Analyzing agricultural financing for resettled farmers in Zimbabwe: the case of targeted Command Agricultural program in Mutare District
- Mafirakurewa, Tariro https://orcid.org/0009-0000-6587-4524
- Authors: Mafirakurewa, Tariro https://orcid.org/0009-0000-6587-4524
- Date: 2023
- Subjects: Agricultural administration--Finance , Farmers -- Zimbabwe , Agriculture -- Economic aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/28255 , vital:73985
- Description: Agriculture plays a paramount role in the economy of many countries including Zimbabwe where more than 70 percent of the population depends on agricultural activities for their livelihoods. Smallholder farmers’ access to agricultural credit is vital for the development and growth of Zimbabwe’s agricultural sector, hence agricultural financing is crucial in rural development. Despite the Government’s efforts to provide affordable agricultural credit services to its majority smallholder farmers’ participation is still meager. The aim of this study is to analyze agricultural financing for resettled farmers in Zimbabwe, with special focus on the command agricultural loans in the Mutare district. A multistage sampling technique was employed in this study. Firstly purposive selection of Manicaland province was carried out because it is endowed with the five natural farming regions found in Zimbabwe. The second stage involved a random selection of 4 out of 7 districts with favorable climatic conditions for maize production. Thirdly, the study also carried out a purposive selection of Mutare district among the four districts with favorable climatic conditions, given the time and financial constraints. The last stage involved the use of stratified sampling technique, where the sample was divided into two strata. Stratum 1 with A1 farmers and stratum two consisting of A2 farmers, and a random sample was selected from each stratum. The study involved 301 A1 farmers and 49 A2 farmers, making a total sample of 350 farmers used for this study. Double hurdle was employed to examine the factors influencing A1 and A2 farmers` participation in command agriculture loans in the study area. Multinomial logistic regression model was also applied to investigate the determinants of command agriculture loan repayment, while propensity score matching technique was used to examine the impacts of command agriculture loans on maize productivity and profitability of A1 and A2 farmers. The results revealed that family size, and distance from the market GMB positively influence farmers likelihood to participate in in the command agricultural loan. While family size, farmer type and distance from the market were proven to have a positive significant influence on the extent of participation in command agriculture. Also training on the command agriculture loan and gender were proven to have a negative signification influence on the extent of farmers` participation in command agriculture loan. The maximum likelihood estimates of the multinomial logistic regression revealed that age and output levels significantly influence resettled farmers` likelihood to partly pay their loans. Also, the likelihood estimates of the multinomial logistic regression showed that distance from the market and output levels have a positive influence on resettled farmers` likelihood of fully paying the command agriculture loan. Access to extension services to extension services was proven to negatively influence farmers` likelihood to fully pay the loan. The results also revealed that participating in command agriculture significantly impacted productivity at the 1 percent level, while it was not significant in the participants' profitability. The results show that participating in command agriculture increases productivity by 0.93 tonnes hectare. The study recommends the intensification of extension service supply to ensure that farmers are receiving relevant agricultural training, mainly on climate change adaptation strategies. This will help resettled farmers to adjust and adapt to their new farming environments and, in turn, have a positive impact on their production levels. Also, to improve farmers’ profitability the GMB selling price should be in American dollars USD and not paid in part RTGS and part USD, because the RTGS part is always outstripped by inflation. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Authors: Mafirakurewa, Tariro https://orcid.org/0009-0000-6587-4524
- Date: 2023
- Subjects: Agricultural administration--Finance , Farmers -- Zimbabwe , Agriculture -- Economic aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/28255 , vital:73985
- Description: Agriculture plays a paramount role in the economy of many countries including Zimbabwe where more than 70 percent of the population depends on agricultural activities for their livelihoods. Smallholder farmers’ access to agricultural credit is vital for the development and growth of Zimbabwe’s agricultural sector, hence agricultural financing is crucial in rural development. Despite the Government’s efforts to provide affordable agricultural credit services to its majority smallholder farmers’ participation is still meager. The aim of this study is to analyze agricultural financing for resettled farmers in Zimbabwe, with special focus on the command agricultural loans in the Mutare district. A multistage sampling technique was employed in this study. Firstly purposive selection of Manicaland province was carried out because it is endowed with the five natural farming regions found in Zimbabwe. The second stage involved a random selection of 4 out of 7 districts with favorable climatic conditions for maize production. Thirdly, the study also carried out a purposive selection of Mutare district among the four districts with favorable climatic conditions, given the time and financial constraints. The last stage involved the use of stratified sampling technique, where the sample was divided into two strata. Stratum 