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1. Retrospective analysis of laboratory diagnostic data to assess the seasonal and proportional distribution of major tick-borne diseases in cattle from selected smallholder farms, Zambia

Author

Silwamba Isaac, Chijikwa Jeremiah, Mutemwa Vigirio K., Chanda James, Nkhata Augustine, Chapple Jenny, Sialyobo Misheck, Mutale Juliet, Zgambo Natasha, Chama Nicholas, Muyangana Lungowe, Phiri Philip, Munyeme Musso, Nalubamba King S., Mainda Geoffrey, and Muma John Bwalya

Subjects
tick-borne diseases, cattle, smallholder farmers, Veterinary medicine, SF600-1100
Abstract

Tick-borne diseases (TBDs) are endemic in Zambia and several other Sub-Saharan countries. They affect livestock production by causing high morbidity and mortality, resulting in increased production losses in terms of live-weight gain, milk production, off-take rates, and draft power. Herein, we applied a facility-based design to assess the proportion and seasonal distribution of theileriosis, babesiosis, anaplasmosis, and heartwater in cattle from selected smallholder farms in Lusaka and Central provinces of Zambia using laboratory records for microscopic examination of haemoparasites. The overall proportions for theileriosis, babesiosis, and anaplasmosis were 33.7% (95% CI: 30.7–38.2%), 8.3% (95% CI: 6.4–10.9%), and 0.5% (95% CI: 0.1–1.4%), respectively. Heartwater was detected in all the six laboratory records reviewed. Lusaka province had the highest proportion of theileriosis at 30.2% (95% CI: 25.5–35.3%), followed by babesiosis, 8.5% (95% CI: 5.8–11.9%), and anaplasmosis, 0.3% (95% CI: 0.01–1.6%). Similarly, Central province had the highest proportion of theileriosis at 39.5% (95% CI: 33.8–45.4%), followed by babesiosis, 8.4% (95% CI: 5.5–12.2%), and anaplasmosis, 0.7% (95% CI: 0.1–2.5%). Among the districts, Rufunsa district had the highest proportion for theileriosis at 70.6% (95% CI: 44.0–89.7%), followed by Kafue, 54.5% (95% CI: 23.4–83.3%), and Shibuyunji, 51.4% (95% CI: 34.0–68.6%). Analysis of seasonal variation revealed no statistical difference between the dry and wet seasons for theileriosis, babesiosis, and anaplasmosis. Furthermore, there was no statistical difference between Central and Lusaka provinces for babesiosis and anaplasmosis except for theileriosis. These data may have implications on farmers’ herd health management strategies with respect to TBDs, and farmers should be sensitized for effective implementation of risk-based disease control.

Published
2023
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3. Antibiotic prescribing patterns and carriage of antibiotic-resistant Escherichia coli and Enterococcus species in healthy individuals from selected communities in Lusaka and Ndola districts, Zambia

Author

Yamba, Kaunda, primary, Mudenda, Steward, additional, Mpabalwani, Evans, additional, Mainda, Geoffrey, additional, Mukuma, Mercy, additional, Samutela, Mulemba Tillika, additional, Lukwesa, Chileshe, additional, Chizimu, Joseph, additional, Kaluba, Ciluvya Kavimba, additional, Mutalange, Matenge, additional, Chilengi, Roma, additional, and Muma, John Bwalya, additional

Published
2024
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4. Molecular epidemiology of antimicrobial resistance (AMR) and Shiga toxin producing E. coli (STEC) in dairy herds of central Zambia

Author

Mainda, Geoffrey, Gally, David, Stevens, Mark, and Broonsvort, Mark

Subjects
636.2, antimicrobial resistance, e. coli, Shiga toxin, dairy cattle, diarrhoea human patients, risk analysis, whole genome sequencing, phylogenetic analysis, genes
Abstract

