Project description:The interactions between Gram-negative respiratory pathogens and the host environment at the site of infection largely unknown. Pulmonary surfactant serves as an initial point of contact for inhaled bacteria entering the lung and is thought to contain molecular cues that aid colonization and pathogenesis. To gain insight into this ecological transition, we characterized the transcriptional responses of Pseudomonas aeruginosa PA14, Burkholderia thailandensis E264, Klebsiella pneumoniae MGH 78578, and Stenotrophomonas maltophilia K279A exposed to purified pulmonary surfactant (Survanta) through microarrays. This study provides novel insight into the interactions occurring between Gram-negative opportunistic pathogens and the host at an important infection site, and demonstrates the utility of purified lung surfactant preparations for dissecting host-lung pathogen interactions in vitro. The goal of this study was to compare the transcriptional responses of Pseudomonas aeruginosa PA14, Burkholderia thailandensis E264, Klebsiella pneumoniae MGH 78578, and Stenotrophomonas maltophilia K279A exposed to pulmonary surfactant using a custom affymetrix chip designed for their genomes. The goal of this study was to compare the transcriptional responses of Pseudomonas aeruginosa PA14, Burkholderia thailandensis E264, Klebsiella pneumoniae MGH 78578, and Stenotrophomonas maltophilia K279A exposed to pulmonary surfactant using a custom affymetrix chip designed for their genomes.
Project description:Bacterial infections of wounds are associated with poor healing and worse scarring. We sought to identify transcriptomic patterns associated with impaired healing of wounds infected with Klebsiella pneumoniae (K.p.) or Pseudomonas aeruginosa (P.a.) using a rabbit ear wound model. Wounds created on post-operative day (POD) 0 were infected on POD3, within the inflammatory phase of healing. On POD4 the infected wounds were harvested for microarray/transcriptome analysis. Other wounds with 24-hour infections were treated with topical antibiotic to promote biofilm formation and harvested on POD6 or POD12. On POD4 before antibiotic treatment, both wounds contained elevated transcripts that enriched predominantly into inflammation/infection-response pathways and functions characteristic of infiltrating leukocytes. But there were 5-fold more elevated transcripts in P.a.- than K.p.-infected wounds. Additionally, unique to P.a.-infected wounds, was a minor network of inflammation/infection-response molecules with predicted upstream regulation predominated by type I interferons. Also on POD4, Dnr-transcripts of both wounds were enriched into stress-response pathways such as EIF2 signaling. But there were 8-fold more Dnr-transcripts in P.a.- than K.p.-infected wounds, and many more of them enriched in the function, cell death, suggesting that resident dermal cells of P.a.-infected wounds failed to survive a more destructive P.a. infection. On POD6, following two days of antibiotic treatment, the biofilm-colonized wounds expressed magnitudes fewer inflammation and stress-response transcripts. However, a single regulatory network of P.a.-infected wounds was found to consist of Upr-transcripts enriching immune/infection-response functions predicted to be regulated by type I interferons, which was similar to the network unique to P.a.-infected wounds on POD4. On POD12, genes expressed by K.p.-infected wounds suggesting healing, while for P.a.-infected wounds they suggested stalled healing. The similarities and differences between the wound responses to these infections further define the molecular foundations of healing impaired by infections. Rabbit ear Wounds created on post-operative day (POD) 0 were infected with Klebsiella pneumoniae (K.p.) or Pseudomonas aeruginosa (P.a.) on POD3 and harvested on POD4 for RNA extraction. Other wounds with 24-hour infections were treated with topical antibiotic to promote biofilm formation and harvested on POD6 or POD12.
Project description:Klebsiella pneumoniae is an arising threat to human health. However, host immune responses in response to this bacterium remain to be elucidated. The goal of this study was to identify the dominant host immune responses associated with Klebsiella pneumoniae pulmonary infection. Pulmonary mRNA profiles of 6-8-weeks-old BALB/c mice infected with/without Klebsiella pneumoniae were generated by deep sequencing using Illumina Novaseq 6000. qRT–PCR validation was performed using SYBR Green assays. Using KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis, we identified several immune associated pathways, including complement and coagulation cascades, Toll-like receptor signaling pathway, Rap1 signaling pathway, chemokine signaling pathway, TNF signaling pathway, phagosome and NOD-like receptor signaling pathway, were involved in Klebsiella pneumoniae pulmonary infection. Using ICEPOP (Immune CEll POPulation) analysis, we found that several cell types were involved in the host immune response to Klebsiella pneumoniae pulmonary infection, including dendritic cells, macrophages, monocytes, NK (natural killer) cells, stromal cells. Further, IL-17 chemokines were significantly increased during Klebsiella pneumoniae infection. This study provided evidence for further studying the pathogenic mechanism of Klebsiella pneumoniae pneumonia infection.
Project description:Gene expression comparison between human colonic epithelial cells cultured with Klebsiella pneumoniae (KP) derived from PSC patients versus KP JCM1662.
Project description:Despite being rarely reported, improved diagnostic and prognostic indicators are necessary for treating malignant melanoma in rabbits. In this study, two cases of primary skin lesions, on the scrotum and on eyelid, with systemic metastases, were examined. The tumors formed intra-dermally by sheet-like proliferation of polymorphic cells, with anisocytosis and varying amount of melanin granules. Tumors had displaced almost 50% of the lung and liver tissue, and tumor metastasis was the cause of early death in both rabbits. Ki-67-positive population was high in both, and it was found to be useful in assessing the outcome and malignancy. In addition, Melan-A, HMB-45, PNL2 and S100 established a useful immunohistochemical panel for the diagnosis of melanocytic tumor in rabbits.
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:Bacterial infections of wounds are associated with poor healing and worse scarring. We sought to identify transcriptomic patterns associated with impaired healing of wounds infected with Klebsiella pneumoniae (K.p.) or Pseudomonas aeruginosa (P.a.) using a rabbit ear wound model. Wounds created on post-operative day (POD) 0 were infected on POD3, within the inflammatory phase of healing. On POD4 the infected wounds were harvested for microarray/transcriptome analysis. Other wounds with 24-hour infections were treated with topical antibiotic to promote biofilm formation and harvested on POD6 or POD12. On POD4 before antibiotic treatment, both wounds contained elevated transcripts that enriched predominantly into inflammation/infection-response pathways and functions characteristic of infiltrating leukocytes. But there were 5-fold more elevated transcripts in P.a.- than K.p.-infected wounds. Additionally, unique to P.a.-infected wounds, was a minor network of inflammation/infection-response molecules with predicted upstream regulation predominated by type I interferons. Also on POD4, Dnr-transcripts of both wounds were enriched into stress-response pathways such as EIF2 signaling. But there were 8-fold more Dnr-transcripts in P.a.- than K.p.-infected wounds, and many more of them enriched in the function, cell death, suggesting that resident dermal cells of P.a.-infected wounds failed to survive a more destructive P.a. infection. On POD6, following two days of antibiotic treatment, the biofilm-colonized wounds expressed magnitudes fewer inflammation and stress-response transcripts. However, a single regulatory network of P.a.-infected wounds was found to consist of Upr-transcripts enriching immune/infection-response functions predicted to be regulated by type I interferons, which was similar to the network unique to P.a.-infected wounds on POD4. On POD12, genes expressed by K.p.-infected wounds suggesting healing, while for P.a.-infected wounds they suggested stalled healing. The similarities and differences between the wound responses to these infections further define the molecular foundations of healing impaired by infections.