Author
Rice, William | |
Purdy, Charles |
Submitted to: Meeting Proceedings
Publication Type: Proceedings Publication Acceptance Date: 12/23/2004 Publication Date: 1/5/2005 Citation: Rice, W.C., Purdy, C.W. 2005. Diversity of Escherichia coli and Salmonella spp isolates from playa waters and sediments. In: State of the Science Animal Manure and Waste Management, January 4-7, 2005, San Antonio, Texas. 2005 CDROM. Also available at: http://www.cals.ncsu.edu/waste_mgt/. Interpretive Summary: The genetic diversity of Escherichia coli and Salmonella spp that occur in confined animal feeding operations (CAFO) is unknown. Research was conducted at seven feedyards and three control playas with periodic summer and winter samples collected over a two year period. Selective and nonselective media were used to isolate Escherichia coli and Salmonella sp and other microorganisms. The CAFO environment was shown to be populated by various strains of Escherichia coli, Salmonella spp., and numerous other members of the family Enterobacteriaceae. The genetic structure of Escherichia coli and Salmonella spp that occupy the beef CAFO environment of the high plains of Texas was then determined using repetitive element PCR (Rep-PCR) analysis. Genetic analysis of Escherichia coli and Salmonella strains using repetitive element PCR based assays indicate presence of five to seven dominate DNA fingerprint patterns for the population of Escherichia coli and Salmonella strains. Serological analysis of Salmonella sp. indicates the presence of 13 serotypes of Salmonella sp. Playa waters and sediments represent an environment suitable for the habitation of a small number of dominant Escherichia coli and Salmonella sp along with a wide variety of less frequently occurring strains as indicated by genotype. Technical Abstract: Preliminary work indicates that the confined animal feeding operation (CAFO) environment is populated by various strains of Escherichia coli and Salmonella sp, numerous other members of the Enterobacteriaceae along with a wide variety of naturally occurring microorganisms. A central question to be addressed, are CAFO playa environments populated by resident genotypes and associated antibiotic resistant phenotypes or is there a shifting spectrum of genotypes and pathotypes? Answers to this question may influence management practices concerning the handling of animal waste. We report on the genetic structure of Escherichia coli and Salmonella sp that occupy the beef CAFO environment of the high plains of Texas. Research was conducted at seven feedyards and three control playas with periodic summer and winter samples collected over a two year period. Selective and nonselective media were used to isolate Escherichia coli and Salmonella sp and other microorganisms. Genetic analysis of Escherichia coli and Salmonella strains using for example repetitive element PCR (Rep-PCR) based assays indicate presence of five to seven dominate DNA fingerprint patterns for each genus. Serological and phenotypic analysis of 239 Salmonella sp indicates the presence of approximately 15 serotypes of Salmonella sp. Playa waters and sediments represent an environment suitable for the habitation of a small number of dominant Escherichia coli and Salmonella sp along with a wide variety of less frequently occurring strains as indicated by genotype. |