Pseudomonas aeruginosa displays an epidemic population structure

Abstract

SummaryBacteria can have population structures ranging from the fully sexual to the highly clonal. Despite numerous studies, the population structure of Pseudomonas aeruginosa is still somewhat contentious. We used a polyphasic approach in order to shed new light on this issue. A data set consisting of three outer membrane (lipo)protein gene sequences ( oprI , oprL and oprD ), a DNA-based fingerprint (amplified fragment length polymorphism), serotype and pyoverdine type of 73 P. aeruginosa clinical and environmental isolates, collected across the world, was analysed using biological data analysis software. We observed a clear mosaicism in the results, non-congruence between results of different typing methods and a microscale mosaic structure in the oprD gene. Hence, in this network, we also observed some clonal complexes characterized by an almost identical data set. The most recent clones exhibited serotypes O1, 6, 11 and 12. No obvious correlation was observed between these dominant clones and habitat or, with the exception of some recent clones, geographical origin. Our results are consistent with, and even clarify, some seemingly contradictory results in earlier epidemiological studies. Therefore, we suggest an epidemic population structure for P. aeruginosa , comparable with that of Neisseria meningitidis , a superficially clonal structure with frequent recombinations, in which occasionally highly successful epidemic clones arise.

Development of a Multilocus Sequence Typing Scheme for the Opportunistic Pathogen Pseudomonas aeruginosa

“…In fact, some of these environmental isolates were members of clones or clonal complexes that possessed isolates from cases of invasive disease. This corroborates assumptions based on previous studies which found no correlations between habitat and particular clones (17,20).…”

Genetic features of Pseudomonas aeruginosa isolates from cystic fibrosis patients compared with those of isolates from other origins

“…Previous studies have suggested that there is no correlation between P. aeruginosa clones and diseases or environmental habitats (Foght et al, 1996;Kiewitz & Tummler, 2000;Pirnay et al, 2002;Romling et al, 1994). The use of one or a few strains to represent one disease or environmental habitat may have limited the conclusions of these studies.…”

“…Most of these studies have included few or no CF isolates (Denamur et al, 1993;Kiewitz & Tummler, 2000;Lomholt et al, 2001;Pirnay et al, 2002;Ruimy et al, 2001) or have specifically explored the genome of P. aeruginosa isolates from CF patients, especially for epidemiological purposes (Boukadida et al, 1993;Hoogkamp-Korstanje et al, 1995). Fewer studies have demonstrated a link between isolates from CF patients and isolates from environmental habitats (Romling et al, 1994).…”

Phenotypic and genotypic diversity of Pseudomonas aeruginosa strains isolated from hospitals in siedlce (Poland)

“…Pyocin production was tested on selective Cetrimide Agar aeruginosa strains isolated from faeces (10,11,12,13,14), NCTC 6749 (15) and wound (16,17,18 Results of antibiotic resistance and genotyping showed poor correlation. Resistance patterns from bacterial isolates which had identical genotypes differed in up to 9 antibiotics.…”