Antimicrobial resistance (AMR) is a worldwide public health concern. While it is evident that the use of antibiotics creates selection pressure for the evolution of antibiotic resistance genes, there are still considerable knowledge gaps relating to the status quo of antibiotic use, emergence of resistant pathogens in different livestock production systems and spread within human and animal communities. This thesis includes a survey of antibiotic use in the dairy sector within a specific area of Zambia and analysis of AMR and virulence factors in E. coli isolated from dairy cattle and diarrhoea human patients with the following objectives. 1. To investigate the usage of antibiotics in the dairy sector and the drivers for use. 2. To determine the prevalence and patterns of antimicrobial resistance in E. coli isolated from faecal samples of dairy cattle. 3. To use whole genome sequencing (WGS) to investigate the molecular epidemiology of resistance determinants in E. coli strains isolated from both dairy cattle and humans. 4. To assess the zoonotic potential of isolated E. coli focusing on Shiga toxin-producing E. coli (STEC) and relationship to STEC associated with clinical disease in the UK. In view of these objectives, the first part of the work was carried out in Zambia and involved a questionnaire, a field survey, isolation of E. coli from dairy cattle faecal samples and phenotypic testing for AMR. In addition, E. coli isolates were obtained from another study that was focused on human patients presenting with diarrhoea at the University Teaching Hospital in Lusaka. The second part involved whole genome sequencing and molecular analyses of E. coli for resistance and virulence genotypes at the Roslin Institute (UK). For the field study, a stratified random sample of 104 farms was studied, representing approximately 20% of all dairy farms in the region. On each farm, faecal samples were collected from a random sample of animals and a standardised questionnaire on the usage of antibiotics was completed. An E. coli isolate was obtained from 98.67% (371/376) of the sampled animals and tested for resistance against the six types of antibiotics (tetracycline, ampicillin, sulfamethoxazole/trimethoprim, cefpodoxime, gentamicin and ciprofloxacin). These E. coli were then analysed together with those from humans for genotypes in the laboratory and from Illumina short read whole genome sequences using bioinformatics tools. Tetracylines and penicillin were the commonly used antibiotics in dairy herds. This finding was in line with the resistance phenotypes detected in E. coli isolated from the dairy cattle. The most prevalent AMR was to tetracycline (10.61; 95%CI: 7.40-13.82), followed by ampicillin (6.02; 95%CI: 3.31-8.73), sulfamethoxazole/ trimethoprim (4.49; 95%CI: 2.42-6.56), cefpodoxime (1.91; 95%CI: 0.46-3.36), gentamicin (0.89; 95%CI: 0.06-1.84) and ciprofloxacin (0%). The risk analysis indicated that AMR was associated with livestock diseases (lumpy skin disease and foot rot), exotic breeds (Jersey and Friesian), location, farm size and certain management practices. Analysis of whole genome sequences showed that isolates from humans had both higher levels and a greater diversity of resistance alleles than the cattle isolates. Common genotypes in both populations were: tetA (16%), tetB (10%), tetC (2%) for cattle isolates with tetA (32%), tetB (22%) and tetD (1%) in human isolates. Other common genotypes were blaTEM (56%), sul1 (29%), sul2 (66%), strA4 (57%) and strB1 (64%) in isolates of human origin while blaTEM (15%), sul1 (3%), sul2 (17%), strA4 (13%) and strB1 (19%) were in the cattle isolates. Whilst the E. coli isolates from cattle encoded resistance to common antibiotics of limited significance to human clinical medicine, isolates from humans had additional extended spectrum beta-lactamases (blaOXA, blaCMY, blaNDM, and blaDHA, blaOKP and blaCTX-M) that encode for resistance to essential antibiotics such as third generation cephalosporins and carbapenems. This was an evidence that AMR is an ongoing public health subject in Zambia but the exclusivity of certain resistances in the human population points to limited or no exchange of genotypes between E. coli of human origin and those from cattle. AMR in humans was probably independently selected by the use of antibiotics of clinical importance such as cephalosporin and fluoroquinolones. The virulence analysis focused on STEC, 11% (41/371) of E. coli isolates from cattle contained Shiga toxin genes (stx) while none (0/73) of the human isolates were positive. Phylogenetic analysis showed a random distribution of bovine STEC, with no indication of clonal spread. Although 89% (16/18) of the STEC tested had a cytotoxic effect on Vero cells, indicative of Shiga toxin production, only three (O45, O111, O157) belonged to one of the seven serogroups (O26, O157, O111, O103, O121, O145 and O45) associated with life-threatening enterohaemorrhagic E. coli (EHEC) infections in humans. In line with this, only the O157 serotype encoded a type 3 secretion system. This shows that, while Stx-encoding strains are common in these dairy herds of Zambia, they are not strain backgrounds known to pose an immediate threat to human health as they lack colonisation factors that are found in typical human EHEC. However, we must remain vigilant as emergence of EHEC strains in these animals remains an ever-present threat.

