Published in:
01-06-2014 | Article
Fast and simple epidemiological typing of Pseudomonas aeruginosa using the double-locus sequence typing (DLST) method
Authors:
P. Basset, D. S. Blanc
Published in:
European Journal of Clinical Microbiology & Infectious Diseases
|
Issue 6/2014
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Abstract
Although the molecular typing of
Pseudomonas aeruginosa is important to understand the local epidemiology of this opportunistic pathogen, it remains challenging. Our aim was to develop a simple typing method based on the sequencing of two highly variable loci. Single-strand sequencing of three highly variable loci (
ms172,
ms217, and
oprD) was performed on a collection of 282 isolates recovered between 1994 and 2007 (from patients and the environment). As expected, the resolution of each locus alone [number of types (N
T) = 35–64; index of discrimination (ID) = 0.816–0.964] was lower than the combination of two loci (N
T = 78–97; ID = 0.966–0.971). As each pairwise combination of loci gave similar results, we selected the most robust combination with
ms172 [reverse; R] and
ms217 [R] to constitute the double-locus sequence typing (DLST) scheme for
P. aeruginosa. This combination gave: (i) a complete genotype for 276/282 isolates (typability of 98 %), (ii) 86 different types, and (iii) an ID of 0.968. Analysis of multiple isolates from the same patients or taps showed that DLST genotypes are generally stable over a period of several months. The high typability, discriminatory power, and ease of use of the proposed DLST scheme makes it a method of choice for local epidemiological analyses of
P. aeruginosa. Moreover, the possibility to give unambiguous definition of types allowed to develop an Internet database (
http://www.dlst.org) accessible by all.