Project description:TIGR4 and R6 bacterial strains of Streptococcus pneumoniae treated and not treated with the iron chelator deferoxamine mesylate (DFO)
Project description:Alterations in genes for penicillin-binding proteins (pbp) are well-known determinants for the resistance of Streptococcus pneumoniae to B-lactam antibiotics. Surprisingly, some mutations in non-pbp genes were also found to contribute to B-lactam resistance. Two of them discovered in the piperacillin resistant mutants P106 and P104, affect the expression of cpoA (encoding a glycosyltransferase) and of the rgtABCDHR cluster (encoding two small membrane proteins, an ABC transporter and a regulatory two-component system), respectively. cpoA and rgtABCDHR are involved in maintaining the synthesis and the proper ratio of the two major membrane glycolipids, and deletions in these genes led to complex phenotypes. In attempts to identify genetic determinants for these phenotypes, the global trancription patterns of the deletion mutants R6 delta cpoA, R6 delta rgtA and R6 delta rgtD were compared to that of the parent strain R6.
Project description:The most basic level of transcription regulation in Streptococcus pneumoniae is the organization of its chromosome in topological domains. In response to drugs that caused DNA-relaxation, a global transcriptional response was observed. Separate domains were identified depending of the transcription of their genes: up-regulated (U), down-regulated (D), non-regulated (N), and flanking (F). We show here that these distinct domains have different expression and conservation tendencies. Microarray fluorescence units under non-relaxation conditions, taken as a measure of gene transcription level, were significantly lower in F genes than in the other domains in the same range of AT content. Transcription level categorization of the domains was D>U>F. In addition, a comparison of 12 S. pneumoniae genome sequences evidenced conservation of gene composition in the U and D domains and extensive gene interchange in F domains. We tested domain organization by measuring the relaxation-mediated transcription of eight insertions of a heterologous Ptccat cassette, two in each type of domain, showing that transcription depended on their chromosomal location. Moreover, transcription from the four promoters directing the five genes involved in supercoiling homeostasis, located either in U (gyrB), D (topA), or N (gyrA and parEC) domains was analyzed both in their chromosomal locations and in a replicating plasmid. Although expression from the chromosomal PgyrB and PtopA showed the expected domain regulation, their expression was down-regulated in the plasmid, which behaved as a D domain. However, both PparE and PgyrA carried their own regulatory signals, their topology-dependent expression being equivalent in the plasmid or in the chromosome. In PgyrA a DNA bend acted as a DNA supercoiling sensor. These results revealed that DNA topology works as a general transcriptional regulator, superimposed to other kind of more specific regulatory mechanisms.
Project description:We performed a comparative study of the two control sample options with a Streptococcus pneumoniae microarray designed with three fully sequenced strains. We hybridized two of these strains (R6 and G54) as test samples using the third strain alone (TIGR4) or a mix of the three strains as the control sample.
Project description:The Antibiotic Resistant Sepsis Pathogens Framework Initiative aims to develop a framework dataset of 5 sepsis pathogens (5 strains each) using an integrated application of genomic, transcriptomic, metabolomic and proteomic technologies. The pathogens included in this initiative are: Escherichia coli, Klebsiella pneumoniae complex, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae. This submission pertains to Streptococcus pneumoniae strains 4496, 947, 4559, 180-2 and 180-15.
Project description:The Antibiotic Resistant Sepsis Pathogens Framework Initiative aims to develop a framework dataset of 5 sepsis pathogens (5 strains each) using an integrated application of genomic, transcriptomic, metabolomic and proteomic technologies. The pathogens included in this initiative are: Escherichia coli, Klebsiella pneumoniae complex, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae. This submission pertains to strain 4496.
Project description:The Antibiotic Resistant Sepsis Pathogens Framework Initiative aims to develop a framework dataset of 5 sepsis pathogens (5 strains each) using an integrated application of genomic, transcriptomic, metabolomic and proteomic technologies. The pathogens included in this initiative are: Escherichia coli, Klebsiella pneumoniae complex, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae. This submission pertains to strain 947.
Project description:The Antibiotic Resistant Sepsis Pathogens Framework Initiative aims to develop a framework dataset of 5 sepsis pathogens (5 strains each) using an integrated application of genomic, transcriptomic, metabolomic and proteomic technologies. The pathogens included in this initiative are: Escherichia coli, Klebsiella pneumoniae complex, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae. This submission pertains to strain 4559.
