Researchers at the University of Torino in Italy have discovered a novel way to test for low concentrations of legionella pneumophila in water. One of the most commonly used methods of testing for legionella in water involves growing a culture from the biofilm (slime) that rests on the surfaces of water systems. Large amounts of water are also included and tested in this method. The samples are then taken into a lab where it takes anywhere from 7-14 days for any potential bacteria culture to grow. Another common testing method is what is called Quantitative Polymer Chain Reaction (qPCR). This method uses DNA testing to search for genetic traces of legionella bacteria. However the downside to this method is that the genetic testing cannot determine between active legionella cells and dead legionella cells. The researchers primarily used the qPCR method, and added elements of another testing method that better differentiates between alive and dead cells. The combined testing method is more accurate at testing for legionella pneumophila. Their method presents a quicker, more viable option for testing for legionella in water systems believed to have low concentrations, where previous methods would fail to detect trace levels of the bacteria.
The full study can be found here.