Rapid Detection of Pseudomonas aeruginosa and Legionella pneumophila in Water

摘要

Pseudomonas aeruginosa and Legionella pneumophila are the most frequently reported pathogens in whirlpool and hot tub infection. Potable water is an important source for the infections by these pathogens. Traditional culture-based methods for determining these pathogens are time-consuming. If a rapid determination of the pathogens in whirlpools and hot water system is available, the infection risks due to the high level of the pathogens can be avoided before exposure occurs. The purpose of this study was to evaluate a rapid method (<1 hour) for the detection of these pathogens in water. For this, immunomagnetic separation (IMS) and a detection method, ATP bioluminescence, have been investigated.The magnetic beads were coated with the antibodies, which are specific for either P. aeruginosa or L. pneumophila. The artificially inoculated water was used. The immunomagnetically separated bacteria were measured by both ATP bioluminescence method and plate count method. Various experimental conditions were tested to find the shortest reaction time while obtaining high recovery. Different concentrations of antibody-magnetic bead complex that capture target bacteria were also tested. The results showed that a reaction time between 10 and 30 min is long enough to allow the reaction between bacteria and antibody-magnetic bead complex. The optimal concentration of antibody-bead complex was 5 μl per ml of sample. The comparison of the level of the target pathogens captured by IMS with the initial level of the bacteria followed a very similar pattern. The results appear promising for a rapid on-site assay of pathogens within an hour without enrichment process.