Microbiology & Infectious Disease Publications

Alicia Gill, Jere Koskela, Xavier Didelot, Richard G Everitt

Inference of the reproduction number through time is of vital importance during an epidemic outbreak. Typically, epidemiologists tackle this using observed prevalence or incidence data. However, prevalence and incidence data alone are often noisy or partial. Models can also have identifiability issues with determining whether a large amount of a small epidemic or a small amount of a large epidemic has been observed. Sequencing data however are becoming more abundant, so approaches which can incorporate genetic data are an active area of research. We propose using particle MCMC methods to infer the time-varying reproduction number from a combination of prevalence data reported at a set of discrete times and a dated phylogeny reconstructed from sequences. We validate our approach on simulated epidemics with a variety of scenarios. We then apply the method to real datasets of HIV-1 in North Carolina, USA and tuberculosis in Buenos Aires, Argentina. The models and algorithms are implemented in an open source R package called EpiSky which is available at https://github.com/alicia-gill/EpiSkyLink opens in a new window.

Journal of the Royal Statistical Society Series C (Applied Statistics), December 2025

Nabil Karah, Nathan Faille​, Nancy Allard, Frédéric Grenier, Antoine Abou-Fayad, Paul G. Higgins, Leena Al-Hassan, Benjamin A. Evans, Laurent Poirel, Rémy A. Bonnin, Anette M. Hammerum, Frank Hansen, Rayane Rafei, Monzer Hamze, Xavier Didelot, Santiago Castillo-Ramírez, Simon Lévesque, Sébastien Rodrigue, Bernt Eric Uhlin, Louis-Patrick Haraoui

Infections caused by carbapenem-resistant Acinetobacter baumannii (CRAB) are of great concern, as mortality is high, and treatment options are very limited. Despite having among the highest rates reported worldwide, scarce genomic data are available on CRAB strains from the Middle East. Here, we report the global emergence of a novel International Clone (IC), designated IC12, based on the epidemiological, phenotypic and genome sequencing data (short reads and long reads) of a set of 60 A. baumannii isolates belonging to multilocus sequence type 158 (Pasteur scheme). IC12, prevailing in the Middle East since 2007, has also been found in Europe, Asia and South America. Alleles OXA-65 and ADC-117, coded by the blaOXA-51-like and blaADC A. baumannii-intrinsic genes, respectively, were hallmarks shared by all the isolates. Plasmid pIC12-2 (80,000 bp), which carries a repAci6 replication initiator (RP-T1) and a type IV conjugative transfer system, played a major role in the antimicrobial resistance profile of 54/60 of the IC12 isolates. This resistance was mediated by three mobile genetic elements, namely Tn2008, MITEAb-IC12 and TnaphA6. All four Peruvian IC12 isolates lacked pIC12-2 and carried a different set of plasmids. Two of the Peruvian isolates carried a chromosomal resistance island of 79,396 bp long (designated IC12-RI) marked by the occurrence of tet(X3). The global spread of IC12 is worrying and calls for further studies on the virulence features and clinical impact of this clone.

Microbial Genomics, November 2025

Chao Yan,Shanwei Tong, Yarong Wu, Yujie Chen,Xinyu Jia,Yan Guo,Mengnan Cui,Guangqian Pei, Zuming Zhang, Hao Zhou, BAdmin , Kai Mu,Xue Ren,Bing Du, Hanqing Zhao,Yanling Feng,Jinghua Cui,Yuyan Xia, MBBS , Zhen Wang, Yu Sun,Prof Linqing Zhao, Prof Chuangli Hao, Zhijie Zhu, Shengqiang Luo, Han Zhang, Yongjun Wang , Prof Lili Zhong, DehuiChen , Prof Yong Yin , Longji Hu, Prof Yuehua Ke, Prof Guanhua Xue, Prof Ling Cao, , Prof Xavier Didelot, Prof Jing Yuan, Prof Yujun Cui,

Background: After a prolonged period of low detection rates, Mycoplasma pneumoniae resurged in China, during September to November, 2023, raising global concern. This study aims to gain a better understanding of the genetic mechanisms underlying the 2023 increase in cases and the evolutionary dynamics of the epidemic populations, which has been previously hampered due to limited genomic data of this pathogen.

Methods: We sequenced 685 M pneumoniae isolates, including 248 isolates from 11 Chinese provinces and municipalities in 2023 and 437 isolates from Beijing (2013–22). By analysing these isolates and 436 publicly global sequences, we reconstructed the pathogen’s evolutionary history using time-calibrated phylogenies and effective population size inference. We investigated potential genomic variations contributing to the 2023 resurgence through genome-wide association study and conducted phylogeographic analysis of the 2023 isolates across China.

Findings: Two macrolide-resistant epidemic clusters (T1-2-EC1 and T2-2-EC2) were responsible for the 2023 resurgence in China. Both clusters, having acquired the 23S ribosomal RNA A2063G mutation conferring macrolide resistance, emerged in approximately 1997 and 2014, respectively, and subsequently outcompeted their predecessor populations. This coincided with China’s large-scale adoption of azithromycin for paediatric community-acquired pneumonia around the early 2000s. Aside from macrolide resistance, T1-2-EC1 independently acquired 17 clade-specific mutations and T2-2-EC2 four clade-specific mutations, which could further explain their increased competitiveness. Whole-genome analysis revealed no resurgence-specific mutations in the 2023 isolates. Phylogeographic analysis showed rapid mixing of T1-2-EC1 isolates between different sampled regions within China.

Interpretation: Our study provides evidence that the 2023 resurgence in China is a continuation of the pre-COVID epidemic, rather than emergence of novel variants. The high prevalence of macrolide resistance and rapid intranational spread emphasise the urgent need for enhanced global surveillance of this pathogen.

The Lancet (Microbe), December 2025

Kandas Traore, Damien Seyer, Agnes Mihajlovski, Antonia P Sagona

Antimicrobial resistance represents one of the most serious threats to both public health and economic sustainability. One of the promising approaches to address this problem is phage therapy – treatment of pathogenic bacterial infections using bacteriophages. Bacteriophages have a narrow host spectrum of activity, minimal side effects and self-replication at the infection site, which positions them as promising candidates to complement or replace conventional antibiotics. Moreover, they can be easily genetically modified to enhance their effectiveness and safety. In this At a Glance article, we highlight the timely relevance of engineered phages as an innovative solution in a rapidly evolving healthcare landscape. First, we introduce bacteriophages' life cycle, ecology and therapeutic history, emphasizing their role in One Health strategies. Then, we describe advanced engineering techniques that can be used to expand bacteriophages' functionalities. Finally, we discuss innovative applications of engineered bacteriophages in biotechnological applications and as a potential countermeasure for antimicrobial resistance, including serving as a shuttle for delivering genes and drugs to the targeted bacterial and eukaryotic cells, targeting intracellular bacteria, contributing to vaccine development, facilitating advancements in tissue engineering and improving bacteriophages' antibacterial properties.

