| Legionella pneumophila, Aeromonas hydrophila, and Yersinia enterocolitica are all potential human pathogens that are commonly found in the environment. These gram-negative bacilli are all notoriously difficult, expensive and time-consuming to identify. It was the purpose of this study to determine if PCR could be used as a definitive, more efficient test for these organisms. Soil and water samples were spiked with each organism to determine the sensitivity of the primers, and then water and sediment samples were tested quarterly from 15 sites along the Rio Grande. Legionella pneumophila was not detected in any environmental samples. Yersinia enterocolitica tested positive only at Arroyo Hondo, New Mexico. Aeromonas hydrophila was detected once in a microbial sample. The positive PCR control for presence of bacterial DNA, consisting of primers specific for Kingdom eubacteria, detected 81 positives in environmental samples. Overall, this study suggests that positive identification of Legionella pneumophila and Yersinia enterocolitica is more definitive with PCR than with previous culture methods. Results for Aeromonas hydrophila were insufficient for analysis. Statistical analysis of eubacteria data demonstrates that culturing is more efficient than PCR at that level. |
