1.9 Detecting in water systems Legionella The association of with protozoa and its occurrence within biofilms, in Legionella they hide, complicates its detection. The current standard and validated technique for detecting in water is Legionella based on culturing for (ISO 11731:1998). This technique is however Legionella lengthy and complex, and detects only planktonic, free-living, and extracellular Legionella. molecular tests for the detection of Deoxyribonucleic Acid (DNA) Legionella have been developed (Mahbubani 1990). Although these tests detect planktonic, et al., sessile, extracellular and intracellular nonviable cells are also Legionella, Legionella detected. Since it is likely that water samples contains nonviable cells, Legionella which were killed by disinfection measures, false-positive readings of Legionella samples are possible which could lead to unnecessary and expensive emergency decontamination procedures (Shih and Lin, 2006). 21
1.9 Detecting Legionella in water systems The association of Legionella with protozoa and its occurrence within biofilms, in they hide, complicates its detection. The current standard and validated technique for detecting Legionella in water is based on culturing for Legionella (ISO 11731:1998). This technique is however lengthy and complex, and detects only planktonic, free-living, and extracellular Legionella. molecular tests for the detection of Legionella Deoxyribonucleic Acid (DNA) have been developed (Mahbubani et al., 1990). Although these tests detect planktonic, sessile, extracellular and intracellular Legionella, nonviable Legionella cells are also detected. Since it is likely that water samples contains nonviable Legionella cells, which were killed by disinfection measures, false-positive readings of Legionella samples are possible which could lead to unnecessary and expensive emergency decontamination procedures (Shih and Lin, 2006). 21
Birgitta-Bedford-Thesis-2012.docx