Infection by Ralstonia Species in Cystic Fibrosis Patients: Identification of R. pickettii and R. mannitolilytica by Polymerase Chain Reaction

摘要

The frequency of respiratory tract infections caused by Ralstonia species in persons with cystic fibrosis(CF) and the role of these species in CF pulmonary disease are not well documented. In part, this lack ofdocumentation may be attributed to the difficulty in accurately identifying Ralstonia species; R. mannitoli-lytica and R. pickettii in particular may be misidentified as other closely related species, particularly thoseof the Burkholderia cepacia complex. We used polyphasic analyses to identify 42 Ralstonia isolates fromsputum cultures from 38 CF patients. Several isolates that could not be identified to the species level maybelong to novel Ralstonia species. We demonstrated chronic colonization by using genotyping of serialisolates recovered from the same patient. To facilitate identification of R. mannitolilytica and R. pickettii, wedeveloped 16S ribosomal DNA-based polymerase chain reaction assays that allo w sensitive and specificidentification of these species.