Biology subjects

Mainda, G.

Publications and source records attributed to Mainda, G..

5 recordsLinked to original sources

bioRxiv2025

Antibiotic Use and Resistance in Zambia's Aquaculture Sector: Assessing Knowledge, Attitudes, and Practices Among Fish Farmers

Aquaculture in Zambia is rapidly growing, contributing significantly to food security and income generation. However, the intensification of fish farming raises concerns about antimicrobial use (AMU) and the emergence of antimicrobial resistance (AMR). This study assessed the knowledge, attitudes, and practices (KAP) of fish farmers regarding AMU and AMR across 25 districts in Zambias ten provinces. Data were collected from fish farmers using a structured questionnaire distributed via district fisheries officers and analyzed through descriptive and inferential statistics, including logistic regression. The results revealed significant gaps in knowledge, with only 17.4% of farmers classified as knowledgeable about AMU and AMR. Attitude assessments showed that 60.5% exhibited positive attitudes toward responsible AMU practices, while the remaining 39.5% displayed negative perceptions. In terms of practices, 76.5% adhered to good practices, including consulting veterinary professionals and responsible antibiotic use, whereas 23.5% engaged in poor practices. Key factors influencing KAP outcomes included age, farming experience, and annual production capacity. Farmers aged 30-39 years and those with 1-5 years of experience demonstrated significantly more positive attitudes (p < 0.05), while those with higher production capacities (501-1000 kg) exhibited better practices (p < 0.001). The findings highlight critical knowledge gaps and inconsistent practices regarding AMU and AMR among Zambian fish farmers. Targeted interventions, including education programs, enhanced access to veterinary services, and strengthened regulatory frameworks, are essential to promote responsible AMU, mitigate AMR risks, and ensure the sustainability of aquaculture in Zambia.

scientific communication and education↗

bioRxiv2022

Optical mapping compendium of structural variants across global cattle breeds

Structural variants (SV) have been linked to important bovine disease phenotypes, but due to the difficulty of their accurate detection with standard sequencing approaches, their role in shaping important traits across cattle breeds is largely unexplored. Optical mapping is an alternative approach for mapping SVs that has been shown to have higher sensitivity than DNA sequencing approaches. The aim of this project was to use optical mapping to develop a high-quality database of structural variation across cattle breeds from different geographical regions, to enable further study of SVs in cattle. To do this we generated 100X Bionano optical mapping data for 18 cattle of nine different ancestries, three continents and both cattle sub-species. In total we identified 13,457 SVs, of which 1,200 putatively overlap coding regions. This resource provides a high-quality set of optical mapping-based SV calls that can be used across studies, from validating DNA sequencing-based SV calls to prioritising candidate functional variants in genetic association studies and expanding our understanding of the role of SVs in cattle evolution.

genomics↗

bioRxiv2020

Antibiotic-resistant Salmonella species and Escherichia coli in broiler chickens from farms, abattoirs and open markets in selected districts of Zambia

Salmonella species and Escherichia coli are major bacterial enteropathogens of global public health importance that cause foodborne diseases, thereby contributing to increased human morbidity and mortality. Both pathogens have also been found to contribute towards the spread of antimicrobial resistance through the food chain, especially in poultry. The aim of this study was to determine the occurrence of antibiotic-resistant Salmonella sp. and E. coli in broiler chickens at farm level, abattoirs and open markets in selected districts of Zambia. A cross-sectional study was undertaken in seven districts of Zambia to determine the resistance profiles of Salmonella sp. and E. coli obtained from broiler chickens at farms, abattoirs and open markets. A total of 470 samples were collected, including litter, cloacal swabs and carcass swabs. Samples were inoculated into buffered peptone water, sub-cultured onto MacConkey and Xylose Lysine Deoxycholate agar plates. Identification of Salmonella sp. and E. coli was done using the API-20E kit and confirmation by 16S rDNA sequencing. Confirmed isolates were tested against a panel of 10 antibiotics using the Kirby-Bauer disc-diffusion method and interpreted according to the Clinical Laboratory Standards Institute guidelines. Analysis of the antibiotic susceptibility test results was done using WHONET 2018 software. Overall, 4 Salmonella spp. and 280 E. coli were isolated. One of the Salmonella sp. was resistant to ampicillin (25%), amoxicillin/clavulanic acid (25%) and cefotaxime (25%). E. coli antibiotic resistance was highest to tetracycline (81.4%) and lowest to imipenem (0.7%). The antibiotic susceptibility profile revealed 55% (154/280) multidrug resistant E. coli, with the highest multidrug resistance profile (20.7%) in the ampicillin-tetracycline-trimethoprim/sulfamethoxazole drug combination. Furthermore, 4.3% (12/280) of the isolates showed Extensive Drug resistance. The levels of antimicrobial resistance to E. coli and Salmonella observed in market-ready chickens is of public health concern.View Full Text

scientific communication and education↗

bioRxiv2019

Towards a bottom-up understanding of antimicrobial use and resistance on the farm: A knowledge, attitudes, and practices survey across livestock systems in five African countries