Published
2016

5. Antimicrobial Use Survey and Detection of ESBL- Escherichia coli in Commercial and Medium-/Small-Scale Poultry Farms in Selected Districts of Zambia.

Author

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, and Egyir, Beverly

Subjects
POULTRY farms, ESCHERICHIA coli, WHOLE genome sequencing, MICROBIAL sensitivity tests, MULTIDRUG resistance
Abstract

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. [ABSTRACT FROM AUTHOR]

Published
2024
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6. Drivers of antimicrobial resistance in layer poultry farming: Evidence from high prevalence of multidrug-resistant Escherichia coli and enterococci in Zambia

Author

Mudenda, Steward, primary, Bumbangi, Flavien Nsoni, additional, Yamba, Kaunda, additional, Munyeme, Musso, additional, Malama, Sydney, additional, Mukosha, Moses, additional, Hadunka, Mwendalubi Albert, additional, Daka, Victor, additional, Matafwali, Scott Kaba, additional, Siluchali, Godfrey, additional, Mainda, Geoffrey, additional, Mukuma, Mercy, additional, Hang’ombe, Bernard Mudenda, additional, and Muma, John Bwalya, additional

Published
2023
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8. Antimicrobial resistance profiles of Escherichia coli isolated from laying hens in Zambia: implications and significance on one health

Author

Mudenda, Steward, primary, Malama, Sydney, additional, Munyeme, Musso, additional, Matafwali, Scott Kaba, additional, Kapila, Penjaninge, additional, Katemangwe, Patrick, additional, Mainda, Geoffrey, additional, Mukubesa, Andrew Nalishuwa, additional, Hadunka, Mwendalubi Albert, additional, and Muma, John Bwalya, additional

Published
2023
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9. Mitigating antimicrobial resistance (AMR) using implementation research: a development funder’s approach

Author

Khurana, Mark P, primary, Essack, Sabiha, additional, Zoubiane, Ghada, additional, Sreenivasan, Nandini, additional, Cordoba, Gloria Cristina, additional, Westwood, Erica, additional, Dalsgaard, Anders, additional, Mdegela, Robinson H, additional, Mpundu, Mirfin, additional, Scotini, Rodrigo, additional, Matondo, Augustine B, additional, Mzula, Alexanda, additional, Chanishvili, Nina, additional, Gogebashvili, Dimitri, additional, Beruashvili, Maia, additional, Tsereteli, Marika, additional, Sooronbaev, Talant, additional, Kjærgaard, Jesper, additional, Bloch, Joakim, additional, Isaeva, Elvira, additional, Mainda, Geoffrey, additional, Muuka, Geoffrey, additional, Mudenda, Ntombi B, additional, Goma, Fusya Y, additional, Chu, Duc-Huy, additional, Chanda, Duncan, additional, Chirwa, Uchizi, additional, Yamba, Kaunda, additional, Kapolowe, Kenneth, additional, Fwoloshi, Sombo, additional, Mwenge, Lawrence, additional, and Skov, Robert, additional

