biofilm and burkholderia

Pseudomonas aeruginosa , Staphylococcus aureus , and Burkholderia cepacia are notorious pathogens known for their ability to form resilient biofilms, particularly within the lung environment of cystic fibrosis (CF) patients. The heightened concentration of NaCl, prevalent in the airway liquid of CF patients' lungs, has been identified as a factor that promotes the growth of osmotolerant bacteria like S. aureus and dampens host antibacterial defenses, thereby fostering favorable conditions for infections. In this study, we aimed to investigate how increased NaCl concentrations impact the development of multi-species biofilms in vitro , using both laboratory strains and clinical isolates of P...

The rapid emergence of antimicrobial resistance (AMR) pathogens highlights the urgent need to approach this global burden with alternative strategies. Cefiderocol (Fetroja®) is a clinically-used sideromycin, that is utilized for the treatment of severe drug-resistant infections, caused by Gram-negative bacteria; there is evidence of cefiderocol-resistance occurring in bacterial strains however. To increase the efficacy and extend the life-span of sideromycins, we demonstrate strong synergisms between cefiderocol and metallodrugs (e...

To explore the effect of ultra-strong static magnetic field on gut microbiota, 16 T static magnetic field was used to study the changes in the structure and composition of human and mouse gut microbiota in this environment. In the mouse gut microbiota, at the genus level, the magnetic field significantly decreased the relative abundances of Escherichia-Shigella, Lactobacillus, Enterococcus, Burkholderia-Caballeronia-Paraburkholderia, Parasutterella, and Ralstonia and significantly increased those of Parabacteroides, Alloprevotella, Alistipes, Odoribacter, Bacteroides, Mucispirillum, Sutterella, and Prevotellaceae_UCG-001...

Aim: This study evaluated the effect of fluoxetine (FLU) on planktonic and biofilm growth and the antimicrobial susceptibility of Burkholderia pseudomallei . Materials & methods: The minimum inhibitory concentrations (MICs) for FLU were determined by broth microdilution. Its effect on growing and mature biofilms and its interaction with antibacterial drugs were evaluated by assessing biofilm metabolic activity, biomass and structure through confocal microscopy. Results: The FLU MIC range was 19.53-312...

Burkholderia multivorans is the dominant Burkholderia pathogen recovered from lung infection in people with cystic fibrosis. However, as an understudied pathogen there are knowledge gaps in relation to its population biology, phenotypic traits and useful model strains. A phylogenomic study of B. multivorans was undertaken using a total of 283 genomes, of which 73 were sequenced and 49 phenotypically characterized as part of this study. Average nucleotide identity analysis (ANI) and phylogenetic alignment of core genes demonstrated that the B...

Reverse vaccinology is a powerful tool that was recently used to develop vaccines starting from a pathogen genome. Some bacterial infections have the necessity to be prevented then treated. For example, individuals with chronic pulmonary diseases, such as Cystic Fibrosis, are prone to develop infections and biofilms in the thick mucus that covers their lungs, mainly caused by Burkholderia cepacia complex, Haemophilus influenzae , Mycobacterium abscessus complex , Pseudomonas aeruginosa and Staphylococcus aureus...

Aggregated bacteria embedded within self-secreted extracellular polymeric substances, or biofilms, are resistant to antibiotics and cause chronic infections. As such, they are a significant public health threat. Heme is an abundant iron source for pathogenic bacteria during infection; many bacteria have systems to detect heme assimilated from host cells, which is correlated with the transition between acute and chronic infection states. Here, we investigate the heme-sensing function of a newly discovered multifactorial sensory hemoprotein called NosP and its role in biofilm regulation in the soil-dwelling bacterium Burkholderia thailandensis , the close surrogate of Bio-Safety-Level-3 pathogen Burkholderia pseudomallei ...

The Burkholderia cepacia complex comprises environmental and clinical Gram-negative bacteria that infect particularly debilitated people, such as those with cystic fibrosis. Their high level of antibiotic resistance makes empirical treatments often ineffective, increasing the risk of worst outcomes and the diffusion of multi-drug resistance. However, the discovery of new antibiotics is not trivial, so an alternative can be the use of vaccination. Here, the reverse vaccinology approach has been used to identify antigen candidates, obtaining a short-list of 24 proteins...

INTRODUCTION: Burkholderia thailandensis is a study model for Burkholderia pseudomallei , a highly virulent pathogen, known to be the causative agent of melioidosis and a potential bioterrorism agent. These two bacteria use an (acyl-homoserine lactone) AHL-mediated quorum sensing (QS) system to regulate different behaviors including biofilm formation, secondary metabolite productions, and motility. METHODS: Using an enzyme-based quorum quenching (QQ) strategy, with the lactonase Sso Pox having the best activity on B...

Opportunistic infections from multidrug-resistant pathogens such as Burkholderia cenocepacia are a threatening risk for hospital-bound patients suffering from immunocompromised conditions or cystic fibrosis. B. cenocepacia BC2L-C lectin has been linked to bacterial adhesion and biofilm formation, thus hindering its activity is seen as a promising strategy to reduce the severity of the infection. We recently described the first bifunctional ligands of the trimeric N-terminal domain of BC2L-C (BC2L-C-Nt), capable of simultaneously engaging its fucose-specific sugar binding site and a vicinal region at the interface between two monomers...

