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)

DNA fingerprinting of 15 reference strains and 24 clinical isolates of Chlamydia trachomatis, 2 strains of C. psittaci and one strain of C. pneumoniae was studied by use of universal 16 + 23S RNA from Escherichia coli, 16S rDNA-directed oligonucleotide and randomly cloned chlamydial DNA probes. The rRNA-gene restriction patterns (ribotypes) enabled the differentiation of chlamydial species. Following DNA cleavage by restriction endonuclease PvuII, lymphogranuloma venereum and trachoma biovars of C. trachomatis could be differentiated. An oligonucleotide, designed to hybridize the C. trachomatis 16S rDNA, also allowed for both species-specific identification and biovar typing of C. trachomatis human strains. Molecular typing system using 3 lambda clones containing C. trachomatis serotype E random DNA inserts, combined to ribotyping, revealed 12 groups of variable banding patterns within C. trachomatis, and could provide an alternative epidemiological tool.
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PMID:DNA fingerprinting of Chlamydia trachomatis by use of ribosomal RNA, oligonucleotide and randomly cloned DNA probes. 129 28

Eight strains of Chlamydia psittaci isolated from swine with pneumonia, pleuritis, pericarditis, and enteritis were characterized through analysis of the major outer membrane protein gene ompA by a two-step polymerase chain reaction, by their interactions with cells in culture, and by the morphologic features and ultrastructure of intracellular inclusions. Amplified chlamydial ompA DNA fragments were differentiated by restriction endonuclease digestion. Chlamydial isolates were separated into 2 types on the basis of ompA restriction fragment length polymorphism. Strains of type L71 had finely granular inclusions, whereas those of type 1710S contained pleomorphic reticulate bodies (RB) in the inclusions, which are characteristic of aberrant chlamydial developmental forms. Chlamydial types L71 and 1710S required centrifuge-assisted inoculation for efficient infection of cell cultures. Cultivation in cell culture medium containing cycloheximide increased the numbers of chlamydial inclusions about 1.5-fold. These strains formed few elementary bodies in yolk sac cells of chicken embryos. Ultrastructurally, unique doublet RB were observed, particularly in strains of the ompA type L71. These doublets consisted of 2 RB, bounded by a cytoplasmic membrane, contained within a common cell wall and an extended periplasmic space. Ultrastructural examination of strains of the ompA type 1710S confirmed the aberrant chlamydial developmental forms, but evidence of viral infection of the RB as a cause of these aberrant forms was not found. The strain S45 isolated from intestinal sites of swine was a trachoma restriction fragment length polymorphism type. With the mouse biotype, it represented the second isolate from animals of Chlamydia trachomatis.
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PMID:Biological properties and genetic analysis of the ompA locus in chlamydiae isolated from swine. 135 14

Twelve serovar type strains (C, D, E, F, G, H, I, J, K, L1, L2 and L3) and eight isolates (D, 4; E, 2; K, 2) of C. trachomatis were examined by restriction endonuclease analysis (REA) of DNA extracted from the elementary bodies. No difference was observed in DNA patterns of three serotypes (L1, L2 and L3) of the biovar LGV when they were digested with EcoRI and analysed by electrophoresis in a 0.6% agarose gel. The genital strains of the biovar trachoma (serovars D-K) showed similar EcoRI patterns with or without detectable differences. Serovar C of the biovar trachoma differed from the biovar LGV and the genital strains. Comparative analysis of DNAs digested with EcoRI, BamHI, HindIII, SalI and NcoI revealed that C. trachomatis isolates belonging to serovars D and K, but not E, could be subdivided into different genome types. These results suggest that DNA cleavage pattern analysis is useful for epidemiological, clinical, and taxonomic studies of C. trachomatis.
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PMID:[Restriction endonuclease analysis of Chlamydia trachomatis DNA]. 168 Sep 37

