Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Enteropathogenic Yersinia enterocolitica is an important cause of human and animal disease. Phenotypic and genotypic characteristics currently used to identify Y. enterocolitica are not necessarily sufficient to differentiate pathogenic from non-pathogenic strains or to analyse the epidemiology of yersiniae at a molecular level. To improve the characterisation of Yersinia isolates, NotI restriction fragment length polymorphisms (RFLPs) of chromosomal DNA of more than 100 clinical, animal and environmental isolates were analysed in pulsed-field gel electrophoresis. Highly conserved RFLP patterns with fragments ranging from 15 to 400 kb were detected within each of 10 Y. enterocolitica serogroups tested. Determination of RFLP types makes it possible to discriminate between isolates of different Y. enterocolitica serogroups and other Yersinia spp. Moreover, NotI restriction endonuclease analysis allows even subtyping of strains belonging to a unique serogroup-biotype. Identification of NotI fragments hybridising with inv- or ail-homologous sequences was used as an additional discriminating marker. The results indicate that NotI RFLP typing can provide a powerful new tool for the differentiation of clinical Y. enterocolitica isolates.
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PMID:Characterisation of pathogenic Yersinia enterocolitica serogroups by pulsed-field gel electrophoresis of genomic NotI restriction fragments. 796 5

A generally applicable procedure was used to isolate a spontaneous restriction-deficient mutant of Yersinia enterocolitica serotype O:8. Transposition frequency in the mutant strain 8081-res was approximately 6.7 x 10(-6) per recipient, while it was practically zero in the wild-type strain 8081-c. Mobilization frequency into 8081-res was 10(5) times higher than that into the wild-type strain. The mutant had lost the ability to express the YenI restriction endonuclease activity present in serotype O:8 strains. This allowed the construction of a transposon library in 8081-res. Insertion mutants with transposons in the genes of the rfa region were selected from this library.
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PMID:Isolation of an R- M+ mutant of Yersinia enterocolitica serotype O:8 and its application in construction of rough mutants utilizing mini-Tn5 derivatives and lipopolysaccharide-specific phage. 813 71

Two different clonal groups of pathogenic Yersinia enterocolitica strains, American and non-American, have been recognized. These are distinguished by a number of criteria, including their virulence in a murine model of infection. However, genetic analysis of virulence in American strains has been hampered due to the severe restriction of transformed or electroporated DNA. Thus, we cloned the yenIMR locus from the American serotype strain 8081c, which encodes YenI, an isoschizomer of PstI. This clone encodes both the restriction endonuclease and methyltransferase. The location of the genes on the clone was determined and this information was used to construct a small deletion (400 bp) that results in an R-M+ phenotype. This mutation was recombined onto the Y. enterocolitica chromosome to give an R-M+ mutant which showed at least a 1000-fold increase in electroporation frequency compared to the wild-type strain. Southern analysis using a probe derived from yenIMR indicated that American serotype strains have this locus whereas non-American serotype strains do not.
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PMID:Cloning of the YenI restriction endonuclease and methyltransferase from Yersinia enterocolitica serotype O8 and construction of a transformable R-M+ mutant. 829 16

Restriction endonuclease analyses of virulence plasmid DNA (REAP) and chromosomal DNA and other phenotypic characteristics were used to study the differentiation of Yersinia enterocolitica serotype O:5,27 strains. There was a close correlation between REAP patterns and the geographical distribution of serotype O:5,27. Human isolates produced only one REAP pattern, which was also found with isolates from pigs and dogs.
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PMID:Differentiation of Yersinia enterocolitica serotype O:5,27 strains by phenotypic and molecular techniques. 839 Oct 27

