scholarly journals Microsporidia MB is found predominantly associated with Anopheles gambiae s.s and Anopheles coluzzii in Ghana

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jewelna Akorli ◽  
Esinam Abla Akorli ◽  
Seraphim Naa Afoley Tetteh ◽  
Godwin Kwame Amlalo ◽  
Millicent Opoku ◽  
...  

AbstractA vertically transmitted microsporidian, Microsporidia MB, with the ability to disrupt Plasmodium development was reported in Anopheles arabiensis from Kenya, East Africa. To demonstrate its range of incidence, archived DNA samples from 7575 Anopheles mosquitoes collected from Ghana were screened. MB prevalence was observed at 1.8%. An. gambiae s.s constituted 87% of positive mosquitoes while the remaining were from An. coluzzii. Both sibling species had similar positivity rates (24% and 19%; p = 0.42) despite the significantly higher number of An. gambiae s.s analysed (An. gambiae s.s = 487; An. coluzzii = 94; p = 0.0005). The microsporidian was also more prevalent in emerged adults from field-collected larvae than field-caught adults (p < 0.0001) suggestive of an efficient vertical transmission and/or horizontal transfer among larvae. This is the first report of Microsporidia MB in Anopheles mosquitoes in West Africa. It indicates possible widespread among malaria vector species and warrants investigations into the symbiont’s diversity across sub-Saharan Africa.

GigaScience ◽  
2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Anton Zamyatin ◽  
Pavel Avdeyev ◽  
Jiangtao Liang ◽  
Atashi Sharma ◽  
Chujia Chen ◽  
...  

Abstract Background Anopheles coluzzii and Anopheles arabiensis belong to the Anopheles gambiae complex and are among the major malaria vectors in sub-Saharan Africa. However, chromosome-level reference genome assemblies are still lacking for these medically important mosquito species. Findings In this study, we produced de novo chromosome-level genome assemblies for A. coluzzii and A. arabiensis using the long-read Oxford Nanopore sequencing technology and the Hi-C scaffolding approach. We obtained 273.4 and 256.8 Mb of the total assemblies for A. coluzzii and A. arabiensis, respectively. Each assembly consists of 3 chromosome-scale scaffolds (X, 2, 3), complete mitochondrion, and unordered contigs identified as autosomal pericentromeric DNA, X pericentromeric DNA, and Y sequences. Comparison of these assemblies with the existing assemblies for these species demonstrated that we obtained improved reference-quality genomes. The new assemblies allowed us to identify genomic coordinates for the breakpoint regions of fixed and polymorphic chromosomal inversions in A. coluzzii and A. arabiensis. Conclusion The new chromosome-level assemblies will facilitate functional and population genomic studies in A. coluzzii and A. arabiensis. The presented assembly pipeline will accelerate progress toward creating high-quality genome references for other disease vectors.


2020 ◽  
Author(s):  
NWAMAKA OLUCHUKWU AKPODIETE ◽  
FREDERIC TRIPET

Abstract Background The sibling species of the malaria mosquito, Anopheles gambiae s.s and Anopheles coluzzii co-exist in many parts of West Africa and are thought to have recently diverged through a process of ecological speciation with gene flow. Divergent larval ecological adaptations, resulting in Genotype × Environment interactions have been proposed as important drivers of speciation in these species. In West Africa, An. coluzzii tends to be associated with permanent man-made larval habitats such as irrigated rice fields which are typically more eutrophic and mineral and ammonia-rich than the temporary rain pools exploited by An. gambiae s.s. Methods To highlight G×E interactions at the larval stage and their possible role in ecological speciation of these species, we first investigated the effect of exposure to ammonium hydroxide and water mineralisation on larval developmental success. Mosquito larvae were exposed to two water sources and increasing ammonia concentrations in small containers until adult emergence. In a second experiment, larval developmental success was compared across 2 contrasted microcosms to highlight G × E interactions under conditions like those found in the natural environment. Results The first experiment revealed significant G × E interactions in developmental success and phenotypic quality for both species in response to increasing ammonia concentrations and water mineralisation. The An. coluzzii strain outperformed the An. gambiae s.s. strain under limited conditions that were closer to more eutrophic habitats. The second experiment revealed divergent crisscrossing reaction norms in the developmental success of the sibling species in the two contrasted larval environments. As expected, An. coluzzii had higher emergence rates in the rice paddy environment with emerging adults of superior phenotypic quality compared to An. gambiae s.s, and vice versa in the rain puddle environment. Conclusions Evidence for such G x E interactions lends support to the hypothesis that divergent larval adaptations to the environmental conditions found in man-made habitats such as rice-fields in An. coluzzii may have been an important driver of its ecological speciation.


