Culex torrentium mosquitoes from Germany are negative for Wolbachia

Abstract

Abstract. Wolbachia (Rickettsiales: Anaplasmataceae) infects a wide range of arthropods, including several mosquito species. The bacterium is known to induce a plethora of phenotypes in its host, examples being the reproductive phenotype cytoplasmic incompatibility or resistance against infection with arboviruses. The latter is especially relevant when assessing the vector competence of mosquito species for emerging arboviruses. Thus, knowledge of Wolbachia infection status is important for the assessment of vector competence. To facilitate Wolbachia screening in mosquito populations, a quantitative polymerase chain reaction (qPCR) assay was developed to enable high-throughput analysis of mosquito samples. Using this assay, the Wolbachia infection status of the two most common Culex mosquito species in Germany, Culex pipiens biotype pipiens Linnaeus (Diptera: Culicidae) and Culex torrentium Martini (Diptera: Culicidae), was assessed. About 93% of all tested C. pipiens biotype pipiens individuals were positive for Wolbachia, whereas none of the C. torrentium samples was found to be infected. Furthermore, other applications of the qPCR assay were explored by assessing a potential link between the levels of Wolbachia and West Nile virus (WNV) infections in German C. pipiens biotype pipiens mosquitoes. No relationship was found between the two variables, indicating that a Wolbachia-induced antiviral phenotype in this mosquito population is not exclusively attributable to the general level of bacterial infection.

Diverse novel residentWolbachiastrains in Culicine mosquitoes from Madagascar

“…pipiens complex (particularly Cx. pipiens pipiens which were confirmed by PCR and CO1 sequencing) was surprising given high infection rates of the wPip strain are often observed in wild populations [53][54][55][56][57] . Furthermore, our results contrast with a study undertaken in Madagascar as part of a wider Incompatible Insect Technique (IIT) from southwestern Indian Ocean islands in which the wPip strain was detected in Cx.…”

Meta-transcriptomic comparison of the RNA viromes of the mosquito vectors Culex pipiens and Culex torrentium in northern Europe

“…pipiens is commonly infected with Wolbachia , while this bacterium is absent from Cx. torrentium (9). Wolbachia is well-known for its ability to influence virus infection in mosquitoes, but has mostly been studied in systems with pathogenic viruses such as dengue (25).…”

“…pipiens harbours a high prevalence of the intracellular bacteria Wolbachia pipientis , it is seemingly absent in Cx. torrentium (9).…”

Wolbachia Infection in Wild Mosquitoes (Diptera: Culicidae): Implications for Transmission Modes and Host-Endosymbiont Associations

“…Detection in the gastrointestinal tract suggests horizontal transmission through uptake from the environment or host sharing [34,37,38], whereas a detection in non-gastrointestinal somatic tissues, such as the jointed appendages, could be a case of horizontal bacterial genome integration into the host genome [36]. Currently, most research on the detection of Wolbachia in mosquitoes adopts conventional PCR methods which extract DNA from the entire individual or its abdomen [39][40][41][42][43][44][45][46][47]. This limits our ability to identify the exact location of endosymbiont infection within an individual.…”