The nutritional and economic potentials of livestock systems are compromised by the emergence and spread of antimicrobial resistance. A major driver of resistance is the misuse and abuse of antimicrobial drugs. The likelihood of misuse may be elevated in low- and middle-income countries where limited professional veterinary services and laissez faire access to drugs are assumed to promote non-prudent practices (e.g., self-administration of drugs). The extent of these practices, as well as the knowledge and attitudes motivating them, are largely unknown within most agricultural communities in low- and middle-income countries. The main objective of this study was to document dimensions of knowledge, attitudes and practices related to antimicrobial use and antimicrobial resistance in livestock systems and identify the livelihood factors associated with these dimensions. A mixed-methods ethnographic approach was used to survey households keeping layers in Ghana (N=110) and Kenya (N=76), pastoralists keeping cattle, sheep, and goats in Tanzania (N=195), and broiler farmers in Zambia (N=198), and Zimbabwe (N=298). Across countries, we find that it is individuals who live or work at the farm who draw upon their knowledge and experiences to make decisions regarding antimicrobial use and related practices. Input from animal health professionals is rare and antimicrobials are sourced at local, privately owned agrovet drug shops. We also find that knowledge, attitudes, and particularly practices significantly varied across countries, with poultry farmers holding more knowledge, desirable attitudes, and prudent practices compared to pastoralists households. Multivariate models showed that variation is related to several factors, including education, disease dynamics on the farm, and sources of animal health information. Study results emphasize that interventions to limit antimicrobial resistance must be founded upon a bottom-up understanding of antimicrobial use at the farm-level given limited input from animal health professionals and under-resourced regulatory capacities within most low- and middle-income countries. Establishing this bottom-up understanding across cultures and production systems will inform the development and implementation of the behavioral change interventions to combat AMR globally.

scientific communication and education↗

bioRxiv2019

Resistance to change? The impact of group medication on AMR gene dynamics during commercial pig production

The anthropogenic selection of antimicrobial resistance (AMR) genes is under intense scrutiny, particularly in livestock production, where group antimicrobial administration is used to control disease. Whilst large epidemiological studies provide important data on the diversity and distribution of AMR genes, we have little insight into how group antimicrobial administration impacts AMR gene abundance and diversity within a system. Here, faecal microbiome and AMR gene dynamics were tracked for six months through a standard production cycle on a commercial pig unit. Our results demonstrate that specific AMR genes have reached an equilibrium across this farming system to the extent that the levels measured were maintained from suckling through to slaughter, despite increases in microbiome diversity in early development. These levels were not influenced by antibiotic use, either during the production cycle or following whole herd medication. Some AMR genes were found at levels higher than that of the bacterial 16S rRNA gene, indicating widespread distribution across the most common bacterial genera. The targeted AMR genes were also detected in nearby soil samples, several with decreasing abundance with increasing distance from the unit, demonstrating that the farm acts as a point source of AMR gene pollution. Metagenomic sequencing of a subset of samples identified 144 AMR genes, with higher gene diversity in the piglet samples compared to the sow samples. Critically, despite overwhelming and stable levels of resistance alleles against the main antimicrobials used on this farm, these compounds continue to control the bacterial pathogens responsible for production losses and compromised welfare.\n\nImportanceGroup antibiotic treatment has been used for decades to control bacterial diseases that reduce the productivity and compromise the welfare of livestock. Recent increases in antibiotic resistant infections in humans has resulted in concerns that antibiotic use in livestock may contribute to the development of untreatable bacterial infections in humans. There is however little understanding as to how the genes that bacteria require to become resistant to antibiotics respond during and after group antibiotic treatment of livestock, particularly in systems where high levels of antibiotics have been used for a prolonged period of time. We show that in such a system, levels of specific antibiotic resistance genes are high irrespective of group antibiotic treatments, whilst dramatic reductions in antibiotic use also fail to reduce the levels of these genes. These findings have important implications for public policy relating to the use of antibiotic in livestock farming.

microbiology↗