Contribution of midgut bacteria to blood digestion and egg production in aedes aegypti (diptera: culicidae) (L.).

Background: The insect gut harbors a variety of microorganisms that probably exceed the number of cells in insects themselves. These microorganisms can live and multiply in the insect, contributing to digestion, nutrition, and development of their host.Recent studies have shown that midgut bacteria appear to strengthen the mosquito's immune system and indirectly enhance protection from invading pathogens.

Culture-dependent and culture-independent characterization of microorganisms associated with Aedes aegypti (Diptera: Culicidae) (L.) and dynamics of bacterial colonization in the midgut.

In this work we show that the lumen of Aedes aegypti midgut is highly colonized by bacteria that were identified by culture-dependent and culture-independent methods. rDNA sequences obtained were compared with those from GenBank and the main bacterial genera identified were: Serratia, Klebsiella, Asaia, Bacillus, Enterococcus, Enterobacter,Kluyvera and Pantoea. All genera were identified in midgut except Enterobacter that was observed only in eggs.

First isolation of microorganisms from the gut diverticulum of Aedes aegypti (Diptera: Culicidae): new perspectives for an insect-bacteria association.

We show for the first time that the ventral diverticulum of the mosquito gut (impermeable sugar storage organ) harbors microorganisms. The gut diverticulum from newly emerged and non-fed Aedes aegypti was dissected under aseptic conditions, homogenized and plated on BHI medium. Microbial isolates were identified by sequencing of 16S rDNA for bacteria and 28S rDNA for yeast.

Selection of entomopathogenic fungi for use in combination with sub-lethal doses of imidacloprid: perspectives for the control of the leaf-cutting ant Atta sexdens rubropilosa Forel (Hymenoptera: Formicidae).

In the first part of this study, four isolates of the fungus Beauveria bassiana (Bals.) Vuillemin (LPP1, LPP2, CG05 and CG24) and one isolate of Metarhizium anisopliae (Metsch.) Sorokin (CG46) were tested against adult foragers of Atta sexdens rubropilosa.

Ocurrence of the antibiotic producing bacterium Burkholderia sp. in colonies of the leaf-cutting ant Atta sexdens rubropilosa.

Fungus garden material from recently established Atta sexdens rubropilosa colonies (6-12 months old) was sampled to detect antibiotic producing microorganisms that inhibited the growth of pathogens of insects and of the fungus gardens but did not affect their mutualistic fungus. A bacterium with activity against the entomopathogenic fungus Beauveria bassiana was isolated from 56% of the gardens tested (n=57) and identified from its biochemical profile and from 16S and 23S ribosomal DNA sequences as a member of the genus Burkholderia. The ant-associated Burkholderia isolates secreted a potent, anti-fungal agent that inhibited germination of conidia of the entomopathogenic fungi B.