Prevalence, genomic and metabolic profiles ofAcinetobacterandAsaiaassociated with field-caughtAedes albopictusfrom Madagascar

Abstract

The presence of cultivable bacteria Acinetobacter and Asaia was recently demonstrated in the mosquito vector Aedes albopictus. However, it is not known how prevalent these bacteria are in field populations. Here, the presence of these bacteria in Ae. albopictus populations from Madagascar was diagnosed by amplification of 16S rRNA gene fragments. Both genera were detected at relatively high frequencies, 46% for Asaia and 74% for Acinetobacter. The prevalence of Acinetobacter correlated significantly with mosquito gender, and the prevalence of Asaia with the interaction between mosquito gender and the sampling site. For each bacterial genus, more male than female mosquitoes were infected. Using pulse field gel electrophoresis, no significant difference in genome size was found between Acinetobacter isolates from mosquitoes compared with free‐living Acinetobacter. However, a great diversity was observed in plasmid numbers (from 1 to 12) and sizes (from < 8 to 690 kb). Mosquito isolates utilized fewer substrates than free‐living isolates, but some substrates known as blood or plant components were specifically utilized by mosquito isolates. Therefore it is likely that a specific subpopulation of Acinetobacter is selected by Ae. albopictus. Overall, this study emphasizes the need to gain a global view on the bacterial partners in mosquito vectors.

Pyrosequencing 16S rRNA genes of bacteria associated with wild tiger mosquito Aedes albopictus: a pilot study

“… The asterisks ( * ) represent newly identified genera in mosquitoes according to Minard et al, 2013a,b .…”

“…Mosquitoes were surface-disinfected with 70% ethanol and rinsed with sterile water, as previously described (Minard et al, 2013b). Each mosquito was individually crushed using a Bioblock Scientific MM 2000 mill (Retsch, France) in an Eppendorf tube with 5-mm diameter inox beads and 200 μl of extraction buffer (2% hexadecyltrimethyl ammonium bromide, 1.4 M NaCl, 0.02 M EDTA, 0.1 M Tris pH 8.0, 0.2% 2-β-mercaptoethanol) and heated at 60°C for 2 h. Lipids and proteins were extracted with phenol-chloroform-isoamyl alcohol (25:24:1; v/v/v) and then chloroform:isoamyl alcohol (24:1; v/v).…”

“…albopictus has mainly been investigated using classical microbiological and molecular techniques. Various culture-dependent isolation methods were used to identify cultivable bacteria (Zouache et al, 2009; Chouaia et al, 2010; Minard et al, 2013a,b; Valiente Moro et al, 2013). In parallel, non-culture-based methods such as DGGE fingerprinting (Chouaia et al, 2010; Zouache et al, 2011) or taxonomic microarray hybridization (Zouache et al, 2012) were employed.…”

Multiorganismal Insects: Diversity and Function of Resident Microorganisms

“…In the gut of the mosquito Aedes albopictus , the prevalence of Asaia and Acinetobacter spp. is positively related (78), but in the desert locust Schistocerca gregaria the abundance of Serratia marcescens is negatively correlated with the abundance of other bacteria (33). …”

The microbiome modulates arbovirus transmission in mosquitoes

“…Culture-based experiments have also found inhibition between bacterial isolates from mosquitoes [27 • ,40], although this interplay needs to be confirmed in vivo . Contrary to these inhibitory interactions, a positive correlation was seen between Asaia and Acinetobacter in the midgut of A. albopictus [41]. …”