Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017160 (gastroenteritis)
 11,398 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Campylobacter is the most common bacterial cause of gastroenteritis in the European Union with over 200,000 laboratory-confirmed cases reported annually. This is the first study to describe findings related to comparative genomics analyses of the sequence type (ST)-677 clonal complex (CC), a Campylobacter jejuni lineage associated with bacteremia cases in humans. We performed whole-genome sequencing, using Illumina HiSeq sequencing technology, on five related ST-677 CC isolates from two chicken farms to identify microevolution taking place at the farms. Our further aim was to identify novel putative virulence determinants from the ST-677 CC genomes. For this purpose, clinical isolates of the same CC were included in comparative genomic analyses against well-known reference strains of C. jejuni. Overall, the ST-677 CC was recognized as a highly clonal lineage with relatively small differences between the genomes. Among the farm isolates differences were identified mainly in the lengths of the homopolymeric tracts in genes related to the capsule, lipo-oligosaccharide, and flagella. We identified genomic features shared with C. jejuni subsp. doylei, which has also been shown to be associated with bacteremia in humans. These included the degradation of the cytolethal distending toxin operon and similarities between the capsular polysaccharide biosynthesis loci. The phase-variable GDP-mannose 4,6-dehydratase (EC 4.2.1.47) (wcbK, CAMP1649), associated with the capsular polysaccharide biosynthesis locus, may play a central role in ST-677 CC conferring acid and serum resistance during different stages of infection. Homology-based searches revealed several additional novel features and characteristics, including two putative type Vb secretion systems and a novel restriction modification/methyltransferase gene cluster, putatively associated with pathogenesis and niche adaptation.
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PMID:Evolution and comparative genomics of Campylobacter jejuni ST-677 clonal complex. 2519 5

Campylobacter jejuni is a major pathogen in bacterial gastroenteritis worldwide and can cause bacteremia in severe cases. C. jejuni is highly structured into clonal lineages of which the ST677CC lineage has been overrepresented among C. jejuni isolates derived from blood. In this study, we characterized the genomes of 31 C. jejuni blood isolates and 24 faecal isolates belonging to ST677CC in order to study the genome biology related to C. jejuni invasiveness. We combined the genome analyses with phenotypical evidence on serum resistance which was associated with phase variation of wcbK; a GDP-mannose 4,6-dehydratase involved in capsular biosynthesis. We also describe the finding of a Type III restriction-modification system unique to the ST-794 sublineage. However, features previously considered to be related to pathogenesis of C. jejuni were either absent or disrupted among our strains. Our results refine the role of capsule features associated with invasive disease and accentuate the possibility of methylation and restriction enzymes in the potential of C. jejuni to establish invasive infections. Our findings underline the importance of studying clinically relevant well-characterized bacterial strains in order to understand pathogenesis mechanisms important in human infections.
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PMID:Comparative genomics and genome biology of invasive Campylobacter jejuni. 2660 14