Pseudomonas aeruginosa is the most common pathogen infecting cystic fibrosis (CF) lungs, causing acute and chronic infections. Intrinsic and acquired antibiotic resistance allow P. aeruginosa to colonize and persist despite antibiotic treatment, making new therapeutic approaches necessary. Combining high-throughput screening and drug repurposing is an effective way to develop new therapeutic uses for drugs. This study screened a drug library of 3,386 drugs, mostly FDA approved, to identify antimicrobials against P...

Endophytic biostimulant with pesticide bioremediation activities may reduce agrochemicals application in rice cultivation. The present study evaluates diazinon-degrading endophytic bacteria, isolated from rice plants grown in the fields with pesticide amalgamation, leading to increased productivity in high-yielding rice plants. These endophytes showed capabilities of decomposing diazinon, confirmed by FT-IR spectra analysis. Growth promoting activities of these endophytes can be attributed to their abilities to produce an increased level of IAA content and to demonstrate high level ACC-deaminase activities...

Small non-coding RNAs (sRNAs) are key regulators of post-transcriptional gene expression in bacteria. Despite the identification of hundreds of bacterial sRNAs, their roles on bacterial physiology and virulence remain largely unknown, as is the case of bacteria of the Burkholderia cepacia complex (Bcc). Bcc is a group of opportunistic pathogens with relatively large genomes that can cause lethal lung infections amongst cystic fibrosis (CF) patients. To characterise sRNAs expressed by Bcc bacteria when infecting a host, the nematode Caenorhabditis elegans was used as an infection model by the epidemic CF strain B...

Biofilms inhabiting pipeline walls are critical to drinking water quality and safety. With massive pipeline replacement underway, however, biofilm formation process in newly built pipes and its effects on water quality are unclear. Moreover, differences and connections between biofilms in newly built and old pipes are unknown. In this study, early succession (≤ 120 days) of biofilm bacterial communities (abundance and diversity) in upper, middle and bottom areas of a newly built cement-lined ductile iron pipeline were evaluated using improved Propella™ biofilm reactor and multi-area analysis...

Secretion of quorum sensing (QS) molecules is important for the effective colonization of host plants by plant growth-promoting rhizobacteria. The current study aims at the isolation and characterization of tea rhizo bacteria, which produce the QS molecules, acyl homoserine lactone (AHLs), along with multiple plant growth-promoting (PGP) activities. Thirty-one isolates were isolated from the tea rhizosphere, and screening for PGP activities resulted in the selection of isolates RTE1 and RTE4 with multiple PGP traits, inhibiting the growth of tea fungal pathogens...

Burkholderia pseudomallei , a Gram-negative pathogen, is the causative agent of melioidosis in humans. This bacterium can be isolated from the soil, stagnant and salt-water bodies, and human and animal clinical specimens. While extensive studies have contributed to our understanding of B. pseudomallei pathogenesis, little is known about how a harmless soil bacterium adapts when it shifts to a human host and exhibits its virulence. The bacterium's large genome encodes an array of factors that support the pathogen's ability to survive under stressful conditions, including the host's internal milieu...

Burkholderia gladioli strain NGJ1 exhibits mycophagous activity on a broad range of fungi, including Rhizoctonia solani, a devastating plant pathogen. Here, we demonstrate that the nicotinic acid (NA) catabolic pathway in NGJ1 is required for mycophagy. NGJ1 is auxotrophic to NA and it potentially senses R. solani as a NA source. Mutation in the nicC and nicX genes involved in NA catabolism renders defects in mycophagy and the mutant bacteria are unable to utilize R. solani extract as the sole nutrient source...

This study evaluated the effect of the iron chelator deferiprone (DFP) on antimicrobial susceptibility and biofilm formation and maintenance by Burkholderia pseudomallei . Planktonic susceptibility to DFP alone and in combination with antibiotics was evaluated by broth microdilution and biofilm metabolic activity was determined with resazurin. DFP minimum inhibitory concentration (MIC) range was 4-64 µg/mL and in combination reduced the MIC for amoxicillin/clavulanate and meropenem. DFP reduced the biomass of biofilms by 21 and 12% at MIC and MIC/2, respectively...

BACKGROUND: Burkholderia pyrrocinia strain P10 is a plant growth-promoting rhizobacterium (PGPR) that can substantially increase peanut growth. However, the mechanisms and pathways involved in the interaction between B. pyrrocinia P10 and peanut remain unclear. To clarify complex plant-PGPR interactions and the growth-promoting effects of PGPR strains, the B. pyrrocinia P10 transcriptome changes in response to the peanut root exudate (RE) were elucidated and the effects of RE components on biofilm formation and indole-3-acetic acid (IAA) secretion were analyzed...

Regulation of porin expression in bacteria is complex and often involves small-RNA regulators. Several small-RNA regulators have been described for Burkholderia cenocepacia, and this study aimed to characterize the biological role of the conserved small RNA NcS25 and its cognate target, outer membrane protein BCAL3473. The B. cenocepacia genome carries a large number of genes encoding porins with yet-uncharacterized functions. Expression of the porin BCAL3473 is strongly repressed by NcS25 and activated by other factors, such as a LysR-type regulator and nitrogen-depleted growth conditions...