title: Rapid dissemination of Mycobacterium bovis from cattle dung to soil by the earthworm Lumbricus terrestris.
abstract: Indirect transmission of Mycobacterium bovis, the causative agent of bovine tuberculosis (bTB), between wildlife and livestock is thought to occur by inhalation or ingestion of environmental substrates contaminated through animal shedding. The role of the soil fauna, such as earthworms, in the circulation of M. bovis from contaminated animal feces is of interest in the epidemiology of bTB. The objective of this study was to assess the impact of earthworm activity on M. bovis transfer from animal dung to castings and the surrounding soil. For this purpose, microcosms of soil containing the anecic earthworms Lumbricus terrestris were prepared and covered with cattle feces spiked with the M. bovis BCG strain Pasteur to carry out two separate experiments. The dissemination, the gut carriage and the excretion of M. bovis were all monitored using a specific qPCR-based assay. Our results showed that the earthworm L. terrestris was able to rapidly disseminate M. bovis from the contaminated cattle feces to the surrounding soil through casting egestion. Moreover, contaminated earthworms were shown to shed the bacteria for 4 days when transferred to a M. bovis-free soil. This study highlights for the first time the possible role of earthworms in the dissemination and the persistence of M. bovis in soils within bTB endemic areas.
authors.affiliation: INRA, UMR 1347 Agroécologie, Dijon Cedex, France; Université de Bourgogne Franche Comté, Dijon Cedex, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Barbier
authors.affiliation: INRA, UMR 1347 Agroécologie, Dijon Cedex, France; Université de Bourgogne Franche Comté, Dijon Cedex, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Chantemesse
authors.affiliation: INRA, UMR 1347 Agroécologie, Dijon Cedex, France; Université de Bourgogne Franche Comté, Dijon Cedex, France.
authors.forename: Murielle
authors.initials: M
authors.lastname: Rochelet
authors.affiliation: INRA, UMR 1347 Agroécologie, Dijon Cedex, France.
authors.forename: Léon
authors.initials: L
authors.lastname: Fayolle
authors.affiliation: Université de Bourgogne Franche Comté, Dijon Cedex, France; Laboratoire Chrono-environnement, UMR CNRS 6249 Besançon, France.
authors.forename: Loïc
authors.initials: L
authors.lastname: Bollache
authors.affiliation: Université Paris-Est, Laboratoire National de Référence de la Tuberculose, Unité des Zoonoses Bactériennes, Laboratoire de Santé Animale, ANSES, Maisons-Alfort Cedex, France.
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Boschiroli
authors.affiliation: INRA, UMR 1347 Agroécologie, Dijon Cedex, France. Electronic address: alain.hartmann@dijon.inra.fr.
authors.forename: Alain
authors.initials: A
authors.lastname: Hartmann
mesh_terms: D000818:Animals; D002417:Cattle; D005243:Feces / Q000382:microbiology*; D009163:Mycobacterium bovis / Q000502:physiology*; D009835:Oligochaeta / Q000382:microbiology*; D012988:Soil Microbiology; D014380:Tuberculosis, Bovine / Q000635:transmission
keywords: Cattle; Earthworms; Lumbricus terrestris; Mycobacterium bovis; Quantitative PCR; Soil; Spreading