1 with A1 farmers and stratum two consisting of A2 farmers, and a random sample was selected from each stratum. The study involved 301 A1 farmers and 49 A2 farmers, making a total sample of 350 farmers used for this study. Double hurdle was employed to examine the factors influencing A1 and A2 farmers` participation in command agriculture loans in the study area. Multinomial logistic regression model was also applied to investigate the determinants of command agriculture loan repayment, while propensity score matching technique was used to examine the impacts of command agriculture loans on maize productivity and profitability of A1 and A2 farmers. The results revealed that family size, and distance from the market GMB positively influence farmers likelihood to participate in in the command agricultural loan. While family size, farmer type and distance from the market were proven to have a positive significant influence on the extent of participation in command agriculture. Also training on the command agriculture loan and gender were proven to have a negative signification influence on the extent of farmers` participation in command agriculture loan. The maximum likelihood estimates of the multinomial logistic regression revealed that age and output levels significantly influence resettled farmers` likelihood to partly pay their loans. Also, the likelihood estimates of the multinomial logistic regression showed that distance from the market and output levels have a positive influence on resettled farmers` likelihood of fully paying the command agriculture loan. Access to extension services to extension services was proven to negatively influence farmers` likelihood to fully pay the loan. The results also revealed that participating in command agriculture significantly impacted productivity at the 1 percent level, while it was not significant in the participants' profitability. The results show that participating in command agriculture increases productivity by 0.93 tonnes hectare. The study recommends the intensification of extension service supply to ensure that farmers are receiving relevant agricultural training, mainly on climate change adaptation strategies. This will help resettled farmers to adjust and adapt to their new farming environments and, in turn, have a positive impact on their production levels. Also, to improve farmers’ profitability the GMB selling price should be in American dollars USD and not paid in part RTGS and part USD, because the RTGS part is always outstripped by inflation. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
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Impact assessment of genetically modified TELA® Bt. maize variety adoption on yield, household income, technical efficiency and food security: a case of maize farmers in Limpopo and Mpumalanga Provinces, South Africa.
- Authors: Mailula, Lesiba Pertunia
- Date: 2023
- Subjects: Food security , Farmers -- Training of , Seed technology -- Economic aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/28266 , vital:74040
- Description: The agricultural sector is widely recognized as a crucial factor for promoting sustainable economic development, reducing poverty, and ensuring food security in developing countries. However, in Africa, the agricultural sector continues to underperform, with growth rates falling behind the population growth, this can be attributed to various challenges, including climate change and pest infestation. This has over the years weakened the defence of crops leading to the disruptions in crop production and food security. As such, calls have been made that adoption of the agricultural technology may promote food security through high yields. This is because agricultural technology crops have improved varieties such as drought tolerance and pest resistance traits. However, adoption of improved agricultural technology in Africa has been very sluggish amongst smallholder farmers, particularly for GM seed, this is due to the on-going controversies and compliance requirements regarding GM technologies. The controversies are raised by the unknown benefits and risks associated with the adoption of GM seeds technology. Furthermore, there are mixed benefits associated with GM technology adoption as well as methodological and data gaps associated with assessment of GM impact on the farmer’s welfare. In 2016, five Bt. maize varieties trademarked TELA were developed through the WEMA project. Trials were approved and launched with smallholder farmers in various countries in Africa, and South Africa is not an exception. Several smallholder maize farmers have accessed the TELA Bt. maize varieties through local seed companies and have been producing it for the past seasons. Yet, no study that has been conducted on the impact of the GM TELA Bt. maize technology adoption on yield, income, food security and technical efficiency, hence, a need for such a study. The primary data was collected from 289 183 TELA Bt. and 106 non-TELA Bt. smallholder farmers in Mpumalanga and Limpopo provinces using convenience and snowball sampling techniques. Data were analysed using various analytical tools that included descriptive statistics, gross margin analysis, Household Dietary Diversity Score, Stochastic Frontier Model and the Propensity Score Matching, modelled through the Probit regression model. These tools were utilised to address the objectives. The descriptive statistics show that the TELA Bt. maize variety yielded 61.1 percent more maize output as compared to non-TELA Bt. maize farmers, with an average of 691kg ha and 429kg ha, respectively. The gross margin analysis showed higher subsequent income for the TELA Bt. maize farmers R2 834.93 compared to R2 124.96 for the non-TELA Bt. maize farmers. The results of the HDDS showed a marginal effect of TELA Bt. maize seed technology on food diversity. The average HDDS scores were 8.4 and 7.5 for the TELA Bt. and non-TELA Bt. maize