Latest Publications
Controlling endemic foot-and-mouth disease: Vaccination is more important than movement bans. A simulation study in the Republic of Turkey
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.
Knockout of fatty acid elongase1 homeoalleles in amphidiploid Brassica juncea leads to undetectable erucic acid in seed oil
Nelesh Patra , Guy C. Barker , Mrinal K. Maiti
Indian mustard (Brassica juncea L.) seed oil offers valuable dietary benefits due to a balanced ratio of human essential fatty acids, the traditional high oil-yielding varieties contain an elevated level of erucic acid (EA, C22:1) associated with adverse health effects. Therefore, developing low erucic acid (LEA) mustard cultivars is crucial for broader utilization and consumer safety. In this study, CRISPR/Cas9 genome editing tool was employed to disrupt the fatty acid elongase1 (FAE1) gene that encodes a key enzyme in EA biosynthesis in two high erucic acid (HEA) B. juncea cultivars, PCR7 (∼39% EA) and JD6 (∼45% EA). Our findings underscore the effectiveness of CRISPR/Cas9 technology for editing B. juncea genome, developing plant lines producing LEA seed oil with improved nutritional quality and broadening the utility of this important oilseed crop for food and non-food applications.
Phylodynamic analysis of a prolonged meningococcal epidemic reveals multiple introductions and pre-epidemic expansion
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.
Piperideine-6-carboxylic acid regulates vitamin B6 homeostasis and modulates systemic immunity in plants
Huazhen Liu, Lakshminarayan M. Iyer, Paul Norris, Ruiying Liu, Keshun Yu, Murray Grant, L. Aravind, Aardra Kachroo & Pradeep Kachroo
Dietary consumption of lysine in humans leads to the biosynthesis of Δ1-piperideine-6-carboxylic acid (P6C), with elevated levels linked to the neurological disorder epilepsy. Here we demonstrate that P6C biosynthesis is also a critical component of lysine catabolism in Arabidopsis thaliana. P6C regulates vitamin B6 homeostasis, and increased P6C levels deplete B6 vitamers, resulting in compromised plant immunity. We further establish a key role for pyridoxal and pyridoxal-5-phosphate biosynthesis in plant immunity. Our analysis indicates that P6C metabolism probably evolved through combining select lysine and proline metabolic enzymes horizontally acquired from diverse bacterial sources at different points during evolution. More generally, certain enzymes from the lysine and proline metabolic pathways were probably recruited in evolution as potential guardians of B6 vitamers and for semialdehyde detoxification.
International Consortium to Classify Ageing related Pathologies (ICCARP) senescence defnitions: achieving international consensus
Emma Short, Robert T.R. Huckstepp et al
It is paramount that the language used in the scienitifc and medical literature is clear and unambiguous to ensure shared understanding amongst researchers, clinicians, and policymakers. The aim of the ICCARP is to develop a systematic and comprehensive classifcation system for ageingrelated changes including pathologies, diseases, and syndromes. Currently, the ICCARP is in the process of identifying all phenomena that meet the criteria for ageing-related pathologies, to develop proposals for grouping and naming them within a comprehensive classification system. We expect that these defnitions, and subsequent classifcations, will contribute to improving discourse, research methodologies, clinical diagnostics, and public health planning.
Quantifying infectious disease epidemic risks: A practical approach for seasonal pathogens
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.