Molecular epidemiology ofPseudomonas aeruginosa in cystic fibrosis patients from Southeast Austria

Abstract

Pseudomonas aeruginosa is the major pathogen in the cystic fibrosis (CF) lung, the predominant source of its acquisition, however, is under discussion. In order to study the molecular epidemiology, we evaluated 86 P. aeruginosa isolates from 43 CF patients from southeast Austria. The DiversiLab system was used to identify genetic relationships among the isolates. Antibiotic susceptibilities were tested with a broth microdilution method (Micronaut Merlin). A total of 39 unrelated P. aeruginosa genotypes were found of which 34 were unique to a single patient and one was unique to a sibling pair. We found low rates of resistance for β-lactams with resistance to piperacillin/tazobactam and ceftazidime ranging from 4 to 6%. Resistance rates for meropenem and ciprofloxacin were 11% and 15%, respectively. The prevalence of multidrug-resistant isolates was 2%. We conclude that the majority of P. aeruginosa isolates from CF patients originate from environmental sources and patient-to-patient spread is very uncommon in our centre.

Successful implementation of infection control strategies prevents P. aeruginosa transmission among cystic fibrosis patients inside the hospital

“…Our findings are in concordance with a similar study published recently [ 10 ]. Masoud-Landgraf et al typed 86 P. aeruginosa isolates from 43 CF patients under care in the CF centre of the Medical University of Graz, Austria, and found that the majority of CF patients under their investigation harboured unique P. aeruginosa genotypes.…”

“…Masoud-Landgraf et al typed 86 P. aeruginosa isolates from 43 CF patients under care in the CF centre of the Medical University of Graz, Austria, and found that the majority of CF patients under their investigation harboured unique P. aeruginosa genotypes. Putting our data together with results published by Masoud-Landgraf et al and [ 10 ], it may be argued, that for the majority of CF patients in Austria nosocomial acquisition of P. aeruginosa does not constitute a relevant source of infection.…”

“…Similarly to Masoud-Landgraf et al [ 10 ], most of our patients with alleged polyclonal infection with P. aeruginosa seemed to harbour merely two members of a single genotype exhibiting phenotypic differences, namely in their morphotypes or their antibiotic resistance profiles, possibly acquired by mutation during infection or culturing. This suggests that chronic infection with more than one genotype of P. aeruginosa is rare, at least in the population under investigation.…”

The deletion of TonB-dependent receptor genes is part of the genome reduction process that occurs during adaptation ofPseudomonas aeruginosato the cystic fibrosis lung

“…The first approach comprised typing P. aeruginosa CF isolates, which is based on the amplification of repetitive elements in the genome via the DiversiLab method, which has been used extensively to rapidly detect hospital outbreaks of P. aeruginosa (Doleans-Jordheim et al, 2009;Fluit et al, 2010;Ratkai et al, 2010;Deplano et al, 2011;Masoud-Landgraf et al, 2012). The first approach comprised typing P. aeruginosa CF isolates, which is based on the amplification of repetitive elements in the genome via the DiversiLab method, which has been used extensively to rapidly detect hospital outbreaks of P. aeruginosa (Doleans-Jordheim et al, 2009;Fluit et al, 2010;Ratkai et al, 2010;Deplano et al, 2011;Masoud-Landgraf et al, 2012).…”

“…To gain an insight into the P. aeruginosa population that is present among patients with CF attending the CF reference center at UZ Brussel, a combination of two previously described typing methods was used. The first approach comprised typing P. aeruginosa CF isolates, which is based on the amplification of repetitive elements in the genome via the DiversiLab method, which has been used extensively to rapidly detect hospital outbreaks of P. aeruginosa (Doleans-Jordheim et al, 2009;Fluit et al, 2010;Ratkai et al, 2010;Deplano et al, 2011;Masoud-Landgraf et al, 2012). However, a number of studies have shown that typing solely based on DiversiLab can lead to an underestimation of the 1 Core *A deletion event was considered independent if the deleted region was identified in the genome of a distinct P. aeruginosa isolate at a distinct time point in a distinct patient with CF.…”