CHRONIC LUNG INFECTION BY BURKHOLDERIA CONTAMINANS IN CHILDREN WITH CYSTIC FIBROSIS: PHENOTYPIC AND GENOTYPIC CHARACTERIZATION AND EVALUATION OF PATIENTS? CLINICAL OUTCOME

LEÓN, BELTINA; LEGUIZAMÓN, MARIANA; RENTERÍA, FERNANDO; BETTIOL, MARISA; VESCINA CECILIA; CASCO, DANIELA; DALESSANDRO, VIRGINIA; BOSCH, ALEJANDRA

Dublin

Workshop; 21st International Burkholderia cepacia Working Group meeting (IBCGW 2018); 2019

International Burkholderia cepacia Working Group

Among Burkholderia cepacia complex species, B. contaminans represents the most prevalent species in patients with cystic fibrosis (CF) in Argentina. Although B. contaminans respiratory tract infections may be transient, its acquisition generally results in a chronic pulmonary infection very difficult to eradicate even under aggressive antimicrobials treatments. Throughout the course of chronic infections these organisms undergo adaptations that contribute to their long-term persistence in the airways. The aim of this investigation was to study the phenotypic and genotypic changes of isolates consecutively recovered along B. contaminans chronic lung infections in children with CF, and to analyze if those changes were related or reflected in patients? clinical outcome.The study was performed with 14 patients colonized by B. contaminans attended at Hospital de Niños ?Sor María Ludovica?, La Plata, Argentina, in the period 2005-2017. Among them, 12 patients were chronically infected, while 2 presented transient infections. For each chronically infected patient 2 isolates were analyzed: the one which was believed to have initiated the infection, and the last isolate available of the chronic infection. All isolates were analyzed by multilocus sequence typing, MLST, and characterized by the presence of BCESM, HaeIII recA?RFLP, RAPD and BOX-PCR-fingerprinting. Different phenotypes of each isolate, including colony morphology, mucoid morphotype, quorum sensing, biofilms formation capacity, protease and hemolysin activities, growth profiles, and antibiotic resistance were determined. Patients? clinical status was evaluated at the time of recovering the airway sample by their weight and height, and the zBMI and percBMI parameters were further calculated. The MLST analysis revealed a low genetic diversity among the isolates; only the ST102 and ST872 were found. Among patients colonized by ST872 bacteria, different clinical outcomes were observed. The clinical evolution was unfavorable when the isolates recovered along the infection gained virulence determinants and antibiotic resistance to multiples antibiotics. In contrast ST102 isolates did not show remarkable modifications in their phenotypes, and for most of the patients carrying this ST, the clinical status remained stable during the chronic infection. It is worthwhile to remark that none of the patients acquired ?cepacia syndrome? due to septicemia caused by B. contaminans