Comparison of polymerase chain reaction and conventional culture for the detection of legionellae in cooling tower waters in Singapore

Abstract

A total of 80 cooling tower water samples were investigated for legionellae using both cultural and polymerase chain reaction (PCR) methods. PCR was performed with the Perkin Elmer EnviroAmp Legionella kit. Forty-seven samples (58.8%) were found positive by both methods; 29 samples (36.3%) were positive by PCR only, while four samples (5%) showed PCR inhibition despite the adoption of the more stringent sample preparation protocol especially designed to eliminate inhibitors.