1H-NMR-Based Endometabolome Profiles of Burkholderia cenocepacia Clonal Variants Retrieved from a Cystic Fibrosis Patient during Chronic Infection

Abstract

During cystic fibrosis (CF) chronic lung infections, bacteria of the Burkholderia cepacia complex (Bcc) are exposed for several years to a stressful and changing environment. These environmental challenges results in genetic changes of the initial infecting strain with the consequent diversification of genotypes and phenotypes. The exploitation of functional and comparative genomic approaches has suggested that such diversification is associated with massive metabolic remodeling but these alterations are poorly understood. In the present work, we have explored a high resolution 1H-NMR-based metabolomic approach coupled to multivariate analysis to compare the endometabolome of three B. cenocepacia clonal variants retrieved from a CF patient from the onset of infection (IST439) until death with cepacia syndrome after 3.5 years (IST4113 and IST4134), to complement former proteomic and transcriptomic analyses. A fourth clonal variant (IST4129) retrieved from the same CF patient when the clinical condition worsened during the last months of life, was also examined since it was found to lack the third replicon. The metabolomic profiles obtained, based on the complete 1H-NMR spectra, highlight the separation of the four clonal variants examined, the most distinct profile corresponding to IST4129. Results indicate a variable content of several amino acids in the different isolates examined and suggest that glycolysis and the glyoxylate shunt are favored in late variants. Moreover, the concentration of two metabolites with demonstrated cellular protective functions against stress, glycine-betaine and trehalose, is different in the different isolates examined. However, no clear correlation could be established between their content and stress tolerance. For example, IST4113, previously found to be the most resistant variant to antimicrobials of different classes, exhibits low levels of trehalose and glycine-betaine but the highest resistance to heat and oxidative stress. Also, IST4129, with a high level of glycine-betaine but lacking the third replicon, previously associated with stress resistance and virulence, exhibits the highest susceptibility to all the stresses tested. Taken together, results from this study provide insights into the metabolic diversification of B. cenocepacia clonal variants during long-term infection of the CF airways.

Using a multi-omic approach to investigate the mechanism of 12-bis-THA activity against Burkholderia thailandensis

“…NMR-based metabolomics has previously been used to investigate bacterial stress adaption in response to environmental stimuli or antimicrobial exposure (Hoerr et al, 2016). Taking a similar approach, we identified 45 metabolites in the cytoplasm of B. thailandensis which is comparable with a study that identified 25 metabolites in the cytoplasm of B. cenocepacia (Moreira et al, 2016). Our complementary data sets analyzing the proteome and metabolome of E555 treated cells will provide insight into the metabolic pathways affected by 12-bis-THA.…”

Structure of O-Antigen and Hybrid Biosynthetic Locus in Burkholderia cenocepacia Clonal Variants Recovered from a Cystic Fibrosis Patient

“…This patient was also co-infected with B. multivorans , another member of the Bcc, which appeared before the isolation of the early B. cenocepacia strain (isolate IST439); co-infection continued until near the patient’s death ( Cunha et al, 2003 ). The B. cenocepacia isolates from this patient were characterized by phenotypic ( Coutinho et al, 2011a ), transcriptomic ( Mira et al, 2011 ), proteomic ( Madeira et al, 2011 , 2013 ) and metabolic profiling ( Moreira et al, 2016a ), as well as by comparative genomics (still unpublished). Isolates of particular interest are B. cenocepacia IST4113 (a highly antibiotic resistant variant retrieved after an exacerbation treated with intravenous therapy), IST4134 (obtained just before the patient’s death), and IST4129 (a variant that exhibits attenuated virulence related with the loss of the third replicon ( Moreira et al, 2016b ).…”

Variation of Burkholderia cenocepacia cell wall morphology and mechanical properties during cystic fibrosis lung infection, assessed by atomic force microscopy

“…These isolates were picked at random from selective agar plates obtained in the major Portuguese CF Center at Hospital de Santa Maria during consultation routines. The clinical isolates examined are of high interest in the context of this study because they were previously characterized by phenotypic 11 , transcriptomic 40 , proteomic 27,41 and metabolic profiling 42 . Results on the comparison of the virulence potential of these isolates using non-mammalian infection models and of their ability to modulate dendritic cell function are also available 25,43 .…”