Deep sequencing reveals extensive variation in the gut microbiota of wild mosquitoes from Kenya

Abstract

The mosquito midgut is a hostile environment that vector-borne parasites must survive to be transmitted. Commensal bacteria in the midgut can reduce the ability of mosquitoes to transmit disease, either by having direct anti-parasite effects or by stimulating basal immune responses of the insect host. As different bacteria have different effects on parasite development, the composition of the bacterial community in the mosquito gut is likely to affect the probability of disease transmission. We investigated the diversity of mosquito gut bacteria in the field using 454 pyrosequencing of 16S rRNA to build up a comprehensive picture of the diversity of gut bacteria in eight mosquito species in this population. We found that mosquito gut typically has a very simple gut microbiota that is dominated by a single bacterial taxon. Although different mosquito species share remarkably similar gut bacteria, individuals in a population are extremely variable and can have little overlap in the bacterial taxa present in their guts. This may be an important factor in causing differences in disease transmission rates within mosquito populations.

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

“…Previous studies mainly focused on noneukaryotic microbes in the midgut using either culture‐dependent or culture‐independent methods (Minard, Mavingui, & Moro, 2013). Those that applied the culture‐independent deep sequencing approach were mainly restricted to gut bacterial communities (Minard et al., 2012; Wang, Gilbreath, Kukutla, Yan, & Xu, 2011) or other isolated adult arthropod parts (Damiani et al., 2010; Sharma et al., 2014), although one study investigated bacteria diversity from whole Ae. albopictus (Minard et al., 2014).…”

“…For example, a median of 42 bacterial OTUs was estimated from the guts of eight mosquito species (Minard et al., 2012); higher still by at least 200 OTUs was the bacterial richness in the gut of a single adult Anopheles gambiae (Wang et al., 2011). This enormous variability amongst studies, including ours, likely reflects inherent differences in microbiota diversity, composition, and heterogeneity amongst individuals, due to vector species and site of mosquito collection.…”

“…This enormous variability amongst studies, including ours, likely reflects inherent differences in microbiota diversity, composition, and heterogeneity amongst individuals, due to vector species and site of mosquito collection. In addition, individual mosquitoes can be extremely variable in their gut microbiota as observed by Osei‐Poku, Mbogo, Palmer, and Jiggins (2012) of wild mosquitoes from Kenya. Thus, estimates are extremely sensitive to sample size (both number of individual vectors sampled and numbers of microbes sampled as a function of sequencing depth) and sample processing.…”

“…quinquefasciatus (Werren, Baldo, & Clark, 2008). Other bacterial taxa, such as Providencia and Erwinia (all Family Enterobacteriaceae), are commonly identified with Aedes, Culex , and other mosquitoes (Demaio, Pumpuni, Kent, & Beier, 1996; Minard et al., 2012, 2014; Rani, Sharma, Rajagopal, Adak, & Bhatnagar, 2009; Zouache, Michelland, Failloux, Grundmann, & Mavingui, 2012). Likewise, the most common eukaryotic microbes identified in this study have also been previously found associated with mosquitoes.…”

“…Recent improvements in the exploration of microscopic organisms through the use of metagenomic PCR (Hugenholtz, Goebel, & Pace, 1998; Liles, Manske, Bintrim, Handelsman, & Goodman, 2003) and next‐generation sequencing (Logares et al., 2012) have allowed more accurate and sensitive documentation of these organisms. Several studies have characterized and compared mosquito bacterial microbiota in natural habitats (Akorli et al., 2016; Buck et al., 2016; Gimonneau et al., 2014; Minard et al., 2012, 2014, 2015; Tchioffo et al., 2015; Yadav et al., 2015; Zouache et al., 2010) but few have characterized eukaryotes and in such cases have targeted fungi (Muturi, Bara, Rooney, & Hansen, 2016; Muturi, Ramirez, Rooney, & Dunlap, 2016; Steyn, Roets, & Botha, 2016). We document mosquito microbiota composition and diversity for vector species Aedes aegypti , Aedes albopictus , and Culex quinquefasciatus across ecologically distinct, yet geographically proximate, habitats in Thailand where many mosquito‐borne diseases circulate.…”