Differential Microbial Diversity inDrosophila melanogaster: Are Fruit Flies Potential Vectors of Opportunistic Pathogens?

Abstract

Drosophila melanogaster has become a model system to study interactions between innate immunity and microbial pathogens, yet many aspects regarding its microbial community and interactions with pathogens remain unclear. In this study wild D. melanogaster were collected from tropical fruits in Puerto Rico to test how the microbiota is distributed and to compare the culturable diversity of fungi and bacteria. Additionally, we investigated whether flies are potential vectors of human and plant pathogens. Eighteen species of fungi and twelve species of bacteria were isolated from wild flies. The most abundant microorganisms identified were the yeast Candida inconspicua and the bacterium Klebsiella sp. The yeast Issatchenkia hanoiensis was significantly more common internally than externally in flies. Species richness was higher in fungi than in bacteria, but diversity was lower in fungi than in bacteria. The microbial composition of flies was similar internally and externally. We identified a variety of opportunistic human and plant pathogens in flies such as Alcaligenes faecalis, Aspergillus flavus, A. fumigatus, A. niger, Fusarium equiseti/oxysporum, Geotrichum candidum, Klebsiella oxytoca, Microbacterium oxydans, and Stenotrophomonas maltophilia. Despite its utility as a model system, D. melanogaster can be a vector of microorganisms that represent a potential risk to plant and public health.

Culturomics revealed the bacterial constituents of the microbiota of a 10-year-old laboratory culture of planarian species S. mediterranea

“…In the planarian S. mediterranea , the major genus found is Pseudomonas , unlike in Drosophila , where the most common genus is Klebsiella 64 . Several bacterial species found in planarians are common to the Drosophila microbiota, such as Micrococcus luteu s, Micrococcus yuennansis , and Microbacterium oxydans .…”

Diversity of culturable endophytic fungi vary through time in Manihot esculenta Crantz

“…For sporulating fungi, we used morphology-based taxonomy (Barnett and Hunter, 1972). Pure colonies were transferred to a 2 mL glass vial with 2% of malt extract agar (MEA) supplemented with the antibiotic above described and grouped by morphospecies based on morphological characteristics in the mycelium growing in tubes (Ramírez-Camejo et al, 2017).…”

The microbiome of pest insects: it is not just bacteria

“…Recent studies based on meta-barcoding using fungalspecific primers have revealed a rich fungal community in both pest and non-pest insects (Chandler & Kopp, 2012;Hu et al, 2015;Miller et al, 2016;Boccazzi et al, 2017;Ram ırez-Camejo et al, 2017;Mohammed et al, 2018;Quan & Eisen, 2018). Fungal species that have been associated with pest insects comprise, among others, species of molds belonging to the genera Aspergillus, Beauveria, Metarhizium, Cordyceps, Isaria, and Pandora (Shang et al, 2015).…”