Published
2023
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10. Mitigating antimicrobial resistance (AMR) using implementation research:a development funder's approach

Author

Khurana, Mark P., Essack, Sabiha, Zoubiane, Ghada, Sreenivasan, Nandini, Cordoba, Gloria Cristina, Westwood, Erica, Dalsgaard, Anders, Mdegela, Robinson H., Mpundu, Mirfin, Scotini, Rodrigo, Matondo, Augustine B., Mzula, Alexanda, Chanishvili, Nina, Gogebashvili, Dimitri, Beruashvili, Maia, Tsereteli, Marika, Sooronbaev, Talant, Kjærgaard, Jesper, Bloch, Joakim, Isaeva, Elvira, Mainda, Geoffrey, Muuka, Geoffrey, Mudenda, Ntombi B., Goma, Fusya Y., Chu, Duc-Huy, Chanda, Duncan, Chirwa, Uchizi, Yamba, Kaunda, Kapolowe, Kenneth, Fwoloshi, Sombo, Mwenge, Lawrence, Skov, Robert, Khurana, Mark P., Essack, Sabiha, Zoubiane, Ghada, Sreenivasan, Nandini, Cordoba, Gloria Cristina, Westwood, Erica, Dalsgaard, Anders, Mdegela, Robinson H., Mpundu, Mirfin, Scotini, Rodrigo, Matondo, Augustine B., Mzula, Alexanda, Chanishvili, Nina, Gogebashvili, Dimitri, Beruashvili, Maia, Tsereteli, Marika, Sooronbaev, Talant, Kjærgaard, Jesper, Bloch, Joakim, Isaeva, Elvira, Mainda, Geoffrey, Muuka, Geoffrey, Mudenda, Ntombi B., Goma, Fusya Y., Chu, Duc-Huy, Chanda, Duncan, Chirwa, Uchizi, Yamba, Kaunda, Kapolowe, Kenneth, Fwoloshi, Sombo, Mwenge, Lawrence, and Skov, Robert

Abstract

Despite the escalating burden of antimicrobial resistance (AMR), the global response has not sufficiently matched the scale and scope of the issue, especially in low- and middle-income countries (LMICs). While many countries have adopted national action plans to combat AMR, their implementation has lagged due to resource constraints, dysfunctional multisectoral coordination mechanisms and, importantly, an under-recognized lack of technical capacity to adapt evidence-based AMR mitigation interventions to local contexts. AMR interventions should be tailored, context-specific, cost-effective and sustainable. The implementation and subsequent scale-up of these interventions require multidisciplinary intervention-implementation research (IIR). IIR involves both quantitative and qualitative approaches, occurs across a three-phase continuum (proof of concept, proof of implementation and informing scale-up), and across four context domains (inner setting, outer setting, stakeholders and the implementation process). We describe the theoretical underpinnings of implementation research (IR), its various components, and how to construct different IR strategies to facilitate sustainable uptake of AMR interventions. Additionally, we provide real-world examples of AMR strategies and interventions to demonstrate these principles in practice. IR provides a practical framework to implement evidence-based and sustainable AMR mitigation interventions., Despite the escalating burden of antimicrobial resistance (AMR), the global response has not sufficiently matched the scale and scope of the issue, especially in low- and middle-income countries (LMICs). While many countries have adopted national action plans to combat AMR, their implementation has lagged due to resource constraints, dysfunctional multisectoral coordination mechanisms and, importantly, an under-recognized lack of technical capacity to adapt evidence-based AMR mitigation interventions to local contexts. AMR interventions should be tailored, context-specific, cost-effective and sustainable. The implementation and subsequent scale-up of these interventions require multidisciplinary intervention-implementation research (IIR). IIR involves both quantitative and qualitative approaches, occurs across a three-phase continuum (proof of concept, proof of implementation and informing scale-up), and across four context domains (inner setting, outer setting, stakeholders and the implementation process). We describe the theoretical underpinnings of implementation research (IR), its various components, and how to construct different IR strategies to facilitate sustainable uptake of AMR interventions. Additionally, we provide real-world examples of AMR strategies and interventions to demonstrate these principles in practice. IR provides a practical framework to implement evidence-based and sustainable AMR mitigation interventions.

