Publications

3841

Abstract Understanding vector dispersal capacity is key to assessing the risk of spread of vector borne pathogens. For flying vectors, flight performance is associated with primary and secondary pathogen spread. However, because pathogens induce changes in vector physiology, pathogen status in the vector may impact vector dispersal. In this work, by using flight mills, we assessed the flight performance of Bactericera cockerellithat were infected or not by the plant pathogenic bacterium ‘CandidatusLiberibacter solanacearum’ (CLso), the causal agent of potato zebra chip disease and vein greening in tomato. Bactericera cockerelliperformed short and long-distance flights, but CLso infection status affected the propensity to engage in long flights. CLso-free insects engaged in long flights significantly more often (57%) compared to CLso infected insects (25%). Average distance dispersed for long flyers was 185.33 m for CLso-free insects and 122.99 m for insects infected with CLso. However, distance dispersed was not statistically different by pathogen status of the vector. Maximal flight capacity recorded was 980 m. Overall, our data suggest that CLso reduces the propensity to engage in long distance flights. Our results can be utilized to fine-tune strategies to mitigate CLso establishment in new areas.

AbstractThiovulum spp. (Campylobacterota) are large sulfur bacteria that form veil-like structures in aquatic environments. The sulfidic Movile Cave (Romania), sealed from the atmosphere for ~5 million years, has several aqueous chambers, some with low atmospheric O2 (~7%). The cave’s surface-water microbial community is dominated by bacteria we identified as Thiovulum. We show that this strain, and others from subsurface environments, are phylogenetically distinct from marine Thiovulum. We assembled a closed genome of the Movile strain and confirmed its metabolism using RNAseq. We compared the genome of this strain and one we assembled from public data from the sulfidic Frasassi caves to four marine genomes, including Candidatus Thiovulum karukerense and Ca. T. imperiosus, whose genomes we sequenced. Despite great spatial and temporal separation, the genomes of the Movile and Frasassi Thiovulum were highly similar, differing greatly from the very diverse marine strains. We concluded that cave Thiovulum represent a new species, named here Candidatus Thiovulum stygium. Based on their genomes, cave Thiovulum can switch between aerobic and anaerobic sulfide oxidation using O2 and NO3- as electron acceptors, the latter likely via dissimilatory nitrate reduction to ammonia. Thus, Thiovulum is likely important to both S and N cycles in sulfidic caves. Electron microscopy analysis suggests that at least some of the short peritrichous structures typical of Thiovulum are type IV pili, for which genes were found in all strains. These pili may play a role in veil formation, by connecting adjacent cells, and in the motility of these exceptionally fast swimmers.

The article demonstrates the results of the molecular analysis of 'Candidatus Phytoplasma solani' presence in some weed species, possible reservoirs of infection. During the study, the optimal conditions for the determination of phytoplasma in weeds were selected. The research was carried out over three years. The presence of the pathogen 'Ca. P. solani' was found in the plants of Solanum nigrum and Convolvulus arvense. Also, as a result of the study, it was established that the method of isolation by boiling in alkaline solution is the most efficient and allows to obtain truthful results compared to other methods used.