Ecological and epidemiological consequences of rapid urbanisation at wildlife-livestock-human interfaces

Urbanization is characterized by rapid intensification of agriculture, socioeconomic change, and ecological fragmentation, which can have profound impacts on the distributional ecology of host populations and epidemiology of infectious disease within them. In this thesis, results from a large-scale field study conducted in Nairobi, Kenya are used to explore how anthropogenic and ecological changes associated with urbanisation influence the structure of sympatric wildlife, livestock and human host populations, and dictate bacterial epidemiology in wildlife hosts. As likely points of contact (and thus parasite transmission) between vertebrate wildlife, livestock, and humans, household ‘interfaces’ were chosen as sampling units. The ecological and sociological status of households was characterised through ecological surveys, questionnaire data and geospatial mapping, and faecal samples were collected from wildlife occurring within the household compound, and livestock and human inhabitants. Escherichia coli was isolated from faecal samples, and characterised both phenotypically (through antimicrobial sensitivity testing) and genetically (through whole genome sequencing). In the first part of this thesis I consider the influence of urban land-use change on the structure of host populations at household interfaces. Using unsupervised machine learning I describe variation in the host composition of wildlife-livestockhuman interfaces and, through multivariate regression analysis, demonstrate that citywide variation in ecological and anthropogenic factors (such as biotic habitat diversity and wealth) drive structural changes in wildlife, livestock and human populations across the urban landscape of Nairobi. Utilising commensal E. coli as an exemplar organism, I proceed to explore epidemiological connectivity between wildlife, livestock and humans at household interfaces, and link epidemiological processes in urban wildlife to their drivers across the urban landscape. Firstly, I explore the epidemiology of clinically relevant antimicrobial resistant (AMR)-E. coli in urban wildlife in Nairobi. Comparing E. coli isolates in wildlife to livestock, humans and the environment, I find that E. coli isolated from wildlife have a lower diversity of resistance phenotypes, and are thus an unlikely source of AMR. At household interfaces, I find evidence of AMR-E. coli exchange between rodents/seed-eating birds, and cattle and humans, and demonstrate that transmission is facilitated through anthropogenic resource provision in households. Next, utilising high resolution sequencing data, I explore the response of microbial communities in wildlife hosts to urban land-use change. Specifically, I test the hypothesis that communities of bacterial mobile genetic elements (MGEs) are deterministically structured, according to changes in host community structure. I show that the diversity of genes encoding virulence and AMR in avian-borne E. coli is determined by variation in the distribution and density of birds, livestock and humans at household interfaces, and that this varies along gradients of urbanisation. To conclude, I relate the findings in this thesis across multiple scales, linking the influence of abiotic factors such as habitat alteration and socioeconomics to host community structure at household interfaces and the epidemiology of wildlife-borne E. coli. Using this framework, I suggest future directions for research on urban disease emergence, and discuss implications of my findings for public health and urban planning

2023- The Twenty-seventh Annual Symposium of Student Scholars

The full program book from the Twenty-seventh Annual Symposium of Student Scholars, held on April 18-21, 2023. Includes abstracts from the presentations and posters.https://digitalcommons.kennesaw.edu/sssprograms/1027/thumbnail.jp

Factors Influencing Customer Satisfaction towards E-shopping in Malaysia

Online shopping or e-shopping has changed the world of business and quite a few people have decided to work with these features. What their primary concerns precisely and the responses from the globalisation are the competency of incorporation while doing their businesses. E-shopping has also increased substantially in Malaysia in recent years. The rapid increase in the e-commerce industry in Malaysia has created the demand to emphasize on how to increase customer satisfaction while operating in the e-retailing environment. It is very important that customers are satisfied with the website, or else, they would not return. Therefore, a crucial fact to look into is that companies must ensure that their customers are satisfied with their purchases that are really essential from the ecommerce’s point of view. With is in mind, this study aimed at investigating customer satisfaction towards e-shopping in Malaysia. A total of 400 questionnaires were distributed among students randomly selected from various public and private universities located within Klang valley area. Total 369 questionnaires were returned, out of which 341 questionnaires were found usable for further analysis. Finally, SEM was employed to test the hypotheses. This study found that customer satisfaction towards e-shopping in Malaysia is to a great extent influenced by ease of use, trust, design of the website, online security and e-service quality. Finally, recommendations and future study direction is provided. Keywords: E-shopping, Customer satisfaction, Trust, Online security, E-service quality, Malaysia

