Clinical characteristics of bacteraemia caused by Burkholderia cepacia complex species and antimicrobial susceptibility of the isolates in a medical centre in Taiwan

Abstract

This study investigated the clinical characteristics and outcomes of bacteraemia due to Burkholderia cepacia complex (BCC) species among 54 patients without cystic fibrosis from January 2013 to February 2015. BCC isolates were identified to the species level by the Bruker Biotyper MALDI-TOF MS system and by sequencing analysis of the 16S rRNA and recA genes. Antimicrobial susceptibilities of the isolates were determined by the agar dilution method. Sequencing of the recA gene in the 54 blood isolates revealed 37 (68.5%) isolates of B. cenocepacia, 9 (16.7%) of B. cepacia, 4 (7.4%) of B. multivorans and one isolate each of B. arboris, B. pseudomultivorans, B. seminalis, and B. vietnamiensis. The overall performance of the Bruker Biotyper MALDI-TOF MS system for correctly identifying the 54 BCC isolates to the species level was 79.6%, which was better than that (16.7%) by 16S RNA sequencing analysis. Bacteraemic pneumonia (n = 23, 42.6%) and catheter-related bacteraemia (n = 21, 38.9%) were the most common types of infection. Higher rates of ceftazidime and meropenem resistance were found in B. cepacia isolates (33.3% and 22.2%, respectively) than in isolates of B. cenocepacia (21.6% and 10.8%, respectively) and other species (12.5% and 12.5%, respectively). Overall, the 30-day mortality rate was 38.9% (21/54). Bacteraemia caused by BCC species other than B. cenocepacia and B. cepacia (adjusted odds ratio [aOR] 20.005, P = 0.024) and high SOFA score (aOR 1.412, P = 0.003) were predictive of higher 30–day mortality. Different BCC species are associated with different outcomes of bacteraemia and exhibit different susceptibility patterns.