Project description:Investigation of whole genome gene expression level changes in a Clostridium difficile fur (ferric uptake regulator) mutant, compared to the wild type strain 630 erm. The fur mutant analyzed in this study is further described in Ho and Ellermeier (2015) J. Bacteriology A microarray study using total RNA recovered from three separate wild type cultures of Clostridium difficile 630 erm strain and three separate cultures of a fur mutant strain (ltrA::ermR) were grown in Tryptone-Yeast Extract medium containing 0.25 mM ferric chloride . Each chip measures the expression level of 3,786 of the 3,787 open reading frames of the C. difficile 630 genome with 18 probes (60 oligomers each) for each gene.
Project description:Investigation of whole genome gene expression level changes in a Clostridium difficile fur (ferric uptake regulator) mutant, compared to the wild type strain 630 erm. The fur mutant analyzed in this study is further described in Ho and Ellermeier (2015) J. Bacteriology
Project description:Grad-seq in Clostridium difficile 630. Cell lysate is analyzed in a gradient and fractionated into 21 fractions which are analysed for proteins by MS and for transcripts by RNA-sequencing.
Project description:Clostridium difficile (C. difficile) strains belonging to PCR ribotype 027, PFGE type NAP1, REA type B1 and toxinotype III, termed NAP1/027, have been implicated in the increased frequency of outbreaks of Clostridium difficile-associated diarrhoea (CDAD) in North America and Europe. The NAP1/027 strains appears to be more virulent with an increased mortality and frequency of relapse. Current European C. difficile microarrays are designed to the first sequenced and annotated C. difficile complete genome - strain 630 (ribotype 12). A high density oligonucleotide microarray was designed to C. difficile 630 (CD630) sequence and extra probes corresponding to two PCR ribotypes O27 strains C. difficile R20291 and QCD-32g58 were also included. Comparative genomic hybridisation was used to identify markers of ribotype 027 strains and markers to identify CD630. Strains hybridised to the array included the most prevalent ribotypes found in the UK and Europe (106 and 001) as well as the emerging hypervirulent ribotype 078.
Project description:The Gram-positive bacterium Clostridium difficile, a leading cause of antibiotic-associated pseudomembranous colitis, has received increasing attention due to a rising incidence of clinical C. difficile infections (CDI). Despite progress understanding bacterial factors that promote CDI-associated morbidity and mortality, many fundamental aspects of C. difficile biology remain to be explored. Compared to other Gram-positive pathogens, little is known about the bacterium’s transcriptome architecture and in particular mechanisms of post-transcriptional control. To close this knowledge gap, we have applied a suite of transcriptome-focused techniques, including transcription start site mapping (dRNA-seq), transcription termination mapping, and Hfq RIP-seq, resulting in a single-nucleotide resolution RNA map of C. difficile strain 630.
Project description:Clostridium difficile is a gram-positive, spore-forming enteric anaerobe which can infect humans and a wide variety of animal species. Recently, the incidence and severity of human C. difficile infection has markedly increased. In this study, we evaluated the genomic content of 73 C. difficile strains isolated from humans, horses, cattle, and pigs by comparative genomic hybridization with microarrays containing coding sequences from C. difficile strains 630 and QCD-32g58. The sequenced genome of C. difficile strain 630 was used as a reference to define a candidate core genome of C. difficile and to explore correlations between host origins and genetic diversity. Approximately 16% of the genes in strain 630 were highly conserved among all strains, representing the core complement of functional genes defining C. difficile. Absent or divergent genes in the tested strains were distributed across the entire C. difficile 630 genome and across all the predicted functional categories. Interestingly, certain genes were conserved among strains from a specific host species, but divergent in isolates with other host origins. This information provides insight into the genomic changes which might contribute to host adaptation. Due to a high degree of divergence among C. difficile strains, a core gene list from this study offers the first step toward the construction of diagnostic arrays for C. difficile.
Project description:Clostridium difficile is a gram-positive, spore-forming enteric anaerobe which can infect humans and a wide variety of animal species. Recently, the incidence and severity of human C. difficile infection has markedly increased. In this study, we evaluated the genomic content of 73 C. difficile strains isolated from humans, horses, cattle, and pigs by comparative genomic hybridization with microarrays containing coding sequences from C. difficile strains 630 and QCD-32g58. The sequenced genome of C. difficile strain 630 was used as a reference to define a candidate core genome of C. difficile and to explore correlations between host origins and genetic diversity. Approximately 16% of the genes in strain 630 were highly conserved among all strains, representing the core complement of functional genes defining C. difficile. Absent or divergent genes in the tested strains were distributed across the entire C. difficile 630 genome and across all the predicted functional categories. Interestingly, certain genes were conserved among strains from a specific host species, but divergent in isolates with other host origins. This information provides insight into the genomic changes which might contribute to host adaptation. Due to a high degree of divergence among C. difficile strains, a core gene list from this study offers the first step toward the construction of diagnostic arrays for C. difficile.investigated by determining changes in transcript profiles when aerobic steady-state cultures were depleted of air.
Project description:Transcriptional analysis of Clostridium difficile R20291 in biofilm formation, planktonic state and grown on blood agar RNA sequencing was performed on Clostridium difficile R20291 in three different conditions: Biofilm formation, plantonic state and grown on blood agar plates. Each condtion has 3 replicates.
Project description:C. difficile infections have become a major challenge in medical facilities today. The bacterium is capable of spore formation, which even allows survival of antibiotic treatment. Therefore, research on the physiology of C. difficile is important for the development of alternative treatment strategies. In this study, we investigated eight putative flavodoxins of C. difficile 630. Flavodoxins are small electron transfer proteins of specifically low potential. The unusually high number of flavodoxins in C. difficile compared to other bacteria suggests that they are expressed under different conditions. Therefore, we investigated expression along bacterial growth and found high transcription levels during the exponential growth phase, especially for floX. Since flavodoxins in other bacteria are capable of replacing ferredoxins with their [2Fe-2S] clusters under iron deficiency conditions, we also examined flavodoxin expression in C. difficile under low iron and no iron levels.