The Burkholderia contaminans prevalent phenotypes as possible markers of poor clinical outcomes in chronic lung infection of children with cystic fibrosis.

Burkholderia contaminans, a species of the Burkholderia cepacia complex-prevalent in certain Latin-American and European countries-can cause chronic pulmonary infection in persons with cystic fibrosis. Our aim was to gain insights into long-term lung infections with a focus on correlating how bacterial phenotypic traits in the chronic infection impact on patients' clinical outcome. Genotypic characteristics of 85 B. contaminans isolates recovered from 70 patients were investigated. For 16 of those patients, the clinical status and bacterial phenotypic characteristics, e.g. several virulence factors, phenotypic variants, and the antimicrobial susceptibility pattern, were evaluated. Two clones were found in the whole bacterial population: (i) the multiresistant ST 872 PCR-recA-RFLP-HaeIII-K-pattern clone, which carries a pathogenic island homologous to BcenGI11 of B. cenocepacia J2315, and (ii) the ST 102 PCR-recA-RFLP-HaeIII-AT-pattern clone. The emergence of certain bacterial phenotypes in the chronic infection such as the nonmucoid phenotype, small colony variants, brownish pigmented colonies, and hypermutators, proved to be, together with coinfection with Pseudomonas aeruginosa, the possible markers of more challenging infections and poor prognosis. The presence of cocolonizers and the bacterial phenotypes that are especially adapted to persist in long-term respiratory tract infections have a crucial role in patients' clinical outcomes.

The Genetic relatedness of Burkholderia contaminans clinical isolates from cystic fibrosis and non-cystic fibrosis patients in Argentina.

INTRODUCTION: The Burkholderia cepacia complex (BCC) bacteria are opportunistic pathogens that cause nosocomial infections and are especially dangerous for cystic fibrosis (CF) patients. Burkholderia contaminans is an emerging BCC species isolated from CF patients that also occurs as a contaminant in pharmaceutical and personal care products, sometimes linking it with outbreaks. METHODOLOGY: A total of 55 B. contaminans isolates from CF and non-CF patients in Argentina were identified by recA sequencing and MALDI TOF MS. A standardized Pulsed Field Gel Electrophoresis (PFGE) protocol was set up in order to assess genetic diversity, outbreak investigations, and possible clone persistence. RESULTS: All isolates were identified as B. contaminans by both MALDI-TOF MS and recA sequence analysis. PFGE has enabled us to compare and determine the genetic relationship between B. contaminans isolates. Isolates were distributed in different PFGE clusters with evidence of the presence and persistence of a clone, over a period of 3 years, in the same hospital. This large hospital outbreak involved CF and non-CF patients. Moreover, PFGE results showed a good correlation between sporadic or outbreak-related isolates and the available epidemiological information. CONCLUSIONS: These findings highlight the importance of B. contaminans in Argentina and provide evidence for encouraging the surveillance of highly transmissible clones. The study also contributes to global knowledge about B. contaminans infections.

Performing under pressure: esterification activity of dry fermented solids in subcritical and supercritical CO2.

OBJECTIVE: Lipases are often used in immobilized form, but commercial immobilized lipases are costly. An alternative is to produce lipases in solid-state fermentation, dry the solids and then use the "dry fermented solids" (DFS) directly. We produced DFS by growing Burkholderia contaminans on a mixture of sugarcane bagasse and sunflower seed meal and used the DFS to esterify oleic acid with ethanol in subcritical and supercritical CO2 at 40 °C. RESULTS: Compared to a control without CO2 at atmospheric pressure, subcritical CO2 at 30 bar improved esterification activity 1.2-fold. Higher pressures, including supercritical pressures up to 150 bar, reduced activity to less than 80% of the control. At 30 bar, the esterification activity was improved a further 1.8-fold with the addition of 9% water (i.e. 9 g water per 100 g oleic acid) to the reaction medium. CONCLUSION: A subcritical CO2 atmosphere, with the addition of a small amount of water, improved the esterification activity of DFS containing lipases of Burkholderia contaminans.

Polyhydroxybutyrate and polyhydroxydodecanoate produced by Burkholderia contaminans IPT553.

AIMS: In this paper, we introduce a new Burkholderia contaminans capable of producing a newly characterized polymer. METHODS AND RESULTS: CG-MS and magnetic nuclear resonance 1 H and 13 C were used to determine the constitution of polymers produced in glucose, glucose with casein, sucrose and sucrose with casein. Three pairs of primers were used to find the polyhydroxyalkanoates (PHA) synthase class and sequence. The synthesized polymers were composed by short-chain length PHA (scl-PHA), especially polyhydroxybutyrate (PHB), and medium chain length PHA (mcl-PHA), especially polyhydroxydodecanoate (PHDd), and their concentration, constitution and molecular weight depend on carbon source used. The bacterium showed only class I synthase which could not explain the mcl-PHA production. CONCLUSIONS: Burkholderia contaminans has a class I PHA synthase and produces PHB combined to PHDd when cultivated in sucrose or glucose, and PHDd concentration is affected when casein is used. SIGNIFICANCE AND IMPACT OF THE STUDY: PHA are natural polymers produced by a wide range of bacteria. The presence of PHDd monomers confers to the polymer elastomeric properties. Previously, PHDd was only obtained when bacteria were cultivated in related carbon source. In this work, B. contaminansIPT553 produced PHB with PHDd using simple and low-cost carbon sources that can make possible the cheaper production of a more flexible biopolymer with crystallinity and elasticity different from the more common PHAs.