In June 1991, there were large scale outbreaks of Yersinia pseudotuberculosis at 4 primary schools and 1 junior high-school in Noheji-machi in Aomori Prefecture. A total of 732 patients (725 pupils and school children, 7 teachers and personnel) were affected and 134 were hospitalized. Sex ratio of incidence was 1.1:1.0 without appreciable difference. Clinical symptoms (478 patients) were represented frequently by pyrexia (86.4%), eruption (73.8%), abdominal pain (66.7%), vomiting nausea (63.4%), etc., and were characterized by a strawberry tongue, pharyngeal redness, membranous desquamation of the fingers and arthralgia during convalescence. Yersinia pseudotuberculosis was isolated from 27 (81.8%) of 33 patients stool specimens, 1 waste water specimen and 2 (11.7%) of cooking employees' stool specimens. The isolates were confirmed serotype 5a, and positive for calcium-dependency and autoagglutination, and harboring 40-50 megadalton virulent plasmid. Restrictive endonuclease digestive pattern of plasmid proved to be identical. In many cases, patients' serum antibody titer showed a significant increase ratio to the isolated strain. In term of drug susceptibility, all the strains were sensitive to cefem, penicillin and amino-glycoside series and resistant to macrolide and sulfa series. The infectious source was limited to the school feeding, but the responsible food remained unknown. Mean latency and exposure day were presumed to be 6.5 days and May 30, respectively.
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PMID:[Large scale outbreak of Yersinia pseudotuberculosis serotype 5a infection at Noheji-machi in Aomori Prefecture]. 845 Feb 73

Thirty-seven strains of Yersinia isolated from human and environmental sources were investigated for virulence and molecular characteristics. Clinical isolates of Y. enterocolitica serotypes 0:3 and 0:9, harbouring the 45 MDa virulence plasmid were Ca++ dependent and responded positively to the CV-binding assay. The environmental Y. kristensenii strain, although harbouring a 45 MDa plasmid proved to be negative for both assays. All the environmental strains showed pyrazinamidase activity, while isolates from human sources proved negative. Two different plasmid profiles were disclosed: one Y. enterocolitica strain (serotype 0:7, 8) showed one plasmid of 67 MDa and one plasmid of 1.5 MDa. Eleven human isolates of Y. enterocolitica and one environmental strain of Y. krinstensenii showed only one plasmid of 45 MDa. Restriction endonuclease analysis of the 45 MDa plasmids supported the hypothesis that the environmental Y. krinstensenii plasmid is unrelated to the family of homologous virulence plasmids of Y. enterocolitica.
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PMID:Molecular characterization of Yersinia strains isolated from human and environmental sources. 846 71

Ribotyping performed with five restriction endonucleases was used in an attempt to subtype Yersinia enterocolitica serotype O:3 and also as a tool for clonal analysis. DNA from organisms under study (48 isolates from diarrheic human feces, 24 from food, and 5 reference strains) was tested by Southern hybridization using a DNA probe carrying an rRNA operon from Escherichia coli. Strains were grouped into seven ribotypes by the HindIII restriction endonuclease, into five ribotypes by Ncil, Bg/l, and Sa/l; and into two ribotypes by EcoRI, resulting in a discrimination index (DI) of 0.37, 0.17, 0.43, 0.13, and 0.03 for the five endonucleases. By combining the results obtained with two or more restriction endonucleases, a further discrimination was registered, the most efficient combination (in terms of discriminatory power vs. cost in work, time, and money) for routine typing being HindIII-Bg/l (9 types, DI=0.58). In the clonal analysis, results obtained with the five restriction endonucleases allowed us to define 11 groupings or clonal lines, which showed a remarkable degree of genetic heterogeneity (genetic distance coefficients between 0.03 and 0.73) and were grouped into two major clusters. One cluster included 93% of the strains and eight lines. At least two of the most frequent lines can be considered endemic in Asturias, Spain, because organisms belonging to these lines have been circulating and causing human yersiniosis in recent years and have also been isolated from commercial raw meat products. Two Ncil ribotypes from the series under study (92.2% of strains included in the prevalent cluster) were similar but not identical to ribotypes of 0.3 organisms from other geographic areas described in the literature, indicating that the genetic structure of prevalent human pathogens of this serotype is basically clonal.
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PMID:Discriminatory power and application of ribotyping of Yersinia enterocolitica O:3 in an epidemiological study. 874 Aug 57