2020 ◽  
Author(s):  
Nwamaka Oluchukwu Akpodiete ◽  
Frederic Tripet

Abstract Background The sibling species of the malaria mosquito, Anopheles gambiae s.s and Anopheles coluzzii co-exist in many parts of West Africa and are thought to have recently diverged through a process of ecological speciation with gene flow. Divergent larval ecological adaptations, resulting in Genotype × Environment interactions have been proposed as important drivers of speciation in these species. In West Africa, An. coluzzii tends to be associated with permanent man-made larval habitats such as irrigated rice fields which are typically more eutrophic and mineral and ammonia-rich than the temporary rain pools exploited by An. gambiae s.s. Methods To highlight G×E interactions at the larval stage and their possible role in ecological speciation of these species, we first investigated the effect of exposure to ammonium hydroxide and water mineralisation on larval developmental success. Mosquito larvae were exposed to two water sources and increasing ammonia concentrations in small containers until adult emergence. In a second experiment, larval developmental success was compared across 2 contrasted microcosms to highlight G × E interactions under conditions like those found in the natural environment. Results The first experiment revealed significant G × E interactions in developmental success and phenotypic quality for both species in response to increasing ammonia concentrations and water mineralisation. The An. coluzzii strain outperformed the An. gambiae s.s. strain under limited conditions that were closer to more eutrophic habitats. The second experiment revealed divergent crisscrossing reaction norms in the developmental success of the sibling species in the two contrasted larval environments. As expected, An. coluzzii had higher emergence rates in the rice paddy environment with emerging adults of superior phenotypic quality compared to An. gambiae s.s, and vice versa in the rain puddle environment.Conclusions Evidence for such G x E interactions lends support to the hypothesis that divergent larval adaptations to the environmental conditions found in man-made habitats such as rice-fields in An. coluzzii may have been an important driver of its ecological speciation.


2020 ◽  
Vol 26 (3) ◽  
pp. 219-238
Author(s):  
Adam Mohr

The 1918–19 influenza pandemic killed between 30 and 50 million people worldwide. In Sub-Saharan Africa, as Terence Ranger points out, the pandemic left an indelible mark, including the unforeseen emergence of anti-medical religious movements. None were as significant as Faith Tabernacle Congregation, the Philadelphia-based divine-healing church that spurred a massive revival in West Africa – and a network stretching from Ivory Coast to Nigeria – without ever sending missionaries. They evangelised through personal letters exchanged across the Atlantic, and Faith Tabernacle literature sent from Philadelphia to various leaders in West Africa. The 1918–19 influenza pandemic was the spark that led to the church's massive growth, from one small branch before the pandemic began in 1918 to 10,500 members and nearly 250 branches of Faith Tabernacle in West Africa at its zenith in 1926. After the church's rapid demise between 1926 and 1929, leaders of Faith Tabernacle established most of the oldest Pentecostal Churches in the Gold Coast and Nigeria – such as the Apostolic Faith, the Apostolic Church, the Christ Apostolic Church and the Assemblies of God (Nigeria). Classical Pentecostalism, therefore, is Faith Tabernacle's legacy in West Africa, while abstinence from orthodox medicine continued to be debated within these Pentecostal circles.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nwamaka Oluchukwu Akpodiete ◽  
Frédéric Tripet

Abstract Background The sibling species of the malaria mosquito, Anopheles gambiae (sensu stricto) and Anopheles coluzzii co-exist in many parts of West Africa and are thought to have recently diverged through a process of ecological speciation with gene flow. Divergent larval ecological adaptations, resulting in Genotype-by-Environment (G × E) interactions, have been proposed as important drivers of speciation in these species. In West Africa, An. coluzzii tends to be associated with permanent man-made larval habitats such as irrigated rice fields, which are typically more eutrophic and mineral and ammonia-rich than the temporary rain pools exploited by An. gambiae (s.s.) Methods To highlight G × E interactions at the larval stage and their possible role in ecological speciation of these species, we first investigated the effect of exposure to ammonium hydroxide and water mineralisation on larval developmental success. Mosquito larvae were exposed to two water sources and increasing ammonia concentrations in small containers until adult emergence. In a second experiment, larval developmental success was compared across two contrasted microcosms to highlight G × E interactions under conditions such as those found in the natural environment. Results The first experiment revealed significant G × E interactions in developmental success and phenotypic quality for both species in response to increasing ammonia concentrations and water mineralisation. The An. coluzzii strain outperformed the An. gambiae (s.s.) strain under limited conditions that were closer to more eutrophic habitats. The second experiment revealed divergent crisscrossing reaction norms in the developmental success of the sibling species in the two contrasted larval environments. As expected, An. coluzzii had higher emergence rates in the rice paddy environment with emerging adults of superior phenotypic quality compared to An. gambiae (s.s.), and vice versa, in the rain puddle environment. Conclusions Evidence for such G × E interactions lends support to the hypothesis that divergent larval adaptations to the environmental conditions found in man-made habitats such as rice fields in An. coluzzii may have been an important driver of its ecological speciation.


