Biodiversity of cultivable Burkholderia species in Argentinean soils under no-till agricultural practices

No-tillage crop production has revolutionized the agriculture worldwide. In our country more than 30 Mha are currently cultivated under no-till schemes, stressing the importance of this management system for crop production. It is widely recognized that soil microbiota is altered under different soil managements. In this regard the structure of Burkholderia populations is affected by soils management practices such as tillage, fertilization, or crop rotation. The stability of these structures, however, has not been evaluated under sustainable schemes where the impact of land practices could be less deleterious to physicochemical soils characteristics. In order to assess the structure of Burkholderia spp. populations in no-till schemes, culturable Burkholderia spp. strains were quantified and their biodiversity evaluated. Results showed that Burkholderia spp. biodiversity, but not their abundance, clearly displayed a dependence on agricultural managements. We also showed that biodiversity was mainly influenced by two soil factors: Total Organic Carbon and Total Nitrogen. Results showed that no-till schemes are not per se sufficient to maintain a richer Burkholderia spp. soil microbiota, and additional traits should be considered when sustainability of productive soils is a goal to fulfil productive agricultural schemes.Fil: Draghi, Walter Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Degrossi, Jose. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bialer, Magali Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Brelles Mariño, Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Abdian, Patricia Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Soler Bistue, Alfonso Jc. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Wall, Luis Gabriel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zorreguieta, Ángeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

Draft Genome Sequences of Burkholderia contaminans FFI-28, a Strain Isolated from a Contaminated Pharmaceutical Solution

Burkholderia contaminans is a species of the Burkholderia cepacia complex, a group of bacteria that can grow in pharmaceutical products and are capable of infecting the immunocompromised and people with cystic fibrosis. Here, we report draft genome sequences for Burkholderia contaminans FFI-28, a strain isolated from a contaminated pharmaceutical solution.Fil: Haim, Maria Sol. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mollerach, Marta Eugenia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Van Domselaar, Gary. Public Health Agency of Canada; CanadáFil: Teves, Sergio A.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Degrossi, Jose. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Cardona, Silvia T.. University of Manitoba; Canad

Understanding the Pathogenicity of Burkholderia contaminans, an Emerging Pathogen in Cystic Fibrosis.

Several bacterial species from the Burkholderia cepacia complex (Bcc) are feared opportunistic pathogens that lead to debilitating lung infections with a high risk of developing fatal septicemia in cystic fibrosis (CF) patients. However, the pathogenic potential of other Bcc species is yet unknown. To elucidate clinical relevance of Burkholderia contaminans, a species frequently isolated from CF respiratory samples in Ibero-American countries, we aimed to identify its key virulence factors possibly linked with an unfavorable clinical outcome. We performed a genome-wide comparative analysis of two isolates of B. contaminans ST872 from sputum and blood culture of a female CF patient in Argentina. RNA-seq data showed significant changes in expression for quorum sensing-regulated virulence factors and motility and chemotaxis. Furthermore, we detected expression changes in a recently described low-oxygen-activated (lxa) locus which encodes stress-related proteins, and for two clusters responsible for the biosynthesis of antifungal and hemolytic compounds pyrrolnitrin and occidiofungin. Based on phenotypic assays that confirmed changes in motility and in proteolytic, hemolytic and antifungal activities, we were able to distinguish two phenotypes of B. contaminans that coexisted in the host and entered her bloodstream. Whole genome sequencing revealed that the sputum and bloodstream isolates (each representing a distinct phenotype) differed by over 1,400 mutations as a result of a mismatch repair-deficient hypermutable state of the sputum isolate. The inferred lack of purifying selection against nonsynonymous mutations and the high rate of pseudogenization in the derived isolate indicated limited evolutionary pressure during evolution in the nutrient-rich, stable CF sputum environment. The present study is the first to examine the genomic and transcriptomic differences between longitudinal isolates of B. contaminans. Detected activity of a number of putative virulence factors implies a genuine pathogenic nature of this novel Bcc species

Staphylococcus aureus Potentiates the Hemolytic Activity of Burkholderia cepacia Complex (Bcc) Bacteria