The biological properties of non-melibiose-fermenting (NMF) strains of Yersinia pseudotuberculosis O3 were investigated. These strains were clearly distinguished from representative melibiose-fermenting (MF) strains of Y. pseudotuberculosis O3 by their pathogenicity in mice, sensitivity to some phages, production of catalase, restriction endonuclease analysis of virulence plasmid DNA with BamHI, detection of specific yersinia outer-membrane proteins with SDS-PAGE, antigenicity of the outer-membrane proteins and neutrophil resistance to phagocytosis. The pathogenicity of NMF strains was clearly less than that of MF strains. In addition, the resistance of NMF strains to phagocytosis and catalase activity was evidently weaker than that of MF strains. These results suggested that the difference of pathogenicity was due to the ability of catalase production. Although the relationship between the above characteristics and melibiose-fermentation was not analysed, the pathogenicity of Y. pseudotuberculosis O3 strains can probably be predicted by testing melibiose-fermentation and catalase production.
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PMID:Characteristics and pathogenicity of non-melibiose-fermenting strains of Yersinia pseudotuberculosis O3. 913 Feb 28

By the method of alkaline lysis the occurrence was studied of plasmid DNA in 122 strains of Yersinia. In 29 strains a single plasmid was found with characteristic growth of the organism on CRMOX (CRMOX+) medium. These features are encoded by genes located on the pYV virulence plasmid. The group of Yersinia strains possessing the virulence plasmid included 27 strains of Y. enterocolitica 0:3 isolated from clinical materials, among them 21 strains isolated from patients between January and September 1996, while the remaining two strains with the virulence plasmid belonged to Y. pseudotuberculosis antigenic group I. Following restriction analysis with the EcoRI enzyme of the virulence plasmids isolated from 27 strains of Y. enterocolitica 0:3 occurrence of only one restriction endonuclease pattern agreeing with the virulence plasmid pattern of Y. enterocolitica 0:3 strains reported in the literature was found in all strains. On the other hand, the restriction analysis of the virulence plasmids obtained from Y. enterocolitica 0:3 and Y. pseudotuberculosis I strains showed evident differences between these plasmids in the size of the particle and the restriction pattern. The plasmid size calculated on the basis of the analysis of the restriction endonuclease patterns for virulence plasmids isolated from the strains of Y. enterocolitica 0:3 and Y. pseudotuberculosis I was 71.5 thousands and 62.7 thousands of base pairs respectively, and was in the range 60-75 thousands bp (40-50 Mda) reported in the literature for virulence plasmids of Yersinia. The study showed that finding of characteristic growth of Yersinia organisms on the CRMOX medium can be useful for the detection of strains containing the pYV virulence plasmid and for the determination of their potential pathogenicity.
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PMID:[Occurrence of virulent plasmids in strains of Yersinia obtained from various sources]. 918 36

The aim of our study was to find out if plasmids of foodborne Yersinia enterocolitica biogroup 1A strains harbour genes related to the virulence genes located on the virulence plasmid pYV of Yersinia enterocolitica. The foodborne strains were isolated from pork, as pigs are considered as an important reservoir for enteropathogenic Y. enterocolitica 0:3 and 0:9 strains. The plasmids of the foodborne strains were characterized by restriction enzyme analysis and hybridized to the virulence plasmid pYV of pathogenic Y. enterocolitica strains (0:3 biogroup 4; 0:9 biogroup 2). In several cases the plasmids of the foodborne strains showed homologies to parts of the pYV plasmid. Analysis of the hybridizing regions revealed that genes involved in replication, sequences of transposable elements and an endonuclease gene caused the observed hybridization to the virulence plasmid. In cause of the study also a remnant of a Tn3-like transposon was shown to be present adjacent to the yadA gene on the pYV plasmid. Although there is evidence that at least some strains of Y. enterocolitica biogroup 1A might possess pathogenic properties none of the well known plasmid encoded virulence genes were present on the plasmids of the investigated foodborne biogroup 1A strains.
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PMID:Characterization of plasmid regions of foodborne Yersinia enterocolitica biogroup 1A strains hybridizing to the Yersinia enterocolitica virulence plasmid. 970 8


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