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Biology subjects

Lumley, S.

Publications and source records attributed to Lumley, S..

4 recordsLinked to original sources

A Zika virus-responsive sensor-effector system in Aedes aegypti

Zika virus (ZIKV) is a recently re-emerged flavivirus transmitted primarily through the bite of an infected mosquito, Aedes aegypti being the main vector. ZIKV infection is associated with a range of adverse effects; infection during pregnancy can lead to foetal abnormalities, including microcephaly. Lacking a licensed vaccine, or specific therapeutics, control of ZIKV transmission focuses on vector control. However, in most transmission settings, current methods are insufficient to successfully control ZIKV, or other similarly-transmitted arboviruses such as dengue and chikungunya viruses. This has stimulated interest in genetics-based methods, either to reduce the number of mosquitoes ("population suppression"), or to make mosquitoes less able to transmit ("population modification"). Here, we describe a method to selectively eliminate infected mosquitoes, using a virus sensor inserted into the mosquito genome and coupled to a quorum-counting lethal effector. In mosquitoes, ZIKV normally establishes persistent, lifelong infection; survival of these infected mosquitoes is crucial to transmission potential. Correspondingly, removal of infected mosquitoes can reduce vectorial capacity of a mosquito population, i.e. ability to transmit. Since relatively few mosquitoes become infected, typically <2%, engineered hypersensitivity to ZIKV would have only a modest population-level fitness cost, and lower still if transmission were successfully reduced by such means.

bioengineering↗

Fake it to break it: mimicking superinfection exclusion disrupts alphavirus infection and transmission in the yellow fever mosquito Aedes aegypti

Multiple viruses cause a phenomenon termed superinfection exclusion whereby a currently infected cell is resistant to secondary infection by the same or a closely related virus. In alphaviruses, this process is thought to be mediated, at least in part, by the viral protease (nsP2) which is responsible for processing the non-structural polyproteins (P123 and P1234) into individual proteins (nsP1-nsP4), forming the viral replication complex. Taking a synthetic-biology approach, we mimicked this naturally occurring phenomenon by generating a superinfection exclusion-like state in Aedes aegypti mosquitoes, rendering them refractory to alphavirus infection. By artificially expressing Sindbis virus (SINV) and chikungunya virus (CHIKV) nsP2 in mosquito cells and transgenic mosquitoes, we demonstrated a reduction in both SINV and CHIKV viral replication rates in cells following viral infection as well as reduced infection prevalence, viral titres and transmission potential in mosquitoes.

microbiology↗

Nanopore metagenomic sequencing of full length human metapneumovirus (HMPV) within a unique sub-lineage

Human metapneumovirus (HMPV) has been recognized as an important pathogen which can cause a spectrum of respiratory tract disease. Here, we report Nanopore metagenomic sequencing of the first full length HMPV genome directly from a throat swab from a UK patient with complex lung disease and immunocompromise. We found a predominance (26.4%) of HMPV reads in the metagenomic sequencing data and consequently assembled the full genome at a high depth of coverage (mean 4,786). Through phylogenetic analyses, we identified this HMPV strain to originate from a unique genetic group in A2b, showing the presence of this group in the UK. Our study demonstrated the effectiveness of Nanopore metagenomic sequencing for diagnosing infectious diseases and recovering complete sequences for genomic characterization, highlighting the applicability of Nanopore sequencing in clinical settings.\n\nImportanceNanopore metagenomic sequencing has the potential to evolve as a point-of-care test for a range of infectious diseases. Here, we report the first full length human metapneumovirus (HMPV) genome in the UK sequenced by Nanopore from a non-invasive sample from an immunocompromised patient. We demonstrate the presence of HMPV from a unique genetic group not previously reported from the UK. Our study demonstrates the effectiveness of Nanopore sequencing for diagnosing an infection that was not detected by routine first-line tests in the clinical microbiology laboratory. We report sufficient genomic data to provide insight into the epidemiology of infection and with the potential to inform treatment decisions.

microbiology↗

Detection of viral pathogens with multiplex Nanopore MinION sequencing: be careful with cross-talk

Metagenomic sequencing with the Oxford Nanopore MinION sequencer offers potential for point-of-care testing of infectious diseases in clinical settings. To improve cost-effectiveness, multiplexing of several, barcoded samples upon a single flow cell will be required during sequencing. We generated a unique sequencing dataset to assess the extent and source of cross barcode contamination caused by multiplex MinION sequencing. Sequencing libraries for three different viruses, including influenza A, dengue and chikungunya, were prepared separately and sequenced on individual flow cells. We also pooled the respective libraries and performed multiplex sequencing. We identified 0.056% of total reads in the multiplex sequencing data that were assigned to incorrect barcodes. Chimeric reads were the predominant source of this error. Our findings highlight the need for careful filtering of multiplex sequencing data before downstream analysis, and the trade-off between sensitivity and specificity that applies to the barcode demultiplexing methods.

bioinformatics↗