Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To assess the risk of acquiring Clostridium difficile diarrhoea or colitis in patients colonised with C difficile, rectal swabs taken weekly for 9 weeks from patients with long-term (at least 7 days) hospital stays on three wards were cultured for C difficile. 60 (21%) of 282 patients were culture-positive for C difficile during their hospital stay, of whom 51 were symptom-free faecal excretors. C difficile diarrhoea developed in the other 9 patients; 2 were culture-positive for C difficile and had diarrhoea at the time of first culture, and 7 had diarrhoea or pseudomembranous colitis after 1-6 previously negative weekly rectal cultures. All patients with diarrhoea were on one ward, but symptom-free, excretors were found on all wards. HindIII chromosomal restriction endonuclease analysis (REA) of the C difficile isolates revealed 18 distinct types. All isolates from the patients with diarrhoea were one of two nearly identical REA types, B or B2. 26 of the 29 total B/B2 isolates were from patients on the same ward, which points to a nosocomial outbreak. The symptom-free excretors were not at increased risk of subsequent clinical illness.
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PMID:Nosocomial Clostridium difficile colonisation and disease. 197 32

A total of 246 live Clostridium difficile cultures were serotyped by a slide agglutination technique. Fifteen grouping antisera were produced which serotyped 98% of the cultures (241 of 246). Our results indicated that certain serogroups may have specific pathogenicity. Strains of serogroups A, G, H, K, S1, and S4 were cytotoxigenic and were isolated mainly from adult patients with pseudomembranous colitis or antibiotic-associated diarrhea. Nontoxigenic strains of serogroups D and Cd-5 were isolated mainly from asymptomatic neonates and small children. Some cross-reactions occurred among some strains of serogroups A, Cd-5, G, and K. These strains were further examined by analysis of protein profiles and restriction endonuclease patterns to elucidate their serology. Typing of C. difficile by using slide agglutination is a simple technique suitable for routine examination. Serogrouping may be a useful epidemiological marker and could help in elucidating the medical relevance of some C. difficile isolates.
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PMID:Serotyping of Clostridium difficile. 283 28

Two patients in one hospital room acquired pseudomembranous colitis, one shortly after the other. The DNA restriction patterns of isolates from the patients and of four isolates from the environment were indistinguishable from one another and differed from isolates of other patients. Restriction endonuclease digest analysis appears to be a useful method for studying the epidemiology of Clostridium difficile.
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PMID:Application of whole-cell DNA restriction endonuclease profiles to the epidemiology of Clostridium difficile-induced diarrhea. 303 17

Clostridium difficile causes pseudomembranous colitis and antibiotic-associated diarrhea. The definitive diagnosis of C. difficile infection is finally accomplished by the isolation of toxigenic C. difficile. However, only a small number of Japanese clinical laboratories are able to reach a definitive diagnosis of C. difficile infection, probably because simple reliable assays for toxins in the isolates are not available. In this study, we examined the compatibility of a polymerase chain reaction (PCR) assay and tissue culture assay to identify toxigenic C. difficile, in toxigenic and nontoxigenic C. difficile isolates from Japanese patients and healthy carriers. The specificity of PCR primers was demonstrated by restriction endonuclease digestion and seminested PCR in C. difficile VPI 10463 strain. No PCR product was amplified in the eight other clostridial species used to check the specificity of the PCR assay. The detection limit was 10(3) cells. Both toxin A and toxin B genes (the genes encoding the major virulence factors of C. difficile) were detected in 58 toxigenic C. difficile isolates, which showed a wide range of cytotoxic activity in tissue culture assays. Neither of the toxin genes was carried by 40 nontoxigenic strains of C. difficile. The results of this study strongly suggest that a definitive diagnosis of C. difficile infection can be accomplished by PCR detection of the toxin genes rather than by tissue culture assay of isolates.
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PMID:Laboratory diagnosis of toxigenic Clostridium difficile by polymerase chain reaction: presence of toxin genes and their stable expression in toxigenic isolates from Japanese individuals. 1020 9

