Burkholderia contaminans in cystic fibrosis over a 15-year period in a reference centerin Argentina

V. D´ALESSANDRO; M. ALGARAÑAS; C. PRIETO; C. VESCINA; A. BOSCH; B. LEÓN; M. BETTIOL; C. VITA; N. IRIGOYEN; F. RENTERIA; M. LEGUIZAMÓN; D. CASCO; C. FIGOL; OM. YANTORNO

Liverpool

Conferencia; 42nd EUROPEAN CYSTIC FIBROSIS CONFERENCE; 2019

EUROPEAN CYSTIC FIBROSIS SOCIETY

Objectives:Airways colonization byBurkholderia contaminansis generally associated witha rapidlung function declineand increased mortality in patientswith CF. The aim of this study is to contribute to the understanding of the relevant aspects of chronic respiratory infections mediated byB. contaminansbased on the analysis of microbial characteristics and patients? clinical outcome.Methods:Thisstudy wasconducted with 16 patients with CF colonized byB. contaminansbeing attended at the CF reference center, Hospital ?Sor María Ludovica?, La Plata, Argentina since 2004. A total of 31 isolates recovered from respiratory sample were analyzed. They were identified by MLSTand characterized by colony morphology, mucoidicity, quorum sensing, and other virulence factors. Children ́s clinical status was evaluated by the nutritional parameter zBMI, and the number of pulmonary exacerbations during the infection.Results:A considerable low diversity amongB. contaminanssequence types (STs) was encountered (872, 102 and 432 STs). Although long-term respiratory infections by all STs lead to a significant decline in patients ́ lung function, colonization by ST 102, results in an earlier lung deterioration. Interestingly,among the 3patients with the worse clinical outcome, 2 were colonized by bacteria that converted to brown-pigmented-small-colony variant (SCV), whileisolates recovered from the third patient, switched to non-mucoid phenotype during the infection. None of the 4 patients in the studied population who died developed ?cepacia syndrome? but, interestingly isolates recovered from 3 of them also switched to the non-mucoid phenotype in last years of infection.Conclusion:We here report for the first time thatB. contaminansadaptation that results, either in a switch to non-mucoid phenotype, the emergence of SCV, and/or the acquisition of pigmentation along the chronic infection, leads to a rapid lung decline, independently of the species linage.