Dataset Information

Population genetics of forest type of Trypanosoma congolense circulating in Glossina palpalis palpalis of Fontem in the South-West region of Cameroon.

ABSTRACT: BACKGROUND: Genetic variation of microsatellite loci is a widely used method for the analysis of population genetic structure of several organisms. To improve our knowledge on the population genetics of trypanosomes, Trypanosoma congolense forest and savannah types were identified in the mid-guts of Glossina palpalis palpalis caught in five villages of Fontem in the South-West region of Cameroon. From the positive samples of Trypanosoma congolense forest, the genetic diversity and the population genetic structure of these parasites were evaluated. METHOD: For this study, pyramidal traps were set up during three entomological surveys and 3347 tsetse flies were collected, dissected and 1903 midguts collected. DNA was extracted from midguts and specific primers were used to identify Trypanosoma congolense forest and savannah. All Trypanosoma congolense forest positive samples were characterized with seven microsatellite markers. RESULTS: Microscopic examination revealed 25 (1.31%) mid-gut infections with trypanosomes while the PCR method identified 120 (6.3%) infections due to Trypanosoma congolense: 94 (78.33%) Trypanosoma congolense forest and 28 (21.77%) Trypanosoma congolense savannah. The trypanosome infection rates varied significantly between villages and years of capture. Menji recorded the highest infection rate (15.11%); and samples captured in 2009 were more infected (14.33%). The microsatellite markers revealed a genetic variability between Trypanosoma congolense forest populations of Fontem villages and 6.38% of mixed infections due to different genotypes of T. congolense "forest type". CONCLUSION: Our data on the population genetics play in favor of a clonal reproduction of this parasite. The microsatellite markers used here showed a low genetic differentiation and an absence of sub-structuration (FST???0.0003) between Trypanosoma congolense forest populations of Fontem villages. However, the high FST value (FST???0.3911) between samples of the Democratic Republic of Congo and those of Fontem villages indicates low migration rates between trypanosomes of these subpopulations.

SUBMITTER: Simo G

PROVIDER: S-EPMC4261900 | biostudies-other | 2014

REPOSITORIES: biostudies-other

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Population genetics of forest type of Trypanosoma congolense circulating in Glossina palpalis palpalis of Fontem in the South-West region of Cameroon.

Simo Gustave G Fogue Pythagore Soubgwi PS Melachio Tresor Tito Tanekou TT Njiokou Flobert F Kuiate Jules Roger JR Asonganyi Tazoacha T

Parasites & vectors 20140820

<h4>Background</h4>Genetic variation of microsatellite loci is a widely used method for the analysis of population genetic structure of several organisms. To improve our knowledge on the population genetics of trypanosomes, Trypanosoma congolense forest and savannah types were identified in the mid-guts of Glossina palpalis palpalis caught in five villages of Fontem in the South-West region of Cameroon. From the positive samples of Trypanosoma congolense forest, the genetic diversity and the pop ...[more]

PMID: 25142136

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Project description:BACKGROUND:Human African Trypanosomiasis is still a public health threat in Cameroon. To assess Trypanosoma brucei strains circulating in the Fontem sleeping sickness focus, we conducted a genetic structure study using microsatellites to assess genotypes circulating in both tsetse flies and domestic animals. METHOD:For this study, pyramidal traps were set up and 2695 tsetse flies were collected and 1535 (57%) living flies were dissected and their mid-guts collected. Furthermore, blood samples were collected from 397 domestic animals (pigs, goats, sheep and dogs). DNA was extracted from midguts and blood samples, and specific primers were used to identify trypanosomes of the subgenus Trypanozoon. All positive samples were genetically characterized with seven microsatellite markers. RESULTS:Seventy five (4.7%) midguts of tsetse flies and 140 (35.2%) domestic animals were found infected by trypanosomes of the subgenus Trypanozoon. The genetic characterization of 215 Trypanozoon positive samples (75 from tsetse and 140 from animals) revealed a genetic diversity between Trypanosoma brucei circulating in tsetse and domestic animals. Of these positive samples, 87 (40.5%) single infections were used here to investigate the population genetics of Trypanosoma brucei circulating in tsetse and domestic animals. The dendrogram illustrating the genetic similarities between Trypanosoma brucei genotypes was subdivided into four clusters. The samples from tsetse belonged to the same cluster whereas the samples from domestic animals and espcially pigs were distributed in the four clusters. CONCLUSION:Pigs appeared as the animal species harboring the highest number of different Trypanosoma brucei strains. They may play an important role in the propagation of different genotypes. The FST values revealed a sub structuration of Trypanosoma brucei according to hosts and sometimes villages. The data obtained from this study may have considerable importance for the understanding of the transmission and the spread of specific genotypes of Trypanosoma brucei.

