DNA testing can rapidly solve Legionella outbreaks

DNA testing can rapidly solve Legionella outbreaks



Legionnaires’ disease is a potentially-fatal bacterial lung infection caused by legionella contamination. An estimated 8,000 to 18,000 cases a year in the United States require hospitalization.

To detect potential legionella risk in an environment suspected, water samples are studied. Then bacterial cutlure show the potential presence of legionella. This analysis take few days before detect the pathogen bacteria and develop measure of prevention and control.


New approach with DNA ?

“polymerase chain reaction (PCR)”

American scientifics studied DNA (Acid desoxyribonucleic) in order to detect rapidly the bacteria. Fragments of DNA are run through a machine called a thermocycler, which heats and cools the sample repeatedly to produce multiple copies of these DNA fragments, amplifying them for analysis in just a few hours. Scientifics affirmed that this method (PCR) can confirm the presence of Legionella bacteria in a water sample.

Analysis by culture need to be done, to detect if bacteria are alive or dead. Indeed, legionella lead to disease just if they are alive.

In late 2014, an hypothetic legionella risk was annunced in a cooling tower.  A PCR allowed to detect in one day legionella in water samples,. This result leaded to closing and deinfection of the cooling tower. After few days, bacterial culture showed tht legionella were alive.

It is important to detect rapidly the presence of bacteria in order to prevent and protect residents from a legionella risk.


Source : Journal of Environmental Health.

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