Disease Models and Mechanisms, September 2025

Matt Combes, Nathan Brown, Robin N. Thompson, Alexander Mastin, Peter Crow, Stephen Parnell

Invasive plant pests and pathogens cause substantial environmental and economic damage. Visual inspection remains a central tenet of plant health surveys, but its sensitivity (probability of correctly identifying the presence of a pest) and specificity (probability of correctly identifying the absence of a pest) are not routinely quantified. As knowing sensitivity and specificity of visual inspection is critical for effective contingency planning and outbreak management, we address this deficiency using empirical data and statistical analyses. Twenty-three citizen scientist surveyors assessed up to 175 labelled oak trees for three symptoms of acute oak decline. The same trees were also assessed by an expert who has monitored these individual trees annually for over a decade. The sensitivity and specificity of surveyors was calculated using the expert data as the ‘gold-standard’ (i.e., assuming perfect sensitivity and specificity). The utility of an approach using Bayesian modelling to estimate the sensitivity and specificity of visual inspection in the absence of a rarely available ‘gold-standard’ dataset was then examined with simulated plant health survey datasets. There was large variation in sensitivity and specificity between surveyors and between different symptoms, although the sensitivity of detecting a symptom was positively related to the frequency of the symptom on a tree. By leveraging surveyor observations of two symptoms from a minimum of 80 trees on two sites, with reliable prior knowledge of sites with a higher (~0.6) and lower (~0.3) true disease prevalence we show that sensitivity and specificity can be estimated without ‘gold-standard’ data using Bayesian modelling. We highlight that sensitivity and specificity will depend on the symptoms of a pest or disease, the individual surveyor, and the survey protocol. This has consequences for how surveys are designed to detect and monitor outbreaks, as well as the interpretation of survey data that is used to inform outbreak management.

PLOS - Computational Biology, November 2025

Shannon F. Greer, Sneha Chakravorty, Kieran Cooney-Nutley, Dave Chandler*, Gregory Firth, Rajesh Odedra, Mojgan Rabiey

Bacteriophages, phages or viruses that specifically infect bacteria, have shown promise for the biocontrol of bacterial plant diseases. However, one of the main challenges of using phages in agricultural systems is their precision application, being able to deliver an effective dose to the site of bacterial infection. In this study, a series of artificial and real cherry flower experiments was conducted to test whether commercially managed bumblebees (Bombus terrestris audax) could deliver phage effective against the cherry canker pathogen Pseudomonas syringae pv. syringae (Pss). Freeze-dried phage powder was formulated with powdered-skimmed milk and when tested, was found to retain viability for seven days in artificial bee feed after storage at 4 °C, room temperature or under glasshouse conditions. In both artificial and cherry flower experiments, bees successfully transferred the formulated phage from their hive to up to 88 % of flowers, resulting in significant reduction in Pss populations. Bees were also able to transfer phage between cherry flowers. The application of phages disrupted the cycle of Pss transmission by bees. These results highlight the potential of bee-mediated phage delivery as an effective biocontrol strategy against floral pathogens like Pss.

Biological Control, December 2025

Anna Lazar, Fabrizio Alberti, George Muscatt, Ryan M. Mushinski, Christopher Quince, Gary D. Bending

Background: Tetracladium spp. represent a group of fungi that inhabit various ecological niches, including soil and aquatic environments, where they are considered to have a saprotrophic lifestyle and within plant roots as endophytes. To date, a lack of sequenced Tetracladium spp. genomes has inhibited our understanding of their metabolic potential and ecological interactions. In this study, we aimed to elucidate the genetic differences between aquatic saprotrophic and endophytic strains of Tetracladium spp. by sequencing and analysing the genomes of T. maxilliforme (isolated from Brassica napus roots) and T. marchalianum (isolated from freshwater), alongside 41 publicly available saprotrophic and endophytic Ascomycetes.

Results: Genomic sequencing revealed that T. maxilliforme possesses a genome size of 35.5 Mbp with 9657 predicted genes, while T. marchalianum has a genome size of 33.2 Mbp with 15,230 predicted genes. Our analyses primarily focused on carbohydrate-active enzymes (CAZymes). Both genomes possessed the full range of enzymatic machinery for cellulose degradation, as well as the complete repertoire of genes necessary to degrade plant cell walls. Notably, the genomes lacked essential enzymes for lignin degradation or modification. Furthermore, we observed a complete repertoire of known fungal chitin-degrading enzymes in both genomes, which might be related to potential interactions with other fungi. Enzyme composition profiles revealed distinct groupings, with T. maxilliforme primarily clustering with endophytic or ecologically versatile species, while T. marchalianum was predominantly associated with saprotrophic species. We also identified secondary metabolite biosynthetic gene clusters in both genomes, including several that showed high homology to those of known bioactive compounds.

Conclusions: In summary, our findings offer valuable insights into the genomic adaptations of Tetracladium spp. to various ecological niches, highlighting their enzymatic capabilities for carbohydrate degradation and potential interactions within fungal communities.

BMC Genomics, November 2025

George W Sundin, Sara M Villani, Quan Zeng, Michelle Hulin, Mojgan Rabiey, Kerik Cox

Bacteriophages are viruses capable of infecting bacterial cells. Lytic phages, which infect and kill bacterial cells, are of interest in disease management in human, animal, and plant systems. In plant pathology, the biocontrol of bacterial diseases is of heightened interest because of the lack of efficacious options in many pathosystems. Numerous papers have been published in the past few decades on phage that target plant pathogenic bacteria, and a large majority of these have been focused on phage isolation and characteristics that highlight the promise and potential of phage as biocontrol agents. In contrast, relatively few of these papers have reported results from studies conducted in the field. Of the recent papers (2022 to 2025) reporting field studies, disease efficacy results are inconsistent. We argue that field studies should be an essential component of phage biocontrol research to understand how to best utilize and deploy phages to generate consistently effective disease management.

Plant Disease, November 2025.

Marina Romanello, Maria Walawender, Shih-Che Hsu, Annalyse Moskeland, Yasna Palmeiro-Silva, Daniel Scamman, James W Smallcombe, Sabah Abdullah, Melanie Ades, Abdullah Al-Maruf, Nadia Ameli, Denitsa Angelova, Sonja Ayeb-Karlsson, Joan Ballester, Xavier Basagaña, Hannah Bechara, Paul J Beggs, Wenjia Cai, Diarmid Campbell-Lendrum, Gina E C Charnley, Orin Courtenay, Troy J Cross, Carole Dalin, Niheer Dasandi, Shouro Dasgupta, Michael Davies, Matthew Eckelman, Chris Freyberg, Paulina Garcia Corral, Olga Gasparyan, Joseph Giguere, Georgiana Gordon-Strachan, Sophie Gumy, Samuel H Gunther, Ian Hamilton, Yun Hang, Risto Hänninen, Stella Hartinger, Kehan He, Julian Heidecke, Jeremy J Hess, Slava Jankin, Ollie Jay, Dafni Kalatzi Pantera, Ilan Kelman, Harry Kennard, Gregor Kiesewetter, Patrick Kinney, Dominic Kniveton, Vally Koubi, Rostislav Kouznetsov, Pete Lampard, Jason K W Lee, Bruno Lemke, Bo Li, Andrew Linke, Yang Liu, Zhao Liu, Rachel Lowe , Siqi Ma, Tafadzwanashe Mabhaudhi, Carla Maia, Anil Markandya, Greta Martin, Jaime Martinez-Urtaza, Mark Maslin, Lucy McAllister, Celia McMichael, Zhifu Mi, James Milner, Kelton Minor, Jan Minx, Nahid Mohajeri, Natalie C Momen, Maziar Moradi-Lakeh, Karyn Morrisey, Simon Munzert, Kris A Murray, Nick Obradovich, Papa Orgen, Matthias Otto, Fereidoon Owfi, Olivia L Pearman, Frank Pega, Andrew J Pershing, Ana-Catarina Pinho-Gomes, Jamie Ponmattam, Mahnaz Rabbaniha, Tim Repke, Jorge Roa, Elizabeth Robinson, Joacim Rocklöv, David Rojas-Rueda, Jorge Ruiz-Cabrejos, Matilde Rusticucci, Renee N Salas, Adrià San José Plana, Jan C Semenza, Jodi D Sherman, Joy Shumake-Guillemot, Pratik Singh, Henrik Sjödin, Matthew R Smith, Mikhail Sofiev, Cecilia Sorensen, Marco Springmann, Jennifer D Stowell, Meisam Tabatabaei, Federico Tartarini, Jonathon Taylor, Cathryn Tonne, Marina Treskova, Joaquin A Trinanes, Andreas Uppstu, Nicolas Valdes-Ortega, Fabian Wagner, Nick Watts, Hannah Whitcombe, Richard Wood, Pu Yang, Ying Zhang, Shaohui Zhang, Chi Zhang, Shihui Zhang, Qiao Zhu, Peng Gong, Hugh Montgomery, Anthony Costello

