Project description:Circumventing or overwhelming the bacterial adaptation capabilities is key to combatting multidrug-resistant pathogens like Pseudomonas aeruginosa. In an effort to understand the physiological response of P. aeruginosa to clinically relevant antibiotics, we investigated the proteome after exposure to ciprofloxacin, levofloxacin, rifampicin, gentamicin, tobramycin, azithromycin, tigecycline, polymyxin B, colistin, ceftazidime, meropenem, and piperacillin/tazobactam. We further investigated the response to CHIR-90, which represents a promising class of lipopolysaccharide biosynthesis inhibitors currently under evaluation. Radioactive pulse-labeling of newly synthesized proteins followed by 2D-PAGE was used to monitor the acute response of P. aeruginosa to antibiotic treatment. Marker proteins were excised from non-radioactive gels and identified by mass spectrometry. The proteomic profiles provide insights into the cellular defense strategies for each antibiotic. A mathematical comparison of these response profiles based on upregulated marker proteins revealed similarities of responses to antibiotics acting on the same target area.
Project description:Circumventing or overwhelming the bacterial adaptation capabilities is key to combatting multidrug-resistant pathogens like Pseudomonas aeruginosa. We investigated the physiological stress exerted by approved antibiotics (ciprofloxacin, levofloxacin, rifampicin, gentamicin, tobramycin, azithromycin, tigecycline, polymyxin B, colistin, ceftazidime, meropenem, piperacillin/tazobactam), experimental antibiotics (CHIR-090) and NSAIDs (acetylsalicylic acid (aspirin), diclofenac, ibuprofen), and studied the bacterial response on the proteome level. Radioactive pulse-labeling of newly synthesized proteins followed by 2D-PAGE was used to monitor the acute response of P. aeruginosa to antibiotic treatment. Subsequently, marker proteins were excised from non-radioactive gels and identified by mass spectrometry. We generated a reference library of P. aeruginosa proteomic responses and implemented a mathematical comparison of the profiles. Proteomic signatures were derived for clinically relevant target areas.
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.
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:Analysis of Pseudomonas aeruginosa PAO1 treated with 200 µM sphingomyelin. Results provide insight into the response to sphingomyelin in P. aeruginosa.
Project description:Drosophila melanogaster is a validated eukaryotic model for immunity-concerned studies in the post-genomic era. In the present study we performed oral experimental infection of D. melanogaster with Pseudomonas aeruginosa (strain ATCC27853). By using a whole genome microarray approach, we intended to identify significant alterations in the expression profile of relevant genes amenable to qualify as new models for the investigation of specific host-parasite interactions.
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 from S. aureus affect gene expression in P. aeruginosa. Therefore, media control or S. aureus supernatant was added to P. aeruginosa cultures at 25% total volume and gene expression was measured at 20 min, 1 h, and 2 h using RNA-seq. Overall, after addition of S. aureus supernatant, there was an upregulation in genes involved in metal deprivation and intermediate metabolite uptake.
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.