Biology subjects

Manzano-Alvarez, J.

Publications and source records attributed to Manzano-Alvarez, J..

4 recordsLinked to original sources

bioRxiv2025

Effect of prolonged dehydration stress on the vector competence of Aedes aegypti for Mayaro virus

Aedes aegypti is a competent vector for a variety of mosquito-borne viruses including Zika, chikungunya, Mayaro, yellow fever, and dengue, which cause debilitating diseases in animals and humans. It is highly invasive and is widely distributed across Asia, Europe, Oceania, and the Americas. Climatic factors such as relative humidity (RH) can have substantial effects on mosquito biological characteristics and the dynamics of pathogen spread. Low RH leads to dehydration in mosquitoes causing modifications in behavioral and physiological responses pertaining to pathogen spread, such as host-seeking behavior and blood-feeding patterns. Here, we evaluated the effects of prolonged dehydration stress on Mayaro virus infection and vector competence in Ae. aegypti mosquitoes. Our findings suggest that prolonged dehydration stress following Mayaro virus infection alters viral dissemination dynamics in mosquitoes, indicating that humidity may modulate intra-vector viral dissemination potentially impacting vector competence and pathogen spread. The previously observed effects of higher feeding and altered survival and our current observations on altered vector competence suggest that the impact of dehydration on viral transmission is expected to be complex and will be crucial to understanding the dynamic disease patterns of mosquito-borne viruses across diverse climatic conditions.

microbiology↗

bioRxiv2025

Virome profiling of Culex tarsalis through small RNA-seq: A challenge of suboptimal samples

Viral infections in mosquitoes trigger the RNA interference (RNAi) pathway, a key antiviral defense mechanism that generates virus-derived small RNAs (vsRNAs). Given the natural enrichment of vsRNAs during infection and their stability, small RNA sequencing (sRNA-seq) has emerged as a powerful tool for virome characterization. Culex tarsalis is a widely distributed mosquito species in North America and is an important vector of West Nile virus (WNV). Previous studies have shown that co-infection with insect-specific viruses (ISVs) can modulate WNV replication in Cx. tarsalis, highlighting the importance of characterizing the virome of this species. Here, we investigated the virome of Cx. tarsalis populations across 5 states of the Midwestern United States using sRNA-seq. We analyzed samples from 17 geographic locations which were collected under suboptimal field conditions during the COVID-19 pandemic, presenting challenges related to sample integrity. Despite these challenges, sRNA-seq proved to be a reliable method for virome analysis. We identified seven viruses associated with Cx. tarsalis, along with their respective sRNA (siRNA and piRNA) profiles. These findings not only deepen our understanding of ISVs, but also demonstrate the utility of sRNA-seq in non-ideal situations, enabling the collection and analysis of samples under real-world surveillance scenarios.

microbiology↗

bioRxiv2023

Temperature affects viral kinetics and vectorial capacity of Aedes aegypti mosquitoes co-infected with Mayaro and Dengue viruses

Increasing global temperatures and unpredictable climatic extremes have contributed to the spread of vector-borne diseases. The mosquito Aedes aegypti is the main vector of multiple arboviruses that negatively impact human health, mostly in low socioeconomic areas of the world. Co-circulation and co-infection of these viruses in humans have been increasingly reported; however, how vectors contribute to this alarming trend remains unclear. Here, we examine single and co-infection of Mayaro virus (-D strain, Alphavirus) and dengue virus (serotype 2, Flavivirus) in Ae. aegypti adults and cell lines at two constant temperatures, moderate (27{degrees}C) and hot (32{degrees}C), to quantify vector competence and the effect of temperature on infection, dissemination and transmission, including on the degree of interaction between the two viruses. Both viruses were primarily affected by temperature but there was a partial interaction with co-infection. Dengue virus quickly replicates in adult mosquitoes, with a tendency for higher titers in co-infected mosquitoes at both temperatures and mosquito mortality was more severe at higher temperatures in all conditions. For dengue, and to a lesser extent Mayaro, vector competence and vectorial capacity were higher at hotter temperature in co- vs single infections and was more evident at earlier timepoints (7 vs 14 days post infection). The temperature-dependent phenotype was confirmed in vitro by faster cellular infection and initial replication at higher temperatures for dengue but not for Mayaro virus. Our study suggests that contrasting kinetics of the two viruses could be related to their intrinsic thermal requirements, where alphaviruses thrive better at lower temperatures compared to flaviviruses, but further studies are necessary to clarify the role of co-infection at different and variable temperature regimes. Author summaryGlobal warming is having devastating consequences for the environment, and a cause of concern is the increase in local abundance and geographic range of mosquitoes and the associated viruses they transmit. This study explores how temperature affects the mosquitos ability to survive and potentially spread two viruses, Mayaro and dengue, in single or co-infections. We found that Mayaro virus was not clearly affected by temperature or the presence of dengue infection. In contrast, dengue virus showed higher infection and potential for higher transmission in mosquitoes kept at high temperatures, and this trend was stronger in co-infections compared to single infections. Mosquito survival consistently decreased at high temperatures. We hypothesize the differences observed for dengue virus are due to the faster growth and viral activity in the mosquito at hotter temperatures, a pattern not observed for Mayaro virus. More studies under different temperature regimes are needed to clarify the role of co-infection.

microbiology↗

bioRxiv2023

Dehydration stress and Mayaro virus vector competence in Aedes aegypti

The mosquito Aedes aegypti is a competent vector of multiple pathogens including dengue, Zika, yellow fever, chikungunya, and Mayaro viruses. Ae. aegypti is highly invasive and is currently present in the Americas, Oceania, Asia, and Europe, but its distribution and the pathogens it transmits are expected to change due to climate change. Relative humidity is an environmental variable that affects mosquito biology and distribution and can differ between location, habitat, and season, with mosquitoes facing significant variation in relative humidity during their lifespan. Low relative humidity can induce dehydration in mosquitoes, leading to alterations in physiological and behavioral responses relevant for pathogen transmission such as bloodfeeding and host-seeking behavior. In this study, we evaluated the short and long-term effects of dehydration stress on mortality and Mayaro virus vector competence in Ae. aegypti. Our results show that exposure to dehydration does not impact viral titers, nor infection, dissemination and transmission rates, in mosquitoes infected with Mayaro virus. However, we detected a significant effect of dehydration on mosquito mortality and blood feeding frequency regardless of infection status. The previously observed effects of higher feeding during dehydration and the current observation of altered survival along with no impact on vector competence suggest that the impact of dehydration on viral transmission in mosquitoes will likely be complex.

microbiology↗