# Study of Bacterial Communities in Water and Different Developmental Stages of Aedes aegypti from Aquatic Breeding Sites in Leticia City, Colombian Amazon Biome

## TL;DR

This study explores how bacteria in water and Aedes aegypti mosquitoes interact in the Amazon, linking environmental factors to mosquito development and disease transmission.

## Contribution

The study identifies key bacterial genera and physicochemical markers in Aedes aegypti breeding sites, offering insights for biological vector control strategies.

## Key findings

- Bacterial genera like Ottowia, Xanthobacter, and Rhodocyclaceae dominate breeding site water.
- Physicochemical variables like dissolved oxygen and conductivity correlate with bacterial community profiles.
- Distinct bacterial communities are found in different developmental stages of Aedes aegypti.

## Abstract

The number of arboviral diseases, such as dengue, that are transmitted in the Amazon basin has significantly increased during the last 3 years, with its control becoming more complex as the environmental plasticity and geographical distribution of vectors such as Aedes aegypti also increase. Likewise, bacterial communities have favored rapid adaptation to environmental changes at different developmental stages. This problem, from an ecological context, raises the need to generate new knowledge regarding the influence of physicochemical parameters of water and the microbial diversity that are related to the type of artificial breeding sites, and how these interactions can impact the life cycle of Ae. aegypti. In the present study, a high richness in bacteria genera from Ae. aegypti breeding sites and developmental stages was observed. Some of these genera have biotechnological, entomopathogenic, or antiviral potential. Additionally, we found a close relationship between the bacterial composition profile in the water body and the physicochemical characteristics of the different types of breeding sites. The information derived from this study allowed us to describe the dissolved oxygen, conductivity, and total dissolved solids as key ecological markers associated with the breeding sites from the Amazon basin and highlights the need to understand the microbiome of Ae. aegypti for the design of biological control strategies for insect vectors.

Aedes aegypti is a key vector in the transmission of arboviral diseases in the Colombian Amazon. This study aimed to characterize microbiota composition using DNA extracted from water in artificial breeding sites, immature stages, and adults of Ae. aegypti in Leticia, Amazonas. Additionally, the physicochemical water variables were correlated with the bacterial communities present. Eight artificial breeding sites were identified, with bucket, plant pot, and tire being the most frequent. The breeding sites exhibited similar physicochemical profiles, with significant temperature and salinity differences (p-value < 0.03). The most representative bacterial genera included Ottowia (82%), Xanthobacter (70.59%), and Rhodocyclaceae (92.78%) in breeding site water; Aquabacterium (61.07%), Dechloromonas (82.85%), and Flectobacillus (58.94%) in immature stages; and Elizabethkingia (70.89%) and Cedecea (39.19%) in males and females of Ae. aegypti. Beta diversity analysis revealed distinct clustering between adults and the water and immature communities (p-value < 0.001). Multivariate analysis showed strong correlations among bacterial communities, breeding sites, and physicochemical variables such as tire and drum cover which exhibited high levels of total dissolved solids, conductivity, and salinity associated with Flectobacillus, Leifsonia, Novosphingobium, Ottowia, and Rhodobacter. Bacterial genera such as Mycobacterium, Escherichia, Salmonella, and Clostridium, present in artificial breeding sites, are associated with public health relevance. This study provides insights into bacterial community dynamics across Ae. aegypti’s life cycle and underscores the importance of water physicochemical and biological characteristics for developing new vector control strategies.