Impact of Wolbachia on Infection with Chikungunya and Yellow Fever Viruses in the Mosquito Vector Aedes aegypti

Abstract

Incidence of disease due to dengue (DENV), chikungunya (CHIKV) and yellow fever (YFV) viruses is increasing in many parts of the world. The viruses are primarily transmitted by Aedes aegypti, a highly domesticated mosquito species that is notoriously difficult to control. When transinfected into Ae. aegypti, the intracellular bacterium Wolbachia has recently been shown to inhibit replication of DENVs, CHIKV, malaria parasites and filarial nematodes, providing a potentially powerful biocontrol strategy for human pathogens. Because the extent of pathogen reduction can be influenced by the strain of bacterium, we examined whether the wMel strain of Wolbachia influenced CHIKV and YFV infection in Ae. aegypti. Following exposure to viremic blood meals, CHIKV infection and dissemination rates were significantly reduced in mosquitoes with the wMel strain of Wolbachia compared to Wolbachia-uninfected controls. However, similar rates of infection and dissemination were observed in wMel infected and non-infected Ae. aegypti when intrathoracic inoculation was used to deliver virus. YFV infection, dissemination and replication were similar in wMel-infected and control mosquitoes following intrathoracic inoculations. In contrast, mosquitoes with the wMelPop strain of Wolbachia showed at least a 104 times reduction in YFV RNA copies compared to controls. The extent of reduction in virus infection depended on Wolbachia strain, titer and strain of the virus, and mode of exposure. Although originally proposed for dengue biocontrol, our results indicate a Wolbachia-based strategy also holds considerable promise for YFV and CHIKV suppression.

Invasiveness ofAedes aegyptiandAedes albopictusand Vectorial Capacity for Chikungunya Virus

“…Several innovative approaches to vector control are in trial, one being population replacement with Wolbachia-infected A. aegypti. These mosquitoes have shorter life spans and high resistance to DENV, CHIKV, and YFV infection, and the intracellular Wolbachia bacteria remains established in the population [52]. However, A. albopictus is unaffected by this technique.…”

Mosquito vector‐associated microbiota: Metabarcoding bacteria and eukaryotic symbionts across habitat types in Thailand endemic for dengue and other arthropod‐borne diseases

“…In the past decade, studies have shown that certain microbes associated with insect vectors could be used to mediate the transmission of diseases including those transmitted by mosquitoes (Capone et al., 2013; Cirimotich et al., 2011; Dong, Manfredini, & Dimopoulos, 2009; Mourya, Pidiyar, Patole, Gokhale, & Shouche, 2002; Ramirez et al., 2014; Tchioffo et al., 2013; Xi, Ramirez, & Dimopoulos, 2008), tsetse flies (Pais, Lohs, Wu, Wang, & Aksoy, 2008; Wang, Wu, Yang, & Aksoy, 2009; Weiss, Wang, Maltz, Wu, & Aksoy, 2013), sand flies (Sant'Anna et al., 2014), and ticks (Gall et al., 2016; Narasimhan et al., 2014). The most striking example is the inhibition by bacterium Wolbachia pipientis of virus and parasite infection in mosquito vectors (Bian, Xu, Lu, Xie, & Xi, 2010; Blagrove, Arias‐Goeta, Di Genua, Failloux, & Sinkins, 2013; Frentiu et al., 2014; van den Hurk et al., 2012; Hussain et al., 2012; Moreira et al., 2009). Unfortunately, while studies on the application of microbes such as Wolbachia to control human disease have advanced, we still lack basic insight into the natural microbial communities associated with vectors, from viruses to bacteria to single‐celled eukaryotes.…”

Wolbachia enhances insect‐specific flavivirus infection in Aedes aegypti mosquitoes

“…These findings were unexpected given that Wolbachia has been extensively shown to inhibit flaviviruses of medical importance in Ae. aegypti (Bian et al., 2010; van den Hurk et al., 2012; Moreira et al., 2009; Walker et al., 2011). …”

“…aegypti populations. This sharply contrasts previous studies where Wolbachia infection significantly reduced the proportion of individuals infected with other flaviviruses such as DENV (Amuzu & McGraw, 2016; Amuzu, Simmons, & McGraw, 2015; Bian et al., 2013; Frentiu et al., 2014; Moreira et al., 2009; Walker et al., 2011), Zika (Aliota et al., 2016; Dutra et al., 2016), and YFV (van den Hurk et al., 2012). Our findings are, however, supported by studies performed in Cx.…”

“…albopictus (Xi, Dean, Khoo, & Dobson, 2005), and w Mel w AlbB (Joubert et al., 2016) that is a superinfection of w Mel and w AlbB. Wolbachia ‐mediated pathogen blocking has now been observed for arboviruses such as WNV (Glaser & Meola, 2010), YFV (van den Hurk et al., 2012), DENV (Bian et al., 2010; Frentiu, Robinson, Young, McGraw, & O'Neill, 2010; Moreira et al., 2009; Walker et al., 2011), ZIKV (Aliota, Peinado, Velez, & Osorio, 2016; Dutra et al., 2016), and Chikungunya virus (van den Hurk et al., 2012; Moreira et al., 2009). Wolbachia is currently being released into populations of Ae.…”