Wolbachia at the Crossroads of Symbiosis and Public Health: A Comparative Analysis of Arthropod and Nematode Hosts

Abstract

Wolbachia is a maternally inherited intracellular bacterium that is widely distributed among arthropods and filarial nematodes, where it plays diverse roles ranging from reproductive manipulation to essential symbiosis. In insects, Wolbachia alters host reproduction through mechanisms such as cytoplasmic incompatibility, parthenogenesis, and feminization, while also enhancing antiviral defense. These properties have made it a valuable tool in biocontrol programs, particularly for reducing the transmission of mosquito-borne diseases. In filarial nematodes, especially Onchocerca species responsible for river blindness, Wolbachia is essential for parasite development, survival, and host immune modulation. This dependency has positioned the bacterium as a promising chemotherapeutic target. Antibiotics like doxycycline have proven effective in depleting Wolbachia, reducing worm viability and providing an alternative to conventional drugs such as ivermectin, which faces challenges due to emerging parasite resistance. Additionally, the presence of bacteriophage WO within Wolbachia genomes facilitates horizontal gene transfer and may influence host interactions and bacterial evolution. While current interventions show promise, concerns regarding the potential emergence of resistance to anti-Wolbachia therapies underscore the need for continued research into novel treatment strategies, including combination therapies. This review synthesizes existing knowledge on Wolbachia’s biological roles, host interactions, and implications for integrated control of vector-borne and helminthic diseases. By exploring Wolbachia’s dual function as both a reproductive manipulator and a mutualistic endosymbiont, the review highlights its growing relevance in One Health approaches to improve global public health.