Microbiota composition of Culex perexiguus mosquitoes during the West Nile virus outbreak in southern Spain.
Authors: Garrigós Marta, Garrido Mario, Ruiz-López María José, García-López María José, Veiga Jesús, Magallanes Sergio, Soriguer Ramón, Moreno-Indias Isabel, Figuerola Jordi, Martínez-de la Puente Josué
Journal: PloS one
Summary
# West Nile Virus and Mosquito Microbiota: What We've Learned from Spain's 2020 Outbreak Following Spain's significant West Nile virus outbreak in 2020—which affected 77 people and resulted in 8 deaths, predominantly in the south—researchers investigated whether the bacterial microbiota composition of *Culex perexiguus*, the primary WNV vector in the region, might influence viral transmission. Using 16S rRNA gene metabarcoding on wild-caught mosquitoes from the outbreak area, they characterised the microbial communities and compared WNV-positive and WNV-negative populations, seeking correlations between microbiota structure and infection status. The *Cx. perexiguus* microbiota was dominated by Proteobacteria, particularly Burkholderiaceae and Erwiniaceae families, though notably *Wolbachia*—a genus known to suppress WNV replication in other *Culex* species—showed only low prevalence and abundance with no significant difference between infected and uninfected mosquitoes. Contrary to observations in other mosquito vectors, neither overall microbiota diversity nor compositional differences were significantly associated with WNV infection status in this population. For equine professionals managing disease risk, these findings suggest that microbiota-based interventions (such as *Wolbachia* introduction strategies) may have limited applicability to *Cx. perexiguus* populations in endemic WNV regions, though continued surveillance of vector biology remains essential for understanding outbreak dynamics and informing control strategies.
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Practical Takeaways
- •This research identifies natural mosquito vector microbiota composition but does not establish a causal link to disease transmission in equine or human populations
- •The absence of protective Wolbachia in Cx. perexiguus may contribute to its efficiency as a WNV vector, but this study does not provide actionable interventions for equine practitioners
- •Understanding vector microbiota may eventually inform disease prevention strategies, but current findings require further translational research before practical application
Key Findings
- •Culex perexiguus microbiota is dominated by Proteobacteria, with Burkholderiaceae and Erwiniaceae as most abundant families
- •Wolbachia genus had low prevalence and abundance in Cx. perexiguus compared to other Culex species
- •Microbiota diversity and composition showed no significant relationship with WNV infection status in mosquito pools