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DNA probe analysis for the carriage of enterotoxigenic Clostridium perfringens in feces of a Mexican subpopulation.

Clostridium perfringens has been implicated as a causative agent of foodborne poisoning, infectious diarrhea (not associated with foods), gas gangrene, and several veterinary diseases. Fecal carriage of enterotoxigenic strains of this bacterium appears to be important in the development of infectious diarrhea and as a source of C. perfringens contamination of foods. In this work, carriage of this bacterium in feces of a Mexican population was analyzed. C. perfringens was found in 126 of the 200 fecal samples obtained from healthy individuals from northern Mexico. The samples had an average of

Evaluation of reformulated chemiluminescent DNA probe (AccuProbe) for culture identification of Mycobacterium kansasii.

A panel of 104 isolates belonging to the species Mycobacterium kansasii and 78 mycobacterial isolates belonging to other species was tested in parallel with the present commercially available DNA probe (AccuProbe; Gen-Probe) and with a new probe just developed by the same manufacturer. While the old version of the probe confirmed the previously reported low sensitivity (only 59% of the M. kansasii isolates reacted), the new one was 100% sensitive. Only two non-M. kansasii strains, both M. gastri isolates, gave false-positive hybridization results.

Use of a DNA probe for the rapid detection of group B streptococci in obstetric patients.

OBJECTIVE: To determine the accuracy of a DNA probe as a rapid diagnostic test for detecting colonization of the female genital tract by group B streptococci during pregnancy. METHODS: Two rayon-tipped applicators were used to collect secretions from the posterior vaginal wall of 440 pregnant women. One of the applicators was inoculated into selective Todd-Hewitt broth and used as the reference standard for identification of group B streptococci. The other applicator was used for analysis with the DNA probe, preceded by either 2.5 hours of incubation for the initial 75 patients, or 3.5 hours'

Evaluation of a DNA-based probe for the detection of cattle experimentally infected with Babesia bigemina.

A digoxigenin-labeled probe was used for hybridization to various preparations of Babesia bigemina-infected erythrocyte extracts. Dot blot hybridization and immunological detection of DNA hybrids revealed that the probe was specific for B. bigemina DNA because it did not hybridize to the DNA of B. bovis, a closely related species. Studies of sensitivity showed that the probe would bind to as little as 1 ng of B. bigemina DNA, but not to 1 microgram of the B. bovis DNA. The probe reacted with equal intensity against seven B. bigemina isolates from different geographic areas. The lowest percenta

Diagnosis of tetrasomy 18p using in situ hybridization of a DNA probe to metaphase chromosomes.

We identified an isochromosome of 18p [47,XY, +i(18p)] conclusively by in situ hybridization of an 18p-specific probe (B74; D18S3) to metaphase chromosomes of an affected patient. Clinical findings included mental retardation, microcephaly, and an atrial septal defect. Although there is similarity to patients previously described with tetrasomy 18p, it is impossible to rule out a low frequency of misdiagnoses in karyotypes determined solely by standard cytogenetic analyses. We expect the ability to conclusively identify an i(18p) to lead to the delineation of tetrasomy 18p as a distinct clinic

[Design of a species-specific DNA probe based on the pFra plasmid of the plague pathogen].

The recombinant plasmid pBS1 carrying a 2 kb SalGI fragment of Yersinia pestis pFra plasmid was constructed by insertion of the fragment into a vector plasmid pBR327. SalGI-BspRI 400 bp subfragment was recloned into a pBR322 vector plasmid. Open reading frame was found in the fragment by DNA sequencing technique. The subfragment designated F1-probe permits one to identify specifically the Yersinia pestis strains harbouring pFra plasmid, thus, differing them from closely related Yersiniea and other representatives of Enterobacteriaceae family.

[Use of a specific DNA probe to confirm sickle cell anemia in a caucasian woman].

A specific DNA probe containing part of the structural B-globulin gene was used to confirm the diagnosis of sickle cell anemia in a caucasian woman. The patient's genomic DNA was digested with the restriction endonuclease Dde I, fractioned by agarose electrophoresis and Southern blotting. Molecular hybridization was performed with the DNA probe prepared by chemical labelling with photobiotin. The beta 8/beta 8 genotype rendered only 1 fragment of length 376 bp. Upon digestion with Dde I, the DNA of an individual with the normal genotype containing the enzyme recognition sequence at the site of

DNA probe for detection of the Leptospira interrogans serovar hardjo genotype hardjo-bovis.

A DNA probe is described for the diagnostic and taxonomic identification of the North American cattle pathogen Leptospira interrogans genotype hardjo-bovis. The probe is specific for this genotype and does not hybridize to genomic DNA of any other leptospire pathogen commonly found in North America.

Vision of Life's Code: Molecular Probe Nanoarchitectonics for Deep RNA/DNA Illumination.

Visualization of RNA and DNA provides a window of opportunity for the early detection of multiple diseases and approaches to manipulate them before any pathological processes occur. However, current imaging systems often fail to meet these demands due to the need for multiple RNA and DNA chemical probes, which increases experimental complexity, reduces awareness of false positives, and limits imaging accuracy in complex biosystems. In this work, we identify the key challenges associated with using multiple probes for RNA and DNA imaging and analyze the mechanisms and performance of existing im

Совпадение в полном тексте источника
… These four examples provide further possibilities as a fundamental framework for designing chemical probes with properties that extend beyond the simple combination of individual RNA or DNA probes. … Below, we summarize the requirements for future RNA/DNA probe molecules. …

Probing Electrostatics in a DNA Repair Enzyme with a pH-Sensitive Nitroxyl Spin Label.