farmers, respectively. The Stochastic Frontier Analysis SFA results revealed that both the TELA Bt. maize farmers and non-TELA Bt. maize farmers were technically inefficient. However, the TELA Bt. maize farmers were better-off than their counterparts, with mean technical efficiency scores of 0.416 and 0.328, respectively. The Propensity Score Matching PSM using the Probit model revealed that gender 0.6064, number of years in farming 0.0099 credit 1.1438 and market access 0.4427 had a positive and significant influence on the decision taken by the farmers to adopt TELA Bt. maize seed technology. However, access to extension services was found to have a negative and significant impact on the adoption of TELA Bt. maize seed technology. The Average Treatment Effect of the Treated ATT using the Nearest Neighbour Matching algorithm indicated that adoption of TELA Bt. maize technology improved farmers’ yields by 254.3kg, income by 0.36 cents and technical efficiency by 8.6 percent. There was no significant relationship observed between adoption of the GM technology and food security. Generally, the results from this study imply that adoption of GM TELA Bt. maize seed technology improves farmers’ yields, income, technical efficiency, as well as food security. The study therefore, recommends increased awareness of the GM seed technology benefits to farmers, coupled with training and capacity development to enhance adoption of seed technology towards improved farmers’ welfare. In addition, there is a need for sustained Research and Development investments towards GM seed technologies to enhance maize productivity and technical efficiency of the farmers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Authors: Mailula, Lesiba Pertunia
- Date: 2023
- Subjects: Food security , Farmers -- Training of , Seed technology -- Economic aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/28266 , vital:74040
- Description: The agricultural sector is widely recognized as a crucial factor for promoting sustainable economic development, reducing poverty, and ensuring food security in developing countries. However, in Africa, the agricultural sector continues to underperform, with growth rates falling behind the population growth, this can be attributed to various challenges, including climate change and pest infestation. This has over the years weakened the defence of crops leading to the disruptions in crop production and food security. As such, calls have been made that adoption of the agricultural technology may promote food security through high yields. This is because agricultural technology crops have improved varieties such as drought tolerance and pest resistance traits. However, adoption of improved agricultural technology in Africa has been very sluggish amongst smallholder farmers, particularly for GM seed, this is due to the on-going controversies and compliance requirements regarding GM technologies. The controversies are raised by the unknown benefits and risks associated with the adoption of GM seeds technology. Furthermore, there are mixed benefits associated with GM technology adoption as well as methodological and data gaps associated with assessment of GM impact on the farmer’s welfare. In 2016, five Bt. maize varieties trademarked TELA were developed through the WEMA project. Trials were approved and launched with smallholder farmers in various countries in Africa, and South Africa is not an exception. Several smallholder maize farmers have accessed the TELA Bt. maize varieties through local seed companies and have been producing it for the past seasons. Yet, no study that has been conducted on the impact of the GM TELA Bt. maize technology adoption on yield, income, food security and technical efficiency, hence, a need for such a study. The primary data was collected from 289 183 TELA Bt. and 106 non-TELA Bt. smallholder farmers in Mpumalanga and Limpopo provinces using convenience and snowball sampling techniques. Data were analysed using various analytical tools that included descriptive statistics, gross margin analysis, Household Dietary Diversity Score, Stochastic Frontier Model and the Propensity Score Matching, modelled through the Probit regression model. These tools were utilised to address the objectives. The descriptive statistics show that the TELA Bt. maize variety yielded 61.1 percent more maize output as compared to non-TELA Bt. maize farmers, with an average of 691kg ha and 429kg ha, respectively. The gross margin analysis showed higher subsequent income for the TELA Bt. maize farmers R2 834.93 compared to R2 124.96 for the non-TELA Bt. maize farmers. The results of the HDDS showed a marginal effect of TELA Bt. maize seed technology on food diversity. The average HDDS scores were 8.4 and 7.5 for the TELA Bt. and non-TELA Bt. maize farmers, respectively. The Stochastic Frontier Analysis SFA results revealed that both the TELA Bt. maize farmers and non-TELA Bt. maize farmers were technically inefficient. However, the TELA Bt. maize farmers were better-off than their counterparts, with mean technical efficiency scores of 0.416 and 0.328, respectively. The Propensity Score Matching PSM using the Probit model revealed that gender 0.6064, number of years in farming 0.0099 credit 1.1438 and market access 0.4427 had a positive and significant influence on the decision taken by the farmers to adopt TELA Bt. maize seed technology. However, access to extension services was found to have a negative and significant impact on the adoption of TELA Bt. maize seed technology. The Average Treatment Effect of the Treated ATT using the Nearest Neighbour Matching algorithm indicated that adoption of TELA Bt. maize technology improved farmers’ yields by 254.3kg, income by 0.36 cents and technical efficiency by 8.6 percent. There was no significant relationship observed between adoption of the GM technology and food security. Generally, the results from this study imply that adoption of GM TELA Bt. maize seed technology improves farmers’ yields, income, technical efficiency, as well as food security. The study therefore, recommends increased awareness of the GM seed technology benefits to farmers, coupled with training and capacity development to enhance adoption of seed technology towards improved farmers’ welfare. In addition, there is a need for sustained Research and Development investments towards GM seed technologies to enhance maize productivity and technical efficiency of the farmers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
