Project description:Urinary tract infections (UTIs) constitute a highly relevant model of microbial adaptation, in which the contrasting effects of pathogens and commensals on host tissues are clearly displayed. While virulent Escherichia coli cause severe, potentially life-threatening disease by breaking the inertia of the mucosal barrier and infecting the kidneys, the most common outcome of bacteriuria is an asymptomatic carrier state resembling commensalism at other mucosal sites. It remains unclear if the lack of destructive inflammation merely reflects low virulence or if carrier strains actively inhibit disease associated responses in the host. To address this question, we examined the effects of asymptomatic bacterial carriage on host gene expression. Therapeutic urinary tract inoculation with the prototype ABU strain E. coli 83972 is a safe alternative approach in patients with therapy-resistant recurrent UTI. The strain establishes persistent bacteriuria, protecting patients against super-infection with more virulent strains. Using this protocol, we examined if the establishment of asymptomatic bacterial carriage alters host gene expression.
Project description:Urinary tract infections (UTIs) constitute a highly relevant model of microbial adaptation, in which the contrasting effects of pathogens and commensals on host tissues are clearly displayed. While virulent Escherichia coli cause severe, potentially life-threatening disease by breaking the inertia of the mucosal barrier and infecting the kidneys, the most common outcome of bacteriuria is an asymptomatic carrier state resembling commensalism at other mucosal sites. It remains unclear if the lack of destructive inflammation merely reflects low virulence or if carrier strains actively inhibit disease associated responses in the host. To address this question, we examined the effects of asymptomatic bacterial carriage on host gene expression. Therapeutic urinary tract inoculation with the prototype ABU strain E. coli 83972 is a safe alternative approach in patients with therapy-resistant recurrent UTI. The strain establishes persistent bacteriuria, protecting patients against super-infection with more virulent strains. Using this protocol, we examined if the establishment of asymptomatic bacterial carriage alters host gene expression. After antibiotic treatment to remove prior infection, patients were inoculated with E. coli 83972 through a catheter. Blood samples were obtained before and 24 h after inoculation.
Project description:Urinary tract infections (UTIs) constitute a highly relevant model of microbial adaptation, in which the contrasting effects of pathogens and commensals on host tissues are clearly displayed. While virulent Escherichia coli cause severe, potentially life-threatening disease by breaking the inertia of the mucosal barrier and infecting the kidneys, the most common outcome of bacteriuria is an asymptomatic carrier state resembling commensalism at other mucosal sites. It remains unclear if the lack of destructive inflammation merely reflects low virulence or if carrier strains actively inhibit disease associated responses in the host. To address this question, we examined the effects of asymptomatic bacterial carriage on host gene expression. The asymptomatic strain E. coli 83972 caused reduction in Pol II phosphorylation in the nuclei of human kidney epithelial A498 cells. To specifically address if Pol II inhibition alters the response to infection, A498 cells were pretreated with 5,6-dichloro-1-b-D-ribofuranosylbenzimidazole (DRB). This adenosine analogue has been proposed to specifically and reversibly inhibit Pol II transcription without directly affecting other cellular functions. A498 cultered cells were infected with E. coli 83972 or DRB for 4 hours. The culture medium with DMSO was used as a background control.
Project description:Urinary tract infections (UTIs) constitute a highly relevant model of microbial adaptation, in which the contrasting effects of pathogens and commensals on host tissues are clearly displayed. While virulent Escherichia coli cause severe, potentially life-threatening disease by breaking the inertia of the mucosal barrier and infecting the kidneys, the most common outcome of bacteriuria is an asymptomatic carrier state resembling commensalism at other mucosal sites. It remains unclear if the lack of destructive inflammation merely reflects low virulence or if carrier strains actively inhibit disease associated responses in the host. To address this question, we examined the effects of asymptomatic bacterial carriage on host gene expression. A498 cell line has been validated as a model of uropathogenic E. coli infection; the cells express functional receptors for bacterial virulence ligands and the response to virulent strains reflects human UTI. The cells were infected with asymptomatic and pathogenic E. coli in vitro, and harvested RNA was subjected to whole genome transcriptome analysis.
