Investigation of the Bacterial Communities Associated with Females of Lutzomyia Sand Fly Species from South America

Abstract

Phlebotomine sand flies are vectors of Leishmania that are acquired by the female sand fly during blood feeding on an infected mammal. Leishmania parasites develop exclusively in the gut lumen during their residence in the insect before transmission to a suitable host during the next blood feed. Female phlebotomine sand flies are blood feeding insects but their life style of visiting plants as well as animals, and the propensity for larvae to feed on detritus including animal faeces means that the insect host and parasite are exposed to a range of microorganisms. Thus, the sand fly microbiota may interact with the developing Leishmania population in the gut. The aim of the study was to investigate and identify the bacterial diversity associated with wild adult female Lutzomyia sand flies from different geographical locations in the New World. The bacterial phylotypes recovered from 16S rRNA gene clone libraries obtained from wild caught adult female Lutzomyia sand flies were estimated from direct band sequencing after denaturing gradient gel electrophoresis of bacterial 16 rRNA gene fragments. These results confirm that the Lutzomyia sand flies contain a limited array of bacterial phylotypes across several divisions. Several potential plant-related bacterial sequences were detected including Erwinia sp. and putative Ralstonia sp. from two sand fly species sampled from 3 geographically separated regions in Brazil. Identification of putative human pathogens also demonstrated the potential for sand flies to act as vectors of bacterial pathogens of medical importance in addition to their role in Leishmania transmission.

The Gut Microbiome of the Vector Lutzomyia longipalpis Is Essential for Survival of Leishmania infantum

“…and Asaia spp., were also found in our laboratory-reared sand flies (Fig. S2) (20, 21, 24). The variation in the relative abundance of OTUs under each condition over time is illustrated in the heat map in Fig.…”

“…longipalpis revealed a surprisingly diverse array of bacterial families, which differed on the basis of the source of the insect’s meal and infection status. Controlling for these changes, the presence of L. infantum infection caused a progressive and dramatic loss of bacterial diversity as the infection progressed (20, 21, 24). Furthermore, antibiotic-mediated eradication of midgut bacteria had a severe negative impact on Leishmania replication and, consequently, on development to the infectious metacyclic form.…”

Diversity of bacteriome associated with Phlebotomus chinensis (Diptera: Psychodidae) sand flies in two wild populations from China

“…KK-1, has been shown to support larval development and to be able to pass through pupation and remain in the digestive tract of newly emerged females17. Taxa in Enterobacteriaceae are commonly associated with sand flies, such as Serratia, Enterobacter, Pantoea, Klebsiella , and Citrobacter 781112141731. In this study, Citrobacter and Pluralibacter were found with high frequency in both Sichuna and Henan specimens.…”

“…kandelakii, Ph. perfiliewi and Lutzomyia longipalpis 78910111213141516. Regarding the microbial contributions to the physiology of sand flies, gut bacteria have been shown to play roles in development17 and immunity1819.…”

Bacterial Communities in the Gut and Reproductive Organs of Bactrocera minax (Diptera: Tephritidae) Based on 454 Pyrosequencing

“…Our results showed that the microbial communities of all samples were dominated by Proteobacteria , followed by Firmicutes and Actinobacteria . Other studies have also found an abundance of Proteobacteria in various invertebrates, such as the ground beetles [22], the Lutzomyia Sand Fly [23] and the desert locust, Schistocerca Gregaria [14]. On the contrary, bacterial communities associated with certain insect pests, such as termites [24] and bees [25] are more commonly dominated by Bacteroidetes and Firmicutes .…”