Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012872 (DNA marker)
 929 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Burkholderia cepacia is a problematic pathogen that may spread among patients with cystic fibrosis (CF). One highly infectious CF strain that causes epidemics in both the United Kingdom and eastern Canada has been shown to possess both the cable pilin subunit gene (cblA) and a unique combination of insertion sequences. However, no genetic markers linking this strain type with other types epidemic at various centers have been identified. Using a randomly amplified polymorphic DNA (RAPD) typing scheme, we identified an apparently conserved 1.4-kb fragment in the DNA fingerprint of epidemic B. cepacia strains. Conservation of the DNA marker among epidemic strains was demonstrated by Southern hybridization, and its prevalence was assessed in a collection of chromosomal DNAs extracted from 627 isolates representative of 132 RAPD-defined B. cepacia strain types. The marker was specifically associated with seven epidemic CF strains, was absent among nonepidemic strains infecting individual patients with CF, and rare among strains recovered from the natural environment. Only one of the seven epidemic CF strain types possessed DNA homologous to cblA. The RAPD marker was designated the "B. cepacia epidemic strain marker" (BCESM). Sequence analysis of chromosomal DNA corresponding to the 1.4-kb RAPD marker revealed the presence of a putative open reading frame (ORF) with significant homology to several negative transcriptional regulators; the ORF was designated the "epidemic strain marker regulator," or esmR. The BCESM DNA is the first genetic marker that has been identified to be specifically associated with and conserved among several epidemic B. cepacia strains which infect multiple patients with CF.
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PMID:Identification and characterization of a novel DNA marker associated with epidemic Burkholderia cepacia strains recovered from patients with cystic fibrosis. 915 33

Burkholderia cepacia is an opportunistic respiratory pathogen in cystic fibrosis patients. One highly transmissible and virulent clone belonging to genomovar IIIa expresses pili with unique cable morphology, which enable the bacterium to bind cytokeratin 13 in epithelial cells. The cblA gene, encoding the major pilin subunit, is often used as a DNA marker to identify potentially virulent isolates. The authors have now cloned and sequenced four additional genes, cblB, cblC, cblD and cblS, in the pilus gene cluster. This work shows that the products of the first four genes of the cbl operon, cblA, cblB, cblC and cblD, are sufficient for pilus assembly on the bacterial surface. Deletion of cblB abrogated pilus assembly and compromised the stability of the CblA protein in the periplasm. In contrast, deletion of cblD resulted in no pili, but there was no effect on expression and stability of the CblA protein subunit. These results, together with protein sequence homologies, predicted structural analyses, and the presence of typical amino acid motifs, are consistent with the assignment of functional roles for CblB as a chaperone that stabilizes the major pilin subunit in the periplasm, and CblD as the initiator of pilus biogenesis. It is also shown that expression of Cbl pili in Escherichia coli is not sufficient to mediate the binding of bacteria to the epithelial cell receptor cytokeratin 13, and that B. cepacia still binds to cytokeratin 13 in the absence of Cbl pili, suggesting that additional bacterial components are required for effective binding.
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PMID:Identification and molecular analysis of cable pilus biosynthesis genes in Burkholderia cepacia. 1268 38