Biology subjects

Yee, C. K.

Publications and source records attributed to Yee, C. K..

3 recordsLinked to original sources

bioRxiv2025

A target product profile for a rapid diagnostic test to monitor mosquito gene drive presence and frequency

Malaria remains a major global health challenge, with over 263 million cases and nearly 600,000 deaths reported in 2023, the majority in sub-Saharan Africa. While conventional interventions such as insecticide-treated nets, indoor residual spraying and antimalarial drugs have reduced transmission, progress has stalled due to the limitations of these interventions and the emergence of resistance. Gene drive-modified mosquitoes represent a promising, potentially transformative vector control strategy, capable of spreading malaria-refractory traits or suppressing mosquito populations. Successful field deployment will depend upon monitoring systems to track the presence and frequency of gene drive constructs as they spread and persist. Current molecular surveillance techniques, though effective, are resource-intensive and reliant on laboratory infrastructure and technical competencies. Here, we make the case for a near-universal and low-cost rapid diagnostic test (RDT) designed to detect gene drive mosquitoes in the field, to complement existing surveillance infrastructure. Two use cases are outlined: i) to detect the presence of the drive construct in a new population, and ii) to provide an estimate of drive frequency prior to more accurate laboratory-based measurements. We provide a target product profile for the RDT outlining minimally essential and ideal characteristics, including test procedures, sensitivity, specificity, usability by a range of stakeholders in field settings, and compatibility with pooled testing of mosquito samples. An RDT for gene drive construct detection would support community access and participation in monitoring, enhance regulatory oversight, and promote transparency in field trials, thereby facilitating responsible deployment of gene drive-based malaria interventions.

genetics↗

bioRxiv2025

Targeted genomic surveillance of insecticide resistance in African malaria vectors

The emergence of insecticide resistance is threatening the efforts of malaria control programmes, which rely heavily on a limited arsenal of insecticidal tools, such as insecticide-treated bed nets. Importantly, genomic surveillance of malaria vectors can provide critical, policy-relevant insights into the presence and evolution of insecticide resistance, allowing us to maintain and extend the shelf life of these interventions. Yet the complex genetic architecture of resistance, combined with resource constraints in malaria-endemic settings, have thus far precluded the widespread use of genomics in routine surveillance. Meanwhile, stakeholders in sub-Saharan Africa are moving towards locally driven, decentralised generation of genomic data, underscoring the need for standardised and robust genomics workflows. To address this need, we demonstrate an approach to targeted genomic surveillance in Anopheles gambiae s.l with Illumina sequencing. We target 90 genomic loci in the Anopheles gambiae s.l genome, including 55 resistance-associated mutations and 35 ancestry informative markers. This protocol is coupled with advanced, automated software for accurate and reproducible variant analysis. We are able to elucidate population structure and ancestry in our cohorts and accurately identify most species in the An. gambiae species complex. We report frequencies of variants at insecticide-resistance loci and explore the continued evolution of the pyrethroid target site, the Voltage-gated sodium channel. Applying the platform to a recently established colony of field-caught resistant mosquitoes (Siaya, Kenya), we identified seven independent resistance-associated variants contributing to reduced efficacy of insecticide-treated nets in East Africa. Additionally, we leverage a machine learning algorithm (XGBoost) to demonstrate the possibility of predicting bioassay mortality using genotypes alone. This achieved high accuracy (75%), demonstrating the potential of targeted genomics to predictively monitor insecticide resistance. Together these tools provide a practical, scalable solution for resistance monitoring while advancing the goal of building local genomic surveillance capacity in sub-Saharan Africa.

genomics↗

bioRxiv2021

Polyunsaturated fatty acid arachidonic acid increases the virulence of gut pathogen, Yersinia enterocolitica

Food-borne illnesses are a major health concern worldwide. While 1 in 6 individuals are infected in the United States yearly, there is little research into which dietary factors can alter the risk of infection. Despite evidence suggesting a correlation between obesity and enteric infection, the few reported studies focus on the role of dietary factors and the impact on host tissues and susceptibility. The direct impact of dietary constituents on the virulence of a pathogen has largely been ignored. One component of the Western diet that has been correlated with increasing inflammatory diseases is increased consumption of omega-6 polyunsaturated fatty acids such as arachidonic acid. Here, we show that arachidonic acid directly alters the pathogenicity of the food-borne pathogen Yersinia enterocolitica. Using in vitro cellular adherence assays, proteomic peptide mass fingerprint profiles and in vivo mouse models, we show that arachidonic acid can alter the pathogenesis of Y. enterocolitica by increasing proliferation and intracellular invasion. These findings have major implications in more than food safety, potentially revealing how current dietary habits may increase the virulence of food-borne pathogens.

microbiology↗