Microbial diversity determines the invasion of soil by a bacterial pathogen

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 109; no. 4; pp. 1159 - 1164
• Main Authors: van Elsas, Jan Dirk, Chiurazzi, Mario, Mallon, Cyrus A, Elhottovā, Dana, Krištůfek, Václav, Salles, Joana Falcão
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 24.01.2012; National Acad Sciences
• Subjects: Agricultural soils; Bacteria; bacterial communities; Biodiversity; Biological Sciences; Colony Count, Microbial; E coli; Ecosystems; Escherichia coli; Escherichia coli O157; Escherichia coli O157 - growth & development; Grassland soils; Introduced Species; Microcosms; Netherlands; Pathogens; soil; Soil bacteria; Soil fauna; Soil inoculation; Soil Microbiology; Soil microorganisms; Soils; Species diversity; Survival Analysis; Time Factors; Netherlands
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1109326109

Natural ecosystems show variable resistance to invasion by alien species, and this resistance can relate to the species diversity in the system. In soil, microorganisms are key components that determine life support functions, but the functional redundancy in the microbiota of most soils has long been thought to overwhelm microbial diversity–function relationships. We here show an inverse relationship between soil microbial diversity and survival of the invading species Escherichia coli O157:H7, assessed by using the marked derivative strain T. The invader's fate in soil was determined in the presence of (i) differentially constructed culturable bacterial communities, and (ii) microbial communities established using a dilution-to-extinction approach. Both approaches revealed a negative correlation between the diversity of the soil microbiota and survival of the invader. The relationship could be explained by a decrease in the competitive ability of the invader in species-rich vs. species-poor bacterial communities, reflected in the amount of resources used and the rate of their consumption. Soil microbial diversity is a key factor that controls the extent to which bacterial invaders can establish.