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Investigation into response of wheat genotypes to drought and optimum conditions in the Eastern Cape Province, South Africa
- Authors: Mzileni L S
- Date: 2023
- Subjects: Bonanza farms , Wheat , Drought - tolerant plants
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27732 , vital:69397
- Description: Wheat is generally one of the dominant crops globally, being mainly used for human food and livestock feed. Due to climate change, drought makes it challenging to produce enough wheat mostly under dryland production regions in South Africa. Drought stress has severely reduced wheat yield by up to 70 percent, and adversely compromised wheat grain quality. The adoption of drought-tolerant cultivars offers a sustainable and low-cost solution for increasing wheat yields and minimise importing the crop to meet national requirements. The main objective of this study was to investigate the response of different wheat genotypes to drought and optimum conditions in the Eastern Cape Province, South Africa. Forty diverse wheat genotypes were evaluated in this study. The specific objectives were: (i) to evaluate the response of wheat genotypes under optimum and drought-stressed field conditions; (ii) to determine the effect of terminal drought stress on wheat grain quality composition; and (iii) to identify appropriate drought tolerance indices that can be used as selection tools under field conditions. This study was conducted in the field using a 5x8 alpha lattice design, replicated twice under two water regimes (drought and optimum) over two consecutive winter seasons of 2020 and 2021 at two different sites namely University of Fort Hare Research Farm in Alice, and Zanyokwe irrigation scheme in Keiskamahoek. Drought stress was imposed from 50% flowering up to physiological maturity. Data on agro-physiological traits such as duration to heading (DTH); flowering (DTF); maturity (DTM); plant height (HT); spike length (SL); number of spikelets per spike (SPS); kernels per spike (KPS); and grain yield (GY (kg/ha)) was subjected to the analysis of variance using Genstat 18th edition. As the study took place over two sites, a combined ANOVA table revealed significant differences (p0.001) among genotypes, and all interactions such as genotype by water regime (GWR); genotype by seasons (GS) for all studied traits. Notably, the extent and severity of drought differed between geographical regions and between seasons. This necessitated the adoption of the additive main effect and multiplicative interaction analysis (AMMI) for the identification of stable genotypes under two different water regimes over two sites. Regarding grain yield, superior and/or stable genotypes included G5 (4334 kg/ha under optimum, and 2871kg/ha under drought), and G22 (4418 kg/ha under optimum, and 2624kg/ha under drought) at the UFH site. G21 (3194 kg/ha under optimum, and 2938 kg/ha under drought), G33 (2552kg/ha under optimum, and 3810 kg/ha under drought), and G35 (2688 kg/ha under optimum, and 3309 kg/ha under drought) at the ZAN site. Stable genotypes across sites included G21 and G33. There were generally weak correlations between agro-physiological traits and grain yield. From the experiment, grain quality traits such as fixed protein (PF); wet gluten (WG); hectolitre mass (HLM); and thousand kernel weight (TKW) were also examined. A combined ANOVA revealed significant differences (p0.001) among the interaction of genotypes by environments (GE) for all traits except PF. This implies that the performance of wheat genotypes across sites was also different, and therefore, necessitated separate analysis of variance for each site. Significant differences (p0.001) among genotypes (G), water regimes (WR), and the interaction of genotypes by water regime (GWR) were observed for all studied quality traits except PF in both sites. GWR showed no significant differences for TKW in the ZAN site. The stability in the performance of genotypes across water regimes was further determined. G38 was stable for wet gluten; G31 and G26 were stable for PF; G36 was stable for HLM; and G11, G15, and G29 were stable for TKW at the UFH site. G6 was stable for both WG and PF; G13 and G15 were stable for HLM; and G35, G21, and G40 were stable for TKW at the ZAN site. These results suggest that the quality of wheat grains was affected under drought stress conditions except PF. Average grain yield data under both stressed (Ys) and optimum (Yp) conditions was used to compute a number of different drought tolerance indices. These include mean productivity (MP); geometric mean productivity (GMP); harmonic mean (HM); Tolerance index (TOL), stress susceptible index (SSI), sensitive drought index (SDI), and stress tolerance index (STI). The aim was to identify appropriate drought tolerance indices that can be used as selection tools under drought stress. MP, GMP, and HM were the more appropriate indices as they had a strong and positive correlation with grain yield under both drought and optimum conditions. However, genotypes G5, G22, G8, and G21 were more tolerant and stable as they showed high mean values. Based on the results, G19, G16, G2, and G20 were more sensitive to drought as they showed low values of MP, GMP, and HM. Overall, genotype: G5, G21, G22, and G33 are recommended for production under drought and optimum conditions, as they showed stable performance across water regimes. Principal component analysis also revealed that MP, GMP, and HM were the only indices that had positive loadings into the first principal component. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Authors: Mzileni L S
