant weaning. Fifty healthy 6-month-old infants were randomized to a rice bran intervention (N = 25) or non-intervention control group (N = 25). Intervention infants received dose-escalating rice bran supplementation for 6 months (1-5 g/day). Monthly infant dried blood spot and anthropometric measurements were collected. Dried blood spot metabolite abundances were compared monthly according to diet for six months. Supplementation resulted in favorable weight-for-age and weight-for-length z-score changes. Non-targeted dried blood spot-based metabolomics identified 796 metabolites, of which 33% had significant fold differences between groups (7-12 months). Lipids and amino acids represented 70.6% of the metabolites identified. Rice bran supplementation during infant weaning significantly modulated the metabolites involved in antioxidant defenses and with neuroactive properties including reduced glutathione, glycine, glutamate, cysteinylglycine, tryptophan betaine, and choline. These findings support rice bran as a weaning ingredient to meet infant nutritional requirements and with the potential to reduce oxidative stress and improve cognitive outcomes. This study provides evidence for dried blood spots as a cost-effective tool to detect infant biomarkers of nutritional and metabolic status.


Asunto(s)
Oryza , Preescolar , Suplementos Dietéticos , Humanos , Lactante , Malí , Redes y Vías Metabólicas , Metabolómica , Oryza/química , Destete
20.
PLoS One ; 17(9): e0273083, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36048882

RESUMEN

The creation of global research partnerships is critical to produce shared knowledge for the implementation of the UN 2030 Agenda for Sustainable Development. Sustainability science promotes the coproduction of inter- and transdisciplinary knowledge, with the expectation that studies will be carried out through groups and truly collaborative networks. As a consequence, sustainability research, in particular that published in high impact journals, should lead the way in terms of ethical partnership in scientific collaboration. Here, we examined this issue through a quantitative analysis of the articles published in Nature Sustainability (300 papers by 2135 authors) and Nature (2994 papers by 46,817 authors) from January 2018 to February 2021. Focusing on these journals allowed us to test whether research published under the banner of sustainability science favoured a more equitable involvement of authors from countries belonging to different income categories, by using the journal Nature as a control. While the findings provide evidence of still insufficient involvement of Low-and-Low-Middle-Income-Countries (LLMICs) in Nature Sustainability publications, they also point to promising improvements in the involvement of such authors. Proportionally, there were 4.6 times more authors from LLMICs in Nature Sustainability than in Nature articles, and 68.8-100% of local Global South studies were conducted with host country scientists (reflecting the discouragement of parachute research practices), with local scientists participating in key research steps. We therefore provide evidence of the promising, yet still insufficient, involvement of low-income countries in top sustainability science publications and discuss ongoing initiatives to improve this.


Asunto(s)
Pobreza , Publicaciones , Conocimiento
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