Project description:Traditional vaccines are difficult to deploy against the diverse antibiotic-resistant, nosocomial pathogens that cause Hospital Acquired Infections (HAIs). We developed a unique, protein-free vaccine to present antibiotic-resistant HAIs. This vaccine protected mice from invasive infections caused by methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecalis, multidrug resistant Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Rhizopus delemar, and Candida albicans. Protection persisted even in neutropenic mice infected with A. baumannii or R. delemar. Protection was already apparent after 24 hours and lasted for up to 21 days after a single dose, with a second dose restoring efficacy. Protection persisted without lymphocytes but was abrogated with macrophages depletion. This vaccine induced trained immunity by altering the macrophage epigenetic landscape and the inflammatory response to infection.
Project description:Objectives: This study aimed to investigate the microbiological characteristics of outer membrane vesicles (OMVs) derived from Pseudomonas aeruginosa (P. aeruginosa) to understand their mechanisms of inhibition of Acinetobacter baumannii (A. baumannii) in vitro. Methods: We assessed the inhibitory effects of P. aeruginosa on A. baumannii using a modified cross-streak assay. Subsequently, OMVs were extracted from P. aeruginosa strains using high-speed centrifugation, tangential flow filtration, ultrafiltration, and ultracentrifugation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), transmission electron microscopy (TEM), and nanoparticle tracking assays (NTAs) were performed to confirm the presence of the extracted OMVs. P. aeruginosa-derived OMVs’ inhibitory activity against A. baumannii was tested using a modified time-kill assay. The proteomic analysis of OMVs revealed potential antibacterial protein clusters with diverse functions. Results: P. aeruginosa 022 (PA022) demonstrated inhibition of A. baumannii in the cross-streak assay. The protein levels of OMVs for PA022 and P. aeruginosa ATCC 27853 (PA ATCC 27853) were 1665 and 428.6 μg/mL, respectively. Additionally, PA 022 and PA ATCC 27853 exhibited variable patterns and sizes in the SDS-PAGE, TEM, and NTA. Furthermore, the growth inhibitory effect of PA022 OMVs on A. baumannii was evaluated using a modified time-kill assay. The proteomic analysis of OMVs revealed potential antibacterial protein clusters in PA 022 associated with virulence, motility, and post-translational modifications. Conclusion: Our study contributes to the understanding of P. aeruginosa OMVs characteristics and their inhibitory effect against A. baumannii, providing insights into the development of alternative therapeutic approaches against multi-drug resistance.
Project description:Using Nanopore sequencing, our study has revealed a close correlation between genomic methylation levels and antibiotic resistance rates in Acinetobacter Baumannii. Specifically, the combined genome-wide DNA methylome and transcriptome analysis revealed the first epigenetic-based antibiotic-resistance mechanism in A. baumannii. Our findings suggest that the precise location of methylation sites along the chromosome could provide new diagnostic markers and drug targets to improve the management of multidrug-resistant A. baumannii infections.
Project description:Acinetobacter baumannii AB042, a triclosan-resistant mutant, was examined for modulated gene expression using whole genome sequencing, transcriptomics, and proteomics in order to understand the mechanism of triclosan-resistance as well as its impact on A. Baumannii.
Project description:Two Acinetobacter baumannii strains with low susceptibility to fosmidomycin and two reference with high susceptibility to fosmidomycin were DNA-sequenced to investigate the genomic determinants of fosmidomycin resistance.
Project description:ErfA is a transcription factor of Pseudomonas aeruginosa. We here define the genome-wide binding sites of ErfA by DAP-seq in Pseudomonas aeruginosa PAO1 and IHMA87, Pseudomonas chlororaphis PA23, Pseudomonas protegens CHA0 and Pseudomonas putida KT2440.
Project description:RNA-seq was used to measure gene expression in second instar larvae of the blow fly Lucilia sericata after feeding exposure (1 hour or 4 hours) to Pseudomonas aeruginosa and Acinetobacter baumanii. RNA-seq measurements were also collected from control larvae from each time point that were not exposed to bacteria.