Both clinical and epidemiological data suggest that inapparent infection by Chlamydia trachomatis occurs in humans. To confirm and study such infections, we developed a hybridization screening system directed toward chlamydial ribosomal RNA (rRNA). Six restriction endonuclease fragments derived from the cloned rrnA operon of chlamydial serovar L2(434) were tested as hybridization screening probes, but only one fragment encoding the 5' portion of the 16s rRNA gene plus some upstream flanking sequence was both sensitive and highly specific in such experiments. In Northern slot blot assays, hybridization analyses with this fragment as probe routinely detected one picogram or less of chlamydial RNA when that RNA was bound to membranes alone or as part of a mixture with a vast excess of mammalian RNA. The probe did not hybridize to RNA from mammalian and relevant bacterial sources but did hybridize to rRNA from B (ocular) and E (genital) serovars of C. trachomatis. Experiments using RNA from conjunctival biopsies and standard conjunctival swab samples from cynomolgus monkeys showed that the probe reliably distinguishes between known chlamydia-infected and uninfected samples. This suggests that it may be useful for clinical screening. Characterization assays for the RNA-directed probe screening system in this monkey model of trachoma provide initial molecular evidence that ocular chlamydial infection may persist longer than previously thought, based solely on direct fluorescence antibody assay (DFA) and culture analyses.
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PMID:RNA-directed molecular hybridization screening: evidence for inapparent chlamydial infection. 175 Apr 44

The 60-kDa cysteine-rich outer membrane protein genes of Chlamydia psittaci, Chlamydia pneumoniae, and Chlamydia trachomatis have very different 5' ends, but two areas flanking this variable region show absolute sequence conservation. This observation permitted differentiation of the three species of Chlamydia by the polymerase chain reaction (PCR), forming the basis of a diagnostic test for chlamydial infections. The PCR product containing the variable region of the respective 60-kDa CrP genes was also subjected to restriction endonuclease digestion, enabling differentiation of individual type strains of C. psittaci. Differentiation was possible between lymphogranuloma venereum and trachoma isolates of C. trachomatis. The PCR-based diagnostic test was successful with all strains of chlamydiae studied. The PCR primers showed high specificity and did not produce any product with common bacterial pathogens that may share the same sites of infection.
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PMID:Genetic diversity and identification of human infection by amplification of the chlamydial 60-kilodalton cysteine-rich outer membrane protein gene. 186 38

Genetic relationships were reported for Chlamydia psittaci derived from psittacine birds, pigeons, turkeys, humans, cats, muskrats, cattle, and sheep and for C. trachomatis, including representative strains of the three biovars, through physical analysis of genomic DNA including DNA fingerprinting with restriction endonuclease SalI, DNA-DNA hybridization in solution with S1 nuclease, and Southern analysis with genomic DNA probes. A total of 26 strains were divided into four groups of C. psittaci and two groups of C. trachomatis, on the basis of DNA fingerprints. The six groups of Chlamydia spp. were related to host origin: two avian groups (Av1 and Av2), one feline and muskrat group (Fe1), one ruminant group (Ru1), one C. trachomatis biovars trachoma and lymphogranuloma group (CtHu), and one C. trachomatis mouse biovar group (CtMo), although an ovine abortion strain belonged to the avian group Av2. DNA-DNA hybridization assay and Southern analysis with genomic DNA probes indicated three DNA homology groups in the genus Chlamydia: an avian-feline group (groups Av1, Av2, and Fe1), a ruminant group (group Ru1), and a C. trachomatis group (groups CtHu and CtMo). Furthermore, the Southern analysis indicated that the homologous sequences (DNA homology of at least 14%) within the avian-feline group were distributed along the whole genome, whereas the homologous sequences (DNA homology of less than 24%) among the three DNA homology groups were localized in distinct regions of the genome DNA. These results suggest that Chlamydia spp. are derived from a common ancestor and have diverged into various groups showing restricted host ranges as a natural characteristic and that the species C. psittaci should be differentiated into groups related to host origin and DNA homology.
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PMID:Genetic diversity of avian and mammalian Chlamydia psittaci strains and relation to host origin. 256 33

