Biology subjects

Rapti, Z.

Publications and source records attributed to Rapti, Z..

3 recordsLinked to original sources

bioRxiv2024

Spatiotemporal, environmental, and behavioral predictors of Varroa mite intensity in managed honey bee apiaries

Honey bees contribute substantially to the world economy through pollination services and honey production. In the U.S. alone, honey bee pollination is estimated to contribute at least $11 billion annually, primarily through the pollination of specialty crops. However, beekeepers lose about half of their hives every season due to disease, insecticides, and other environmental factors. Here, we explore and validate a spatiotemporal statistical model of Varroa destructor mite burden (in mites/300 bees) in managed honey bee colonies, exploring the impact of both environmental factors and beekeeper behaviors. We examine risk factors for Varroa infestation using apiary inspection data collected across the state of Illinois over 2018-19, and we test the models using inspection data from 2020-21. After accounting for spatial and temporal trends, we find that environmental factors (e.g., floral quality, insecticide load) are not predictive of Varroa intensity, while several beekeeper behaviors (e.g., smaller colony density, supplemental feeding, and mite monitoring/treatment) are protective against Varroa. Interestingly, while monitoring and treating for Varroa is protective, treating without monitoring is no more effective than not treating at all. This is an important result supporting Integrated Pest Management (IPM) approaches. Author SummaryHoney bees contribute substantially to the world economy through pollination services and honey production. However, beekeepers lose about half of their hives every season due to disease, insecticides, and other environmental factors. Pathogens, such as Varroa mites and the viruses they vector, are especially detrimental to colony health, and best practices for pest management remain contentious. In this study, we model Varroa destructor mite burden in managed honey bee colonies using apiary inspection data collected across the state of Illinois from 2018 - 2021. Our modelling approach accounts for both spatial and temporal trends, allowing us to investigate the marginal impacts of environmental factors and beekeeper interventions on mite burden. We show that treating for Varroa mites has a protective effect only when accompanied by a monitoring strategy, important evidence in favor of Integrated Pest Management (IPM) approaches.

ecology↗

bioRxiv2023

Phage-mediated resolution of genetic conflict alters the evolutionary trajectory of Pseudomonas aeruginosa lysogens

The opportunistic human pathogen Pseudomonas aeruginosa is naturally infected by a large class of temperate, transposable, Mu-like phages. We examined the genotypic and phenotypic diversity of P. aeruginosa PA14 populations as they resolve CRISPR autoimmunity, mediated by an imperfect CRISPR match to the Mu-like DMS3 prophage, and show that lysogen evolution is profoundly impacted by CRISPR autoimmunity and phage transposition around the chromosome. After 12 days of evolution, we measured a decrease in spontaneous induction in both exponential and stationary phase growth. Co-existing variation in spontaneous induction rates in exponential phase corresponded to a difference in the type of CRISPR self-targeting resolution, mediated either by host mutation or phage transposition. Multiple mutational modes to resolve genetic conflict between host and phage resulted in coexistence in evolved populations of single lysogens that maintained CRISPR immunity to other phages and polylysogens that have lost immunity completely. This work highlights a new dimension of the role of lysogenic phages in the evolution of their hosts. ImportanceThe chronic opportunistic multi-drug resistant pathogen Pseudomonas aeruginosa is persistently infected by temperate phages. We assess the contribution of temperate phage infection to the evolution of the clinically relevant strain UCBPP-PA14. We found that a low level of CRISPR-mediated self-targeting resulted in polylysogeny evolution and large genome rearrangements in lysogens; we also found extensive diversification in CRISPR spacers and cas genes. These genomic modifications resulted in decreased spontaneous induction in both exponential and stationary phase growth, increasing lysogen fitness. This work shows the importance of considering latent phage infection in characterizing the evolution of bacterial populations.

microbiology↗

bioRxiv2019

Modeling the control of bacterial infections via antibiotic-induced proviruses

Most bacteria and archaea are infected by latent viruses that change their physiology and responses to environmental stress. We use a population model of the bacteria-phage relationship to examine the role that latent phage play on the bacterial population over time in response to antibiotic treatment. We demonstrate that the stress induced by antibiotic administration, even if bacteria are resistant to killing by antibiotics, is sufficient to control the infection under certain conditions. This work expands the breadth of understanding of phage-antibiotic synergy to include both temperate and chronic viruses persisting in their latent form in bacterial populations.\n\nImportanceAntibiotic-resistance is a growing concern for management of common bacterial infections. Here we show that antibiotics can be effective at sub-inhibitory levels when bacteria carry latent phage. Our findings suggest that specific treatment strategies based on the identification of latent viruses in individual bacterial strains may be an effective personalized medicine approach to antibiotic stewardship.

ecology↗