A toxin variant strain of Clostridium difficile was isolated from two patients with C. difficile-associated disease (CDAD), one of whom died from extensive pseudomembranous colitis. This strain, identified by restriction endonuclease analysis (REA) as type CF2, was not detected by an immunoassay for C. difficile toxin A. Culture supernatants of CF2 failed to elicit significant enterotoxic activity in the rabbit ileal loop assay but did produce atypical cytopathic effects in cell culture assay. Southern hybridization, PCR amplification, and DNA sequence analyses were performed on the toxin A (tcdA) and toxin B (tcdB) genes of type CF2 isolate 5340. Type CF2 5340 tcdA exhibited a 1,821-bp truncation, due to three deletions in the 3' end of the gene, and a point mutation in the 5' end of the gene, resulting in a premature stop codon at tcdA position 139. Type CF2 5340 tcdB exhibited multiple nucleotide base substitutions in the 5' end of the gene compared to tcdB of the standard toxigenic strain VPI 10463. Type CF2 5340 toxin gene nucleotide sequences and deduced amino acid sequences showed a strong resemblance to those of the previously described variant C. difficile strain 1470, a strain reported to have reduced pathogenicity and no association with clinical illness in humans. REA of strain 1470 identified this strain as a distinct type (CF1) within the same REA group as the closely related type CF2. A review of our clinical-isolate collection identified five additional patients infected with type CF2, three of whom had documented CDAD. PCR amplification of the 3' end of tcdA demonstrated identical 1. 8-kb deletions in all seven type CF2 isolates. REA type CF2 is a toxin variant strain of C. difficile that retains the ability to cause disease in humans but is not detected in clinical immunoassays for toxin A.
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PMID:Toxin gene analysis of a variant strain of Clostridium difficile that causes human clinical disease. 1099 43

The clinical spectrum of Clostridium difficile-associated disease (CDAD) ranges from diarrhoea to severe life-threatening pseudomembranous colitis. Although not always associated with previous antibiotic exposure, it is in the majority of cases. CDAD is recognised increasingly in a variety of animal species and in individuals previously not considered to be predisposed. C. difficile can be transmitted via personal contact or environmentally. The role of patients and healthcare workers who are symptom-free but colonised with C. difficile in the intestinal tract is unclear. C. difficile, with more than 150 PCR ribotypes and 24 toxinotypes, has a pathogenicity locus (PaLoc) with genes encoding enterotoxin A (tcdA) and cytotoxin B (tcdB). Genes for the binary toxin are located outside the PaLoc, but the role of this toxin is unclear. The recently completed genome sequence of C. difficile 630 revealed a large proportion of 11% of mobile genetic elements, mainly in the form of conjugative transposons. Diagnostic assays include tests for the detection of C. difficile products or genes and culture methods for isolation of a toxin-producing bacterium. Enzyme immunoassays to detect toxin in faeces are widely available, with varying sensitivities and specificities. Despite practical drawbacks and sensitivity less than 100%, the cell cytototoxicity assay is still considered to be the standard. Rapid diagnostic assays are available on a limited scale and require much improvement. Molecular tests enable the detection of carriers of toxigenic and non-toxigenic strains, as does culture. It is highly recommended to culture C. difficile from toxin-positive faeces samples and to store isolates for future characterisation and typing. The financial impact of CDAD on the healthcare system is substantial (5-15,000 euro/case in England and $1.1 billion/year in the USA). Assuming a European Union population of 457 million, the potential cost of CDAD can be estimated to be 3000 million euro/year, and is expected to almost double over the next four decades. In North America, increasing rates of CDAD have been reported in Canada and the USA since March 2003, involving a more severe course, higher mortality, increased risk of relapse and more complications. This increased virulence is presumably associated with higher levels of toxin production by fluoroquinolone-resistant strains belonging to PCR ribotype 027, pulsed-field gel electrophoresis (PFGE) type NAP1, REA (restriction endonuclease analysis) type BI and toxinotype III. In Europe, outbreaks of CDAD due to the new, highly virulent strain of C. difficile PCR ribotype 027, toxinotype III have been recognised in 75 hospitals in England, 16 hospitals in The Netherlands, 13 healthcare facilities in Belgium and nine healthcare facilities in France. These outbreaks are very difficult to control, and preliminary results from case-control studies indicate a correlation with fluoroquinolones and cephalosporins. Information concerning community-acquired cases of ribotype 027 is lacking, and data concerning its incidence in nursing homes are limited. European countries should first develop early-warning and response capabilities at a national level. Depending on the nature of the notifications received, countries should implement laboratory-based or patient-based surveillance systems in specific, targeted populations.
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PMID:Emergence of Clostridium difficile-associated disease in North America and Europe. 1696 99