Biology subjects

Lazaro, E.

Publications and source records attributed to Lazaro, E..

3 recordsLinked to original sources

bioRxiv2025

Regolith as a Refuge: Differential Survival of Bacteriophage Qβ in Mars-Analog Environments

Viruses are among the simplest biological entities capable of replication. Their robustness and adaptability make them relevant not only to terrestrial ecosystems but also to astrobiological exploration. As durable entities, they may persist in environments far harsher than those tolerable to cellular life and are likely candidates for forward contamination. To assess their relevance in planetary protection and as potential biomarkers, we investigated the preservation of bacteriophage Q{beta}, an RNA virus, in Mars-analog environments using two commercial Martian regolith simulants: MGS-1 and MMS-2. MMS-2, enriched in iron oxides, exhibited higher oxidative potential than MGS-1, which is mainly composed of basaltic material. Viral survival was assessed across variables including time, temperature, concentration, and particle size. Our results show that inactivation in MGS-1 was primarily driven by adsorption, while in MMS-2 it was dominated by chemical oxidation. MGS-1 provided a more protective matrix, mitigating freeze-induced damage and shielding desiccated viral particles from UV-B and UV-C radiation. These findings highlight the importance of mineral composition in modulating viral persistence and suggest that regolith may act as both a barrier and a refuge. Understanding virus-mineral interactions is essential for assessing biosignature preservation, planetary protection, and the potential roles of viruses in the evolution and survival of life beyond Earth.

microbiology↗

bioRxiv2024

Developing epidemiological preparedness for a plant disease invasion: modelling citrus huanglongbingin the European Union

Huanglongbing (HLB; citrus greening) is the most damaging disease of citrus worldwide. While citrus production in the USA and Brazil have been affected for decades, HLB has not been detected in the European Union (EU). However, psyllid vectors have already invaded and spread in Portugal and Spain, and in 2023 the psyllid species known to vector HLB in the Americas was first reported within the EU. We develop a landscape-scale, epidemiological model, accounting for heterogeneous citrus cultivation and vector dispersal, as well as climate and disease management. We use our model to predict HLB dynamics following introduction into high-density citrus areas in Spain, assessing detection and control strategies. Even with significant visual surveillance, we predict any epidemic will be widespread on first detection, with eradication unlikely. Introducing increased inspection and roguing following first detection, particularly if coupled with intensive insecticide use, could potentially sustain citrus production for some time. However, this may require chemical application rates that are not permissible in the EU. Disease management strategies targeting asymptomatic infection will likely lead to more successful outcomes. Our work highlights modelling as a key component of developing epidemiological preparedness for a pathogen invasion that is, at least somewhat, predictable in advance.

ecology↗

bioRxiv2020

Tracking the outbreak. An optimized delimiting survey strategy for Xylella fastidiosa.

O_LICurrent legislation enforces the implementation of intensive surveillance programs for quarantine plant pathogens. After an outbreak, surveys are implemented to delimit the geographic extent of the pathogen and execute disease control. The feasibility of control programs is highly dependent on budget availability, thus it is necessary to target and optimize surveillance strategies. C_LIO_LIA sequential adaptive delimiting survey involving a three-phase and a two-phase design with increasing spatial resolution was developed and implemented for the Xylella fastidiosa outbreak in Alicante, Spain. Inspection and sampling intensities were optimized using simulation-based methods and results were validated using Bayesian spatial models. C_LIO_LIThis strategy made it possible to sequence inspection and sampling considering different spatial resolutions, and to adapt the inspection and sampling intensity according to the information obtained in the previous, coarser, spatial resolution. C_LIO_LIThe proposed strategy was able to delimit efficiently the extent of Xf improving efficiency of the current in terms of survey efforts. From a methodological perspective, our approach provides new insights of alternative delimiting designs and new reference sampling intensity values. C_LI

pathology↗