Comparative assessment of the bacterial communities associated with Aedes aegypti larvae and water from domestic water storage containers

Abstract

BackgroundDomestic water storage containers constitute major Aedes aegypti breeding sites. We present for the first time a comparative analysis of the bacterial communities associated with Ae. aegypti larvae and water from domestic water containers.MethodsThe 16S rRNA-temporal temperature gradient gel electrophoresis (TTGE) was used to identify and compare bacterial communities in fourth-instar Ae. aegypti larvae and water from larvae positive and negative domestic containers in a rural village in northeastern Thailand. Water samples were cultured for enteric bacteria in addition to TTGE. Sequences obtained from TTGE and bacterial cultures were clustered into operational taxonomic units (OTUs) for analyses.ResultsSignificantly lower OTU abundance was found in fourth-instar Ae. aegypti larvae compared to mosquito positive water samples. There was no significant difference in OTU abundance between larvae and mosquito negative water samples or between mosquito positive and negative water samples. Larval samples had significantly different OTU diversity compared to mosquito positive and negative water samples, with no significant difference between mosquito positive and negative water samples. The TTGE identified 24 bacterial taxa, belonging to the phyla Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and TM7 (candidate phylum). Seven of these taxa were identified in larval samples, 16 in mosquito positive and 13 in mosquito negative water samples. Only two taxa, belonging to the phyla Firmicutes and Actinobacteria, were common to both larvae and water samples. Bacilli was the most abundant bacterial class identified from Ae. aegypti larvae, Gammaproteobacteria from mosquito positive water samples, and Flavobacteria from mosquito negative water samples. Enteric bacteria belonging to the class Gammaproteobacteria were sparsely represented in TTGE, but were isolated from both mosquito positive and negative water samples by selective culture.ConclusionsFew bacteria from water samples were identified in fourth-instar Ae. aegypti larvae, suggesting that established larval bacteria, most likely acquired at earlier stages of development, control the larval microbiota. Further studies at all larval stages are needed to fully understand the dynamics involved. Isolation of enteric bacteria from water samples supports earlier outcomes of E. coli contamination in Ae. aegypti infested domestic containers, suggesting the need to further explore the role of enteric bacteria in Ae. aegypti infestation.

Carryover effects of larval exposure to different environmental bacteria drive adult trait variation in a mosquito vector

“…The first aim of our study was to describe habitat-related differences in the bacterial composition of A. aegypti larval development sites. Our observation of distinct bacterial communities between domestic and sylvatic habitats supports previous observations of habitat-related differences in bacterial communities in mosquito larval sites ( 27 – 30 ) and verifies an important assumption of our study. Another marked observation from our targeted metagenomics approach was the dissimilarity between bacteria found in the larval site water and those in the adult midguts emerging from these same sites.…”

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

“…albopictus , and Cx. quinquefasciatus were consistent with previous investigations (Dada et al., 2014; Minard et al., 2013; Moro, Tran, Raharimalala, Ravelonandro, & Mavingui, 2013; Pidiyar, Jangid, Patole, & Shouche, 2004; Tranchida, Riccillo, Rodriguero, Garcia, & Micieli, 2012; Zouache et al., 2010). The most abundant genus of bacteria in terms of numbers of identified taxa was Wolbachia , a common intracellular parasitic bacterium of many insect species including Ae.…”

Effects of environment, dietary regime and ageing on the dengue vector microbiota: evidence of a core microbiota throughout Aedes aegypti lifespan

“…Ae. aegypti breeds almost exclusively in domestic containers recurrent across the globe, such as discarded tires and plastic buckets, in which several of this bacteria taxa have been detected ( Ponnusamy et al 2008 , Dada et al 2014 ). This could partially explain the similarities found in the microbiota of geographically distant populations.…”