- Date: 2023
- Subjects: Bonanza farms , Wheat , Drought - tolerant plants
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27732 , vital:69397
- Description: Wheat is generally one of the dominant crops globally, being mainly used for human food and livestock feed. Due to climate change, drought makes it challenging to produce enough wheat mostly under dryland production regions in South Africa. Drought stress has severely reduced wheat yield by up to 70 percent, and adversely compromised wheat grain quality. The adoption of drought-tolerant cultivars offers a sustainable and low-cost solution for increasing wheat yields and minimise importing the crop to meet national requirements. The main objective of this study was to investigate the response of different wheat genotypes to drought and optimum conditions in the Eastern Cape Province, South Africa. Forty diverse wheat genotypes were evaluated in this study. The specific objectives were: (i) to evaluate the response of wheat genotypes under optimum and drought-stressed field conditions; (ii) to determine the effect of terminal drought stress on wheat grain quality composition; and (iii) to identify appropriate drought tolerance indices that can be used as selection tools under field conditions. This study was conducted in the field using a 5x8 alpha lattice design, replicated twice under two water regimes (drought and optimum) over two consecutive winter seasons of 2020 and 2021 at two different sites namely University of Fort Hare Research Farm in Alice, and Zanyokwe irrigation scheme in Keiskamahoek. Drought stress was imposed from 50% flowering up to physiological maturity. Data on agro-physiological traits such as duration to heading (DTH); flowering (DTF); maturity (DTM); plant height (HT); spike length (SL); number of spikelets per spike (SPS); kernels per spike (KPS); and grain yield (GY (kg/ha)) was subjected to the analysis of variance using Genstat 18th edition. As the study took place over two sites, a combined ANOVA table revealed significant differences (p0.001) among genotypes, and all interactions such as genotype by water regime (GWR); genotype by seasons (GS) for all studied traits. Notably, the extent and severity of drought differed between geographical regions and between seasons. This necessitated the adoption of the additive main effect and multiplicative interaction analysis (AMMI) for the identification of stable genotypes under two different water regimes over two sites. Regarding grain yield, superior and/or stable genotypes included G5 (4334 kg/ha under optimum, and 2871kg/ha under drought), and G22 (4418 kg/ha under optimum, and 2624kg/ha under drought) at the UFH site. G21 (3194 kg/ha under optimum, and 2938 kg/ha under drought), G33 (2552kg/ha under optimum, and 3810 kg/ha under drought), and G35 (2688 kg/ha under optimum, and 3309 kg/ha under drought) at the ZAN site. Stable genotypes across sites included G21 and G33. There were generally weak correlations between agro-physiological traits and grain yield. From the experiment, grain quality traits such as fixed protein (PF); wet gluten (WG); hectolitre mass (HLM); and thousand kernel weight (TKW) were also examined. A combined ANOVA revealed significant differences (p0.001) among the interaction of genotypes by environments (GE) for all traits except PF. This implies that the performance of wheat genotypes across sites was also different, and therefore, necessitated separate analysis of variance for each site. Significant differences (p0.001) among genotypes (G), water regimes (WR), and the interaction of genotypes by water regime (GWR) were observed for all studied quality traits except PF in both sites. GWR showed no significant differences for TKW in the ZAN site. The stability in the performance of genotypes across water regimes was further determined. G38 was stable for wet gluten; G31 and G26 were stable for PF; G36 was stable for HLM; and G11, G15, and G29 were stable for TKW at the UFH site. G6 was stable for both WG and PF; G13 and G15 were stable for HLM; and G35, G21, and G40 were stable for TKW at the ZAN site. These results suggest that the quality of wheat grains was affected under drought stress conditions except PF. Average grain yield data under both stressed (Ys) and optimum (Yp) conditions was used to compute a number of different drought tolerance indices. These include mean productivity (MP); geometric mean productivity (GMP); harmonic mean (HM); Tolerance index (TOL), stress susceptible index (SSI), sensitive drought index (SDI), and stress tolerance index (STI). The aim was to identify appropriate drought tolerance indices that can be used as selection tools under drought stress. MP, GMP, and HM were the more appropriate indices as they had a strong and positive correlation with grain yield under both drought and optimum conditions. However, genotypes G5, G22, G8, and G21 were more tolerant and stable as they showed high mean values. Based on the results, G19, G16, G2, and G20 were more sensitive to drought as they showed low values of MP, GMP, and HM. Overall, genotype: G5, G21, G22, and G33 are recommended for production under drought and optimum conditions, as they showed stable performance across water regimes. Principal component analysis also revealed that MP, GMP, and HM were the only indices that had positive loadings into the first principal component. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
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Molecular characterization of integrons and their associated gene cassettes in multidrug-resistant enterobacteriaceae isolates from environmental sources and the exploration of antibiotic combination against some resistant strains
