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: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: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:We report the profiling of induced mRNA transcripts in two C. elegan replicate populations -- WT (N2) and mutant strain with deficient HLH30. Both strains were fed either OP50 strain of e-coli (normal feed) or S. aureus Examination of infected versus uninfected wildtype and mutant lawns of animals
Project description:The DNA microarray was employed in this study to investigate the gene expression profiles of Escherichia coli treated by an oil-in-water (o/w) microemulsion, in order to better understand the antimicrobial mechanism of the microemulsion as a promising food-grade antimicrobial system. 5,440 open reading frames (ORFs) of E. coli were investigated. 5 ml bacterial cultures with a known inoculum of E. coli cells (1.0 M-CM-^W 109 cfu/ml) was added at 1:1 (v/v) to the microemulsion and incubated on a tube rotator at 200 rpm for 4 h at 37 M-BM-0C for the subsequent DNA microarray analysis.
Project description:Impacts of plasmid carriage on its host cell were comprehensively analyzed using conjugative plasmid pCAR1 in the three different kinds of hosts, Pseudomonas putida KT2440, P. aeruginosa PAO1, and P. fluorescens Pf0-1. Various analyses of the host phenotype showed that pCAR1 carriage reduced host fitness, swimming motility, and resistances to osmotic- or pH-stress, and brought about the alterations of primary metabolic capacities in the TCA cycle or those several steps away from the TCA cycle in the host cells. Growth phase-dependent transcriptome analyses were performed with the classification of the annotated genes based on their identities among the three hosts and their putative functions. pCAR1 carriage affected host transcriptome more greatly at the transition and stationary phases in each host. The transcriptome responses were more similar between KT2440 and PAO1 than between other host combinations, and many genes, such as for ribosomal proteins, F-type ATPase, and RNAP core, in both strains were commonly not suppressed in their stationary phases. These responses may have resulted in the reduction of host fitness, motility, and stress resistances. Host-specific responses to plasmid carriage were transcriptional changes of genes on putative prophage or foreign DNA regions. The extent of the impacts in host phenotypes and transcriptomes was similarly the largest in KT2440 and the lowest in Pf0-1. The host alterations controlled by pCAR1 carriage are important for understanding the fate of the plasmid and its host, plasmid maintenance, expression of plasmid genes, the host cell physiology, and host survivability in the environment. The growth-dependent change of chromosomal RNA maps from exponential to early stationary phases of pCAR1-harboring KT2440 and non-pCAR1 harboring KT2440 were compared. The growth-dependent change of chromosomal RNA maps from exponential to early stationary phases of pCAR1-harboring PAO1 and non-pCAR1 harboring PAO1 were compared. The growth-dependent change of chromosomal RNA maps from exponential to early stationary phases of pCAR1-harboring Pf0-1 and non-pCAR1 harboring Pf0-1 were compared. The growth-dependent change of RNA maps from exponential to early stationary phases of plasmid pCAR1possessed by 3 kinds of hosts were compared.
Project description:Nucleoid-associated proteins (NAPs) are known to fold bacterial DNA and influence global transcription. Incompatibility P-7 plasmid pCAR1 carries three genes encoding NAPs: H-NS family protein Pmr, NdpA-like protein Pnd, and HU-like protein Phu. Because previous reports about plasmid-encoded NAPs mainly focused on H-NS homologs, functions and importance of different kinds of NAPs encoded on a plasmid remained unknown. Here, we assessed the effects of single or double disruption of pmr, pnd, and phu in a host P. putida KT2440. When pmr and pnd or pmr and phu were disrupted simultaneously, stability and conjugation frequency of pCAR1 decreased significantly. In the comprehensive phenotypes comparisons, host availabilities of some compounds, which were reduced by pCAR1carriage, were restored by NAP-gene(s)-disruption. Transcriptome analyses showed that Pmr and Pnd have different regulons, whereas Phu mainly supports their gene regulation. These cooperative functions of the three NAPs were not simply due to protein-protein interactions because hetero-oligomers of them were not detected in pull-down assays. Our present study is the first report about the cooperative function of plasmid-encoded different kinds of NAPs, which show no homology with each other. The NAPs-dependent change of chromosomal RNA maps in early exponential phases.
Project description:Nucleoid-associated proteins (NAPs) are known to fold bacterial DNA and influence global transcription. Incompatibility P-7 plasmid pCAR1 carries three genes encoding NAPs: H-NS family protein Pmr, NdpA-like protein Pnd, and HU-like protein Phu. Because previous reports about plasmid-encoded NAPs mainly focused on H-NS homologs, functions and importance of different kinds of NAPs encoded on a plasmid remained unknown. Here, we assessed the effects of single or double disruption of pmr, pnd, and phu in a host P. putida KT2440. When pmr and pnd or pmr and phu were disrupted simultaneously, stability and conjugation frequency of pCAR1 decreased significantly. In the comprehensive phenotypes comparisons, host availabilities of some compounds, which were reduced by pCAR1carriage, were restored by NAP-gene(s)-disruption. Transcriptome analyses showed that Pmr and Pnd have different regulons, whereas Phu mainly supports their gene regulation. These cooperative functions of the three NAPs were not simply due to protein-protein interactions because hetero-oligomers of them were not detected in pull-down assays. Our present study is the first report about the cooperative function of plasmid-encoded different kinds of NAPs, which show no homology with each other. The NAPs-dependent change of RNA maps in early exponential phases.