Browsing by Author "Musah, A.B."
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Item Genotypic and phenotypic diversity of Mycobacterium tuberculosis complex genotypes prevalent in West Africa(PLOS ONE, 2021) Osei-Wusu, S.; Otchere, I.D.; Morgan, P.; Musah, A.B.; Siam, I.M.; Asandem, D.; Afum, T.; Asare, P.; Asante-Poku, A.; Kusi, K.A.; Gagneux, S.; Yeboah-Manu, D.Findings from previous comparative genomics studies of the Mycobacterium tuberculosis complex (MTBC) suggest genomic variation among the genotypes may have phenotypic implications. We investigated the diversity in the phenotypic profiles of the main prevalent MTBC genotypes in West Africa. Thirty-six whole genome sequenced drug susceptible MTBC isolates belonging to lineages 4, 5 and 6 were included in this study. The isolates were phenotypically characterized for urease activity, tween hydrolysis, Thiophen-2- Carboxylic Acid Hydrazide (TCH) susceptibility, nitric oxide production, and growth rate in both liquid (7H9) and solid media (7H11 and Lo¨wenstein–Jensen (L-J)). Lineage 4 isolates showed the highest growth rate in both liquid (p = 0.0003) and on solid (L-J) media supplemented with glycerol (p<0.001) or pyruvate (p = 0.005). L6 isolates optimally utilized pyruvate compared to glycerol (p<0.001), whereas L5 isolates grew similarly on both media (p = 0.05). Lineage 4 isolates showed the lowest average time to positivity (TTP) (p = 0.01; Average TTP: L4 = 15days, L5 = 16.7days, L6 = 29.7days) and the highest logCFU/mL (p = 0.04; average logCFU/mL L4 = 5.9, L5 = 5.0, L6 = 4.4) on 7H11 supplemented with glycerol, but there was no significant difference in growth on 7H11 supplemented with pyruvate (p = 0.23). The highest release of nitrite was recorded for L5 isolates, followed by L4 and L6 isolates. However, the reverse was observed in the urease activity for the lineages. All isolates tested were resistant to TCH except for one L6 isolate. Comparative genomic analyses revealed several mutations that might explain the diverse phenotypic profiles of these isolates. Our findings showed significant phenotypic diversity among the MTBC lineages used for this study.Item Market Participation of Smallholder Farmers in the Upper West Region of Ghana(University of Ghana, 2013-07) Musah, A.B.; Osei-Asare, Y.B.; Seini, W.This study assesses the levels of market participation by smallholder maize and groundnut farmers in the Upper West Region by estimating the factors that influence the probability and intensity of participating in the maize and groundnut markets and then identifying and ranking the constraints to marketing maize and groundnut. A multi stage random sampling procedure was employed to select 400 farmers (200 maize and 200 groundnut farmers) from four agricultural districts in the region. A semi-structured questionnaire was used to collect household survey data during the 2011 farming season. The Household Commercialisation Index was used to estimate the levels of market participation and the Double Hurdle Model was used to estimate the factors influencing both market participation and intensity of participation. The Garrett ranking technique was used to rank the constraints to marketing. The results indicated that about twenty-four percent and fifty-three percent of maize and groundnut respectively are sold in the region within a production year which implies low and moderate commercialisation indices for maize and groundnut respectively. The results also indicated that farmer characteristics (such as age, gender, education, household size); private assets variables (such as farm size, output, experience); public assets variables (such as credit, extension contact, price); and transaction cost variables (such as market information and point of sale) significantly influenced the probability and intensity of market participation behaviour in the region. With respect to the constraints to marketing, unfavourable market prices was the most pressing constraint faced by farmers while lack of government policy on marketing was the least constraint. The study concludes that maize is produced as a staple for household consumption while groundnut is produced as a cash crop for the market. Based on the findings, the study recommends that government through MoFA should institute productivity enhancing measures to increase the productivity of maize and groundnut as this would subsequently increase marketable surplus of farm households. It is also recommended that MoFA should establish rural finance schemes to address the credit needs of smallholders. The Statistics, Research and Information Directorate (SRID) of MoFA should create a department responsible for the delivery of agricultural market information to make market information delivery effective.