Biology subjects

Ndashe, K.

Publications and source records attributed to Ndashe, K..

4 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↗

bioRxiv2025

Experimental Bacterial Co-infection in Nile Tilapia Shows High Pathogenicity from Lake Kariba Isolates

ObjectiveThis study aimed to determine the pathogenicity of bacteria (Aeromonas spp., Lactococcus garvieae, Acinetobacter spp., and Klebsiella spp.) isolated from Nile tilapia (Oreochromis niloticus) in small-scale aquaculture establishments on Lake Kariba through experimental infections. Materials and methodsHealthy fish (50g {+/-} 5g) were distributed among six transparent fish tanks labeled A to F. Fish in tanks A, B, C, and D were exposed to Aeromonas spp., Lactococcus garvieae, Acinetobacter spp., and Klebsiella spp., respectively, through intraperitoneal inoculation. Tank E received a co-infection of all isolates, while tank F served as the control group with an injection of normal saline. Clinical signs, mortalities and post-mortem lesions were recorded in all experimental groups, with histopathological examinations performed on liver, kidney, and spleen tissues. ResultsThe findings indicate that Acinetobacter spp. and Klebsiella spp. exhibit low pathogenicity, evidenced by few clinical signs such as lethargy, pale skin, and fin erosion. The study further highlighted Aeromonas spp. and Lactococcus garvieae as the bacterial isolates causing significant clinical symptoms in Nile tilapia compared to Acinetobacter spp. and Klebsiella spp. following experimental infection. ConclusionCo-infection with all bacterial pathogens demonstrated very high pathogenicity, with 100% mortality reported within seven days post-infection. The study proposes the development of a polyvalent vaccine to control fish disease outbreaks in small-scale aquaculture operations on Lake Kariba, thereby sustaining aquaculture production in Zambia.

microbiology↗

bioRxiv2023

Antibiotic Resistant Campylobacter spp Isolated from Live Broilers at an Abattoir in Lusaka, Zambia

Antibiotic resistant Campylobacter spp causing campylobacteriosis continue to cause challenges in treatment of the infection. Poultry remains the main source of the foodborne disease. This study was undertaken to isolate and identify antibiotic resistant Campylobacter spp. A total of 160 cloacal swabs were taken from broilers at a poultry abattoir in Lusaka. The samples were analyzed using standard bacteriological test. Antimicrobial susceptibility test was conducted following Clinical and Laboratory Standard Institute guideline and three antibiotics were used ciprofloxacin, tetracycline and erythromycin. Results indicated that Campylobacter spp was isolated from 18.75% of the sample population, furthermore the isolates were resistant to erythromycin and tetracycline and susceptible to ciprofloxacin. The results highlight the growing concern of poultry being a source of multi-drug resistant pathogenic bacteria.

microbiology↗

bioRxiv2020

The Potential of Capsicum annum Extracts to Prevent Lactococcosis in Tilapia

The capsaicin was extracted in-house from locally purchased chili pepper (Capsicum annum) using the conventional solvent extraction method. Varying concentrations of capsaicin were mixed with Lactococcus garvieae each and inoculated on Mueller Hinton agar to determine the minimum bactericidal concentration. Four groups of 100 fish each were injected with either 1) Capsaicin, 2) bacteria and capsaicin, 3) bacteria and 4) normal saline (negative control). The fish were observed for 7 days post treatment and experiment was repeated three times. Protection against infection was measured by the lack of clinical disease and survivability of the fish during period of experimentation. The minimum bactericidal concentration of capsaicin on growth of Lactococcus garvieae was 0.1967mg/ml. Significantly, more fish in the bacteria and capsaicin group survived (p<0.0001) compared to those injected with bacteria only. The findings suggest that chili pepper extract can prevent Lactococcus garvieae infection in tilapia.

microbiology↗