- Fadare, Folake Temitope https://orcid.org/0000-0001-5779-9798
- Authors: Fadare, Folake Temitope https://orcid.org/0000-0001-5779-9798
- Date: 2023
- Subjects: Enterobacteriaceae , Molecular microbiology , Enterobacteria
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27809 , vital:69942
- Description: Globally, the increasing rate of antimicrobial resistance against our currently available drugs has been a serious public concern. Due to the selective nature of antibiotics, bacteria are expected to develop resistance against them over time, but the current scourge of antimicrobial resistance is aggravated by factors other than the expected evolutionary trend. The use and overuse of antibiotics in clinical and agricultural contexts have led to the fast rise of multidrug-resistant MDR microorganisms. A scenario that necessitates an upsurge in the clinical failures observed with our current drug arsenals is expected to rise if left unchecked. One of the significant drivers implicated in the spread of antimicrobial resistance genes is the integrons. These are mobile genetic elements found on pathogenicity islands, transposons, and plasmids, easing their distribution among various bacteria. They are considered efficient gene expression systems that naturally capture, integrate gene cassettes GCs and immediately express the captured antimicrobial resistance genes on the GCs due to the inherent promoters on their structures. Integrons have been known to confer resistance against most classes of antibiotics. These include all known β-lactams, chloramphenicol, trimethoprim, erythromycin, aminoglycosides, quinolones, streptothricin, lincomycin, rifampicin, fosfomycin, and antiseptics of the quaternary ammonium compound family. They have been detected in bacterial populations under direct or indirect antibiotic pressure in clinical, agricultural, and environmental contexts. The emergence of MDR in Enterobacteriaceae is a critical public health issue that has attracted the World Health Organization WHO, which classified them as one of the critical priority pathogens urgently requiring new antibiotics. The resistance phenomenon has proven most of the current antibiotics ineffective, further compounded by the slow pace of the discovery of new antibiotics, necessitating the hunt for new, practical remedies. One of such is the exploration of synergy among existing antibiotics. Two medications combined have a higher impact, thereby allowing current antibiotics to be salvaged for use in treating MDR bacteria, even if the bacteria are resistant against one or both antibiotics separately. Hence, this research focused on the occurrence and prevalence of multidrug resistance and the characterization of integrons and their associated gene cassettes in members of Enterobacteriaceae, including Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Escherichia coli, and Citrobacter spp. recovered from animal droppings, rivers, and effluents of hospital and wastewater treatment plants in Eastern Cape Province, South Africa. The inhibitory effect of combining two drugs belonging to different antibiotic classes to obtain a possible potentiating effect against some multidrug-resistant Enterobacteriaceae isolates harbouring integrons were examined and studied. The isolates were identified using the conventional molecular Polymerase Chain Reaction with specific primers. The antimicrobial resistance profile and the production of Extended-spectrum and metallo β-lactamase were detected using disk diffusion technique DDT, double-disk synergy test DDST, and ethylenediaminetetraacetic acid EDTA tests, respectively. The PCR-based screening method, DNA sequencing analyses, and restriction fragment length polymorphism RFLP were used to characterize the integrons and their associated GCs. Furthermore, Enterobacterial Repetitive Intergenic Consensus ERIC PCR determined the genotypic relationships between some specific species. The various antibiotics' minimum inhibitory concentration MIC was determined using the broth microdilution, while the checkerboard method was used to determine the fractional inhibitory concentration indices FICIs. The time-kill assays TKAs were further used to confirm the synergism observed from the checkerboard assays. Most of the isolates were resistant against most antibiotics tested and were considered MDR. The least resistance was observed against imipenem, a carbapenem, one of the drugs of last resort. Also present were the ESBL and MBL producers, with a few isolates co-producing the enzymes. A high prevalence of integrons was observed in the isolates, with class 1 integrons being the most frequently detected. Some isolates co-harboured the intI1 and intI2 genes and were classified as class1 plus 2 integrons. Although Citrobacter spp. had the least number of isolates among the Enterobacteriaceae studied, it harboured the most diverse gene cassette arrays. The various gene cassette arrays were identified as follows: For Klebsiella spp. Aac 6 Ib, aadA1 dfrA1, and dfrA1 sat2; for Citrobacter spp., dfrA5 aac3 Ib, aac6 ib, aadA1dfrA1 aadA1, aadA1-dfrA1, aadA5 dfrA17, and dfrA21-aac3-Ib; for E. coli dfrA21- aac-3-Ib, dfrA5-aac-3-Ib, aadA1 dfrA1, and aadA5 dfrA17 and for E. cloacae aadA1 dfrA1, dfrA7 dfrA21 dfrA5 aac 3 Ib, and dfrA1 sat2. The GC array dfrA1 sat2 was the only array detected in class 2 integrons which are analogous to that found in Tn7, dfrA1-sat2-aadA1, with the deletion of the last GC aadA1. These detected GCs confer resistance against aminoglycosides, including streptomycin and spectinomycin, and trimethoprim, further increasing the resistance spectrum of the bacterial species harbouring them. The detection of integrons and their associated GC and the presence of these β-lactamases is also associated with coresistance against other classes of antibiotics by bacterial species harbouring them, further limiting treatment options. The checkerboard assays combining antibiotics against these drug-resistant integron harbouring Enterobacteriaceae revealed that 26.3 percent 10 over 38 of the interactions were categorized as synergistic, while 73.7 percent 28 over 38 were indifferent. None of the combinations was antagonistic. The TKAs revealed all the synergistic interactions as bactericidal. Therefore, the combinations of gentamicin with tetracycline, ciprofloxacin, and ceftazidime against Multidrug-resistant MDR Klebsiella pneumoniae; tetracycline-ceftazidime combination against MDR Escherichia coli, colistin combinations with ceftazidime and gentamicin, and tetracycline-gentamicin combinations against MDR Citrobacter freundii may be future therapeutic alternatives. , Thesis (MSci) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Authors: Fadare, Folake Temitope https://orcid.org/0000-0001-5779-9798