Driven by human-caused greenhouse gas emissions, climate change is increasingly claiming lives and harming people's health worldwide. Mean annual temperatures exceeded 1·5°C above those of pre-industrial times for the first time in 2024. Despite ever more urgent calls to tackle climate change, greenhouse gas emissions rose to record levels that same year. Climate change is increasingly destabilising the planetary systems and environmental conditions on which human life depends.

The Lancet, October 2025

McAndrew, Martin B. L., Cook, Jonathan P., Gill, Amy, Sahoo, Kavya, Thomas, Clare, Stansfeld, Phillip J. and Crow, Allister

Type VII ABC transporters are ATP-powered membrane protein complexes that drive key biological processes in the bacterial cell envelope. In Escherichia coli, three of the four Type VII ABC systems have been extensively characterized, including: the FtsEX-EnvC cell division complex, the LolCDE-LolA lipoprotein trafficking machinery, and the MacAB-TolC efflux pump. Here we describe a fourth E. coli Type VII ABC system, YbbAP-TesA, which combines a Type VII ABC transporter with a multifunctional hydrolytic enzyme. Structures of the complete YbbAP-TesA complex, and of YbbAP with and without bound ATP analogues, capture implied long-range transmembrane conformational changes that are the hallmark of this ABC superfamily’s mechanotransmission mechanism. We further show that YbbAP-TesA can hydrolyze a variety of ester and thioester substrates and experimentally confirm a constellation of active site residues in TesA. Our data suggests YbbAP has a role in extracting hydrophobic molecules from the inner membrane and presenting these to TesA for hydrolysis. The work extends collective knowledge of the remarkable diversity of the ABC superfamily and establishes a new function for Type VII ABC transporters in bacterial cells.

PLOS Biology, November 2025

Naomi S. Prosser, Eamonn Ferguson, Jasmeet Kaler, Edward M. Hill, Michael J. Tildesley, Matt J. Keeling, Martin J. Green

BACKGROUND: Psychosocial factors are important for the uptake of livestock disease control measures by farmers and can differ by region, which would have implications for disease control nationally.

METHODS: We investigated altruism, trust, psychological proximity and the COM-B behaviour change framework in a survey of 475 British cattle farmers in 2020. Using regression models, we studied associations between the country farmers lived in and psychosocial and behaviour change factors. RESULTS: There were many between-country differences in farmers' psychosocial and COM-B profiles. Accounting for multiple tests, Scottish cattle farmers reported higher trust in governmental judgements for disease control and greater social opportunity to control disease than English cattle farmers.

LIMITATIONS: There were relatively low numbers of respondents from Scotland and Wales. As such, the results should be interpreted with caution. Northern Irish farmers could not be included in the analyses as there were too few responses.

CONCLUSION: Cattle farmers differed in their psychosocial profiles by country. Our sample of Scottish farmers reported higher trust in, and felt better supported by, government in the context of disease control than the English farmers, which could be due to different disease control approaches between devolved governments. Understanding between-country differences in farmer psychosocial attributes has implications for animal health governance and approaches to disease control.

Veterinary Record, October 2025

Leila T. Alexander, Océane M. Follonier, Andriy Kryshtafovych,| Kim Abesamis, Sabrina Bibi-Triki, Henry G. Box, Cécile Breyton, Françoise Bringel, Loic Carrique, Alessio d'Acapito, Gang Dong, Rebecca DuBois, Deborah Fass, JulianaMartinez Fiesco, Daniel R. Fox, Jonathan M. Grimes, Rhys Grinter, Matthew Jenkins, Roman Kamyshinsky, Jeremy R. Keown, Gerald Lackner, Michael Lammers, Shiheng Liu, Andrew L. Lovering,Tomas Malinauskas, Benoît Masquida, Gottfried J. Palm, Christian Siebold,Tiantian Su, Ping Zhang, Z. Hong Zhou, Krzysztof Fidelis, Maya Topf, John Moult, Torsten Schwed

This article presents an in-depth analysis of selected CASP16 targets, with a focus on their biological and functional significance. The authors highlight the most relevant features of the target proteins and discuss how well these were reproduced in the submitted predictions. While the overall performance of structure prediction methods remains impressive, challenges persist, particularly in modeling rare structural motifs, flexible regions, small molecule interactions, posttranslational modifications, and biologically important interfaces. Addressing these limitations can strengthen the role of structure prediction in complementing experimental efforts and advancing both basic research and biomedical applications.

Proteins (Structure, Function, Bioinformatics), October 2025

Will Scott, Esther Ivorra-Molla, Dipayan Akhuli, Teresa Massam-Wu, Pawel K. Lysyganicz, Rylie Walsh, Matthew Parent, Jonathan Cook, Lijiang Song, Abhishek Kumar, Falk Schneider, Masanori Mishima, Allister Crow, Mohan K. Balasubramanian

Photobleaching of fluorescent proteins often limits the acquisition of high-quality images in microscopy. StayGold, a novel dimeric GFP recently monomerized through sequence engineering, addresses this challenge with its high photostability. There is now a focus on producing different colored StayGold derivatives to facilitate concurrent tagging of multiple targets. The unnatural amino acid 3-aminotyrosine has previously been shown to redshift superfolder GFP upon incorporation into its chromophore via genetic code expansion. Here, we apply the same strategy to redshift StayGold through substitution of tyrosine-58 with 3-aminotyrosine. The resultant red fluorescent protein, StayRose, shows an excitation wavelength maximum of 530 nm and an emission wavelength maximum of 588 nm. Importantly, the monomeric mStayRose retains the favorable photostability in vivo in Escherichia coli and zebrafish embryos. A high-resolution crystal structure of StayRose confirms the modified structure of the amino chromophore within an unperturbed 3D fold. Although reliant on genetic code expansion, StayRose provides an important step toward developing redshifted StayGold derivatives.

Journal of Biological Chemistry, December 2025

Cook Jonathan, Crow Allister

The FtsEX-EnvC-AmiA/B system is a key component of the E. coli cell division machinery that directs breakage of the peptidoglycan layer during separation of daughter cells. Structural and mechanistic studies have shown that ATP binding by FtsEX in the cytoplasm drives periplasmic conformational changes in EnvC, which lead to the binding and activation of peptidoglycan amidases such as AmiA and AmiB. The FtsEX-EnvC amidase system is highly regulated to prevent cell lysis with at least two separate layers of autoinhibition that must be relieved to initiate peptidoglycan hydrolysis during division. Here, we test the FtsEX-EnvC amidase activation mechanism through site-directed mutagenesis. We identify mutations that disrupt the autoinhibition mechanism of FtsEX-EnvC and an N-terminal deletion variant that prevents activation. Finally, we develop a cysteine locking residue pair that stabilizes the complex in its amidase activating conformation. The reported EnvC variants greatly enhance our understanding of the FtsEX-EnvC autoinhibition mechanism and the conformational changes underpinning amidase activation. Our observations are consistent with the proposed mechanism of amidase activation by large-scale conformational changes in FtsEX-EnvC, allowing recruitment and activation of peptidoglycan amidases.

