Browsing by Author "Futse, J.E."
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Item Disaggregating tropical disease prevalence by climatic and vegetative zones within tropical west Africa(Public Library of Science, 2016) Beckley, C.S.; Shaban, S.; Noh, S.M.; Palmer, G.H.; Hudak, A.T.; Futse, J.E.Tropical infectious disease prevalence is dependent on many socio-cultural determinants. However, rainfall and temperature frequently underlie overall prevalence, particularly for vector-borne diseases. As a result these diseases have increased prevalence in tropical as compared to temperate regions. Specific to tropical Africa, the tendency to incorrectly infer that tropical diseases are uniformly prevalent has been partially overcome with solid epidemiologic data. This finer resolution data is important in multiple contexts, including understanding risk, predictive value in disease diagnosis, and population immunity. We hypothesized that within the context of a tropical climate, vector-borne pathogen prevalence would significantly differ according to zonal differences in rainfall, temperature, relative humidity and vegetation condition. We then determined if these environmental data were predictive of pathogen prevalence. First we determined the prevalence of three major pathogens of cattle, Anaplasma marginale, Babesia bigemina and Theileria spp, in the three vegetation zones where cattle are predominantly raised in Ghana: Guinea savannah, semideciduous forest, and coastal savannah. The prevalence of A. marginale was 63%, 26% for Theileria spp and 2% forB. bigemina. A. marginale and Theileria spp. were significantly more prevalent in the coastal savannah as compared to either the Guinea savanna or the semi-deciduous forest, supporting acceptance of the first hypothesis. To test the predictive power of environmental variables, the data over a three year period were considered in best subsets multiple linear regression models predicting prevalence of each pathogen. Corrected Akaike Information Criteria (AICc) were assigned to the alternative models to compare their utility. Competitive models for each response were averaged using AICc weights. Rainfall was most predictive of pathogen prevalence, and EVI also contributed to A marginale and B. bigemina prevalence. These findings support the utility of environmental data for understanding vector-borne disease epidemiology on a regional level within a tropical environment. This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.Item Expression of Anaplasma marginale ankyrin repeat-containing proteins during infection of the mammalian host and tick vector(Infection and Immunity, 2011-07) Ramabu, S.S.; Schneider, D.A.; Brayton, K.A.; Ueti, M.W.; Graça, T.; Futse, J.E.; Noh, S.M.; Baszler, T.V.; Palmer, G.H.Transmission of tick-borne pathogens requires transition between distinct host environments with infection and replication in host-specific cell types. Anaplasma marginale illustrates this transition: in the mammalian host, the bacterium infects and replicates in mature (nonnucleated) erythrocytes, while in the tick vector, replication occurs in nucleated epithelial cells. We hypothesized that proteins containing ankyrin motifs would be expressed by A. marginale only in tick cells and would traffic to the infected host cell nucleus. A. marginale encodes three proteins containing ankyrin motifs, an AnkA orthologue (the AM705 protein), AnkB (the AM926 protein), and AnkC (the AM638 protein). All three A. marginale Anks were confirmed to be expressed during intracellular infection: AnkA is expressed at significantly higher levels in erythrocytes, AnkB is expressed equally by both infected erythrocytes and tick cells, and AnkC is expressed exclusively in tick cells. There was no evidence of any of the Ank proteins trafficking to the nucleus. Thus, the hypothesis that ankyrin-containing motifs were predictive of cell type expression and nuclear localization was rejected. In contrast, AnkA orthologues in the closely related A. phagocytophilum and Ehrlichia chaffeensis have been shown to localize to the host cell nucleus. This difference, together with the lack of a nuclear localization signal in any of the AnkA orthologues, suggests that trafficking may be mediated by a separate transporter rather than by endogenous signals. Selection for divergence in Ank function among Anaplasma and Ehrlichia spp. is supported by both locus and allelic analyses of genes encoding orthologous proteins and their ankyrin motif compositions. © 2011, American Society for Microbiology.Item Microbial carriage and contamination of mangoes by the oriental fruit fly(Open Public Health Journal, 2017-11) Futagbi, G.; Koduah, N.A.G.; Ampah, B.R.; Mattah, P.A.D.; Billah, M.; Futse, J.E.; Sampane-Donkor, E.Background: Fruit flies, especially of the Family Terphritidae, are economically important pests for the horticulture industry because many species cause serious mechanical damage to a number of crops of different plant families. Studies have shown that some species of fruit flies have the potential to contaminate fruits and vegetables with enteric bacterial pathogens. However, this has not been conclusively demonstrated. Methods: In this study, we investigated enteric bacteria carriage by Bactrocera dorsalis and its possible role in transmission of microbes into internal tissues of fruits. Fruit flies trapped using liquid protein bait, ripe mango fruits exposed to the fruit flies and controls, as well as mangoes obtained from farms with and without fly-control traps, were analyzed for microbes, such as total aerobic bacteria, total coliforms, yeast and