Journal article
Proximity-Dependent Inhibition in Escherichia coli Isolates from Cattle
Applied and environmental microbiology, Vol.77(7), pp.2345-2351
04/2011
Handle:
https://hdl.handle.net/2376/104260
PMCID: PMC3067425
PMID: 21296941
Abstract
We describe a novel proximity-dependent inhibition phenotype of
Escherichia coli
that is expressed when strains are cocultured in defined minimal media. When cocultures of “inhibitor” and “target” strains approached a transition between logarithmic and stationary growth, target strain populations rapidly declined >4 log CFU per ml over a 2-h period. Inhibited strains were not affected by exposure to conditioned media from inhibitor and target strain cocultures or when the inhibitor and target strains were incubated in shared media but physically separated by a 0.4-μm-pore-size membrane. There was no evidence of lytic phage or extracellular bacteriocin involvement, unless the latter was only present at effective concentrations within immediate proximity of the inhibited cells. The inhibitory activity observed in this study was effective against a diversity of
E. coli
strains, including enterohemorrhagic
E. coli
serotype O157:H7, enterotoxigenic
E. coli
expressing F5 (K99) and F4 (K88) fimbriae, multidrug-resistant
E. coli
, and commensal
E. coli.
The decline in counts of target strains in coculture averaged 4.8 log CFU/ml (95% confidence interval, 4.0 to 5.5) compared to their monoculture counts. Coculture of two inhibitor strains showed mutual immunity to inhibition. These results suggest that proximity-dependent inhibition can be used by bacteria to gain a numerical advantage when populations are entering stationary phase, thus setting the stage for a competitive advantage when growth conditions improve.
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Details
- Title
- Proximity-Dependent Inhibition in Escherichia coli Isolates from Cattle
- Creators
- Ashish A Sawant - Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington 99164-7040N. Carol Casavant - Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington 99164-7040Douglas R Call - Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington 99164-7040Thomas E Besser - Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington 99164-7040
- Publication Details
- Applied and environmental microbiology, Vol.77(7), pp.2345-2351
- Academic Unit
- Veterinary Microbiology and Pathology, Department of; Paul G. Allen School for Global Animal Health
- Publisher
- American Society for Microbiology (ASM)
- Identifiers
- 99900546744001842
- Language
- English
- Resource Type
- Journal article