Bacteria of the genus Asaia stably associate with Anopheles stephensi , an Asian malarial mosquito vector

Abstract

Here, we show that an ␣-proteobacterium of the genus Asaia is stably associated with larvae and adults of Anopheles stephensi, an important mosquito vector of Plasmodium vivax, a main malaria agent in Asia. Asaia bacteria dominate mosquito-associated microbiota, as shown by 16S rRNA gene abundance, quantitative PCR, transmission electron microscopy and in situ-hybridization of 16S rRNA genes. In adult mosquitoes, Asaia sp. is present in high population density in the female gut and in the male reproductive tract. Asaia sp. from An. stephensi has been cultured in cell-free media and then transformed with foreign DNA. A green fluorescent protein-tagged Asaia sp. strain effectively lodged in the female gut and salivary glands, sites that are crucial for Plasmodium sp. development and transmission. The larval gut and the male reproductive system were also colonized by the transformed Asaia sp. strain. As an efficient inducible colonizer of mosquitoes that transmit Plasmodium sp., Asaia sp. may be a candidate for malaria control. malaria ͉ symbiotic control ͉ insect vector

First isolation of microorganisms from the gut diverticulum of Aedes aegypti (Diptera: Culicidae): new perspectives for an insect-bacteria association

“…Recently, Favia et al (2007) reported that the main bacteria species associated with adults and larvae of the mosquito Anopheles stephensi are from the genus Asaia, that is related to acetic acid bacteria. They found Asaia sp.…”

Native microbiome impedes vertical transmission of Wolbachia in Anopheles mosquitoes

“…Asaia bacteria naturally infect the Anopheles germ line and are vertically transmitted (39,40), and thus may conflict with other maternally transmitted bacteria. This, together with the observed significant and large decrease in frequency of this taxon upon antibiotic treatment in both mosquito species, led us to investigate Asaia as a candidate bacteria involved in the interference of Wolbachia transmission.…”

What Use Are Male Hosts? The Dynamics of Maternally Inherited Bacteria Showing Sexual Transmission or Male Killing

“…Indeed, sexually transmitted strains were observed to take over from existing infections following such a coinfection event. The study of aphid secondary symbionts complements previous work describing male-to-female sexual transmission for a variety of viral and microsporidial associates of insects that also showed maternal inheritance (reviewed in Knell and Webberley 2004), records of a low level of paternal transmission for Wolbachia (Hoffmann and Turelli 1988), and a more recent record of sexual transmission of the bacterium Asaia that is maternally inherited in Anopheles mosquitoes (Favia et al 2007). …”

“…This suggests that constraint is the main reason secondary symbionts do not degrade into feminizers. Indeed, there are many fewer records of host species infected with feminizers (two insect species and a variety of Crustacea; Bouchon et al 1998;Hiroki et al 2002;Terry et al 2004;Negri et al 2006;Favia et al 2007) and even fewer microorganisms that have evolved this trait (Wolbachia, microsporidia).…”

“…Sex ratio distortion can be of two types. First, it may be distortion of the primary sex ratio, feminization, which has been reported in two insect and some crustacean species (Bouchon et al 1998;Hiroki et al 2002;Terry et al 2004;Negri et al 2006;Favia et al 2007). Second, it may be secondary sex ratio distortion, male killing (MK), in which infected males are killed during embryogenesis.…”