Chronic Airway Colonization by Achromobacter xylosoxidans in Cystic Fibrosis Patients Is Not Sustained by Their Domestic Environment.

spp. are nonfermentative Gram-negative bacilli considered emergent pathogens in cystic fibrosis (CF). Although some cross-transmission events between CF patients have been described, strains were mostly patient specific, suggesting sporadic acquisitions from nonhuman reservoirs. However, sources of these emergent CF pathogens remain unknown. A large collection of specimens ( = 273) was sampled in the homes of 3 CF patients chronically colonized by with the aim of evaluating the potential role of domestic reservoirs in sustaining airway colonization of the patients. Samples were screened for the presence of by using genus-specific molecular detection. Species identification, multilocus genotypes, and antimicrobial susceptibility patterns observed for environmental isolates were compared with those of clinical strains. Patient homes hosted a high diversity of species ( = 7), including and , two species previously isolated from human samples only, and genotypes ( = 15), all showing an overall susceptibility to antimicrobial agents. strains were mostly isolated from indoor moist environments and siphons, which are potential reservoirs for several CF emerging pathogens. , the worldwide prevalent species colonizing CF patients, was not the major species inhabiting domestic environments. genotypes chronically colonizing the patients were not detected in their household environments. These results support the notions that the domestic environment could not be incriminated in sustained patient colonization and that after initial colonization, the environmental survival of clones adapted to the CF airways is probably impaired. spp. are worldwide emerging opportunistic pathogens in CF patients, able to chronically colonize the respiratory tract. Apart from regular consultations at the hospital CF center, patients spend most of their time at home. Colonization from nonhuman sources has been suggested, but the presence of spp. in CF patients' homes has not been explored. The domestic environments of CF patients chronically colonized by , especially wet environments, host several opportunistic pathogens, including a large diversity of species and genotypes. However, genotypes colonizing the patients were not detected in their domestic environments, making it unlikely that a shuttle between environment and CF airways is involved in persisting colonization. This also suggests that once the bacteria have adapted to the respiratory tract, their survival in the domestic environment is presumably impaired. Nevertheless, measures for reducing domestic patient exposure should be targeted on evacuation drains, which are frequently contaminated by CF opportunistic pathogens.