Project description:BackgroundThe tsetse transmitted parasitic flagellate Trypanosoma congolense causes animal African trypanosomosis (AAT) across sub-Saharan Africa. AAT negatively impacts agricultural, economic, nutritional and subsequently, health status of the affected populace. The molecular mechanisms that underlie T. congolense's developmental program within tsetse are largely unknown due to considerable challenges with obtaining sufficient parasite cells to perform molecular studies.MethodsIn this study, we used RNA-seq to profile T. congolense gene expression during development in two distinct tsetse tissues, the cardia and proboscis. Indirect immunofluorescent antibody test (IFA) and confocal laser scanning microscope was used to localize the expression of a putative protein encoded by the hypothetical protein (TcIL3000_0_02370).ResultsConsistent with current knowledge, genes coding several variant surface glycoproteins (including metacyclic specific VSGs), and the surface coat protein, congolense epimastigote specific protein, were upregulated in parasites in the proboscis (PB-parasites). Additionally, our results indicate that parasites in tsetse's cardia (C-parasites) and PB employ oxidative phosphorylation and amino acid metabolism for energy. Several genes upregulated in C-parasites encoded receptor-type adenylate cyclases, surface carboxylate transporter family proteins (or PADs), transport proteins, RNA-binding proteins and procyclin isoforms. Gene ontology analysis of products of genes upregulated in C-parasites showed enrichment of terms broadly associated with nucleotides, microtubules, cell membrane and its components, cell signaling, quorum sensing and several transport activities, suggesting that the parasites colonizing the cardia may monitor their environment and regulate their density and movement in this tissue. Additionally, cell surface protein (CSP) encoding genes associated with the Fam50 'GARP', 'iii' and 'i' subfamilies were also significantly upregulated in C-parasites, suggesting that they are important for the long non-dividing trypomastigotes to colonize tsetse's cardia. The putative products of genes that were upregulated in PB-parasites were linked to nucleosomes, cytoplasm and membrane-bound organelles, which suggest that parasites in this niche undergo cell division in line with prior findings. Most of the CSPs upregulated in PB-parasites were hypothetical, thus requiring further functional characterization. Expression of one such hypothetical protein (TcIL3000_0_02370) was analyzed using immunofluorescence and confocal laser scanning microscopy, which together revealed preferential expression of this protein on the entire surface coat of T. congolense parasite stages that colonize G. m. morsitans' proboscis.ConclusionCollectively, our results provide insight into T. congolense gene expression profiles in distinct niches within the tsetse vector. Our results show that the hypothetical protein TcIL3000_0_02370, is expressed on the entire surface of the trypanosomes inhabiting tsetse's proboscis. We discuss our results in terms of their relevance to disease transmission processes.

Project description:BACKGROUND:Tsetse fly-borne trypanosomiasis remains a significant problem in Africa despite years of interventions and research. The need for new strategies to control and possibly eliminate trypanosomiasis cannot be over-emphasized. Entomopathogenic fungi (EPF) infect their hosts through the cuticle and proliferate within the body of the host causing death in about 3-14 days depending on the concentration. During the infection process, EPF can reduce blood feeding abilities in hematophagous arthropods such as mosquitoes, tsetse flies and ticks, which may subsequently impact the development and transmission of parasites. Here, we report on the effects of infection of tsetse fly (Glossina fuscipes fuscipes) by the EPF, Metarhizium anisopliae ICIPE 30 wild-type strain (WT) and green fluorescent protein-transformed strain (GZP-1) on the ability of the flies to harbor and transmit the parasite, Trypanosoma congolense. RESULTS:Teneral flies were fed T. congolense-infected blood for 2 h and then infected using velvet carpet fabric impregnated with conidia covered inside a cylindrical plastic tube for 12 h. Control flies were fed with T. congolense-infected blood but not exposed to the fungal treatment via the carpet fabric inside a cylindrical plastic tube. Insects were dissected at 2, 3, 5 and 7 days post-fungal exposure and the density of parasites quantified. Parasite load decreased from 8.7?×?107 at day 2 to between 8.3?×?104 and 1.3?×?105 T. congolense ml-?1 at day 3 post-fungal exposure in fungus-treated (WT and GZP-1) fly groups. When T. congolense-infected flies were exposed to either fungal strain, they did not transmit the parasite to mice whereas control treatment flies remained capable of parasite transmission. Furthermore, M. anisopliae-inoculated flies which fed on T. congolense-infected mice were not able to acquire the parasites at 4 days post-fungal exposure while parasite acquisition was observed in the control treatment during the same period. CONCLUSIONS:Infection of the vector G. f. fuscipes by the entomopathogenic fungus M. anisopliae negatively affected the multiplication of the parasite T. congolense in the fly and reduced the vectorial capacity to acquire or transmit the parasite.

