Method of detecting pathogenic legionella strains

Abstract

The invention relates to a kit for detecting pathogenic Legionella pneumophila strains by hybridizing genomic DNA of a sample suspected to contain Legionella to two or five specific sequence markers, as identified by MARKER NO. 1 through MARKER NO. 5 or homologues thereof.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a divisional of U.S. patent application Ser. No. 12 / 521,119, having an international filing date of 28 Dec. 2007, now allowed, which is the National Stage Application of PCT / NL2007 / 000332, filed 28 Dec. 2007, which claims benefit of European application No. 06077343.9 filed 29 Dec. 2006. The contents of the above patent applications are incorporated by reference herein in their entirety.SUBMISSION OF SEQUENCE LISTING ON ASCII TEXT FILE[0002]The content of the following submission on ASCII text file is incorporated herein by reference in its entirety: a computer readable form (CRF) of the Sequence Listing (file name: 313632007010SeqList.txt, date recorded: Apr. 2, 2013, size: 21,375 byes).FIELD OF THE INVENTION[0003]The invention relates to a method of typing Legionella pneumophila strains, and in particular to a method of identifying a Legionella pneumophila strain as being either pathogenic or non-pathogenic. The inve...

AI Technical Summary

Benefits of technology

The present invention describes a method to distinguish between clinical or pathogenic strains of Legionella and non-pathogenic strains. This is done by using a hybridization assay with specific genetic markers. The group of molecular markers used in the assay comprises two markers (MARKER NO. 1 and MARKER NO. 2) or five markers (MARKER NO. 1, MARKER NO. 2, MARKER NO. 3, MARKER NO. 4, and MARKER NO. 5). The method can be used with samples derived from pure cultures of Legionella pneumophila or any medium suspected of Legionella infestation. The kit of parts includes an array and reference nucleic acids, as well as software to calculate the result of the test.

Problems solved by technology

The resulting infiltration of the alveoli by neutrophils, additional macrophages and erythrocytes results in capillary leakage and edema and the chemokines and cytokines released by the macrophages help trigger a severe inflammatory response, which may be fatal.

Identification of other L. pneumophila serogroups, and other Legionella species, is often much more difficult.

However, cultivation is slow.

of 95%. Thus, so far, commercially available tests for Legionella urinary antigen detect only L. pneumophila serogroup 1, while the specificity of the assays cannot prevent the occurrence of false positive and false negative r

However, a drawback of such DNA methods is that they cannot differentiate between virulent and non-virulent strains, presumably because the virulence trait is multi-genic.

Most experts however, consider that a large number of Legionella bacteria detected are harmless and non-virulent.

However, there is at present no assay system available to distinguish between virulent and non-virulent strains and it is difficult to avoid the costs involved with false-alarm Legionella detection.