Project description:Wound infections are traditionally thought to occur when microbial burden exceeds the innate clearance capacity of host immune system. Here we introduce the idea that the wound environment itself plays a significant contributory role to wound infection. We developed a clinically relevant murine model of soft tissue infection to explore the role of activation of microbial virulence in response to tissue factors as a mechanism by which pathogenic bacteria cause wound infections. Mice underwent abdominal skin incision and light muscle injury with a crushing forceps versus skin incision alone followed by topical inoculation of Pseudomonas aeruginosa. Pseudomonas aeruginosa whole genome transcriptional profiling demonstrated that fascia induced the activation of multiple genes responsible for the synthesis of the iron scavenging protein pyochelin. Ex-vivo murine fascia homogenates were prepared and Pseudomonas aeruginosa MPAO1 was incubated with an inoculum of the fascia homogenate solution. Pseudomonas aeruginosa MPAO1 incubated under the same condtions without the homogenate was used as the control group. Three biological replicates in each group was used.
Project description:Wound infections are traditionally thought to occur when microbial burden exceeds the innate clearance capacity of host immune system. Here we introduce the idea that the wound environment itself plays a significant contributory role to wound infection. We developed a clinically relevant murine model of soft tissue infection to explore the role of activation of microbial virulence in response to tissue factors as a mechanism by which pathogenic bacteria cause wound infections. Mice underwent abdominal skin incision and light muscle injury with a crushing forceps versus skin incision alone followed by topical inoculation of Pseudomonas aeruginosa. Pseudomonas aeruginosa whole genome transcriptional profiling demonstrated that fascia induced the activation of multiple genes responsible for the synthesis of the iron scavenging protein pyochelin.
Project description:Infections of burn wounds, especially those caused by Pseudomonas aeruginosa, could trigger sepsis or septic shock, which is the main cause of death after burn injury. Compared with traditional saline-wet-to-dry dressings, negative pressure wound therapy (NPWT) is more effective for the prevention and treatment of wound infections. However, the mechanism by which NPWT controls infection and accelerates wound healing remains unclear. Accordingly, in this study, the molecular mechanisms underlying the effects of NPWT were explored using a murine model of P. aeruginosa-infected burn wounds. NPWT significantly reduced P. aeruginosa levels in wounds, enhanced blood flow, and promoted wound healing. Additionally, NPWT markedly alleviated wound inflammation and increased the expression of wound healing–related molecules. Recent evidence points to a role of circular RNAs (circRNAs) in wound healing; hence, whole-transcriptome sequencing of wound tissues from NPWT and control groups was performed to evaluate circRNA expression profiles.
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:Pseudomonas aeruginosa is a threatening, opportunistic pathogen causing disease in immunocompromised individuals. The hallmark of P. aeruginosa virulence is its multi-factorial and combinatorial nature. It renders such bacteria infectious for many organisms and it is often resistant to antibiotics. To gain insights into the physiology of P. aeruginosa during infection, we assessed the transcriptional programs of three different P. aeruginosa strains directly after isolation from burn wounds of humans. We compared the programs to those of the same strains using two infection models: a plant model, which consisted of the infection of the midrib of lettuce leaves, and a murine tumor model, which was obtained by infection of mice with an induced tumor in the abdomen. All control conditions of P. aeruginosa cells growing in suspension and as a biofilm were added to the analysis. We found that these different P. aeruginosa strains express a pool of distinct genetic traits that are activated under particular infection conditions regardless of their genetic variability. The knowledge herein generated will advance our understanding of P. aeruginosa virulence and provide valuable cues for the definition of prospective targets to develop novel intervention strategies. Samples collected from human burn wounds were stabilized and used for P. aeruginosa RNA extraction. The strains from burn wound infection were later used for infection models namely plant and murine tumor infection as well as rich medium controls with planctonic and biofilm growth. The RNA was treated for bacterial RNA enrichment and amplification. All samples were treated in the same way.
Project description:We previously showed that pre-exposure of the cornea to TLR5 ligand flagellin induces profound mucosal innate protection against pathogenic microbes by reprogramming gene expression. To date, there was no genome-wide cDNA array to detect full scale of flagellin mediated reprogramming of gene expression in mucosal surface epithelial cells. Taking advantage of readily accessible, easily procurable epithelial cell population, this study is the first report to use genome-wide cDNA microarray approach to document genes associated with flagellin-induced protection against Pseudomonas aeruginosa infection in corneal epithelial cells (CECs). Total RNA obtained from isolated mouse corneal epithelial cells of the control (cells scrapped off from the corneas without infection), Pseudomonas aeruginosa infected (6 h post infection) and flagellin pretreated (24 h), followed by Pseudomonas aeruginosa infection (6 h).
Project description:Pseudomonas aeruginosa is known to tolerate antibiotic therapy during infection. This prevents clearance of infection and negatively impacts patient outcomes. Here, we report the transcriptome sequence of antibiotic-treated and untreated P. aeruginosa cultures and the differential gene expression observed when treated cells are compared to untreated cells.
Project description:We report a study conducted to investigate the variation on gene expression of the pathogenic fungus Aspergillus fumigatus upon co-cultivation with the pathogenic bacterium Pseudomonas aeruginosa. The study was conducted by investigating the gene expression variation at different time points (45, 90 and 180 minutes after co-incubation). As control, we used data obtained by cultivating the fungus either without bacteria, or with heat-inactivated Pseudomonas.
Project description:Gene expression profiles of two Pseudomonas aeruginosa taxonomic outlier clinical isolates, CLJ1 and CLJ3 [CLJ3] Pseudomonas aeruginosa taxonomic outliers emerged recently as infectious for humans, provoking hemorrhagic pneumonia. Those bacteria lack classical type III secretion system, and utilize the pore-forming toxin for infection. Two clones CLJ1 and CLJ3 belonging to these taxonomic outliers have been isolated from the same patient at two different times during hospitalization. P. aeruginosa CLJ3 displays antibiotic resistance phenotype, while CLJ1 is more cytotoxic on epithelial and endothelial cells.
Project description:Gene expression profiles of two Pseudomonas aeruginosa taxonomic outlier clinical isolates, CLJ1 and CLJ3 [CLJ1] Pseudomonas aeruginosa taxonomic outliers emerged recently as infectious for humans, provoking hemorrhagic pneumonia. Those bacteria lack classical type III secretion system, and utilize the pore-forming toxin for infection. Two clones CLJ1 and CLJ3 belonging to these taxonomic outliers have been isolated from the same patient at two different times during hospitalization. P. aeruginosa CLJ3 displays antibiotic resistance phenotype, while CLJ1 is more cytotoxic on epithelial and endothelial cells.