MBIO-ASM Journals

Matt J. Keeling, Edward M. Hill, Stavros Petrou, Phuong Bich Tran, May Ee Png, Sophie Staniszewska, Corinna Clark, Katie Hassel, Julia Stowe, Nick Andrews

In England, and many other countries, immunity to SARS-CoV-2 infection and COVID-19 disease is highly heterogeneous.. During the height of the pandemic in England, the main aim was to rapidly protect the population and large supplies of vaccine were pre-purchased, eliminating the need for cost-effective calculations. As we move to an era where for the majority of the population SARS-CoV-2 infections cause relatively mild disease, and vaccine stocks need to be re-purchased, it is important we consider the cost-effectiveness and economic value of COVID-19 vaccination programmes. Here using data from 2023 and 2024 in England on COVID-19 hospital admissions, ICU admissions and deaths, coupled with bespoke health economic costs, we consider the willingness to pay threshold for COVID-19 vaccines in different age and risk groups.

Vaccine. March 2025

Michaël Dagne Tadesse, Nala Ali, Martha White, Lijiang Song, Fabrizio Alberti, Antonia P. Sagona 

There is an urgent need for novel antimicrobial therapies, chemical and nonantibiotic. The basidiomycota-derived, secondary metabolite pleurotin has been shown to be effective against Gram-positive bacteria, while bacteriophages could be the ultimate nonantibiotic alternative. In this study, the combination of pleurotin and phage K targeting S. aureus was examined. Pleurotin was isolated from the basidiomycota fungus Hohenbuehelia grisea. The cytotoxicity of pleurotin was assessed in two human cell lines in comparison to pleuromutilin, vancomycin, and phage K. The antibiotics were then tested independently or in combination with phage K against two S. aureus strains. Cytotoxicity of pleurotin in human cells was comparable to vancomycin and pleuromutilin. Results suggest that adding phage K has a synergistic effect and can lower the MIC for pleurotin, pleuromutilin, and vancomycin. This demonstrates that pleurotin could be a viable antistaphylococcal drug.

ACS Omega. March 2025

Matevz Papp-Rupar, Emily R. Grace, Naina Korotania, Maria-Laura Ciusa, Robert W. Jackson, Mojgan Rabiey

Isolation of phages targeting the cherry pathogen Pseudomonas syringae pv. syringae (Pss) led to five distinct phage genotypes. Building on previous in vitro coevolution experiments, the coevolution of the five phages (individually and as a cocktail) with Pss on cherry leaves was conducted in glasshouse and field experiments. Phages effectively reduced Pss numbers on detached leaves, with no evidence of phage resistance emerging in the bacterial population. Field application of phages in a cherry orchard in Southeast England evaluated phage survival, viability and impact on bacterial populations and the microbial community. The bacterial population and phages persisted in the leaf and shoot environment as long as the bacterial host was present. In contrast to in vitro studies, the plant environment constrained the emergence of phage resistant Pss populations.

Environmental Microbiology. March 2025

Niba Rawlings, Ngwa, Bailey, Mark and Courtenay, Orin

This systematic review and meta-analysis of data specific to military populations aims to identify knowledge gaps to mitigate sand fly exposure and Leishmania transmission during deployments. Regular use of long-lasting insecticidal nets to mitigate sand fly exposure demonstrated high potential effectiveness than other reported personal protective measures (PPMs) which yielded mixed or inconclusive results. In summary, the systematic review revealed the substantial variability between study designs and statistical integrity. There is need for more consistent and robustly designed studies including well-define controls and replication. Future studies would be advised to explore the long-term effectiveness and practicality of PPMs, both individually and in combination, across diverse deployment settings.

PLoS Neglected Tropical Diseases. March 2025

Glen Guyver-Fletcher, Erin E. Gorsich, Chris Jewell, Michael J. Tildesley

In this article we present a spatially-explicit stochastic metapopulation model to simulate the spread and control of foot-and-mouth disease (FMD) in an endemic setting. We parameterise and validate the model using detailed outbreak data from the Republic of Turkey, 2001–2012. Subsequently, we assess the efficacy of ring vaccination, mass vaccination, and livestock movement restrictions with regards to incidence-reduction and likelihood of eradication. Our results suggest countries wishing to control the disease within their borders should focus on comprehensive surveillance and vaccination campaigns as their main policy goals. In summary, vaccination-based policies are more effective than movement restrictions in the endemic context.

Infectious Disease Modelling.; February 2025

Zuyu Yang, Heather Davies, Jane Clapham, Liza Lopez, Holly B Bratcher, Audrey Tong, Xavier Didelot, Martin C.J. Maiden, Philip E. Carter, Xiaoyun Ren

Neisseria meningitidis is the causative agent of invasive meningococcal disease (IMD), a form of bacterial meningitis and septicaemia, leading to isolated cases, outbreaks, and epidemics worldwide. Between 1991 and 2008, Aotearoa/New Zealand (NZ) experienced a prolonged hyperendemic group B IMD outbreak caused by the NZMenB epidemic strain. To understand NZMenB origin and initiation we used phylodynamic tools to analyse approximately 97 % of all NZMenB isolates submitted to the NZ Meningococcal Reference Laboratory from 1990 to 2019.. Our evidence from molecular dating and clonal expansion analysis suggests that NZMenB was circulating and had expanded before the epidemic. Comparison with international data showed multiple importations and re-introductions of NZMenB into NZ, while not suggesting close relationships with international variants. We propose the NZMenB epidemic may have been triggered by increasing societal inequality and household crowding resulting from government policies at the time.

Infection, Genetics and Evolution. February 2025

Alexander R Kaye, Giorgio Guzzetta, Michael J Tildesley

For many infectious diseases, the risk of outbreaks varies seasonally. If a pathogen is usually absent from a host population, a key public health policy question is whether the pathogen’s arrival will initiate local transmission, which depends on the season in which arrival occurs. This question can be addressed by estimating the “probability of a major outbreak” (the probability that introduced cases will initiate sustained local transmission). We have devised an approach for inferring outbreak risks for seasonal pathogens (involving calculating the Threshold Epidemic Risk; TER). Estimation of the TER involves calculating the probability that introduced cases will initiate a local outbreak in which a threshold number of cumulative infections is exceeded before outbreak extinction. For simple seasonal epidemic models, such as the stochastic Susceptible-Infectious-Removed model, the TER can be calculated numerically (without model simulations). For more complex models, such as stochastic host-vector models, the TER can be estimated using model simulations.

PLoS Computational Biology. February 2024

Sarbjit Nijjar, Deborah Brotherton, Jack Butler, Valentin-Mihai Dospinescu, Harry G Gannon, Victoria Linthwaite, Martin Cann, Alexander Cameron, Nicholas Dale 

CO2 directly modifies the gating of connexin26 (Cx26) gap junction channels and hemichannels. This gating depends upon Lys125, and the proposed mechanism involves carbamylation of Lys125 to allow formation of a salt bridge with Arg104 on the neighbouring subunit. We demonstrate via carbamate trapping and tandem mass spectrometry that five Lys residues within the cytoplasmic loop, including Lys125, are indeed carbamylated by CO2 . Our findings directly demonstrate carbamylation in connexins, provide further insight into the differential action of CO2 on Cx26 hemichannels and gap junction channels, and increase support for the role of the N-terminus in gating the Cx26 channel. KEY POINTS: Direct evidence of carbamylation of multiple lysine residues in the cytoplasmic loop of Cx26. Concentration-dependent carbamylation at lysines 108, 122 and 125. Only carbamylation of lysine 125 is essential for hemichannel opening to CO2. Carbamylation of lysine 108 along with lysine 125 is essential for CO2-dependent gap junction channel closure.