molds, Escherichia coli and Salmonella/Shigella spp. using direct culture methods. Results and Discussion: The results revealed that a high percentage of these insects carries pathogenic bacteria. This finding shows that, like B. cacuminata and B. tryoni, B. dorsalis also carries pathogenic microbes. It was also observed that mangoes sampled from fly-control farms had significantly lower microbial loads and proportions of fruits contaminated compared to those from farms without fly-control. Additionally, all microbial counts of internal tissues were significantly higher for exposed mangoes compared to unexposed mangoes. These data indicate that B. dorsalis contaminates not only the external but also internal tissues of mangoes. Conclusion: These findings show that B. dorsalis carries pathogenic bacteria and plays a direct role in internalization of microbes in mangoesItem Sequence and immunologic conservation of Anaplasma marginale OmpA within strains from Ghana as compared to the predominant OmpA variant(Plos One, 2019-07-10) Futse, J.E.; Buami, G.; Kayang, B.B.; Koku, R.; Palmer, G.H.; Graca, T.; Noh, S.M.A primary challenge in developing effective vaccines against obligate, intracellular, bacterial tick-borne pathogens that establish persistent infection is the identification of antigens that cross protect against multiple strains. In the case of Anaplasma marginale, the most prevalent tick-borne pathogen of cattle found worldwide, OmpA is an adhesin and thus a promising vaccine candidate. We sequenced ompA from cattle throughout Ghana naturally infected with A. marginale in order to determine the degree of variation in this gene in an area of suspected high genetic diversity. We compared the Ghanaian sequences with those available from N. America, Mexico, Australia and Puerto Rico. When considering only amino acid changes, three unique Ghanaian OmpA variants were identified. In comparison, strains from all other geographic regions, except one, shared a single OmpA variant, Variant 1, which differed from the Ghanaian variants. Next, using recombinant OmpA based on Variant 1, we determined that amino acid differences in OmpA in Ghanaian cattle as compared to OmpA Variant 1 did not alter the binding capacity of antibody directed against OmpA Variant 1, supporting the value of OmpA as a highly conserved vaccine candidate.Item Susceptibility of Indigenous Cattle Breeds to Co-Infection with Multiple Tick-Borne Pathogens(University of Ghana, 2013-12) Beckley, C.S.K.; Futse, J.E.; Kayang, B.B.The control of tick-borne diseases in an endemic region is very challenging and costly due to the presence of multiple pathogens from the seven globally-important livestock intracellular pathogens. This problem is exacerbated by the availability of competent vector ticks for each pathogen strain, thus resulting in enhanced transmission efficiency and higher infection prevalence of disease among cattle from the tropical region than the temperate region. Unfortunately, these diseases are poorly controlled in sub-Saharan Africa largely due to lack of understanding of the infection biology of the pathogen species. Understanding the species composition of pathogens of infected cattle in Ghana will allow for the formulation of cost effective interventions that will enable the development of applicable control strategies and improve the adaptive capacity of tick-borne diseases. In this thesis, Anaplasma marginale, Babesia bigemina and Theileria species were used as model bacterial and protozoan blood-feeding pathogens to examine whether genetic diversity in cattle correlates with quantitative differences in co-infection prevalence among indigenous breeds of cattle from different Agro-ecological zones in Ghana. A low-cost molecular approach (multiplex PCR) was developed to assess the multi- pathogen complex situation in the indigenous cattle of four distinct breeds (Sanga, Gudali, West African Shorthorn (WASH) and White Fulani). The overall pathogen co-infection prevalence in indigenous cattle breeds examined was 26.4% (105/397). Out of this total, only six cattle, representing 1.5% (6/397) of the population were co-infected with all three different tick-borne pathogens - Theileria species, Anaplasma marginale, and Babesia bigemina. 95 cattle 23.9% (95/397) were co- infected with Anaplasma marginale and Theileria species, whereas four cattle 1.0% (4/397) were co-infected with Anaplasma marginale and Babesia bigemina. Surprisingly, no individual cattle were found to be co-infected with Babesia bigemina and Theileria species. The overall infection prevalence of cattle was 62.9% (250/397). Significant (p=0.00) variation was observed in co-infection prevalence between breeds of indigenous cattle examined. Comparisons of quantitative differences in the number of different strains among cattle from diverse agro-ecological zones strongly support the significant (p=0.01) effect of the type of ecological zone on the number of tick-borne pathogens that circulate in cattle. The data also demonstrated that 145 cattle 36.5% (145/397), harboured single pathogen species. Out of the total number of single infected cattle, Anaplasma marginale alone constituted 36.3% (144/397). Only one cattle 0.3% (1/397) was infected with Theileria species alone. Notably no cattle were infected with Babesia bigemina pathogen alone at the time of the study. Importantly high progression of the number of multiple-pathogen infected cattle, over the duration of infection, at both the level of the individual host and the population was found, suggesting the lack of immunity against co- infection of cattle in the endemic region.