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1.
Emerg Infect Dis ; 26(10): 2460-2464, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32946728

RESUMO

Hantaviruses cause hemorrhagic fever in humans worldwide. However, few hantavirus surveillance campaigns occur in Africa. We detected Seoul orthohantavirus in black rats in Senegal, although we did not find serologic evidence of this disease in humans. These findings highlight the need for increased surveillance of hantaviruses in this region.

2.
Vector Borne Zoonotic Dis ; 20(1): 15-21, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31343384

RESUMO

In sub-Saharan Africa, few studies have addressed the environmental determinants of the incidence of Toxoplasma gondii infection. Free-range chickens are regarded as sensitive indicators for environmental contamination with T. gondii oocysts due to their ground-feeding behavior and have been used as sentinels. A cross-sectional study was conducted from January to April 2018 to estimate the seroprevalence of T. gondii infection in free-range chickens from Senegal, West Africa, using the modified agglutination test. Sampling was performed in two regions of the country: Saint-Louis, a Sahelian area in the North, and Kedougou, a forest and rainy area in the South. A questionnaire was administered to chicken owners to assess potential risk factors for T. gondii seropositivity, and univariable and multivariable logistic regression analyses were used to determine the statistical significance of risk factors. The seroprevalence in chickens was 7.67% (51/665; 95% confidence interval [CI]: 5.51-9.52). The multivariable logistic regression model indicated that the odds to test T. gondii seropositive was higher in chickens provided well water (odds ratio [OR] = 3.17, 95% CI: 1.45-6.93; p = 0.004) than in chickens provided tap water, and in hens having chicks (OR = 80.15, 95% CI: 22.79-281.95; p < 0.001) than in chickens (male or female) not having chicks. The possible role of contaminated well water in the acquisition of infection in chickens-and hence in human-merits consideration and should be addressed in future studies.

3.
mBio ; 10(4)2019 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-31431549

RESUMO

Single-cell microfluidics is a powerful method to study bacteria and determine their susceptibility to antibiotic treatment. Glass treatment by adhesive molecules is a potential solution to immobilize bacterial cells and perform microscopy, but traditional cationic polymers such as polylysine deeply affect bacterial physiology. In this work, we chemically characterized a class of chitosan polymers for their biocompatibility when adsorbed to glass. Chitosan chains of known length and composition allowed growth of Escherichia coli cells without any deleterious effects on cell physiology. Combined with a machine learning approach, this method could measure the antibiotic susceptibility of a diversity of clinical strains in less than 1 h and with higher accuracy than current methods. Finally, chitosan polymers also supported growth of Klebsiella pneumoniae, another bacterial pathogen of clinical significance.IMPORTANCE Current microfluidic techniques are powerful to study bacteria and determine their response to antibiotic treatment, but they are currently limited by their complex manipulation. Chitosan films are fully biocompatible and could thus be a viable replacement for existing commercial devices that currently use polylysine. Thus, the low cost of chitosan slides and their simple implementation make them highly versatile for research as well as clinical use.


Assuntos
Antibacterianos/farmacologia , Quitosana/química , Microfluídica/métodos , Antibacterianos/química , Bactérias/efeitos dos fármacos , Aderência Bacteriana/efeitos dos fármacos , Materiais Biocompatíveis/química , Proliferação de Células/efeitos dos fármacos , Quitosana/classificação , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Vidro , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/crescimento & desenvolvimento , Teste de Materiais , Testes de Sensibilidade Microbiana
4.
PLoS Negl Trop Dis ; 13(7): e0007435, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31295245

