Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2004
Publication Date: November 4, 2004
Citation: Rice, W.C., Purdy, C.W. 2004. Population structure of Escherichia coli isolates from playa waters and sediments within beef CAFO [abstract]. In: Proceedings of the American Society for Microbiology, Texas Branch, Fall Meeting, November 4-6, 2004, Houston, Texas. P55. p. 43. Technical Abstract: One question of interest regarding beef cattle confined animal feeding operation (CAFO) environments is the population structure of various isolates of Escherichia coli. Are these CAFO environments dominated by a few resident genotypes or are there ever-shifting spectrums of genotypes? Playa water and sediment samples within the CAFO environment were obtained from seven feedyards and one control playa via the periodic collection of summer and winter samples over a four year period. Selective media were used for the isolation of members of the family Enterobacteriaceae, Escherichia coli and Salmonella sp. Research results indicate that beef CAFOs are populated by various strains of Escherichia coli and Salmonella sp along with numerous other members of the family Enterobacteriaceae (based on the use selective chromogenic media and biochemical evaluation). We report on the genetic structure of Escherichia coli that occupy the beef CAFO environment of the high plains of Texas. Genetic analysis of 224 suspect Escherichia coli strains using repetitive element (BoxA1R) PCR assay indicates the presence of five dominate DNA fingerprint types (A-E; 13, 10, 10, 9 and 8% respectively) amongst those observed. One DNA pattern was confined primarily to one playa while several DNA patterns were more broadly distributed amongst three to five playas. Playa waters and sediments represent an environment suitable for the habitation of a small number of dominant Escherichia coli along with a wide variety of less frequently occurring strains.