Journal of Physiology. February 2025

Julia A. Fairbairn, Rachel V. Kerr, Nika-Kare A. Pierre-White, Anthony Jacovides, Becca W. A. Baileeves, Phillip J. Stansfeld, Gerhard Bringmann, Andrew T. Merritt and Timothy D. H. Bugg

Escherichia coli translocase MraY is the target for bacteriolytic protein E from bacteriophage fX174, interacting at a site close to Phe-288 on helix 9, on the extracellular face of the protein. A peptide motif Arg-Trp-x-x-Trp from protein E was used to design a set of triazinedione peptidomimetics, which inhibit particulate MraY (6d IC50 48 µM), and show antimicrobial activity against Gram-negative and Gram-positive antibiotic-resistant clinical strains (7j MIC Acinetobacter baumannii 16 µg/mL, Staphyloccoccus aureus MRSA 2-4 µg/mL). Docking against a predicted structure for E. coli MraY revealed two possible binding sites close to helix 9, the binding site for protein E. Antimicrobial activity of analogue 6j was found to be synergistic with bacitracin in Micrococcus flavus, consistent with a link between this inhibition site and undecaprenyl phosphate uptake. Alkaloid michellamine B, also predicted to bind in the cleft adjacent to helix 9, was also found to be synergistic with bacitracin. These data provide experimental evidence that the unusual hydrophobic cleft adjacent to helix 9 in MraY is involved in uptake of undecaprenyl phosphate, in addition to recently identified transporters UptA and PopT, and that this process can be targetted by small molecules as a novel antibacterial mechanism.

RSC Medicinal Chemistry. January 2025

Helekal, David, Koskela, Jere and Didelot, Xavier

Here we consider the problem of detecting the presence of multiple mergers in the context of dating a phylogeny, that is determining the date of each of the nodes. We use the Lambda-coalescent theory as a modelling framework and show how Bayesian inference can be efficiently performed using a Billera-Holmes- Vogtmann space embedding and a customised Markov Chain Monte Carlo sampling scheme. We applied this new analysis methodology to a large number of simulated datasets to show that it is possible to infer if and when multiple merger events occurred, and that the phylogenetic dating is improved as a result of taking this information into account. We also analysed real datasets of Vibrio cholerae and Mycobacterium tuberculosis to demonstrate the relevance of our approach to real pathogen evolutionary epidemiology. We have implemented our new methodology in a R package which is freely available at https://github.com/dhelekal/MMCTime.

Systematic Biology. January 2025

Zdouc, Mitja M. et al inc. Alberti, F

Specialized or secondary metabolites are small molecules of biological origin, often showing potent biological activities with applications in agriculture, engineering and medicine. Usually, the biosynthesis of these natural products is governed by sets of co-regulated and physically clustered genes known as biosynthetic gene clusters (BGCs). To share information about BGCs in a standardized and machine-readable way, the Minimum Information about a Biosynthetic Gene cluster (MIBiG) data standard and repository was initiated in 2015. Here, we describe MIBiG version 4.0, an extensive update to the data repository and the underlying data standard.

Nucleic Acids Research. January 2025

Kelsey Cremin, Gabriel N. Meloni, Orkun S. Soyer, Patrick R. Unwin

This work presents an experimental platform combining scanning ion conductance microscopy (SICM) with confocal laser scanning microscopy (CLSM), using intra- and extracellular pH indicator dyes to study the impact of acid delivery on individual HeLa cells within a population.. We find a strong dependency between the intracellular pH and the extracellular pH gradient imposed by local acid delivery. Postdelivery intracellular pH recovery depends on the extent of the acid challenge, with cells exposed to lower pH not returning to basal intracellular pH values after the extracellular pH recovers. This is a unique method for concentration-gradient challenge studies of cell populations that will have broad applications in cell biology. SICM can be used to deliver different chemicals and enables a wide range of local conditions to be applied across a cell population, for which the effects can be investigated at the single-cell level.

ACS Measurement Science. January 2025

Pawel K Lysyganicz, Antonio D Barbosa, Shoily Khondker, Nicolas A Stewart, George M Carman, Phillip J Stansfeld, Marcus K Dymond, Symeon Siniossoglou

Here we demonstrate that a lipid-degradation pathway inhibits expansion of the endoplasmic reticulum (ER) membrane. Phospholipid diacylglycerol acyltransferases (PDATs) use endogenous phospholipids as fatty-acyl donors to generate triglyceride stored in lipid droplets. The significance of this non-canonical triglyceride biosynthesis pathway has remained elusive. We show that active Lro1 mediates retraction of ER membrane expansion driven by phospholipid synthesis. Furthermore, subcellular distribution and membrane turnover activity of Lro1 are controlled by diacylglycerol produced by the activity of Pah1, a conserved member of the lipin family. Collectively, our findings reveal a lipid-metabolic network that regulates endoplasmic reticulum biogenesis by converting phospholipids into storage lipids.

EMBO Journal. January 2025

Structure of the Nipah virus polymerase complex

Esra Balıkçı, Franziska Günl, Loïc Carrique, Jeremy R Keown, Ervin Fodor, Jonathan M Grimes

Nipah virus is a highly virulent zoonotic paramyxovirus causing severe respiratory and neurological disease. Despite its lethality, there is no approved treatment for Nipah virus infection. The viral polymerase complex, composed of the polymerase (L) and phos-phoprotein (P), replicates and transcribes the viral RNA genome. Here, we describe structures of the Nipah virus L-P polymerase complex and the L-protein’s Connecting Domain (CD). Our findings offer insights into the structural details of the L-P polymerase complex and the molecular interactions between L-proteinand P-protein, shedding light on the mechanisms of the replicationmachinery. This work will underpin efforts to develop antiviraldrugs that target the polymerase complex of Nipah virus.

EMBO Journal. December 2024.

Structural characterization of the full-length Hantaan virus polymerase

Hantaviridae are a family of segmented negative-sense RNA viruses that contain important human and animal pathogens. Hantaviridae contain a viral RNA-dependent RNA polymerase that replicates and transcribes the viral genome. Here we establish the expression and purification of the polymerase from the Old World Hantaan virus and characterise the structure using Cryo-EM. The insights gained here guide future mechanistic studies of both the transcription and replication activities of the hantavirus polymerase and for the development of therapeutic targets.

PLoS Pathogens. December 2024

Felipe J Medina-Aguayo, Xavier Didelot, Richard G Everitt

Bacteria reproduce clonally but most species recombine frequently, so that the ancestral process is best captured using an ancestral recombination graph. This graph model is often too complex to be used in an inferential setup, but it can be approximated for example by the ClonalOrigin model. Inference in the ClonalOrigin model is performed via a Reversible-Jump Markov Chain Monte Carlo algorithm, however this often performs poorly due to the complexity of the target distribution since it needs to explore spaces of different dimensions. Recent developments in Bayesian computation methodology have provided ways to improve existing methods and code, but are not well-known outside the statistics community. We show how exploiting one of these new computational methods can lead to faster inference under the ClonalOrigin model.