RESUMO

Toxoplasma gondii is a zoonotic protozoan with a worldwide occurrence, but the determinants of the current pattern in the geographical distribution of T. gondii lineages and strains remain poorly understood. To test the influence of human trade on T. gondii populations, we conducted a population genetic study of 72 T. gondii animal isolates from Senegal, a West African country in which the ongoing inland progress of invasive murine hosts (introduced in port cities of Senegal since the 16th century by European sailors) is well described. Isolates were mainly collected on free-range poultry, which are considered as relevant bioindicators of T. gondii strain diversity in the domestic environment. Sampling was conducted in two port cities of Senegal (Dakar and Saint-Louis) and in one inland region (Kedougou). Population genetic analyses using 15 microsatellite markers revealed different patterns between port cities where lineages non-virulent for mice (type II, type III, and Africa 4) were predominant, and Kedougou where the mouse-virulent Africa 1 lineage was the most common. By considering the current spatial pattern in the inland progress of invasive rodents in Senegal, our results suggest that the invasive house mouse Mus musculus domesticus counter-selects the Africa 1 lineage in the invaded areas. The comparison of the microsatellite alleles of type II strains from Senegal to type II strains from other areas in Africa and Western Europe, using discriminant analysis of principal components and Network analysis, point to a mainly Western European origin of the type II lineage in Senegal. Collectively, these findings suggest that human-mediated intercontinental migrations of murine hosts are important vectors of T. gondii strains. Differential susceptibility of endemic and introduced murine hosts to various T. gondii strains probably determines the persistence of these strains in the environment, and therefore their availability for human and animal infection.


Assuntos
Comércio , Variação Genética , Doenças das Aves Domésticas/transmissão , Toxoplasma/genética , Toxoplasmose Animal/epidemiologia , Toxoplasmose Animal/transmissão , África Ocidental/epidemiologia , Alelos , Animais , Galinhas/parasitologia , Reservatórios de Doenças/parasitologia , Europa (Continente)/epidemiologia , Genética Populacional , Genótipo , Geografia , Humanos , Camundongos/parasitologia , Repetições de Microssatélites , Filogenia , Filogeografia , Polimorfismo de Fragmento de Restrição , Doenças das Aves Domésticas/parasitologia , Virulência
5.
Acta Crystallogr E Crystallogr Commun ; 75(Pt 3): 378-382, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30867953

RESUMO

Reaction in gel between the sodium salt of 1,4-phenyl-enedi-acetic acid (Na2C10O4H8-Na2 p-pda) and lanthanum chloride yields single crystals of the three-dimensional coordination polymer poly[[tetra-aqua-tris-(µ-1,4-phenyl-enedi-acetato)-dilanthanum(III)] octa-hydrate], {[La2(C10H8O4)3(H2O)4]·8H2O}∞. The LaIII coordination polyhedron can be described as a slightly distorted monocapped square anti-prism. One of the two p-pda2- ligands is bound to four LaIII ions and the other to two LaIII ions. Each LaIII atom is coordinated by five ligands, thereby generating a metal-organic framework with potential porosity properties.

6.
Int J Parasitol ; 49(3-4): 267-275, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30578812

RESUMO

Commensal rodent species are key reservoirs for Toxoplasma gondii in the domestic environment. In rodents, different T. gondii strains show variable patterns of virulence according to host species. Toxoplasma gondii strains causing non-lethal chronic infections in local hosts will be more likely to persist in a given environment, but few studies have addressed the possible role of these interactions in shaping the T. gondii population structure. In addition, the absence of validated techniques for upstream detection of T. gondii chronic infection in wild rodents hinders exploration of this issue under natural conditions. In this study, we took advantage of an extensive survey of commensal small mammals in three coastal localities of Senegal, with a species assemblage constituted of both native African species and invasive species. We tested 828 individuals for T. gondii chronic infection using the modified agglutination test for antibody detection in serum samples and a quantitative PCR assay for detection of T. gondii DNA in brain samples. The infecting T. gondii strains were genotyped whenever possible by the analysis of 15 microsatellite markers. We found (i) a very poor concordance between molecular detection and serology in the invasive house mouse, (ii) significantly different levels of prevalence by species and (iii) the autochthonous T. gondii Africa 1 lineage strains, which are lethal for laboratory mice, only in the native African species of commensal small mammals. Overall, this study highlights the need to reconsider the use of MAT serology in natural populations of house mice and provides the first known data about T. gondii genetic diversity in invasive and native species of small mammals from Africa. In light of these results, we discuss the role of invasive and native species, with their variable adaptations to different T. gondii strains, in shaping the spatial structure of T. gondii genetic diversity in Africa.


