DETECTION OF HIGH LEVELS OF BURKHOLDERIA CONTAMINANS PERSISTER CELLS IN CYSTIC FIBROSIS PATIENTS WITH CHRONIC LUNG INFECTION

MARIANA LEGIZAMÓN; CLAUDIA PRIETO; LAURA BELTINA LEON; CECILIA BEATRIZ FÍGOLI; PABLO MARTINA; OSVALDO YANTORNO; ALEJANDRA BOSCH; MARISA BETTIOL; FERNANDO RENTERÍA

Orlando

Congreso; 30th Annual North American Cystic Fibrosis Conference; 2016

Among the Burkholderia cepacia complex species, B. contaminans represents the most frequently recovered from patients with cystic fibrosis (CF) in Argentina (1). Although for some patients B. contaminans respiratory tract infection is transient, its acquisition most typically results in a chronic infection with a gradual decline in lung function (2). It was recently reported for B. cenocepacia J2315 (belonging to the ET12 lineage) that the Burholderia cepacia epidemic strain marker (BCESM) genomic region located on the genomic island (GI) BcenGI1, contains an operon (BCAM0257-8-9) possible involved in persistence, quorum sensing expression, and virulence (3). We here aimed to study a possible relation between persistence and establishment of B. contaminans chronic infection, and the presence of genes associated to the genomic island BcenGI11, which was not reported for this species, so far. For this purpose, we analyzed 145 B. contaminans isolates recovered from 51 patients attended in the period 2004 2015 in 3 different CF reference centers of Argentina. Persister cells in 24-h old biofilms exposed to ciprofloxacin concentrations of 4 and 128 × the MIC was quantified. The BCESM and the BCAM0257-8-9 regions were detected by PCR -using B. cenocepacia specific primers- and sequenced. The percentage of persister cells was between 5 and 10 % for B. contaminans isolates recovered from chronic lung infections in contrast to less than 2% of persistors for isolates obtained from transient infections. Interestingly, 100 % of the chronic infected patients (37 patients) and the 28.6 % of the patients with transient infections (4 out of 14 patients) harbored both the BCESM and the BCAM257-9 regions. Sequence analysis showed that the amplification products of these regions had an identity of 93 and 95 % with those of B. cenocepacia J2315, respectively. These results showed the presence of the operon contained in the BCESM region might be responsible for the emergence of persistors and therefore the difficulties in the eradications of B. contaminans chronic infection. (1) Martina et al. 2013, J Clin Microbiol 51: 339-344, (2) Martina et al. 2014, Internat J Med Microbiol 304:1182?1191, (3) Van Acker et al. 2014, Future Microbiol 9: 845?860