Reconsidering middle-Income country approaches to a global antimicrobial resistance (AMR) problem: A case study of Sri Lanka

Antimicrobial resistance (AMR) is a major public health threat, posing serious challenges to the effective management of infectious diseases within local, regional and international contexts. Studying multifaceted bases and the impact of AMR on healthcare in Sri Lanka from 1948 onwards, this study argues that the development and mitigation of AMR is a complex process, representing more than just a narrowly clinical issue. It claims that the problem has been underpinned by the socio-political determinants of antibiotic provision and use, in both Sri Lanka and the wider South Asian subcontinent. Adopting integrated critical historical and health policy approaches, this study is a detailed investigation of the evolution of antibiotics use and supply policies, their connections with the advocacy and politics of primary health care and universal health coverage, and interactions between the World Health Organization (WHO) headquarters, its regional office in South Asia and Sri Lankan administrations at all levels. This mixed methods thesis uses archival research and in-depth interviews to demonstrate how AMR be assessed in all its complexities, using techniques that can allow researchers to overcome several common constraints faced in studying this subject. This is also a study of how WHO structures around the world failed to pay sufficient attention to AMR in the face of rising evidence, from multiple national settings, of resistance to antibiotics in common bacterial strains. Studying the past in all its complexity, this thesis identifies contemporary health challenges in Sri Lanka in which disagreements and debates about policy, political and social pressures about expectations and rights, and economic difficulties and international aid flows helped to shape AMR-related health strategies and budgets on the ground. The thesis concludes by proposing that instead of the current approach of tackling AMR based on narrowly and technologically-oriented frameworks proposed by the WHO, Sri Lanka should look for alternative views and actions, rooted in specific socio-political needs that are transparently studied for the greatest public benefit. I argue that only this can help administrative efforts to effectively contain AMR in the national setting. Understanding this recent history of international actions based on AMR will enable the adoption of more self-critical, historically accurate and policy-relevant concepts of antibiotic provision and use and AMR at all different levels of governance

Ultrasensitive detection of toxocara canis excretory-secretory antigens by a nanobody electrochemical magnetosensor assay.

peer reviewedHuman Toxocariasis (HT) is a zoonotic disease caused by the migration of the larval stage of the roundworm Toxocara canis in the human host. Despite of being the most cosmopolitan helminthiasis worldwide, its diagnosis is elusive. Currently, the detection of specific immunoglobulins IgG against the Toxocara Excretory-Secretory Antigens (TES), combined with clinical and epidemiological criteria is the only strategy to diagnose HT. Cross-reactivity with other parasites and the inability to distinguish between past and active infections are the main limitations of this approach. Here, we present a sensitive and specific novel strategy to detect and quantify TES, aiming to identify active cases of HT. High specificity is achieved by making use of nanobodies (Nbs), recombinant single variable domain antibodies obtained from camelids, that due to their small molecular size (15kDa) can recognize hidden epitopes not accessible to conventional antibodies. High sensitivity is attained by the design of an electrochemical magnetosensor with an amperometric readout with all components of the assay mixed in one single step. Through this strategy, 10-fold higher sensitivity than a conventional sandwich ELISA was achieved. The assay reached a limit of detection of 2 and15 pg/ml in PBST20 0.05% or serum, spiked with TES, respectively. These limits of detection are sufficient to detect clinically relevant toxocaral infections. Furthermore, our nanobodies showed no cross-reactivity with antigens from Ascaris lumbricoides or Ascaris suum. This is to our knowledge, the most sensitive method to detect and quantify TES so far, and has great potential to significantly improve diagnosis of HT. Moreover, the characteristics of our electrochemical assay are promising for the development of point of care diagnostic systems using nanobodies as a versatile and innovative alternative to antibodies. The next step will be the validation of the assay in clinical and epidemiological contexts