Project description:Identification and expression analysis of microRNAs in infected larvae of the insect model Galleria mellonella with uropathogenic (UPEC) and commensal E. coli strains that are known to cause symptomatic and asymptomatic bacteriuria (ABU) in humans, respectively.
Project description:Urinary tract infections (UTIs) constitute a highly relevant model of microbial adaptation, in which the contrasting effects of pathogens and commensals on host tissues are clearly displayed. While virulent Escherichia coli cause severe, potentially life-threatening disease by breaking the inertia of the mucosal barrier and infecting the kidneys, the most common outcome of bacteriuria is an asymptomatic carrier state resembling commensalism at other mucosal sites. It remains unclear if the lack of destructive inflammation merely reflects low virulence or if carrier strains actively inhibit disease associated responses in the host. To address this question, we examined the effects of asymptomatic bacterial carriage on host gene expression. The asymptomatic strain E. coli 83972 caused reduction in Pol II phosphorylation in the nuclei of human kidney epithelial A498 cells. To specifically address if Pol II inhibition alters the response to infection, A498 cells were pretreated with 5,6-dichloro-1-b-D-ribofuranosylbenzimidazole (DRB). This adenosine analogue has been proposed to specifically and reversibly inhibit Pol II transcription without directly affecting other cellular functions. A498 cultered cells were infected with E. coli 83972 or DRB for 4 hours. The culture medium with DMSO was used as a background control. A498 cells were infected with E. coli 83972 or DRB for 4 h. Isolated RNA was subjected to whole genome transcriptome analysis.
Project description:Genome sequence of Escherichia coli SN25 isolated from urine of a patient therapeutically colonized with asymptomatic bacteriuria E. coli strain 83972
Project description:Urinary tract infections (UTIs) constitute a highly relevant model of microbial adaptation, in which the contrasting effects of pathogens and commensals on host tissues are clearly displayed. While virulent Escherichia coli cause severe, potentially life-threatening disease by breaking the inertia of the mucosal barrier and infecting the kidneys, the most common outcome of bacteriuria is an asymptomatic carrier state resembling commensalism at other mucosal sites. It remains unclear if the lack of destructive inflammation merely reflects low virulence or if carrier strains actively inhibit disease associated responses in the host. To address this question, we examined the effects of asymptomatic bacterial carriage on host gene expression. A498 cell line has been validated as a model of uropathogenic E. coli infection; the cells express functional receptors for bacterial virulence ligands and the response to virulent strains reflects human UTI. The cells were infected with asymptomatic and pathogenic E. coli in vitro, and harvested RNA was subjected to whole genome transcriptome analysis. A498 human kidney epithelial cells were infected with the asymptomatic (E. coli 83972) or virulent strains (E. coli CFT073) for 4 hours. The cells with culture medium alone were used as a control. The experiment was performed in biological duplicates or triplicates.
Project description:Escherichia coli strains are the major cause of urinary tract infections in humans. Such strains can be divided into virulent, UPEC strains causing symptomatic infections, and asymptomatic, commensal-like strains causing asymptomatic bacteriuria, ABU. The best-characterized ABU strain is strain 83972. Global gene expression profiling of strain 83972 has been carried out under seven different sets of environmental conditions ranging from laboratory minimal medium to human bladders. The data reveal highly specific gene expression responses to different conditions. A number of potential fitness factors for the human urinary tract could be identified. Also, presence/ absence data of the gene expression was used as an adaptive genomics tool to model the gene pool of 83972 using primarily UPEC strain CFT073 as a scaffold. In our analysis, 96% of the transcripts filtered present in strain 83972 can be found in CFT073, and genes on six of the seven pathogenicity islands were expressed in 83972. Despite the very different patient symptom profiles, the two strains seem to be very similar. Genes expressed in CFT073 but not in 83972 were identified and can be considered as virulence factor candidates. Strain 83972 is a deconstructed pathogen rather than a commensal strain that has acquired fitness properties.