Evaluation of the usefulness of a new direct immunofluorescence assay (ScanVIT-Legionella) for monitoring hospital water systems contaminated with Legionella spp

Lett Appl Microbiol. 2010 Apr;50(4):341-6. doi: 10.1111/j.1472-765X.2010.02797.x. Epub 2010 Jan 15.

Abstract

Aims: To compare the efficiency of the ScanVIT-Legionella test (Vermicon, Munich, Germany) vs a conventional culture method for the quantification of Legionella spp. in hospital water samples in daily hospital practice.

Methods and results: The detection of Legionella spp. takes place on a cultivated filter brought into contact with dye-marked gene probes. The results are analysed under fluorescence microscopy. Bacteria that light up green belong to the genus Legionella; those that light up both green and red belong to the species Legionella pneumophila. Our results showed that the ScanVIT test has a sensitivity of 90%; agreement between the two methods was 82%. In the 48 samples that tested positive with both methods, the Legionella concentration detected by the culture method was consistently higher. A statistically significant difference between the results obtained with the two test methods emerged at the Wilcoxon test (P < 0.001).

Conclusion: The ScanVIT test may be recommended for investigating the presence of Legionella by qualitative testing.

Significance and impact of the study: Given the simplicity of colony identification by fluorescence, the ScanVIT test can be used in laboratories where staffs are not experienced in identifying typical colonies of Legionella.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Bacteriological Techniques
  • Equipment Contamination*
  • Filtration
  • Fluorescent Antibody Technique, Direct / methods*
  • Fresh Water / microbiology
  • Germany
  • Hospitals*
  • Legionella pneumophila / genetics
  • Legionella pneumophila / isolation & purification*
  • Sensitivity and Specificity
  • Water Microbiology
  • Water Supply*