Assuntos
Biota , Variação Genética , Genótipo , Doenças dos Roedores/parasitologia , Toxoplasma/classificação , Toxoplasma/isolamento & purificação , Toxoplasmose Animal/parasitologia , Animais , Técnicas de Genotipagem , Repetições de Microssatélites , Prevalência , Roedores , Senegal , Toxoplasma/genética , Toxoplasmose Animal/epidemiologia
7.
Parasite ; 25: 32, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30016257

RESUMO

Risks related to Toxoplasma gondii infection in humans remain poorly known in Senegal. Although rodent surveys could help to assess the circulation of T. gondii, they have seldom been set up in sub-Saharan Africa. The aim of this study was to examine Toxoplasma seroprevalence in rodents from villages and towns across Senegal. Rodents were sampled in 40 localities using a standardised trapping protocol. Detection of T. gondii antibodies was performed on 1205 rodents, using a modified agglutination test (MAT) technique. Seroprevalence data were analysed depending on geography, the local rodent community, and individual characteristics of the rodent hosts. We found 44 seropositive rodents from four different species (Mastomys erythroleucus, Mastomys natalensis, Mus musculus domesticus, Rattus rattus). Toxoplasma seroprevalence was low, averaging 4% in the localities. Higher Toxoplasma seroprevalence (up to 24%) was found in northern Senegal, a region known to be the heart of pastoral herding in the country.


Assuntos
Anticorpos Antiprotozoários/sangue , Murinae/parasitologia , Estudos Soroepidemiológicos , Toxoplasma/imunologia , Toxoplasmose Animal/epidemiologia , Toxoplasmose Animal/imunologia , África Ocidental/epidemiologia , Testes de Aglutinação , Animais , Feminino , Humanos , Masculino , Doenças dos Roedores , Senegal/epidemiologia , Simbiose , Toxoplasmose Animal/sangue , Toxoplasmose Animal/parasitologia
8.
PLoS Negl Trop Dis ; 12(6): e0006615, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29958273

RESUMO

Bioinvasion is a major public health issue because it can lead to the introduction of pathogens in new areas and favours the emergence of zoonotic diseases. Rodents are prominent invasive species, and act as reservoirs in many zoonotic infectious diseases. The aim of this study was to determine the link between the distribution and spread of two parasite taxa (Leishmania spp. and Trypanosoma lewisi) and the progressive invasion of Senegal by two commensal rodent species (the house mouse Mus musculus domesticus and the black rat Rattus rattus). M. m. domesticus and R. rattus have invaded the northern part and the central/southern part of the country, respectively. Native and invasive rodents were caught in villages and cities along the invasion gradients of both invaders, from coastal localities towards the interior of the land. Molecular diagnosis of the two trypanosomatid infections was performed using spleen specimens. In the north, neither M. m. domesticus nor the native species were carriers of these parasites. Conversely, in the south, 17.5% of R. rattus were infected by L. major and 27.8% by T. lewisi, while very few commensal native rodents were carriers. Prevalence pattern along invasion gradients, together with the knowledge on the geographical distribution of the parasites, suggested that the presence of the two parasites in R. rattus in Senegal is of different origins. Indeed, the invader R. rattus could have been locally infected by the native parasite L. major. Conversely, it could have introduced the exotic parasite T. lewisi in Senegal, the latter appearing to be poorly transmitted to native rodents. Altogether, these data show that R. rattus is a carrier of both parasites and could be responsible for the emergence of new foci of cutaneous leishmaniasis, or for the transmission of atypical human trypanosomiasis in Senegal.


Assuntos
Reservatórios de Doenças/parasitologia , Leishmania major/isolamento & purificação , Leishmaniose Cutânea/epidemiologia , Trypanosoma lewisi/isolamento & purificação , Tripanossomíase/epidemiologia , Animais , Humanos , Espécies Introduzidas , Leishmania major/genética , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/transmissão , Camundongos , Ratos , Roedores , Senegal/epidemiologia , Trypanosoma lewisi/genética , Tripanossomíase/parasitologia , Tripanossomíase/transmissão , Zoonoses
9.
Sci Rep ; 7(1): 14995, 2017 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-29101373

RESUMO

Changes in host-parasite ecological interactions during biological invasion events may affect both the outcome of invasions and the dynamics of exotic and/or endemic infections. We tested these hypotheses, by investigating ongoing house mouse (Mus musculus domesticus) and black rat (Rattus rattus) invasions in Senegal (West Africa). We used a 16S gene rRNA amplicon sequencing approach to study potentially zoonotic bacterial communities in invasive and native rodents sampled along two well-defined independent invasion routes. We found that individual host factors (body mass and sex) were important drivers of these bacterial infections in rodents. We observed that the bacterial communities varied along invasion routes and differed between invasive and native rodents, with native rodents displaying higher overall bacterial diversity than invasive rodents. Differences in prevalence levels for some bacterial Operational Taxonomic Units (OTUs) provided support for ecological processes connecting parasitism and invasion success. Finally, our results indicated that rodent invasions may lead to the introduction of exotic bacterial genera and/or to changes in the prevalence of endemic ones. This study illustrates the difficulty of predicting the relationship between biodiversity and disease risks, and advocate for public health prevention strategies based on global pathogen surveillance followed by accurate characterization of potential zoonotic agents.


