Browsing by Author "Mainda Geoffrey"

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Antimicrobial Use Survey and Detection of ESBL-Escherichia coli in Commercial and Medium-/Small-Scale Poultry Farms in Selected Districts of Zambia
(2024-5-20) Sinyawa Taona; Shawa Misheck; Muuka Geoffrey M.; Goma Fusya; Fandamu Paul; Chizimu Joseph Yamweka; Khumalo Cynthia Sipho; Mulavu Malala; Ngoma Masuzyo; Chambaro Herman Moses; Kamboyi Harvey Kakoma; Kajihara Masahiro; Sawa Hirofumi; Suzuki Yasuhiko; Higashi Hideaki; Mainda Geoffrey; Munyeme Musso; Muma John Bwalya; Nyantakyi Christian Owusu; Egyir Beverly; Hang’ombe Bernard Mudenda
Antimicrobial resistance (AMR) among Escherichia coli from food animals is a rising problem, and heavy antimicrobial use in poultry is a contributing factor. In Zambia, studies linking poultry-associated AMR and antibiotic use (AMU) are rare. This study aimed to investigate commercial and medium-/small-scale poultry farmers’ usage of antimicrobials based on a questionnaire survey in ten districts of Zambia. In addition, the study characterized extended-spectrum β-lactamase (ESBL)-producing E. coli isolates obtained from poultry in the same districts. Data regarding knowledge and usage of antimicrobials were collected from commercial and medium-/small-scale poultry farmers using a pre-tested structured questionnaire. At the same time, cloacal samples were collected and analyzed. One hundred and fifty E. coli isolates were tested for antimicrobial susceptibility using eight antibiotic classes. The isolates were further screened for ESBL production by streaking them on cefotaxime (CTX)-supplemented MacConkey agar, then subjecting them to sequencing on a NextSeq. The questionnaire survey showed that more medium-/small-scale than commercial poultry farmers used antimicrobials (OR = 7.70, 95% CI = 2.88–20.61) but less prescriptions (OR = 0.02, 95% CI = 0.00–0.08). Susceptibility testing revealed that resistance was highest to ampicillin (128/148, 86.5%) and tetracycline (101/136, 74.3%) and that the prevalence of multidrug resistance (MDR) (28/30, 93.3%) was high. Whole-genome sequencing (WGS) of eight (8/30, 26.7%) isolates with CTX Minimum Inhibitory Concentration (MIC) ≥ 4 µg/mL revealed the presence of ESBL-encoding genes blaCTX-M-14, blaCTX-M-55, and blaTEM. WGS also detected other AMR genes for quinolones, aminoglycosides, phenicols, tetracycline, macrolides, and folate-pathway antagonists. Altogether, the questionnaire survey results showed a higher proportion of AMU and lower prescription usage among medium-/small-scale farmers. In addition, our results emphasize the circulation of ESBL-producing E. coli strains with associated MDR. It is critical to educate farmers about AMR risks and to encourage responsible usage of antimicrobials. Furthermore, there is a need to strengthen regulations limiting access to antimicrobials. Finally, there is a need to establish a one health system to guide public health response.
Factors Associated with Occurrence of Antibiotic Resistance in Broiler Chickens in Selected Districts, Zambia
(2025-1-3) Mirisho Robert; Mukuma Mercy; Mainda Geoffrey; Bumbangi Flavien Nsoni; Mudenda Steward; Silwamba Isaac; Phiri Nelson; Muonga Elizabeth Muligisa; Mwansa Mwaba; Munyeme Musso; M’kandawire Ethel; Muma John Bwalya
A cross-sectional study was conducted in five districts of Zambia. The study aimed to investigate the risk factors associated with antimicrobial resistance (AMR) in broiler chickens in Zambia. A total of 109 broiler farms were included in the study, of which 104 were small-scale farms, two were medium-scale, and three were commercial-scale. A semi-structured questionnaire was administered alongside the collection of cloacal swabs and litter samples to determine the risk factors associated with the occurrence of AMR of food pathogen microorganisms on the selected broiler farms. Data collected was analysed using STATA version 12. The broiler farm-level AMR prevalence was 84.4% (n= 109). Gender, marital status, administration of drugs by veterinary personnel or the farmer and the poultry house drainage destination were among the predictors of AMR on broiler chicken farms. The high prevalence of AMR in broiler chicken farms suggests a high dependence on antimicrobials in poultry production in Zambia. In addition, socio-demographics such as gender and age, as well as farm characteristics and management practices, may primarily contribute to the high prevalence of antibiotic resistance. This study has demonstrated the association between the AMR of foodborne pathogens and the risk factors for AMR during poultry production. It is, therefore, necessary for risk management measures such as biosecurity to be put in place to target the identified AMR predictor variables. There is also a need to strengthen AMR surveillance to ensure intervention strategies are appropriate to the existing risk.
Identification of MHC Alleles Associated With Disease Resistance/Susceptibility In Smallholder Cattle In Zambia
(2021-4-1) Silwamba Isaac K.; Simuunza Martin; Ndebe Joseph; Simulundu Edgar; Mainda Geoffrey; Muma John B.
Background: The occurrence of Major Histocompatibility complex (MHC) alleles associated with resistance to Mastitis, Bovine Leukaemia Virus (BLV), Theileriosis, Foot and Mouth Disease (FMD) and susceptibility Dermatophilosis in African cattle is ill defined. Methods: Here, we used manual annotation to screen for five MHC alleles previously known to be associated with resistance/susceptibility to these diseases from a database of alleles sequenced from 846 cattle in Zambia. Results: Overall, we found 28 (3.3%), 21 (2.6%), 55 (6.5%), and 15 (1.8%) animals with resistance alleles to Mastitis, BLV, Theileriosis, FMD and 39 (4.6%) animals with susceptibility alleles to Dermatophilosis, respectively. Conclusion: This study provides the first evidence of resistance/susceptibility alleles in smallholder cattle in Zambia and the data could aid strategies for breeding cattle with enhanced resistance to disease in endemic countries.