A new field method to measure viable Legionella and total heterotrophic aerobic bacteria was evaluated in the laboratory, in split-sample blinded comparisons and in actual operating field conditions. The method was proven reliable for determining viable cell concentrations of Legionella pneumophila serogroup 1, serogroups 2-14 and Legionella species. Total heterotrophic aerobic bacteria results are obtained from the same sample. The new method was shown to be more accurate, faster and more convenient compared to standard methods. Comparisons to other methods are given. Guidance is provided for use of the new method within the context of hazard analysis and control to prevent legionellosis.
The patents pending Phigenics Validation Test® (PVT) is a “dipslide format” field sampler that hason its surfaces the standard growth media required for Legionella enumeration. Both viable Legionella and total heterotrophic aerobic bacteria counts can be obtained from the same test.Laboratory experiments, split sample comparisons and case histories of field use under actual operating conditions were used to evaluate the PVT.