Diversity of the Bacterial and Fungal Microflora from the Midgut and Cuticle of Phlebotomine Sand Flies Collected in North-Western Iran

Abstract

BackgroundPhlebotomine sand flies are the vectors of the leishmaniases, parasitic diseases caused by Leishmania spp. Little is known about the prevalence and diversity of sand fly microflora colonizing the midgut or the cuticle. Particularly, there is little information on the fungal diversity. This information is important for development of vector control strategies.Methodology/Principal FindingsFive sand fly species: Phlebotomus papatasi, P. sergenti, P. kandelakii, P. perfiliewi and P. halepensis were caught in Bileh Savar and Kaleybar in North-Western Iran that are located in endemic foci of visceral leishmaniasis. A total of 35 specimens were processed. Bacterial and fungal strains were identified by routine microbiological methods. We characterized 39 fungal isolates from the cuticle and/or the midgut. They belong to six different genera including Penicillium (17 isolates), Aspergillus (14), Acremonium (5), Fusarium (1), Geotrichum (1) and Candida (1). We identified 33 Gram-negative bacteria: Serratia marcescens (9 isolates), Enterobacter cloacae (6), Pseudomonas fluorescens (6), Klebsiella ozaenae (4), Acinetobacter sp. (3), Escherichia coli (3), Asaia sp. (1) and Pantoea sp. (1) as well as Gram-positive bacteria Bacillus subtilis (5) and Micrococcus luteus (5) in 10 isolates.Conclusion/SignificanceOur study provides new data on the microbiotic diversity of field-collected sand flies and for the first time, evidence of the presence of Asaia sp. in sand flies. We have also found a link between physiological stages (unfed, fresh fed, semi gravid and gravid) of sand flies and number of bacteria that they carry. Interestingly Pantoea sp. and Klebsiella ozaenae have been isolated in Old World sand fly species. The presence of latter species on sand fly cuticle and in the female midgut suggests a role for this arthropod in dissemination of these pathogenic bacteria in endemic areas. Further experiments are required to clearly delineate the vectorial role (passive or active) of sand flies.

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

“…The diversity and abundance of the phylotypes in family Enterobacteriaceae were enriched in the blood-fed specimens from both Henan and Sichuan. A similar composition shift has been found in sand fly8 and mosquito gut microbiota29. Intracellular bacteria appear to be distinct in the two geographic collections.…”

“…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.…”

“…are commonly found in sand flies78101131. In this study, the phylotypes similar to Pseudomonas were grouped into two clades with 11 known species (Fig.…”

“…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.…”

Isolation of Novel Trypanosomatid, Zelonia australiensis sp. nov. (Kinetoplastida: Trypanosomatidae) Provides Support for a Gondwanan Origin of Dixenous Parasitism in the Leishmaniinae

“…Multiple phylogenies suggest that Viannia emerged millions of years later (Fig 8) [3, 11, 57], implying that their divergence from other Euleishmania was not triggered by the separation of Africa and South America. The presence of the Leishmania subgenus in the New World is often discussed as a migration from the Old World to the New [58]. However, based on current evidence, an alternate scenario is proposed.…”