2021 ◽  
Vol 18 (S1) ◽  
Author(s):  
Martin K. Mutua ◽  
Yohannes D. Wado ◽  
Monica Malata ◽  
Caroline W. Kabiru ◽  
Elsie Akwara ◽  
...  

Abstract Background The use of modern contraception has increased in much of sub-Saharan Africa (SSA). However, the extent to which changes have occurred across the wealth spectrum among adolescents is not well known. We examine poor-rich gaps in demand for family planning satisfied by modern methods (DFPSm) among sexually active adolescent girls and young women (AGYW) using data from national household surveys. Methods We used recent Demographic and Health Surveys and Multiple Indicator Cluster Surveys to describe levels of wealth-related inequalities in DFPSm among sexually active AGYW using an asset index as an indicator of wealth. Further, we used data from countries with more than one survey conducted from 2000 to assess DFPSm trends. We fitted linear models to estimate annual average rate of change (AARC) by country. We fitted random effects regression models to estimate regional AARC in DFPSm. All analysis were stratified by marital status. Results Overall, there was significant wealth-related disparities in DFPSm in West Africa only (17.8 percentage points (pp)) among married AGYW. The disparities were significant in 5 out of 10 countries in Eastern, 2 out of 6 in Central, and 7 out of 12 in West among married AGYW and in 2 out of 6 in Central and 2 out of 9 in West Africa among unmarried AGYW. Overall, DFPSm among married AGYW increased over time in both poorest (AARC = 1.6%, p < 0.001) and richest (AARC = 1.4%, p < 0.001) households and among unmarried AGYW from poorest households (AARC = 0.8%, p = 0.045). DPFSm increased over time among married and unmarried AGYW from poorest households in Eastern (AARC = 2.4%, p < 0.001) and Southern sub-regions (AARC = 2.1%, p = 0.030) respectively. Rwanda and Liberia had the largest increases in DPFSm among married AGYW from poorest (AARC = 5.2%, p < 0.001) and richest (AARC = 5.3%, p < 0.001) households respectively. There were decreasing DFPSm trends among both married (AARC = − 1.7%, p < 0.001) and unmarried (AARC = − 4.7%, p < 0.001) AGYW from poorest households in Mozambique. Conclusion Despite rapid improvements in DFPSm among married AGYW from the poorest households in many SSA countries there have been only modest reductions in wealth-related inequalities. Significant inequalities remain, especially among married AGYW. DFPSm stalled in most sub-regions among unmarried AGYW.


2012 ◽  
Vol 44 (2) ◽  
pp. 7 ◽  
Author(s):  
S. Epis ◽  
M. Montagna ◽  
F. Comandatore ◽  
C. Damiani ◽  
A. Diabaté ◽  
...  

The acetic acid bacterium <em>Asaia</em> spp. was successfully detected in <em>Anopheles arabiensis</em> Patton, 1905, one of the major vector of human malaria in Sub-Saharan Africa. A collection of 45 <em>Asaia</em> isolates in cellfree media was established from 20 individuals collected from the field in Burkina Faso. 16S rRNA universal polymerase chain reaction (PCR) and specific qPCR, for the detection of <em>Asaia</em> spp. were performed in order to reveal the presence of different bacterial taxa associated with this insect. The isolates were typed by internal transcribed spacer-PCR, BOX-PCR, and randomly amplified polymorphic DNA-PCR, proved the presence of different <em>Asaia</em> in <em>A. arabiensis</em>.


2017 ◽  
Vol 51 (1) ◽  
pp. 77-84
Author(s):  
Keiichi HAYASHI ◽  
Yasuhiro TSUJIMOTO ◽  
Tamao HATTA ◽  
Yukiyo YAMAMOTO ◽  
Jun-Ichi SAKAGAMI ◽  
...  

2021 ◽  
pp. 1-17
Author(s):  
Ayokunle Olumuyiwa Omobowale ◽  
Natewinde Sawadogo

Abstract The West African political economy has been shaped by the policies, decisions and actions of dominant European imperialist countries since about over 500 years. Starting with imperial merchant capitalism along the West African coast in the 16th Century and French gradual acquisition of Senegal as a colony as from 1677, West Africa has remained under the imperialist hold. West Africa remains economically dependent on its former colonial masters despite more than 60 years since the countries started gaining independence. The consequences of economic imperialism on West Africa have included exploitative resource extraction, proxy and resource influenced civil wars, illegal trade in natural resources, mass poverty, and external migration of skilled workers necessary for national development. The world sees and broadcasts poverty, starvation, conflict and Saharan migration in the West African sub-continent, but hardly reports the exploitative imperialistic processes that have produced poverty and misery in West Africa in particular and across sub-Saharan Africa in general.


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