Project description:BackgroundIncreased risk of schistosomiasis in peri-urban and urban towns is not uncommon. An epidemiological survey was carried out in the Tiko Health District (THD), an unmapped transmission focus for urogenital schistosomiasis (UGS), to assess the distribution, intensity, and risk factors associated with the occurrence of UGS.MethodsIn this cross-sectional survey, 12 communities were purposively selected from four health areas (HAs) (Likomba, Holforth, Holforth-Likomba, and Mutengene) in South West Region of Cameroon between June and August 2018. Consenting individuals were enrolled using a convenient sampling technique and administered a semi-structured questionnaire to document information on socio-demographic and water contact behaviour. Urine samples were examined for Schistosoma haematobium infection using test strip, filtration, and microscopy methods. Bivariate and binary logistic regression analyses were used to identify predictors of infection.ResultsThe overall prevalence of UGS in Likomba, Holforth-Likomba and Holforth was 31.5% [95% confidence interval (CI): 28.3-34.8] with geometric mean (GM) egg count of 28.7 (range: 2-450) eggs per 10 ml of urine. S. haematobium infection was not found in Mutengene HA. Infection was unevenly distributed among the HAs, Holforth-Likomba and Holforth being the most and least affected, respectively. The prevalence of infection varied (P < 0.001) among the affected communities, ranging from 12.0 to 56.9%. Infection status of the community related positively (P < 0.001) with proximity to stream (< 100 m), the degree of contact with water and number of improved water sources. Younger age group (5-14 years) [adjusted odds ratio (aOR): 3.7, 95% CI: 1.1-12.2] and intense water contact (degree II) (aOR: 5.2, 95% CI: 3.4-8.1) were associated with increased risk of infection. Similarly, significantly higher egg load was observed among younger aged groups (P = 0.02) and those who carried out intense water contact activities (P < 0.001).ConclusionsGenerally, THD is a moderate risk endemic focus for UGS but prevalence higher than 50.0% was observed in some communities. These findings warrant immediate mass chemotherapy with praziquantel to reduce morbidity. Provision of portable water and health education are proposed measures to reduce and eventually eliminate transmission in the area.

Project description:BackgroundEarly diagnosis and adequate treatment of Group A streptococcal throat infection is an important initial stage in the primary prevention of acute rheumatic fever and rheumatic heart disease. This preventable condition associated with high mortality rates mandates a thorough understanding by the general public and the health.ObjectiveThe aim of the study was to assess the level of awareness about different aspects of rheumatic heart disease in patients coming to the outpatient department of the Buea regional Hospital, South West region of Cameroon.MethodsThis was a cross-sectional descriptive study carried in the outpatient department of the Buea Regional Hospital, Cameroon. The study population was adults and children aged 9 years and above. Data collection was done by using a self-administered questionnaire addressed to assess awareness on rheumatic heart disease.ResultsA total of 256 participants were interviewed, of which 70 (27.3%) were males. Their mean age was 34.4 ± 11.9 years (males: 36.2 ± 12.7 years versus females: 33.7 ± 11.6 years, p = 0.129). Most of the participants were in the 20 to 29 year old group (37.9%). More than two thirds (71.1%) of the participants reported having had sore throat at least once. The disease was treated with antibiotics in only 45.4%, with the treatment prescribed by a health care professional in 35.8% of the cases. About 73% of the respondents did not know what causes sore throat, and most (71.1%) were unaware of any complications that could arise from poorly treated sore throat. More than 70% of the participants did not know that sore throat can be associated with heart disease. Rheumatic heart disease was unknown to 82% of the participants and 95% of them did not know what causes RHD. Only 5.1% percent of the participants had an adequate knowledge of RHD. Age ? 35 years, post-secondary level of education, and having heard of RHD were significantly associated with an adequate knowledge. After adjusting for age, post-secondary education (aOR: 9, [95% C: 1.2-67.5], p = 0.019), and having heard of RHD (aOR: 18.1, [95% CI: 4.7-70.3], p<0.001) were still associated with a fair knowledge.ConclusionsLevels of knowledge and awareness on rheumatic heart disease is low. This study provides important insight into the perception and practices related to sore throat that can be used in the design of awareness activities aimed reducing the risk of RHD in Cameroon. The appropriateness of antibiotics prescribed, and the health care provider awareness and knowledge levels regarding RHD in Cameroon has not been reported yet in the literature. This grey area deserves more research.

Dataset Information

Population genetics of forest type of Trypanosoma congolense circulating in Glossina palpalis palpalis of Fontem in the South-West region of Cameroon.

Publications

Population genetics of forest type of Trypanosoma congolense circulating in Glossina palpalis palpalis of Fontem in the South-West region of Cameroon.

Similar Datasets

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