Bayesian Analysis. December 2024

Diana Vinchira-Villarraga, Sabrine Dhaouadi, Vanja Milenkovic, Jiaqi Wei, Emily R. Grace, Katherine G. Hinton, Amy J. Webster, Andrea Vadillo-Dieguez, Sophie E. Powell, Naina Korotania, Leonardo Castellanos, Freddy A. Ramos, Richard J. Harrison, Mojgan Rabiey & Robert W. Jackson

This study aimed to develop a methodological approach to obtain extracts from different tree species with the highest reproducibility and chemical diversity possible, to ensure proper coverage of the trees’ metabolome. Each tree species has a unique metabolic profile, which means that no single protocol is universally effective. Extraction at 50 °C for three cycles using 80% methanol or chloroform/methanol/water showed the best results and is suggested for studying wood metabolome. These observations highlight the need to tailor extraction protocols to each tree species to ensure comprehensive metabolome coverage for metabolic profiling.

Metabolomics. December 2024

Valeriya Bezkorovayna, Brooke K. Hayes, Francesca N. Gillett, Amy Wright, David I. Roper, Marina Harper, Sheena McGowan, John D. Boyce

Acinetobacter baumannii is a Gram-negative opportunistic pathogen and is a common cause of nosocomial infections.). Here we define the regions of interaction between Tae17 and its cognate delivery protein VgrG17 and identify that amino acids G1069 and W1075 in VgrG17 are essential for Tae17 delivery via the T6SS, the first time such specific delivery determinants of T6SS cargo effectors have been defined. Furthermore, we determine that the Tae17 effector is a multidomain, bifunctional, peptidoglycan-degrading enzyme that has both amidase activity, which targets the sugar-peptide bonds, and lytic transglycosylase activity, which targets the peptidoglycan sugar backbone. Moreover, we show that the Tae17 transglycosylase activity is more important than amidase activity for the killing of Escherichia coli. This study provides molecular insight into how the T6SS allows A. baumannii strains to gain dominance in polymicrobial communities and thus improve their chances of survival and transmission.

mBio. December 2024

The impact of natural climate variability on the global distribution of Aedes aegypti : a mathematical modelling study

Kaye, A. R., Obolski, U., Sun, L., Hart, W. S., Hurrell, J. W., Tildesley, M. J. and Thompson, R. N.

Aedes aegypti spread pathogens affecting humans, including dengue, Zika, and yellow fever viruses. Anthropogenic climate change is altering the spatial distribution of Ae aegypti and therefore the locations at risk of vector-borne disease. In addition to climate change, natural climate variability, resulting from internal atmospheric processes and interactions between climate system components (eg, atmosphere–land and atmosphere–ocean interactions), determines climate outcomes. However, the role of natural climate variability in modifying the effects of anthropogenic climate change on future environmental suitability for Ae aegypti has not been assessed fully. In this study, we aim to assess uncertainty arising from natural climate variability in projections of Ae aegypti suitability up to the year 2100. Lancet Planetary Health. December 2024

The time between symptom onset and various clinical outcomes : a statistical analysis of MERS-CoV patients in Saudi Arabia

Althobaity, Yehya, Alkhudaydi, Muhammad, Hill, Edward M., Thompson, Robin N. and Tildesley, Michael J

In this study, we investigate the impact of demographic characteristics on MERS-CoV cases in Saudi Arabia, specifically focusing on the time intervals between symptom onset and key events such as hospitalization, case confirmation, reporting and death. Importantly, we observe age-based differences in the risk of hospitalization and other measures of infection severity, including the probability of death conditional on hospitalization. Careful quantification of epidemiological characteristics, including inference of key epidemiological periods and assessments of differences between cases of different ages, plays a crucial role in understanding the progression of MERS-CoV outbreaks and formulating effective public health strategies to mitigate their impact.

Royal Society Open Society. November 2024

Kołodziej, Marta, Tsapras, Panagiotis, Cameron, Alexander and Nezis, Ioannis P

LC3 (microtubule-associated protein 1 light chain 3, called Atg8 in yeast and Drosophila) is one of the most well-studied autophagy-related proteins. LC3 controls the selectivity of autophagic degradation by interacting with LIR (LC3-interacting region) motifs also known as AIM (Atg8-interacting motifs) on selective autophagy receptors that carry cargo for degradation. Although the function of Atg8 family proteins is primarily cytoplasmic, they are also enriched in the nucleus. Here, we used yeast two-hybrid screening, and we identified transcription factor Deformed wings (Dwg) as an Atg8a-interacting protein in Drosophila. Dwg-Atg8a interaction is LIR motif-dependent. We have created Dwg Y129A/I132A LIR mutant flies and shown that they exhibit elevated autophagy, improved resistance to oxidative stress, and starvation. Our results provide novel insights into the transcriptional regulation of autophagy in Drosophila.

Cells. November 2024

Claudia Simm, Tzong-Hsien Lee, Harshini Weerasinghe, Dean Walsh, Ioanna T Nakou, Madhu Shankar, Wai Chung Tse, Rebecca Inman, Robert J Mulder, Freya Harrison, Marie-Isabel Aguilar, Gregory L Challis, Ana Traven

Amphotericin B (AmpB) is an effective but toxic antifungal drug.. AmpB disrupts fungal membranes by two proposed mechanisms: ergosterol sequestration from the membrane and pore formation. Whether these two mechanisms operate in conjunction and how they could be potentiated remains to be fully understood. Here, we report that gladiolin, a polyketide antibiotic produced by Burkholderia gladioli, is a strong potentiator of AmpB and acts synergistically against Cryptococcus and Candida species, including drug-resistant C. auris. Gladiolin also synergizes with AmpB against drug-resistant fungal biofilms, while exerting no mammalian cytotoxicity.. Collectively, our findings shed light on AmpB’s mechanism of action and characterize gladiolin as an AmpB potentiator, showing an antifungal mechanism distinct from its proposed antibiotic activity. We shed light on the synergistic mechanism at the membrane, and provide insights into potentiation strategies to improve AmpB’s activity/toxicity relationship.

mBio. November 2024

Chris L B Graham, Jack Bryant, David I Roper, Manuel Banzhaf 

Here we describe a method for in vivo phospholipid labelling by fluorescent imaging in Pseudomonas aeruginosa using a phosphatidylcholine (PC) mimic, “propargyl-choline”(PCho). This click-chemistry liable headgroup mimic is visible by microscopy and allows the covalent labelling of lipids. Fluorescence of the cell membranes, visible in heterogenous patches, is dependent on PCho concentration and is localised in the membrane fraction of cells, demonstrating that it is suitable for membrane labelling and cell imaging.

Access Microbiology. November 2024

Nathan J. Burton, Luís D R. Melo, Michaël F D. Tadesse, Bethany Pearce, Evangelos Vryonis, Antonia P. Sagona

In this study, we produced a cocktail of novel bacteriophages and assessed their viability to eradicate nosocomial staphylococcal biofilms. Here, we used clinical isolates from prosthetic joint infections to isolate and identify four new bacteriophages from sewage effluent. These novel phages were characterized through electron microscopy and full genome sequencing. Subsequently, we combined them into a phage cocktail, which effectively re-sensitized biofilms to vancomycin and flucloxacillin. Notably, this phage cocktail demonstrated low cytotoxicity in vitro to human epithelial cells, even when used alongside antibiotic treatments. These findings highlight the potential of the phage cocktail as a tool to increase antibiotic treatment success in prosthetic joint infections.

