Influence of Red Kidney Bean Seed Proteins on Development, Digestive alpha-amylase Activity and Gut Protein Pattern of Leptinotarsa decemlineata (Say)

WOS: 000418780600009The effects of red kidney bean, Phaseolus vulgaris cv. Goli (L.), seed proteinaceous extract on larval development, digestive alpha-amylase and gut protein pattern of Colorado potato beetle, Leptinotarsa decemlineata (Say) were investigated. The results showed that four proteinaceous ammonium sulfate precipitated fractions (30, 50, 70, and 100%) of bean seed extract caused significant inhibition, in vitro, on alpha-amylase activity of all larval stages and adults up to 69%. Affinity chromatography using larval gut sample as ligand and silicon dioxide as matrix, were used to identify enzyme inhibitor proteins, but purified protein was not recognized on SDS-PAGE. Alpha-amylase activity of larvae fed on the treated leaves of four different potato cultivars (Agria, Burren, Picasso, and Marx) by bean seed extract was inhibited significantly up to the 60% on Burren. In the bioassay, weight of fourth instar larvae was reduced 19 mg and the larval growth was decreased by 45.35% on Picasso, as compared to the control. In two-dimensional electrophoresis and SDS-PAGE, the gut protein patterns were changed in effects of feeding on leaves treated with bean seed extract. These data revealed that red kidney bean seed extract suppressed digestive alpha-amylase activity in vitro and in vivo, caused side effects on the actual parameters monitored and had an impact on the gut protein pattern of L. decemlineata.University of Tabriz; Ege UniversityEge UniversityWe express our gratitude to the University of Tabriz and Ege University for supports during the course of this project. Thanks to Mr. Amir Kahnamouyi for his helpful attempts

Characterization of bacteria expectorated during forced salivation of the Phlebotomus papatasi: A neglected component of sand fly infectious inoculums.

The infectious inoculum of a sand fly, apart from its metacyclic promastigotes, is composed of factors derived from both the parasite and the vector. Vector-derived factors, including salivary proteins and the gut microbiota, are essential for the establishment and enhancement of infection. However, the type and the number of bacteria egested during salivation is unclear. In the present study, sand flies of Phlebotomus papatasi were gathered from three locations in hyperendemic focus of zoonotic cutaneous leishmaniasis (ZCL) in Isfahan Province, Iran. By using the forced salivation assay and targeting the 16S rRNA barcode gene, egested bacteria were characterized in 99 (44%) out of 224 sand flies. Culture-dependent and culture-independent methods identified the members of Enterobacter cloacae and Spiroplasma species as dominant taxa, respectively. Ten top genera of Spiroplasma, Ralstonia, Acinetobacter, Reyranella, Undibacterium, Bryobacter, Corynebacterium, Cutibacterium, Psychrobacter, and Wolbachia constituted >80% of the saliva microbiome. Phylogenetic analysis displayed the presence of only one bacterial species for the Spiroplasma, Ralstonia, Reyranella, Bryobacter and Wolbachia, two distinct species for Cutibacterium, three for Undibacterium and Psychrobacter, 16 for Acinetobacter, and 27 for Corynebacterium, in the saliva. The abundance of microbes in P. papatasi saliva was determined by incorporating the data on the read counts and the copy number of 16S rRNA gene, about 9,000 bacterial cells, per sand fly. Both microbiological and metagenomic data indicate that bacteria are constant companions of Leishmania, from the intestine of the vector to the vertebrate host. This is the first forced salivation experiment in a sand fly, addressing key questions on infectious bite and competent vectors