# Wolbachia Surface Protein (wsp) Gene Sequencing of Strains A and B in Native Aedes albopictus of Mérida, Yucatán

## TL;DR

This study confirms the presence of Wolbachia strains A and B in native Aedes albopictus mosquitoes in Yucatán, offering potential for using Wolbachia to control arbovirus transmission.

## Contribution

The first report of Wolbachia wsp gene sequencing in native Aedes albopictus populations in Yucatán, Mexico.

## Key findings

- Wolbachia strains A and B were confirmed in Aedes albopictus from Mérida using wsp gene sequencing.
- High nucleotide sequence homology was observed between Wolbachia from Mérida and global strains A and B.
- The stability of Wolbachia strains in Aedes albopictus across geographical regions was demonstrated.

## Abstract

The mosquito Aedes (Stegomyia) albopictus is an invasive species that has spread across nearly all continents and is increasingly associated with the transmission of Aedes-borne human viruses (ABVs), such as dengue (DENV), chikungunya (CHIKV), yellow fever (YFV), and Zika (ZIKV). Wolbachia-based strategies are currently among the most innovative alternative biological methods to control vector populations. Wolbachia is an endosymbiotic bacterium known to interfere with the reproductive mechanisms of vectors and, consequently, with virus replication. Previous studies have demonstrated that Ae. albopictus is naturally associated with two Wolbachia strains, A and B. This study provides additional wsp gene DNA sequencing evidence confirming that native populations of Ae. albopictus in Yucatán—an arbovirus-endemic region—naturally harbor both Wolbachia strains A and B. These findings present an opportunity to strategically plan future surveillance and control programs targeting Ae. albopictus through Wolbachia strain B-based approaches, with the potential to lower the burden of arbovirus diseases in human populations.

Aedes (Stegomyia) albopictus (Skuse), a mosquito vector with increasing capacity to transmit human arboviral infections worldwide, naturally harbors the intracellular bacterium Wolbachia spp. This relationship has been observed in native mosquito populations of Ae. albopictus around the world and, more recently, in Mérida, Yucatán, México (abbreviated hereafter as MID). This study provides additional evidence confirming the presence of Wolbachia A (wAlbA) and B (wAlbB) strains in field-collected Ae. albopictus of Mérida, based on wsp gene DNA sequencing analyses of 14 positive PCR samples. Maximum likelihood (ML) analyses of the wsp gene showed high nucleotide sequence homology between Wolbachia from Merida and the globally reported strains A and B, suggesting that these two Wolbachia strains have remained stable in Ae. albopictus over time, regardless of the geographical area. To the best of our knowledge, this is the first report of Wolbachia gene sequencing in native populations of Ae. albopictus in Yucatán, Mexico. Currently many Aedes mosquitoes (e.g., Ae. aegypti) harboring intracellular Wolbachia B bacteria are being released as part of arbovirus and mosquito control programs in Yucatan and globally. Understanding the presence and stability of Wolbachia strains across different Aedes host backgrounds is crucial to ensuring the long-term effectiveness of biological interventions aimed at controlling mosquito populations and arbovirus transmission in endemic areas.