Sustainable Microbiology. November 2024

Rawlings, Ngwa Niba, Bailey, Mark, Craig, Peter, Courtenay, Orin

British soldiers undergoing jungle training in Belize typically experience a relatively low risk of developing cutaneous leishmaniasis. However, an uncharacteristically large outbreak of cutaneous leishmaniasis occurred in 2022. This study aimed to determine the cumulative incidence of the disease and highlight potential shortcomings in personal protective measures to mitigate exposure to sand fly vector bites. A retrospective analysis was conducted on medical records of cutaneous leishmaniasis cases between 2005 and 2022, as well as on questionnaire responses regarding personal protective measures administered to cutaneous leishmaniasis cases in 2022. The reasons behind the unusually high numbers of cutaneous leishmaniasis cases and cumulative incidence in 2022 remain unclear, emphasising the need to improve personal protective measures provision and implement a comprehensive health education programme for troops undergoing jungle training in Belize.

Parasite Epidemiology and Control. November 2024

Praneet Prakash, Xue Jiang , Luke Richards, Zoe Schofield, Patrick Schafer Marco Polin, Orkun S. Soyer & Munehiro Asally

Many species of soil fungi grow in the form of branched networks that enable long-range communication and mass flow of nutrient. While there have been investigations on the branching of the fungal networks, their long-term growth dynamics in space and time is still not very well understood. In this study, we monitor the spatio-temporal growth dynamics of the plant-promoting filamentous fungus Serendipita indica for several days in a controlled environment within a microfluidic chamber. We find that S. indica cells display synchronised growth oscillations with the onset of sporulation and at a period of 3 hours. Quantifying this experimental synchronisation of oscillatory dynamics, we show that the synchronisation can be recapitulated by the nearest neighbour Kuramoto model with a millimetre-scale cell-cell coupling.

Royal Society Interface. October 2024

Georgina Benn, Christian Bortolini, David M Roberts, Alice L B Pyne, Seamus Holden, Bart W Hoogenboom

Complement proteins eliminate Gram-negative bacteria in the blood via the formation of membrane attack complex (MAC) pores in the outer membrane. However, it remains unclear how outer membrane poration leads to inner membrane permeation and cell lysis. Using atomic force microscopy (AFM) on living Escherichia coli (E. coli), we probed MAC-induced changes in the cell envelope and correlated these with subsequent cell death. We conclude that bacterial cell lysis is only an indirect effect of MAC formation; outer membrane poration leads to mechanical destabilization of the cell envelope, reducing its ability to contain the turgor pressure, leading to inner membrane permeation and cell death.

EMBO Journal. October 2024

Luke Richards, Kelsey Cremin, Mary Coates, Finley Vigor, Patrick Schäfer, and Orkun S Soyer

Soil microbial communities host a large number of microbial species that support important ecological functions such as biogeochemical cycling and plant nutrition. The extent and stability of these functions are affected by inter-species interactions among soil microorganisms, yet the different mechanisms underpinning microbial interactions in the soil are not fully understood. Here, we study the extent of nutrient-based interactions among two model, plant-supporting soil microorganisms, the fungi Serendipita indica, and the bacteria Bacillus subtilis. Our findings highlight that ammonia based N-sharing can be a previously under-appreciated mechanism underpinning interaction among soil microorganisms and could be influenced by microbial or abiotic alteration of pH in microenvironments.

ISME Journal. September 2024

Keeling, Matthew James and Dyson, Louise

We discuss the invasion of the Omicron BA.1 variant into England as a paradigm for real-time model fitting and projection. Here we use a mixture of simple SIR-type models, analysis of the early data and a more complex age-structure model fit to the outbreak to understand the dynamics. In particular, we highlight that early data shows that the invading Omicron variant had a substantial growth advantage over the resident Delta variant. However, early data does not allow us to reliably infer other key epidemiological parameters - such as generation time and severity - which influence the expected peak hospital numbers. With more complete epidemic data from January 2022 are we able to capture the true scale of the epidemic in terms of both infections and hospital admissions, driven by different infection characteristics of Omicron compared to Delta and a substantial shift in estimated precautionary behaviour during December. This work highlights the challenges of real time forecasting, in a rapidly changing environment with limited information on the variant’s epidemiological characteristics.

PLoS Computational Biology. September 2024

Matthew Higgins, Mojca Kristan, Emma L. Collins, Louisa A. Messenger, Jamille G. Dombrowski, Leen N. Vanheer, Debbie Nolder, Christopher J. Drakeley, William Stone, Almahamoudou Mahamar, Teun Bousema, Michael Delves, Janvier Bandibabone, Sévérin N’Do, Chimanuka Bantuzeko, Bertin Zawadi, Thomas Walker, Colin J. Sutherland, Claudio R. F. Marinho, Mary M. Cameron, Taane G. Clark & Susana Campino

Malaria caused by neglected Plasmodium parasites is often underestimated due to the lack of rapid diagnostic tools that can accurately detect these species. Here, we present a Pan Plasmodium recombinase polymerase amplification lateral flow (RPA–LF) assay, capable of detecting all six human infecting Plasmodium species in low resource settings.. When combined with crude nucleic acid extraction, the assay can serve as a point-of-need tool for molecular xenomonitoring. This utility was demonstrated by screening laboratory-reared Anopheles stephensi mosquitoes fed with Plasmodium-infected blood, as well as field samples of An. funestus s.l. and An. gambiae s.l. collected from central Africa. Overall, our proof-of-concept Pan Plasmodium diagnostic tool has the potential to be applied for clinical and xenomonitoring field surveillance, and after further evaluation, could become an essential tool to assist malaria control and elimination.

Scientific Reports. August 2024

de Klerk, Joanna N., Tildesley, Michael J., Labuschagne, Karien and Gorsich, Erin E

Culicoides biting midges exhibit a global spatial distribution and are the main vectors of several viruses of veterinary importance, including bluetongue (BT) and African horse sickness (AHS). The aim of this study was to model distributions for two primary vectors for BT and AHS (Culicoides imicola and Culicoides bolitinos) using random forest (RF) machine learning and explore the relative importance of environmental and anthropological factors in a region of South Africa with frequent AHS and BT outbreaks. This study yielded novel insight into the spatial abundance and drivers of abundance of competent vectors of BT and AHS. It also provided valuable data to inform mathematical models exploring disease outbreaks so that Culicoides-transmitted diseases in South Africa can be further analysed.

Parasites & Vectors. August 2024

Christian Vanhille-Campos, Kevin D. Whitley, Philipp Radler, Martin Loose, Seamus Holden & Anđela Šarić

Filaments in the cell commonly treadmill. Driven by energy consumption, they grow on one end while shrinking on the other, causing filaments to appear motile even though individual proteins remain static. This process is characteristic of cytoskeletal filaments and leads to collective filament self-organization. Here we show that treadmilling drives filament nematic ordering by dissolving misaligned filaments. Taking the bacterial FtsZ protein involved in cell division as an example, we show that this mechanism aligns FtsZ filaments in vitro and drives the organization of the division ring in living Bacillus subtilis cells. We find that ordering via local dissolution also allows the system to quickly respond to chemical and geometrical biases in the cell, enabling us to quantitatively explain the ring formation dynamics in vivo. Beyond FtsZ and other cytoskeletal filaments, our study identifies a mechanism for self-organization via constant birth and death of energy-consuming filaments.