Published
2023

12. Determination of antimicrobial resistance patterns of Escherichia coli isolates from farm workers in broiler poultry production and assessment of antibiotic resistance awareness levels among poultry farmers in Lusaka, Zambia

Author

Mwansa, Mwaba, primary, Mukuma, Mercy, additional, Mulilo, Esther, additional, Kwenda, Geoffrey, additional, Mainda, Geoffrey, additional, Yamba, Kaunda, additional, Bumbangi, Flavien Nsoni, additional, Muligisa-Muonga, Elizabeth, additional, Phiri, Nelson, additional, Silwamba, Isaac, additional, and Muma, John Bwalya, additional

Published
2023
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13. Knowledge, attitudes and practices of community pharmacy professionals on poultry antimicrobial dispensing, use and resistance in Zambia : implications on antibiotic stewardship and WHO AWaRe classification of antibiotics

Author

Mudenda, Steward, Mukosha, Moses, Godman, Brian, Fadare, Joseph, Malama, Sydney, Munyeme, Musso, Hikaambo, Christabel Nang'andu, Kalungia, Aubrey Chiconyi, Hamachila, Audrey, Kainga, Henson, Bumbangi, Flavien Nsoni, Daka, Victor, Mfune, Ruth Lindizyani, Mainda, Geoffrey, Mufwambi, Webrod, Mpundu, Prudence, Kasanga, Maisa, Saad, Shereen Ahmed Mohammed, and Muma, John Bwalya

Subjects
RM
Abstract

Globally, the inappropriate dispensing and use of antibiotics in animals has contributed to the development of bacterial antimicrobial resistance (AMR). In Zambia, there is insufficient infor-mation among community pharmacy professionals on antibiotic use (AMU) and AMR in food-producing animals. This study assessed community pharmacy professionals' knowledge, attitudes and practices regarding poultry antibiotic dispensing, use, and bacterial AMR the Lusaka district of Zambia. A cross-sectional study was conducted among 178 community pharmacy pro-fessionals between February and April 2022 using a semi-structured questionnaire. Data were analyzed using Stata version 17. Of the total participants (n=178), 51.1% (n=91) were pharmacists. The most dispensed antibiotic was oxytetracycline, a Watch antibiotic, mainly without prescrip-tions. Good knowledge of AMU and AMR was associated with work experience for more than one year (p=0.016), while good practices were associated with male gender (p=0.039) and work expe-rience of more than one year (p=0.011). The study found moderate knowledge, positive attitudes and moderate practices of pharmacy professionals on poultry AMU and AMR. There was high dispensing of poultry antibiotics without prescriptions, which calls for strict implementation of antimicrobial stewardship and surveillance programs in poultry production in Zambia to reduce AMR.

Published
2022

14. Prevalence and antimicrobial resistance patterns of Enterococcus species isolated from laying hens in Lusaka and Copperbelt provinces of Zambia: a call for AMR surveillance in the poultry sector

Author

Mudenda, Steward, primary, Matafwali, Scott Kaba, additional, Malama, Sydney, additional, Munyeme, Musso, additional, Yamba, Kaunda, additional, Katemangwe, Patrick, additional, Siluchali, Godfrey, additional, Mainda, Geoffrey, additional, Mukuma, Mercy, additional, Bumbangi, Flavien Nsoni, additional, Mirisho, Robert, additional, and Muma, John Bwalya, additional