An 820 bp AccI-PstI fragment of the 60 kDa cysteine rich outer membrane protein (CrP) gene from C. trachomatis serovar L1 was used as a probe to locate the 60 kDa CrP gene of a recent serovar B trachoma isolate (Jali 20/OT). The probe hybridized to a single 1.8 kb SpeI fragment in Southern blot analyses of different restriction endonuclease digests of C. trachomatis serovar B DNA. This fragment was ligated into Lambda Zap II arms and Bluescript SK(-) recombinants, released by infection with the helper phage R408, were used as template for DNA sequence determination. Sequence analysis demonstrated a very high level of homology between the Jali 20/OT 60 kDa CrP and the previously published serovar L1 60 kDa CrP with only 8 out of 507 amino acid substitutions between the two proteins.
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PMID:Chlamydia trachomatis 60 kDa cysteine rich outer membrane protein: sequence homology between trachoma and LGV biovars. 261 91

DNA from a total of 60 Chlamydia trachomatis isolates was examined by restriction endonuclease analysis. Strains from all established biovars and serovars were tested. There was great diversity between the mouse biovar and the lymphogranuloma venereum (LGV) and trachoma biovars. The LGV and trachoma biovar isolates generated similar fragment patterns; however, distinct fragments appeared to be unique to both biovars, thus allowing differentiation of these two major groups. In most cases, strains of the same serovar could be differentiated from one another when a battery of restriction enzymes was used. In addition, in some cases, certain restriction fragments appeared to be characteristic of strains from a particular geographical location. The DNA patterns generated by all C. trachomatis isolates differed greatly from the DNA patterns generated from the Chlamydia psittaci isolates tested, including TWAR, a human C. psittaci strain.
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PMID:Restriction endonuclease analysis of DNA from Chlamydia trachomatis biovars. 283 86

The application of a diagnostic and genotyping technique based on the polymerase chain reaction (PCR) to the study of trachoma epidemiology in the Gambian village of Jali is reported. PCR based on the major outer membrane protein (MOMP) gene of Chlamydia trachomatis appears to be more sensitive than either isolation or antigen detection by enzyme immunoassay; it had a specificity of 95% and sensitivity of 51% against clinical signs. PCR genotyping identified genotypes A and B of Chlamydia trachomatis circulating in Jali. Sequencing revealed a Pst1 restriction endonuclease site in the amplified MOMP gene of some B strains but not others; Pst1 digestion of the PCR product proved an easy method of distinguishing these strains. The distribution of serotypes and B strain variants shows a significant degree of household clustering (p < 0.001). PCR based genotyping combined with strain typing provides a new and powerful epidemiological tool for the study of transmission events in trachoma.
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PMID:Molecular epidemiology of trachoma in a Gambian village. 784 72

We have used nested polymerase chain reaction (PCR) and the PCR-based endonuclease digestion method to genotype Chlamydia trachomatis serovars in 460 infected individuals from the Eastern Highlands Province of Papua New Guinea. Our study groups comprised women who presented in labour to the Goroka Base Hospital, their newborn infants, symptomatic children who presented to the hospital's Outpatients Department and men and women from 15 randomly selected villages in the Asaro Valley. In this analysis, the major outer membrane protein (MOMP) gene, omp1, of C. trachomatis was amplified using DNA obtained from the endocervix of women, urine from men, and both the eye and nasopharynx of children. Amplified DNAs were digested concurrently using Alul and a combination of EcoRI, Hinl and Hpall restriction enzymes. The mixtures were separated on electrophoretic gels and the respective serovars designated on the basis of resolved digested DNA patterns. Our results, which were confirmed also by omp1 sequence data, show serovars D, E, F, G, H and L3 to be present in the studied communities. The overall relative frequencies of these serovars were 30%, 21%, 25%, 1%, 20% and 2% respectively, with serovars D, E, F and H accounting for 97% of these infections. Double infections among these principal serovars were also detected in all our study groups but at a low overall frequency of 3%. Serovar D was the major agent involved in the aetiology of chlamydial infection in both children and adults though serovar F was the most frequent in newborn infants. Serovar H was relatively less frequent in symptomatic children. No trachoma-related serovars were detected, confirming the rarity of this disease in Papua New Guinea. In contrast, although clinical cases of lymphogranuloma venereum have not been described in the country, the detection of serovar L3 in this study suggests that it may occur. However, the association of L3 also with childhood infection indicates that it may be causing the same pathology as the serovars D-K that are associated with non-ulcerative sexually transmitted infections.
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PMID:Chlamydia trachomatis infection and distribution of serovars in the Eastern Highlands Province, Papua New Guinea. 1958 96


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