Polymicrobial lung infections in individuals with Cystic Fibrosis (CF) contribute to the complexity of this disease and are a major cause of morbidity and mortality in the CF community. The microorganisms most commonly associated with severe airway infections in individuals with CF are the opportunistic pathogens S. aureus, P. aeruginosa and bacteria from the Burkholderia cepacia complex (Bcc), particularly B. cenocepacia and B. multivorans. Three Bcc strains, two S. aureus wild-type strains, and two derivative mutants were used to investigate the interplay between S. aureus and Bcc with a focus on the hemolytic activity of Bcc. Our results revealed that extracellular products from S. aureus potentiated the hemolysis of Bcc strains. Moreover, this effect was influenced by the composition of the medium in which S. aureus is grown. These findings contribute towards the understanding of the impact of interactions between S. aureus and Bcc and their possible implications in the context of co-infections by these pathogens in individuals with CF.Fil: Moriano, Alessandro. California State University; Estados UnidosFil: Serra, Diego Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Hoard, Amparo. California State University; Estados UnidosFil: Montaña, Sabrina Daiana. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Degrossi, Jose. Universidad de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y BioquÍmica. Instituto de Investigaciones En Bacteriología y Virología Molecular (IBaViM); ArgentinaFil: Bonomo, Robert A.. Case Western Reserve University School of Medicine; Estados UnidosFil: Papp-Wallace, Krisztina M.. Case Western Reserve University School of Medicine; Estados UnidosFil: Ramirez, Maria Soledad. California State University; Estados Unido

Summary of the genetic differences between <i>B</i>. <i>contaminans</i> isolates 467_S and MF16_B.

<p>Summary of the genetic differences between <i>B</i>. <i>contaminans</i> isolates 467_S and MF16_B.</p

Soil and environmental characteristics at each sampling location.

<p>Soil and environmental characteristics at each sampling location.</p

Diversity values of <i>Burkholderia spp</i>. populations.

<p>Diversity values of <i>Burkholderia spp</i>. populations.</p

Multivariate analysis of <i>Burkholderia spp</i>. diversity according to soil properties.

<p>Lines indicate the magnitude of soil measured variables associated with bacterial community structures. Treatments are depicted as colored spots, and numbers indicate sampling dates (1: February 2010; 2: September 2010; 3: February 2011; 4: September 2011).</p

Biodiversity of cultivable <i>Burkholderia</i> species in Argentinean soils under no-till agricultural practices

<div><p>No-tillage crop production has revolutionized the agriculture worldwide. In our country more than 30 Mha are currently cultivated under no-till schemes, stressing the importance of this management system for crop production. It is widely recognized that soil microbiota is altered under different soil managements. In this regard the structure of <i>Burkholderia</i> populations is affected by soils management practices such as tillage, fertilization, or crop rotation. The stability of these structures, however, has not been evaluated under sustainable schemes where the impact of land practices could be less deleterious to physicochemical soils characteristics. In order to assess the structure of <i>Burkholderia</i> spp. populations in no-till schemes, culturable <i>Burkholderia</i> spp. strains were quantified and their biodiversity evaluated. Results showed that <i>Burkholderia</i> spp. biodiversity, but not their abundance, clearly displayed a dependence on agricultural managements. We also showed that biodiversity was mainly influenced by two soil factors: Total Organic Carbon and Total Nitrogen. Results showed that no-till schemes are not per se sufficient to maintain a richer <i>Burkholderia</i> spp. soil microbiota, and additional traits should be considered when sustainability of productive soils is a goal to fulfil productive agricultural schemes.</p></div

Phylogenetic analysis or <i>recA</i> sequences obtained from <i>Burkholderia spp</i>.

<p>The isolates were ascribed to known species of <i>Burkholderia</i> according to their clustering pattern with the type strains (indicated by the superscript ^T) in highly supported clusters (bootstraps values ≥ 90%). This figure shows the identification of strains belonging to Bengolea site. Same analysis was done over the entire collection. <i>recA</i> sequences were deposited in the Genbank under the Accession numbers MF941496 to MF942066.</p