Temporal dynamics in microbial soil communities at anthrax carcass sites

BMC Microbiology

Research Article

Wendy C. Turner¹  Thomas H. A. Haverkamp²  W. Ryan Easterday²  Nils Chr. Stenseth²  Camilla L. Nesbø³  Karoline Valseth⁴  Jaran S. Olsen⁵ 

[1] Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA;Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES), University of Oslo, The Kristine Bonnevie Building, UiO, campus Blindern, Blindern, Oslo, Norway;Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES), University of Oslo, The Kristine Bonnevie Building, UiO, campus Blindern, Blindern, Oslo, Norway;Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada;Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES), University of Oslo, The Kristine Bonnevie Building, UiO, campus Blindern, Blindern, Oslo, Norway;Norwegian Defence Research Establishment, Kjeller, Norway;Norwegian Defence Research Establishment, Kjeller, Norway;

关键词: Bacillus anthracis;    Metabolism;    Metagenomics;    Semi-arid;    Shotgun sequencing;    Taphonomy;    Time-series analysis;    Sporulation;    Microbial diversity;   

DOI  :  10.1186/s12866-017-1111-6

 received in 2017-06-09, accepted in 2017-09-13,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundAnthrax is a globally distributed disease affecting primarily herbivorous mammals. It is caused by the soil-dwelling and spore-forming bacterium Bacillus anthracis. The dormant B. anthracis spores become vegetative after ingestion by grazing mammals. After killing the host, B. anthracis cells return to the soil where they sporulate, completing the lifecycle of the bacterium. Here we present the first study describing temporal microbial soil community changes in Etosha National Park, Namibia, after decomposition of two plains zebra (Equus quagga) anthrax carcasses. To circumvent state-associated-challenges (i.e. vegetative cells/spores) we monitored B. anthracis throughout the period using cultivation, qPCR and shotgun metagenomic sequencing.ResultsThe combined results suggest that abundance estimation of spore-forming bacteria in their natural habitat by DNA-based approaches alone is insufficient due to poor recovery of DNA from spores. However, our combined approached allowed us to follow B. anthracis population dynamics (vegetative cells and spores) in the soil, along with closely related organisms from the B. cereus group, despite their high sequence similarity. Vegetative B. anthracis abundance peaked early in the time-series and then dropped when cells either sporulated or died. The time-series revealed that after carcass deposition, the typical semi-arid soil community (e.g. Frankiales and Rhizobiales species) becomes temporarily dominated by the orders Bacillales and Pseudomonadales, known to contain plant growth-promoting species.ConclusionOur work indicates that complementing DNA based approaches with cultivation may give a more complete picture of the ecology of spore forming pathogens. Furthermore, the results suggests that the increased vegetation biomass production found at carcass sites is due to both added nutrients and the proliferation of microbial taxa that can be beneficial for plant growth. Thus, future B. anthracis transmission events at carcass sites may be indirectly facilitated by the recruitment of plant-beneficial bacteria.

【 授权许可】

CC BY   
© The Author(s). 2017