Published
2022
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15. Knowledge, Attitudes, and Practices of Community Pharmacy Professionals on Poultry Antibiotic Dispensing, Use, and Bacterial Antimicrobial Resistance in Zambia: Implications on Antibiotic Stewardship and WHO AWaRe Classification of Antibiotics

Author

Mudenda, Steward, primary, Mukosha, Moses, additional, Godman, Brian, additional, Fadare, Joseph, additional, Malama, Sydney, additional, Munyeme, Musso, additional, Hikaambo, Christabel Nang’andu, additional, Kalungia, Aubrey Chichonyi, additional, Hamachila, Audrey, additional, Kainga, Henson, additional, Bumbangi, Flavien Nsoni, additional, Daka, Victor, additional, Mfune, Ruth Lindizyani, additional, Mainda, Geoffrey, additional, Mufwambi, Webrod, additional, Mpundu, Prudence, additional, Kasanga, Maisa, additional, Saad, Shereen Ahmed Mohammed, additional, and Muma, John Bwalya, additional

Published
2022
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16. VCF files from: Optical mapping compendium of structural variants across global cattle breeds

Author

Talenti, Andrea, Powell, Jessica, Wragg, David, Chepkwony, Maureen, Fisch, Andressa, Ferreira, Beatriz, Mercadante, Maria, Santos, Isabel, Ezeasor, Chukwunonso, Obishakin, Emmanuel, Muhanguzi, Dennis, Amanyire, Wilson, Silwamba, Isaac, Muma, John, Mainda, Geoffrey, Kelly, Rob, Toye, Phil, Connelley, Tim, and Prendergast, James

Subjects
optical mapping, cattle, structural variants
Abstract

VCF containing the structural variants called using Bionano Solve on the optical mapping data for 18 cattle samples described in Talenti et al.

Published
2022
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17. Bionano Solve outputs (PT2) for: Optical mapping compendium of structural variants across global cattle breeds

Author

Talenti, Andrea, Powell, Jessica, Wragg, David, Chepkwony, Maureen, Fisch, Andressa, Ferreira, Beatriz, Mercadante, Maria, Santos, Isabel, Eseazor, Chukwunonso, Obishakin, Emmanuel, Muhanguzi, Dennis, Amanyire, Wilson, Silwamba, Isaac, Muma, John, Mainda, Geoffrey, Kelly, Rob, Toye, Phil, Connelley, Tim, and Prendergast, James

Subjects
optical mapping, cattle, structural variants
Abstract

Bionano solve pipeline output for 8 cattle of 4 different breeds (Holstein-Friesian, N'Dama, White Fulani, Nelore) described in Talenti et al. The output can be imported in the Bionano Access software to visualize, filter and export the SVs.

Published
2022
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18. Awareness of Antimicrobial Resistance and Associated Factors among Layer Poultry Farmers in Zambia: Implications for Surveillance and Antimicrobial Stewardship Programs

Author

Mudenda, Steward, primary, Malama, Sydney, additional, Munyeme, Musso, additional, Hang’ombe, Bernard Mudenda, additional, Mainda, Geoffrey, additional, Kapona, Otridah, additional, Mukosha, Moses, additional, Yamba, Kaunda, additional, Bumbangi, Flavien Nsoni, additional, Mfune, Ruth Lindizyani, additional, Daka, Victor, additional, Mwenya, Darlington, additional, Mpundu, Prudence, additional, Siluchali, Godfrey, additional, and Muma, John Bwalya, additional

Published
2022
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21. Antibiotic-resistant Salmonella species and Escherichia coli in broiler chickens from farms, abattoirs, and open markets in selected districts of Zambia

Author

Phiri, Nelson, primary, Mainda, Geoffrey, additional, Mukuma, Mercy, additional, Sinyangwe, Ntazana N., additional, Banda, Luke J., additional, Kwenda, Geoffrey, additional, Muonga, Elizabeth M., additional, Flavien, Bumbangi N., additional, Mwansa, Mwaba, additional, Yamba, Kaunda, additional, Munyeme, Musso, additional, and Muma, John B., additional

