Project description:Rapid evaporative ionisation mass spectrometry (REIMS) is a novel technique for the real-time analysis of biological material. It works by conducting an electrical current through a sample, causing it to rapidly heat and evaporate, with the analyte containing vapour channelled to a mass spectrometer. It was used to characterise the metabolome of 45 Pseudomonas aeruginosa (P. aeruginosa) isolates from cystic fibrosis (CF) patients and compared to 80 non-CF P. aeruginosa. Phospholipids gave the highest signal intensity; 17 rhamnolipids and 18 quorum sensing molecules were detected, demonstrating that REIMS has potential for the study of virulence-related metabolites. P. aeruginosa isolates obtained from respiratory samples showed a higher diversity, which was attributed to the chronic nature of most respiratory infections. The analytical sensitivity of REIMS allowed the detection of a metabolome that could be used to classify individual P. aeruginosa isolates after repeated culturing with 81% accuracy, and an average 83% concordance with multilocus sequence typing. This study underpins the capacities of REIMS as a tool with clinical applications, such as metabolic phenotyping of the important CF pathogen P. aeruginosa, and highlights the potential of metabolic fingerprinting for fine scale characterisation at a sub-species level.
2022-01-26 | MTBLS644 | MetaboLights
Project description:Development and Evaluating a core genome multilocus sequence typing (cgMLST) scheme for whole-genome sequence-based typing of Clostridioides difficile
Project description:In the present study, we employed Affymetrix Pseudomonas aeruginosa GeneChip arrays to investigate global gene expression profiles during the cellular response of Pseudomonas aeruginosa to sodium hypochlorite Keywords: Antimicrobial response
Project description:Pseudomonas aeruginosa is a common bacteria leading to exacerbations of chronic obstructive pulmonary disease (COPD) patients while this bacteria can be easily eradicated by the immune systems of healthy individuals. Human airway organoids derived from healthy individuals and COPD patients were infected with pseudomonas aeruginosa. This project aims (1) to understand the differences in gene expressions in healthy and COPD airway organoids during stable condition, without infection and (2) to investigate differential pathogenic mechanism (i.e. antimicrobial defense) of pseudomonoas aeruginosa infection in healthy and COPD populations. Three healthy donors and three COPD patients were included in this study and samples were collected with and without pseudomonas aeruginosa infection.
Project description:Methylrhodomelol (1) is a bromophenol from the red alga Vertebrata lanosa (L.) T.A.Christensen that has been associated with antimicrobial properties. Aim of the current study was therefore, to assess the antimicrobial potential of this compound in more detail against the gram-negative pathogen Pseudomonas aeruginosa. 1 exerted weak bacteriostatic activity against different strains when grown in minimal medium, whereas other phenolics were inactive. In addition, 1 (35 and 10 µg/mL) markedly enhanced the susceptibility of multidrug resistant P. aeruginosa towards the aminoglycoside gentamicin, while it did not affect the viability of Vero kidney cells up to 100 µM. Finally, pyoverdine release was reduced in bacteria treated at sub-inhibitory concentration, but no effect on other virulence factors was observed. Transcriptome analysis of treated versus untreated P. aeruginosa indicated an interference of 1 with bacterial carbon and energy metabolism, which was corroborated by RT-qPCR and decreased ATP-levels in treated bacteria.
Project description:Approximatively 75% of the genome of S. aureus (“core” genome) are highly conserved between strains, whereas the remaining 25% (“accessory” genome) are composed of variable regions that are mostly composed of mobile genetic elements (MGE), containing virulence and resistance genes. We have developed a composite DNA-microarray (StaphVar Array) which selectively targets 403 genes located on the accessory or core variable genome. Target genes encode antimicrobial resistance factors (35 %), virulence factors (28 %) and adhesins (31%). This microarray was validated with reference strains and used to characterize the genomic DNA of 13 community-acquired methicillin resistant S. aureus (CA-MRSA) strains representative of all the Multilocus Sequence Types (STs) described to date in Belgium. Analysis of gene content of 8 reference strains by the StaphVar Array matched 96 to 99% of the theoretical results. Analysis of CA-MRSA strains showed that 54.4 % of the genes tested were strain-dependent. Strains presented specific exotoxin, enterotoxin, cytolysin and adhesin gene profile by multi-locus sequence typing (MLST) lineage. One exception to these “lineage-specific” gene profile was the variable presence of the Arginin Catabolic Mobile Element (ACME, characteristic of the USA300 clone) within ST8 strains. In conclusion, this novel StaphVar array enables characterization of more than 400 variable resistance and virulence determinants in S. aureus strains. CA-MRSA strains from Belgium displayed extensive diversity in virulence and resistance profile. The presence of the USA 300 clone in our country was confirmed. Although mainly located on MGE, association of virulence genes were highly conserved within strains of the same MLST lineage. CGH microarray was performed on 13 epidemiologically distinct clinical isolates of methicillin resistant S. aureus. S. aureus labeled genomic DNA were hybridized to StaphVar arrays containing 1326 60mer oligonucleotide probes (Eurogentec, Belgium).