Nature Physics. August 2024

Huba L. Marton, Antonia P. Sagona, Peter Kilbride and Matthew I. Gibson

Poly(carboxylic acids) have been reported to inhibit phages’ ability to infect their bacterial hosts and hence offer an exciting route to discover additives to prevent infection. Here, we report the role of pH in inactivating phages to determine if the polymers are unique or simply acidic. It is shown that lower pH (= 3) triggered by either acidic polymers or similar changes in pH using HCl lead to inhibition. There is no inhibitory activity at higher pHs (in growth media). It is also shown that poly(acrylic acid) leads to reversible deactivation of phage, but when the pH is adjusted using HCl alone the phage is irreversibly deactivated. Further experiments using metal binders ruled out ion depletion as the mode of action.  These results show that polymeric phage inhibitors may work by unique mechanisms of action and that pH alone cannot explain the observed effects whilst also placing constraints on the practical utility of poly(acrylic acid).

RSC Applied Polymers. August 2024

Prioritising older individuals for COVID-19 booster vaccination leads to optimal public health outcomes in a range of socio-economic settings

Bouros, Ioana, Hill, Edward M., Keeling, Matt J., Moore, Sam and Thompson, Robin N.

The rapid development of vaccines against SARS-CoV-2 altered the course of the COVID-19 pandemic. In most countries, vaccinations were initially targeted at high-risk populations, including older individuals and healthcare workers. Policy makers must now determine how to deploy booster vaccinations, particularly when constraints in vaccine supply, delivery and cost mean that booster vaccines cannot be administered to everyone. A key question is whether older individuals should again be prioritised for vaccination, or whether alternative strategies (e.g. offering booster vaccines to the individuals who have most contacts with others and therefore drive infection) can instead offer indirect protection to older individuals. Here, we use mathematical modelling to address this question, considering SARS-CoV-2 transmission in a range of countries with different socio-economic backgrounds. We show that the population structures of different countries can have a pronounced effect on the impact of booster vaccination, even when identical booster vaccination targeting strategies are adopted. However, under the assumed transmission model, prioritising older individuals for booster vaccination consistently leads to the most favourable public health outcomes in every setting considered. PLoS Computational Biology. August 2024

Modelling timelines to elimination of sleeping sickness in the Democratic Republic of Congo, accounting for possible cryptic human and animal transmission

Sleeping sickness (gambiense human African trypanosomiasis, gHAT) is a vector-borne disease targeted for global elimination of transmission (EoT) by 2030. There are, however, unknowns that have the potential to hinder the achievement and measurement of this goal. These include asymptomatic gHAT infections (inclusive of the potential to self-cure or harbour skin-only infections) and whether gHAT infection in animals can contribute to the transmission cycle in humans. Using modelling, we explore how cryptic (undetected) transmission impacts the monitoring of progress towards and the achievement of the EoT goal. This study is the first to simulate an (as-yet-to-be available) screen-and-treat strategy and found that removing a parasitological confirmation step was predicted to have a more noticeable benefit to transmission reduction under the asymptomatic model compared with the others. Our simulations suggest vector control could greatly impact all transmission routes in all models, although this resource-intensive intervention should be carefully prioritised. Parasites & Vectors. August 2024

Collette S. Guy, James A. Gott, Jonathan Ramírez-Cárdenas, Christopher de Wolf, Christopher M. Furze, Geoff West, Juan C. Muñoz-García, Jesus Angulo and Elizabeth Fullam 

The sensitive, rapid and accurate diagnosis of Mycobacterium tuberculosis (Mtb) infection is a central challenge in controlling the global tuberculosis (TB) pandemic. Yet the detection of mycobacteria is often made difficult by the low sensitivity of current diagnostic tools, with over 3.6 million TB cases missed each year. To overcome these limitations there is an urgent need for next-generation TB diagnostic technologies. Here we report the use of a discrete panel of native 19F-trehalose (F-Tre) analogues to label and directly visualise Mtb by exploiting the uptake of fluorine-modified trehalose analogues via the mycobacterial trehalose LpqY-SugABC ATP-binding cassette (ABC) importer.. This rapid one-step labelling approach facilitates the direct visualisation of F-Tre-labelled Mtb by Focused Ion Beam (FIB) Secondary Ion Mass Spectrometry (SIMS), enabling detection of the Mtb pathogen. Collectively, our findings highlight that F-Tre analogues have potential as tools to probe and unravel Mtb biology and can be exploited to detect and image TB

Chemical Science.August 2024

Peter Wotherspoon, Hannah Johnston, David J. Hardy, Rachel Holyfield, Soi Bui, Giedrė Ratkevičiūtė, Pooja Sridhar, Jonathan Colburn, Charlotte B. Wilson, Adam Colyer, Benjamin F. Cooper, Jack A. Bryant, Gareth W. Hughes, Phillip J. Stansfeld, Julien R. C. Bergeron & Timothy J. Knowles

The Maintenance of Lipid Asymmetry (Mla) pathway is a multicomponent system found in all gram-negative bacteria that contributes to virulence, vesicle blebbing and preservation of the outer membrane barrier function. Here, we report the structure of E. coli MlaC in complex with the MlaD hexamer in two distinct stoichiometries. Utilising in vivo complementation assays, an in vitro fluorescence-based transport assay, and molecular dynamics simulations, we confirm key residues, identifying the MlaD β6-β7 loop as essential for MlaCD function. We also provide evidence that phospholipids pass between the C-terminal helices of the MlaD hexamer to reach the central pore, providing insight into the trajectory of GPL transfer between MlaC and MlaD.

Nature Communications. July 2024

Behzad Dehghani, Christopher D. A. Rodrigues

During spore development in bacteria, a polar septum separates two transcriptionally distinct cellular compartments, the mother cell and the forespore. The conserved serine phosphatase SpoIIE is known for its critical role in the formation of this septum and activation of compartment-specific transcription in the forespore. Signaling between the mother cell and forespore then leads to activation of mother cell transcription and a phagocytic-like process called engulfment, which involves dramatic remodeling of the septum and requires a balance between peptidoglycan synthesis and hydrolysis to ensure septal stability and compartmentalization. Using Bacillus subtilis, we identify an additional role for SpoIIE in maintaining septal stability and compartmentalization at the onset of engulfment. Our data support a model whereby SpoIIE and its interactions with the peptidoglycan synthetic machinery contribute to the stabilization of the asymmetric septum early in engulfment, thereby ensuring compartmentalization during spore development.

Journal of Bacteriology. July 2024

Michelle Kendall, Luca Ferretti, Chris Wymant, Daphne Tsallis, James Petrie, Andrea di Francia, Franceso di Lauro, Lucie Abeler-Dorner, Harrison Manley, Jasmina Panovska-Griffiths, Alice Ledda, Xavier Didelot and Christophe Fraser

Understanding the drivers of respiratory pathogen spread is challenging, particularly in a timely manner during an ongoing epidemic. Here we present insights obtained using daily data from the NHS COVID-19 app for England and Wales and shared with health authorities in almost real time. Our indicator of the reproduction number R(t) was available days earlier than other estimates, with a novel capability to decompose R(t) into contact rates and probabilities of infection. When Omicron arrived, the main epidemic driver switched from contacts to transmissibility. We separate contacts and transmissions by day of exposure and setting, finding pronounced variability over days of the week and during Christmas holidays and events. As an example, during the Euro football tournament in 2021, days with England matches showed sharp spikes in exposures and transmissibility. Digital contact tracing technologies can help control epidemics not only by directly preventing transmissions but also by enabling rapid analysis at scale and with unprecedented resolution.  

Science. July 2024