Published
2020
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23. 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

Author

Caudell, Mark A., primary, Dorado-Garcia, Alejandro, additional, Eckford, Suzanne, additional, Creese, Chris, additional, Byarugaba, Denis K., additional, Afakye, Kofi, additional, Chansa-Kabali, Tamara, additional, Fasina, Folorunso O., additional, Kabali, Emmanuel, additional, Kiambi, Stella, additional, Kimani, Tabitha, additional, Mainda, Geoffrey, additional, Mangesho, Peter E., additional, Chimpangu, Francis, additional, Dube, Kululeko, additional, Kikimoto, Bashiru Boi, additional, Koka, Eric, additional, Mugara, Tendai, additional, Rubegwa, Bachana, additional, and Swiswa, Samuel, additional

Published
2020
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25. 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

Author

Caudell, Mark A, primary, Dorado-Garcia, Alejandro, additional, Eckford, Suzanne, additional, Byarugaba, Denis, additional, Afakye, Kofi, additional, Chansa-Kabali, Tamara, additional, Kabali, Emmanuel, additional, Kiambi, Stella, additional, Kimani, Tabitha, additional, Mainda, Geoffrey, additional, Mangesho, Peter, additional, Chimpangu, Francis, additional, Dube, Kululeko, additional, Kikimoto, Bashiru Boi, additional, Koka, Eric, additional, Mugara, Tendai, additional, and Swiswa, Samuel, additional

Published
2019
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27. Whole Genome Sequence Analysis Reveals Lower Diversity and Frequency of Acquired Antimicrobial Resistance (AMR) Genes in E. coli From Dairy Herds Compared With Human Isolates From the Same Region of Central Zambia

Author

Mainda, Geoffrey, primary, Lupolova, Nadejda, additional, Sikakwa, Linda, additional, Richardson, Emily, additional, Bessell, Paul R., additional, Malama, Sydney K., additional, Kwenda, Geoffrey, additional, Stevens, Mark P., additional, Bronsvoort, Barend M. deC., additional, Muma, John B., additional, and Gally, David L., additional

Published
2019
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28. Phylogenomic approaches to determine the zoonotic potential of Shiga toxin-producing Escherichia coli (STEC) isolated from Zambian dairy cattle

Author

Mainda, Geoffrey, Lupolova, Nadejda, Sikakwa, Linda, Bessell, Paul R, Muma, John B, Hoyle, Deborah V, McAteer, Sean P, Gibbs, Kirsty, Williams, Nicola J, Sheppard, Samuel K, La Ragione, Roberto M, Cordoni, Guido, Argyle, Sally A, Wagner, Sam, Chase-Topping, Margo E, Dallman, Timothy J, Stevens, Mark P, Bronsvoort, Barend M deC, and Gally, David L

Abstract

This study assessed the prevalence and zoonotic potential of Shiga toxin-producing Escherichia coli (STEC) sampled from 104 dairy units in the central region of Zambia and compared these with isolates from patients presenting with diarrhoea in the same region. A subset of 297 E. coli strains were sequenced allowing in silico analyses of phylo- and sero-groups. The majority of the bovine strains clustered in the B1 'commensal' phylogroup (67%) and included a diverse array of serogroups. 11% (41/371) of the isolates from Zambian dairy cattle contained Shiga toxin genes (stx) while none (0/73) of the human isolates were positive. While the toxicity of a subset of these isolates was demonstrated, none of the randomly selected STEC belonged to key serogroups associated with human disease and none encoded a type 3 secretion system synonymous with typical enterohaemorrhagic strains. Positive selection for E. coli O157:H7 across the farms identified only one positive isolate again indicating this serotype is rare in these animals. In summary, while Stx-encoding E. coli strains are common in this dairy population, the majority of these strains are unlikely to cause disease in humans. However, the threat remains of the emergence of strains virulent to humans from this reservoir.

