title: Fast and simple epidemiological typing of Pseudomonas aeruginosa using the double-locus sequence typing (DLST) method.
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 (NT) = 35-64; index of discrimination (ID) = 0.816-0.964] was lower than the combination of two loci (NT = 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.
authors: Service of Hospital Preventive Medicine, Lausanne University Hospital, Rue du Bugnon 48, 1011, Lausanne, Switzerland, Patrick.Basset@chuv.ch.
authors: P
authors: P
authors: Basset
authors: D S
authors: DS
authors: Blanc
mesh_terms: D005838:Genotype; D006801:Humans; D017720:Molecular Epidemiology / Q000379:methods; D058885:Multilocus Sequence Typing / Q000379:methods*; D011552:Pseudomonas Infections / Q000453:epidemiology / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity