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Leishmaniasis, a neglected tropical disease of humans and animals, is estimated to affect [less than or equal to] 1 million persons annually (https://www.who.int/ health-topics/leishmania). The disease is caused by intracellular [...]

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]

Mycobacterium bovis (M. bovis) causes tuberculosis in mammals and is a major public health threat worldwide. While M. bovis has been reported in humans, domestic and wild ruminants at the human-wildlife-livestock interface area in Zambia, there is paucity of information on the role of primates as reservoir hosts. We screened seven wild chacma baboons (Papio ursinus) for tuberculosis at the human-wildlife interface area in Lochinvar National Park in the Kafue Flats, Zambia. Following necropsy, lung tissue and associated lymph nodes with tuberculous-like lesions collected from four adult male baboons were prepared for Mycobacterium culture. The isolates were initially typed using the Mycobacterium tuberculosis complex-discrimination multiplex PCR assay and further characterized by spoligotyping and 26-loci MIRU-VNTR. Mycobacteria were isolated from all four animals and identified as M. bovis by PCR. On Spoligotyping, all isolates belonged to SB 0120 spoligotype, which is similar to what was previously reported in humans, cattle and Kafue lechwe antelopes in Kafue Flats ecosystem. Furthermore, on MIRU-VNTR typing, the baboon isolates clustered with cattle and Kafue lechwe isolates from the same catchment area. This finding intimates probable cross-species transmission of M. bovis in the Kafue Flats ecosystem. Due to the close interaction of baboons and humans at interface areas in Zambia, our results have potential implications for public health. Equally, this finding raises concerns for conservation. [ABSTRACT FROM AUTHOR]

West Nile virus (WNV) is a mosquito-borne flavivirus that causes encephalitis in humans and infects crocodiles, resulting in rashes and neurological signs. In Zambia, two distinct lineages of WNV have been detected in neighbouring areas: lineage 2 in mosquitoes and lineage 1a in farmed crocodiles. Considering the risk of direct or vector-mediated WNV transmission from crocodiles to mammals, it is necessary to elucidate the pathogenicity of WNV strains derived from crocodiles. In this study, WNV was successfully isolated from naturally infected farmed crocodiles (Croc110/2019/1/ZM, Croc110). We then investigated its proliferation and pathogenicity in mice in comparison with a WNV isolate from mosquitoes in Zambia (Zmq16) and two reference strains, including one highly pathogenic (NY99) and one low pathogenic (Eg101) strain. Although viral proliferation in Vero and mammalian neuronal cells was comparable among the strains, Croc110 exhibited low cell-to-cell transmission efficiency. In vivo , more than 70% of mice (C57BL/6) intracerebrally inoculated with Croc110 displayed neurological signs, and Croc110-infected mice exhibited similarly high mortality rates as NY99- and Zmq16-infected mice. Meanwhile, comparable virus growth was observed among the strains in the brain. However, the virulence of Croc110 was significantly lower than that of Zmq16 and NY99 following intradermal (ID) and intraperitoneal inoculation. Consistently, Croc110 displayed lower growth than Zmq16 and NY99 in the brain and peripheral tissues after ID inoculation. Our study revealed that the crocodile-derived WNV strain is less neuroinvasive in mice, and it exhibits distinct pathogenicity from the highly pathogenic mosquito-derived WNV strain circulating in Zambia.