- Date: 2023
- Subjects: Enterobacteriaceae , Molecular microbiology , Enterobacteria
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27809 , vital:69942
- Description: Globally, the increasing rate of antimicrobial resistance against our currently available drugs has been a serious public concern. Due to the selective nature of antibiotics, bacteria are expected to develop resistance against them over time, but the current scourge of antimicrobial resistance is aggravated by factors other than the expected evolutionary trend. The use and overuse of antibiotics in clinical and agricultural contexts have led to the fast rise of multidrug-resistant MDR microorganisms. A scenario that necessitates an upsurge in the clinical failures observed with our current drug arsenals is expected to rise if left unchecked. One of the significant drivers implicated in the spread of antimicrobial resistance genes is the integrons. These are mobile genetic elements found on pathogenicity islands, transposons, and plasmids, easing their distribution among various bacteria. They are considered efficient gene expression systems that naturally capture, integrate gene cassettes GCs and immediately express the captured antimicrobial resistance genes on the GCs due to the inherent promoters on their structures. Integrons have been known to confer resistance against most classes of antibiotics. These include all known β-lactams, chloramphenicol, trimethoprim, erythromycin, aminoglycosides, quinolones, streptothricin, lincomycin, rifampicin, fosfomycin, and antiseptics of the quaternary ammonium compound family. They have been detected in bacterial populations under direct or indirect antibiotic pressure in clinical, agricultural, and environmental contexts. The emergence of MDR in Enterobacteriaceae is a critical public health issue that has attracted the World Health Organization WHO, which classified them as one of the critical priority pathogens urgently requiring new antibiotics. The resistance phenomenon has proven most of the current antibiotics ineffective, further compounded by the slow pace of the discovery of new antibiotics, necessitating the hunt for new, practical remedies. One of such is the exploration of synergy among existing antibiotics. Two medications combined have a higher impact, thereby allowing current antibiotics to be salvaged for use in treating MDR bacteria, even if the bacteria are resistant against one or both antibiotics separately. Hence, this research focused on the occurrence and prevalence of multidrug resistance and the characterization of integrons and their associated gene cassettes in members of Enterobacteriaceae, including Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Escherichia coli, and Citrobacter spp. recovered from animal droppings, rivers, and effluents of hospital and wastewater treatment plants in Eastern Cape Province, South Africa. The inhibitory effect of combining two drugs belonging to different antibiotic classes to obtain a possible potentiating effect against some multidrug-resistant Enterobacteriaceae isolates harbouring integrons were examined and studied. The isolates were identified using the conventional molecular Polymerase Chain Reaction with specific primers. The antimicrobial resistance profile and the production of Extended-spectrum and metallo β-lactamase were detected using disk diffusion technique DDT, double-disk synergy test DDST, and ethylenediaminetetraacetic acid EDTA tests, respectively. The PCR-based screening method, DNA sequencing analyses, and restriction fragment length polymorphism RFLP were used to characterize the integrons and their associated GCs. Furthermore, Enterobacterial Repetitive Intergenic Consensus ERIC PCR determined the genotypic relationships between some specific species. The various antibiotics' minimum inhibitory concentration MIC was determined using the broth microdilution, while the checkerboard method was used to determine the fractional inhibitory concentration indices FICIs. The time-kill assays TKAs were further used to confirm the synergism observed from the checkerboard assays. Most of the isolates were resistant against most antibiotics tested and were considered MDR. The least resistance was observed against imipenem, a carbapenem, one of the drugs of last resort. Also present were the ESBL and MBL producers, with a few isolates co-producing the enzymes. A high prevalence of integrons was observed in the isolates, with class 1 integrons being the most frequently detected. Some isolates co-harboured the intI1 and intI2 genes and were classified as class1 plus 2 integrons. Although Citrobacter spp. had the least number of isolates among the Enterobacteriaceae studied, it harboured the most diverse gene cassette arrays. The various gene cassette arrays were identified as follows: For Klebsiella spp. Aac 6 Ib, aadA1 dfrA1, and dfrA1 sat2; for Citrobacter spp., dfrA5 aac3 Ib, aac6 ib, aadA1dfrA1 aadA1, aadA1-dfrA1, aadA5 dfrA17, and dfrA21-aac3-Ib; for E. coli dfrA21- aac-3-Ib, dfrA5-aac-3-Ib, aadA1 dfrA1, and aadA5 dfrA17 and for E. cloacae aadA1 dfrA1, dfrA7 