Enzymes use electrostatic interactions to recognize their substrates, preorganize active sites, and stabilize reaction transition states. Formamidopyrimidine-DNA glycosylase (Fpg) is a bacterial enzyme that repairs a pro-mutagenic DNA lesion, 8-oxoguanine; its human homologues are important for cancer prevention. General acid-base catalysis in the active site of Fpg requires a finely tuned proton transfer between Pro1 and Glu2 residues. To assess the protonation state of the active site experimentally, we used EPR spectroscopy with a novel imidazolidine nitroxyl spin label responsive in the ph

Diagnostic performance of DNA probe-based and PCR-based molecular vaginitis testing.

Using retrospective data from U.S. Food and Drug Administration-approved/cleared molecular vaginal panels, molecular methods were found to have higher detection for Candida vaginitis and lower detection for bacterial vaginitis when compared to probe-based methods. In addition, the differentiation of Candida and non-Candida yeast has not reached the physician community as we observed noncompliance in recommended therapy. Furthermore, the pros and cons of migrating to molecular testing from conventional microscopy for identifying bacterial vaginitis and fungal vaginitis have been examined and re

A nucleotide-independent nitroxide probe reports on site-specific stereomeric environment in DNA.

In this report, stereospecific structural and dynamic features in DNA are studied using the site-directed spin labeling technique. A stable nitroxide radical, 1-oxyl-4-bromo-2,2,5,5-tetramethylpyrroline (R5a), was attached postsynthetically to phosphorothioates that were chemically introduced, one at a time, at five sites of a DNA duplex. The two phosphorothioate diastereomers (R(p) or S(p)) were separated, and nitroxide rotational motions were monitored using electron paramagnetic resonance spectroscopy. The resulting spectra vary according to diastereomer identity and location of the labelin

A CdTe nanoparticle-modified hairpin probe for direct and sensitive electrochemical detection of DNA.

Detection of specific sequences of target DNA is of high importance in many fields, especially in medicinal diagnostics. DNA sensors should exhibit fast response to minute concentrations of the target sequence and have the ability to distinguish single-base mismatches from fully complementary target. This study focuses on the response of an electrochemical, CdTe nanoparticle-modified hairpin DNA sensor. The stem-loop structured probes and the blocking poly(ethylene glycol) (PEG) molecules were self-assembled on the gold electrode through S-Au bonding, to form a mixed monolayer employed as the

Specific detection of deleted mitochondrial DNA by in situ hybridization using a chimera probe.

We report a new method for the specific detection of the mutant mitochondrial DNA (mtDNA) that contains the 4977-bp deletion. We designed an oligonucleotide probe that was designated the 'ATP8/ND5 Chimera' probe: its 5'- and 3'-portions correspond to the ATP8 gene and the ND5 gene, respectively, and its middle portion includes the 13-bp direct repeat sequence that flanks the 4977-bp deletion. By Southern blot analysis, this chimeric probe specifically detected the deleted mtDNA, even in the presence of both normal mtDNA and other mtDNA deletions. The specificity of the probe was further confir

Identification of Trypanosoma brucei gambiense group I by a specific kinetoplast DNA probe.

A set of 26 Trypanosoma brucei stocks from various African countries, previously characterized by multilocus enzyme electrophoresis (MLEE) for 18 polymorphic loci, have been selected to be representative of the three T. brucei classic subspecies. The kinetoplast DNA minicircle variable regions from these stocks have been amplified using the polymerase chain reaction (PCR) technique, and hybridized with the amplified variable regions of three T. brucei reference stocks, previously identified as T. brucei brucei, T. brucei gambiense, and T. brucei rhodesiense, respectively. Both T. b. brucei and

Generic affinities among crocodilians as revealed by DNA fingerprinting with a Bkm-derived probe.

Genetic fingerprint profiles have been successfully used for establishing biological relationships, in linkage analysis, and in studies of population structure but have not so far been used for ascertaining phylogenetic relationships among related groups of species and genera. This is largely because these profiles are thought to evolve too rapidly to be informative over large time intervals. However, we show here that among the Crocodilia, whose phylogeny is a debated issue, these profiles can provide phylogenetically useful information. By using the probe Bkm-2(8), DNA fingerprints with dist

Detection of Babesia equi in infected horses and carrier animals using a DNA probe.

The ability of the Babesia equi repetitive probes, pSE2 and pSB20, to detect parasites in blood from experimentally infected, naturally infected and carrier animals was tested using a spot hybridization assay. The clinical course of the experimentally infected horses was monitored using microscopy, indirect fluorescent antibody tests, packed cell volume, temperature and the probe assay. The probes sensitively monitored the parasite level during the development of the disease and correlated well with the other parameters tested. The sensitivity of the probe assay was superior to that of light m

Use of a DNA probe to detect Salmonella typhi in the blood of patients with typhoid fever.

A DNA probe was used to detect Salmonella typhi from blood samples from 14 of 33 patients with culture-confirmed typhoid fever, using the equivalent of 2.5 ml of blood. In contrast, S. typhi was detected in 17 of the same 33 patients by culture of 8 ml of blood. The probe hybridized to blood samples of 4 of 47 patients from whom S. typhi was not isolated.

Identification of a Yersinia pestis-specific DNA probe with potential for use in plague surveillance.

A 900-base-pair DNA fragment derived from a 9.5-kilobase plasmid in Yersinia pestis hybridized specifically with Y. pestis DNA. We demonstrated the feasibility of using this DNA fragment to detect plague bacilli directly in fleas, suggesting that this Y. pestis-specific DNA probe may be used for plague surveillance in the field. Additional applications for this DNA probe may include plague diagnosis and pathogenesis research.