Pre_GI Island

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n1_4mer:GRV/n1_4mer:RV = (Global Relative Variance of OU patterns) / (Local Relative Variance of OU patterns)

n0_4mer:D = Distance between local and global OU patterns

n0_4mer:PS = Distance between 2 strands of same DNA molecule

Selected loci indicated by large D, increased GRV associated with decreased RV and moderate increase in PS




NC_017177: Clostridium difficile BI1, complete genome

NCBI: NC_017177

Host Lineage: Peptoclostridium difficile; Peptoclostridium; Peptostreptococcaceae; Clostridiales; Firmicutes; Bacteria

General Information: Clostridium difficile BI1 is a human strain isolated in the United States in 1988. This species is now recognized as the major causative agent of pseudomembranous colitis (inflammation of the colon) and diarrhea that may occur following antibiotic treatment. C. difficile infection represents one of the most common nosocomial (originating in a hospital) infections. This bacterium causes a wide spectrum of disease, ranging from mild, self-limiting diarrhea to serious diarrhea and, in some cases, complications such as pseudomembrane formation, toxic megacolon (dilation of the colon) and peritonitis, which often lead to lethality among patients. The bacteria produce high molecular mass polypeptide cytotoxins, A and B. Some strains produce only one of the toxins, others produce both. Toxin A causes inflammatory reaction involving hypersecretion of fluid and hemorrhagic necrosis through triggering cytokine release by neutrophils. Cytotoxin B depolymerizes actin, the major protein of the cytoskeleton, and thus aids in destruction of tissues. The combined action of the toxins results in necrosis of superficial epithelium and edema (fluidic swelling) in affected areas of intestine. Proliferation of C. difficile is normally prevented by normal intestinal microflora, which is believed to inhibit attachment of the bacterium and its toxins to intestinal walls. Alteration of intestinal microbial balance with antibiotic therapy and increased exposure to the bacterium in a hospital setting allows C. difficile to colonize susceptible individuals. Moreover, it has been shown that subinhibitory concentrations of antibiotics promote increased toxin production by C. difficile.



Islands with an asterisk (*) contain ribosomal proteins or RNA related elements and may indicate a False Positive Prediction!

#StartEndLengthIsland TextGRV_RVDPSNeighboursClusterSub ClusterBLASTNKey Word ConfirmationOther DB ConfirmationDownload Island
19199312674934757Island text2.6212916.537628.603Neighbours21BLASTN91993.gbk
213608215459918518Island text3.6411715.980729.1083Neighbours21136082.gbk
317500019475319754Island text3.2252916.204630.6036Neighbours21BLASTN175000.gbk
419293321219019258Island text3.283115.992826.6598Neighbours21192933.gbk