Project description:Engineered live bacteria could provide a new modality for treating lung infections , a major cause of mortality worldwide. Here, we engineered a genome-reduced human lung bacterium, Mycoplasma pneumoniae, to treat ventilator-associated pneumonia (VAP), a disease with high hospital mortality when associated with Pseudomonas aeruginosa biofilms. After validating the biosafety of an attenuated M. pneumoniae chassis in mice, we introduced four transgenes in the chromosome by transposition, to implement bactericidal and biofilm degradation activities. We show that this engineered strain has high efficacy against an acute P. aeruginosa lung infection in a mouse model. In addition, we demonstrate that the engineered strain can dissolve biofilms formed in endotracheal tubes of VAP patients and can be combined with antibiotics targeting the peptidoglycan layer to increase efficacy against gram-positive and gram-negative bacteria. We expect that our
Project description:When a biomedical device is implanted into the body, its surface initially encounters biological fluids, resulting in the natural adsorption of various host proteins. This protein-adsorbed layer significantly alters the inherent properties of the biomaterial surface and may play a crucial role in interactions between the implant and bacteria. Here we investigated the influence of an adsorbed layer of albumin, the predominant plasma protein, on the adhesion and biofilm formation of three different bacterial strains: Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa. We showed that the effect of a serum albumin layer on bacterial adhesion was strain-dependent. While pre-adsorption of albumin reduced the initial adhesion of S. aureus and S. epidermidis on the PDMS surface, no impact was observed on the adhesion of P. aeruginosa. In contrast, the albumin-adsorbed surface significantly increased the density of adhered P. aeruginosa for extended incubation time. The proteomic analysis highlighted significant physiological changes in P. aeruginosa when exposed to an albumin-adsorbed surface compared to a control surface. These changes are particularly related to the molecular pathways involved in surface colonization, such as quorum sensing, bacterial motility, adhesion factors, and biofilm formation. These findings suggest that serum albumin adsorption not only affects the initial interaction between bacteria and the surface but also alters the bacteria's adaptive behavior on the biomaterial surface. This study provides a deeper understanding of the complex bacteria-surface interactions, contributing to the development of future strategies for preventing implant-associated infections
Project description:To identify differentially expressed genes (DEGs) potentially involved in the development of endotracheal intubation-induced tracheal injury in septic shock.
Project description:In this work we study the pulmonary toxicological properties of cristalline silica DQ-12 using molecular toxicological approache. For this, we exposed Sprague Dawley rats by endotracheal instillation. Lung samples have been collected up to 180 days after the end of exposure and transcriptomics analysis were performed.
Project description:We sequenced mRNA from three independent biological replicates of Staphylococcus epidermidis biofilms with different proportion of dormant cells. Whole trancriptome analysis of Staphylococcus epidermidis biofilms with prevented and induced dormancy.
Project description:Cystic Fibrosis (CF) is the most common life limiting genetic disorder, characterized by chronic respiratory failure secondary to inflammation and chronic bacterial lung infection. Pseudomonas aeruginosa lung infection is associated with more severe lung disease and rapid progression of respiratory failure when compared to Staphylococcus aureus infection. We hypothesized that a specific signature of epigenetic factors targeting specific gene transcripts contributes to the increased morbidity seen in CF patients with chronic Pseudomonas infection. We collected exhaled breath condensate (EBC) from 27 subjects and evaluated miRNA signatures in these samples using commercial PCR array. We identified predicted mRNA targets and associated signaling pathways using Ingenuity Pathway Analysis. We found 11 differentially expressed miRNAs in EBC of patients infected with Pseudomonas aeruginosa compared to EBC from CF patients who were not chronically infected with Pseudomonas aeruginosa.
Project description:Cerebrospinal fluid (CSF) shunt infection is a common and devastating complication of the treatment of hydrocephalus. Timely and accurate diagnosis is essential as these infections can lead to long term neurologic consequences like seizures, decreased IQ and impaired school performance. Currently the diagnosis of shunt infection relies on bacterial culture, however, culture is not always accurate especially as these infections are frequently caused by bacteria capable of forming biofilms like Staphylococcus epidermidis, Cutibacterium acnes, and Pseudomonas aeruginosa and may have very few planktonic bacteria in the CSF to be picked up on culture. Therefore, there is a critical need to identify a new rapid, and accurate method for diagnosis of CSF shunt infection with broad bacterial species coverage to improve the long-term outcomes of children suffering from these infections.
Project description:We examined the differential gene expression of Staphylococcus epidermidis and Staphylococcus epidermidis in dual species biofilms. Therefore, we performed RNA-Seq on single and dual species biofilms and we compared the gene expression levels in dual species biofilms to those in single species biofilms.
Project description:Pseudomonas aeruginosa and Staphylococcus aureus are often co-isolated in persistent infections. The goal of this study was to determine how secreted products that were identified in S. aureus supernatant affect gene expression in P. aeruginosa. Therefore, media control, the indicated products in media, or S. aureus supernatant was added to P. aeruginosa cultures at 25% total volume and gene expression was measured at 20 min and 2 h using RNA-seq. The individual products induced distinct pathways in P. aeruginosa. The products in combination recapitulated much of the differential gene expression seen in P. aeruginosa in response to S. aureus supernatant.