Assuntos
Bactérias/isolamento & purificação , Camundongos/microbiologia , Ratos/microbiologia , Animais , Biodiversidade , Ecologia , Espécies Introduzidas , Senegal
10.
Parasitol Res ; 116(4): 1265-1271, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28210845

RESUMO

Whipworms were collected from rodents (Muridae) from six West African countries: Burkina-Faso, the Islamic Republic of Mauritania, and the Republics of Benin, Guinea, Mali and Senegal. Molecular sequences (ITS-1, 5.8S and ITS-2 of the ribosomal DNA gene) and morphometric characters were analysed in Trichuris (Nematoda: Trichuridae) specimens found in seven host species: Arvicanthis niloticus, Gerbilliscus gambianus, Gerbillus gerbillus, G. tarabuli, Mastomys erythroleucus, M. huberti and M. natalensis. Phylogenetic analyses revealed three clades, one recognised as Trichuris mastomysi, previously recorded in M. natalensis from Tanzania, and the other two previously undescribed. A new species named Trichuris duplantieri n. sp., found in Gerbillus spp. from Mauritania, was characterised using molecular and morphometric methods.


Assuntos
Filogenia , Doenças dos Roedores/parasitologia , Roedores/parasitologia , Tricuríase/veterinária , Trichuris/genética , África Ocidental/epidemiologia , Animais , DNA Ribossômico , Doenças dos Roedores/epidemiologia , Tricuríase/epidemiologia , Tricuríase/parasitologia , Trichuris/classificação
11.
Int J Parasitol ; 46(13-14): 857-869, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27670366

RESUMO

Understanding why some exotic species become widespread and abundant in their colonised range is a fundamental issue that still needs to be addressed. Among many hypotheses, newly established host populations may benefit from a parasite loss ("enemy release" hypothesis) through impoverishment of their original parasite communities or reduced infection levels. Moreover, the fitness of competing native hosts may be negatively affected by the acquisition of exotic taxa from invaders ("parasite spillover") and/or by an increased transmission risk of native parasites due to their amplification by invaders ("parasite spillback"). We focused on gastrointestinal helminth communities to determine whether these predictions could explain the ongoing invasion success of the commensal house mouse (Mus musculus domesticus) and black rat (Rattus rattus), as well as the associated decrease in native Mastomys spp., in Senegal. For both invasive species, our results were consistent with the predictions of the enemy release hypothesis. A decrease in overall gastrointestinal helminth prevalence and infracommunity species richness was observed along the invasion gradients as well as lower specific prevalence/abundance (Aspiculuris tetraptera in Mus musculus domesticus, Hymenolepis diminuta in Rattus rattus) on the invasion fronts. Conversely, we did not find strong evidence of GIH spillover or spillback in invasion fronts, where native and invasive rodents co-occurred. Further experimental research is needed to determine whether and how the loss of gastrointestinal helminths and reduced infection levels along invasion routes may result in any advantageous effects on invader fitness and competitive advantage.


Assuntos
Helmintíase Animal/parasitologia , Enteropatias Parasitárias/veterinária , Camundongos/parasitologia , Murinae/parasitologia , Ratos/parasitologia , Doenças dos Roedores/parasitologia , Animais , Feminino , Trato Gastrointestinal/parasitologia , Helmintíase Animal/epidemiologia , Himenolepíase/epidemiologia , Himenolepíase/parasitologia , Himenolepíase/veterinária , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/parasitologia , Espécies Introduzidas , Masculino , Oxiuríase/epidemiologia , Oxiuríase/parasitologia , Oxiuríase/veterinária , Prevalência , Doenças dos Roedores/epidemiologia , Senegal/epidemiologia
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