COS 171-6 - Disease Ecology of Buruli ulcer: Aquatic Community Associations of Mycobacterium ulcerans and other Mycolactone Producing Mycobacteria in the Southern USA and French Guiana

Wednesday, August 9, 2023

11:15 AM – 11:30 AM PDT

Location: D138

Presenting Author(s)

MB

M. Eric Benbow, PhD

Michigan State University
East Lansing, Michigan, United States

Coauthor(s)

JP

Jennifer Pechal

Michigan State University, United States
SP

Sophie Picq

Field Museum, United States
MD

Magdalene Dogbe

Mississippi State University, United States
AR

Alex Rakestraw

Michigan State University, United States
KF

Kayla Fast

Mississippi State University, United States
MS

Matthew Scott

Mississippi State University, United States
JR

Joseph Receuver

University of Maryland, Baltimore, United States
AB

Alexandra Bauer

Michigan State University, United States
KW

Kelly Waters

Michigan State University, United States
AG

Anthony Grigsby

Michigan State University, United States
CC

Christine Chevillon

Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Université de Montpellier (UM), Centre National de la Recherche Scientifique (CNRS), Institut pour la Recherche et le Développement, France
MS

Michael Sandel

Mississippi State University, United States
HJ

Heather Jordan

Mississippi State University, United States
JG

Jean-François Guégan

7UMR Animal, santé, territoires, risques et écosystèmes, Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (INRAE), Centre de coopération internationale en recherche agronomique pour le développement (Cirad), Université de Montpellier (UM), France

Abstract: Buruli ulcer (BU) disease is caused by Mycobacterium ulcerans (MU) a mycobacterium related to pathogens of tuberculosis, leprosy and other mycolactone producing mycobacteria (MPM). Mycolactone is a polyketide-derived macrolide that is the toxin responsible for BU disease presentation; it is also used as a presumptive indication of MU and other MPM from environmental samples. While the mode of transmission remains unresolved, aquatic macroinvertebrates and fish have been implicated as vectors and reservoirs of MU and other MPM. While MU/MPM have been found associated with several species of macroinvertebrates and fish, the role of their microbiomes has yet to be investigated. One hypothesis is that host-associated microbial communities affect if and how MU/MPM become part of the host microbiomes, and if these communities determine pathogen persistence and dispersal in aquatic habitats. To determine the role of macroinvertebrates, fish and host bacterial microbiomes in MU/MPM ecology, we employed standardized bioassessments of aquatic habitats in southern USA, where MU was not previously confirmed, compared to those of French Guiana (FG), a BU endemic region of South America. Host internal microbiomes were characterized using 16s rRNA amplicon sequencing after surface nucleic acid decontamination. We also assayed plant macrophyte biofilms, sediment and water column seston for MU/MPM using qPCR of enoyl reductase gene to provide background pathogen habitat contamination. Over three sampling events in the USA of nine sites across Alabama, Mississippi and Louisiana macroinvertebrate family richness ranged 3–44, while in FG it was 8–31 across 28 habitats within river floodplains and isolated waterbodies. In the USA, macroinvertebrate bacterial class-level diversity ranged from 1-49 depending on site and taxon, while fish microbiome diversity in FG varied among six fish species. Macroinvertebrate microbiomes were highly diverse with Gammaproteobacteria, Bacilli, Planctomycetes, and Alphaproteobacteria most dominant depending on site and taxon. Betaproteobacteria were most abundant in Acanthomorpha fish, while Alphaproteobacteria and Gammaproteobacteria dominated Characiformes microbiomes. In the USA, for the first time we confirmed MU and MPM at all sites, while in FG MU/MPM positive sites were restricted to habitats connected to river floodplains. In the USA, MU and MPM positivity was highest in August and most frequent and abundant within seston, while highly variable among substrates and habitats in FG. Additional assays of host associated microbiomes are still underway and will be used to test relationships of pathogen abundance with macroinvertebrates, fish and their microbiomes to better understand reservoir ecology.