dfrA21 dfrA5 aac 3 Ib, and dfrA1 sat2. The GC array dfrA1 sat2 was the only array detected in class 2 integrons which are analogous to that found in Tn7, dfrA1-sat2-aadA1, with the deletion of the last GC aadA1. These detected GCs confer resistance against aminoglycosides, including streptomycin and spectinomycin, and trimethoprim, further increasing the resistance spectrum of the bacterial species harbouring them. The detection of integrons and their associated GC and the presence of these β-lactamases is also associated with coresistance against other classes of antibiotics by bacterial species harbouring them, further limiting treatment options. The checkerboard assays combining antibiotics against these drug-resistant integron harbouring Enterobacteriaceae revealed that 26.3 percent 10 over 38 of the interactions were categorized as synergistic, while 73.7 percent 28 over 38 were indifferent. None of the combinations was antagonistic. The TKAs revealed all the synergistic interactions as bactericidal. Therefore, the combinations of gentamicin with tetracycline, ciprofloxacin, and ceftazidime against Multidrug-resistant MDR Klebsiella pneumoniae; tetracycline-ceftazidime combination against MDR Escherichia coli, colistin combinations with ceftazidime and gentamicin, and tetracycline-gentamicin combinations against MDR Citrobacter freundii may be future therapeutic alternatives. , Thesis (MSci) -- Faculty of Science and Agriculture, 2023
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Prevalence and seasonal changes of gastro-intestinal parasites of ovine on three different veld types in communal farming areas of the Eastern Cape Province, South Africa
- Jansen, Mlungisi Selby https://orcid.org/0000-0002-6735-1054
- Authors: Jansen, Mlungisi Selby https://orcid.org/0000-0002-6735-1054
- Date: 2023
- Subjects: Gastrointestinal system , Parasites , Traditional farming
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/28233 , vital:73956
- Description: The current study aimed to investigate the prevalence and seasonal changes of gastro-intestinal parasites GIP of ovine grazed don three different veld types in the communal farming areas of the Eastern Cape Province. A total of 1242 sheep faecal samples were collected monthly between January 2012 and December 2015 to investigate the prevalence and season occurrence of internal parasites. From September to November 2018, a semi-structured questionnaire survey was conducted in three agro-ecological zones, humid Wartburg, semi-humid Allen waters, and arid region Cradock commonages to investigate farmers’ knowledge of the prevalence and occurrence of GIP in sheep. The prevalence of gastro-intestinal parasites was significantly higher in the humid zone roundworms 81 percent and coccidia 37 percent, followed by the semi-humid zone roundworms 75 percent and coccidia 22 percent and the arid zone was the lowest roundworms 71 percent and coccidia 14 percent. Roundworms had significantly higher counts P 0.05 mostly in hot-wet seasons of the year spring and summer and low during dry cold months of the year autumn and winter across all veld types. The humid zone had significantly higher counts P 0.05 in the seasonal occurrence of roundworms and coccidia, followed by humid zone, and very low counts were encountered in the arid zone during the study period. Seasonal occurrence of roundworm species was significant across all veld types, 64 percent of farmers were males and 36 percent were females. The study reveals that helminths and coccidia are major causative agents causing parasitic infections in livestock production, and therefore, good animal health practices management practices including proper hygiene should be followed to prevent parasitic infection in small ruminants. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Authors: Jansen, Mlungisi Selby https://orcid.org/0000-0002-6735-1054
- Date: 2023
- Subjects: Gastrointestinal system , Parasites , Traditional farming
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/28233 , vital:73956
- Description: The current study aimed to investigate the prevalence and seasonal changes of gastro-intestinal parasites GIP of ovine grazed don three different veld types in the communal farming areas of the Eastern Cape Province. A total of 1242 sheep faecal samples were collected monthly between January 2012 and December 2015 to investigate the prevalence and season occurrence of internal parasites. From September to November 2018, a semi-structured questionnaire survey was conducted in three agro-ecological zones, humid Wartburg, semi-humid Allen waters, and arid region Cradock commonages to investigate farmers’ knowledge of the prevalence and occurrence of GIP in sheep. The prevalence of gastro-intestinal parasites was significantly higher in the humid zone roundworms 81 percent and coccidia 37 percent, followed by the semi-humid zone roundworms 75 percent and coccidia 22 percent and the arid zone was the lowest roundworms 71 percent and coccidia 14 percent. Roundworms had significantly higher counts P 0.05 mostly in hot-wet seasons of the year spring and summer and low during dry cold months of the year autumn and winter across all veld types. The humid zone had significantly higher counts P 0.05 in the seasonal occurrence of roundworms and coccidia, followed by humid zone, and very low counts were encountered in the arid zone during the study period. Seasonal occurrence of roundworm species was significant across all veld types, 64 percent of farmers were males and 36 percent were females. The study reveals that helminths and coccidia are major causative agents causing parasitic infections in livestock production, and therefore, good animal health practices management practices including proper hygiene should be followed to prevent parasitic infection in small ruminants. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
- Full Text:
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