Published
2016
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33. Alternate thermoregulation and functional binding of Escherichia coli type 1 fimbriae in environmental and animal isolates.

Author

Marshall, Jacqueline, Rossez, Yannick, Mainda, Geoffrey, Gally, David L., Daniell, Tim J., and Holden, Nicola J.

Subjects
ESCHERICHIA coli pili, BACTERIAL adhesins, EFFECT of temperature on bacteria
Abstract

Type 1 fimbriae (T1F) are well characterised cell surface organelles expressed by Escherichia coli and required for adherence to mannosylated host tissue. They satisfy molecular Koch's postulates as a virulence determinant and a host-adapted role has been reinforced by reports that T1F expression is repressed at submammalian temperatures. Analysis of a group of 136 environmental and animal E. coli isolates that express T1F at 37°C showed that 28% are also capable of expression at 20°C, in a phase variable manner. The heterogeneous proportions varied widely, and although growth temperature impacted the total proportion expressing T1F, there was no direct correlation between growth at 37°C and 20°C, indicative of differences in thermoregulation of the genetic switch (fimS) that controls phase variation. Specificities of the adhesin (FimH) also varied between the isolates: most bound to α-(1-3) mannan and yeast extracts as expected, but some recognised β-(1-4)-mannans and N-linked glycoproteins from plants, and T1F from two of the isolates mediated binding to plant roots. The results expand our view of a well-described adherence factor to show alternative expression profiles and adhesin specificities, which in turn may confer an advantage for certain isolates in alternative hosts and habitats. [ABSTRACT FROM AUTHOR]

Published
2016
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35. Effects of environmental lead contamination on cattle in a lead/zinc mining area: Changes in cattle immune systems on exposure to lead in vivo and in vitro

Author

Ikenaka, Yoshinori, primary, Nakayama, Shouta M.M., additional, Muroya, Taro, additional, Yabe, John, additional, Konnai, Satoru, additional, Darwish, Wageh Sobhy, additional, Muzandu, Kaampwe, additional, Choongo, Kennedy, additional, Mainda, Geoffrey, additional, Teraoka, Hiroki, additional, Umemura, Takashi, additional, and Ishizuka, Mayumi, additional

Published
2012
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37. Metal distribution in tissues of free-range chickens near a lead-zinc mine in Kabwe, Zambia.

Author

Yabe, John, Nakayama, Shouta M.M., Ikenaka, Yoshinori, Muzandu, Kaampwe, Choongo, Kennedy, Mainda, Geoffrey, Kabeta, Matthew, Ishizuka, Mayumi, and Umemura, Takashi

Subjects
CHICKENS, METALS, MINES & mineral resources, CADMIUM
Abstract

Concentrations of Pb, Cd, and other metals in tissues of 17 free-range and 32 commercial broiler chickens from the Kabwe mining town in Zambia were determined. Mean concentrations of Pb and Cd exceeded maximum levels for human consumption in some organs including muscle (Pb only) in free-range chickens, in contrast to low levels in broiler chickens. Human consumers in Kabwe could be exposed to Pb and Cd in free-range chickens. Environ. Toxicol. Chem. 2013;32:189-192. © 2012 SETAC [ABSTRACT FROM AUTHOR]

Published
2013
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38. Degumming of Vegetable Oil by a New Microbial Lipase.

Author

Ji-Guo Yang, Yong-Hua Wang, Bo Yang, Mainda, Geoffrey, and Yong Guo

Subjects
VEGETABLE oils, HYDROLASES, LIPASES, HYDROGEN-ion concentration, TRIGLYCERIDES, FATS & oils, PLANT lipids, HYDROLYSIS
Abstract

Copyright of Food Technology & Biotechnology is the property of Food Technology & Biotechnology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2006

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