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Results for “Polymerase Chain Reaction”

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PubMed2001

Detection of bancroftian filariasis in human blood samples from Sorsogon province, the Philippines by polymerase chain reaction.

The polymerase chain reaction (PCR) was used for diagnosing Wuchereria bancrofti infection in a small village in the province of Sorsogon, the Philippines. Of 54 night-time blood samples collected, 4 (7.4%) were found to be microfilaremic as determined by combined direct blood film examination and membrane filtration of blood followed by blood film examination. However, utilization of the SspI PCR assay to detect repeated W. bancrofti DNA sequences in human blood doubled the number of microfilaremic individuals to 8 (13.0%). The results of this survey suggest that utilization of diagnostic tools based on microscopy could underestimate the true prevalence of W. bancrofti in the Philippines.

Animals↗

PubMed1993

Detection of tick-borne encephalitis virus RNA in ticks (Ixodes ricinus) by the polymerase chain reaction.

A polymerase chain reaction for the detection of tick-borne encephalitis virus (TBEV) RNA in ticks was developed. Two pairs of primers for nested PCR were selected from the 5'-NCR and the 5'-terminus of the C protein coding region, which are highly conserved among the TBEV isolates sequenced so far. The sensitivity of the nested PCR was tested by dilution experiments of a TBEV positive brain suspension. The specificity of the PCR products was confirmed by Southern blotting. In a pilot study, 60 homogenates of 7200 ticks (I. ricinus) were examined by PCR. Two homogenates were found positive. The PCR for TBEV RNA appears to be a valuable method to define endemic areas of TBE.

Animals↗

PubMed1992

[Detection of the eggs of Echinococcus multilocularis Leuckart, 1863, in the feces of the fox (Vulpes vulpes Linnaeus, 1758) by the polymerase chain reaction].

The polymerase chain reaction (PCR) was applied to the identification of eggs of Echinococcus multilocularis in faeces from foxes. The test was positive in three of six faeces samples from foxes which were harbouring adult worms, and in one of four samples from foxes in which no adult E. multilocularis was found in the intestines. These initial results show that it is possible to use PCR to identify E. multilocularis eggs in faeces. PCR can be used to complement examination of intestinal contents, showing that the distribution of eggs in faeces is uneven. The sensitivity of the test was estimated to be 50 eggs in 5 g of faeces. Further work is needed to confirm these initial results before the test can be used more widely.

Animals↗

PubMed1999

Detection and identification of Mycoplasma from bovine mastitis infections using a nested polymerase chain reaction.

A polymerase chain reaction (PCR) test was compared with culture for the detection and diagnosis of bovine Mycoplasma intramammary infection. The PCR test was applied to 24-hour Mycoplasma enrichment cultures of milk from cows with suspected mastitis and from bulk tank milk. In comparison to culture, the sensitivity and specificity of the PCR method were 96.2% and 99.1% for individual cow milk and 100% and 99.8% for the bulk tank milk, respectively. However, in discrepant cases where PCR was positive and culture was negative, the PCR test was correct; subsequent PCR tests and culturing of the individual cow's milk yielded positive results. The PCR test simultaneously detected and differentiated among 11 bovine Mycoplasma species.

Animals↗

PubMedDate not supplied

[Diagnosis of Helicobacter pylori by polymerase chain reaction].

The Polymerase Chain Reaction (PCR) is a biotechnological useful tool for the diagnosis of bacteria or viruses with high in vitro growth requirements. Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the upper part of the gastrointestinal tract and its diagnosis is very important since it is associated with chronic gastritis, peptic ulcer, and gastric carcinomas. Because of the difficult growth requirements of the H. pylori, the PCR is being used for its diagnosis in samples of gastric biopsy, gastric juices, feces, saliva and subgingival plaque using specific H. pylori DNA fragments. This paper is a literature review that outlines the use of PCR in the diagnosis of H. pylori, the benefits and future applications of this technique in this area.

Helicobacter Infections↗

PubMed1991

Detection of human papillomavirus type 16 in sexual partners of patients having cervical cancer by polymerase chain reaction.

The polymerase chain reaction (PCR) was employed to detect human papillomavirus (HPV) 16 and 18 in cytological samples from the uterine cervix and in urine samples from the male consorts. HPV 16 was detected in 2 (25%) of 8 males whose wives were positive for HPV 16, while it was detected in only one (7%) of 14 consorts whose wives were negative for HPV 16 and 18. This is the first report of the detection of HPV 16 in urine. Viral detection in urine samples by the PCR method is a non-invasive, convenient and useful tool for large-scale epidemiologic studies and investigations of the mechanism of virus transmission.

Adenocarcinoma↗

PubMed1997

Detection of Clostridium septicum hemolysin gene by polymerase chain reaction.

A polymerase chain reaction (PCR) was developed for the detection of the hemolysin (alpha toxin) gene of Clostridium septicum. The PCR primers were designed from the sequence of the hemolysin gene and synthesized. A DNA fragment of 270 bp was amplified from 10 strains of C. septicum, but was not from strains of C. chauvoei, C. perfringens, C. novyi, or C. haemolyticum. When the PCR product was digested with Sau3AI, two DNA fragments of the expected 148 bp and 122 bp were recognized. The lowest detectable threshold of PCR for the hemolysin gene was 3.8 x 10(3) cells/ml. The PCR technique may be useful for rapid detection or identification of C. septicum associated with malignant edema.

Animals↗

PubMed1998

[Infection of sexually transmitted diseases in female patients with inflammation of genitourinary tract by polymerase chain reaction].

Using polymerase chain reaction (PCR), Neisseria gonorrhoeae (NG) from 5899 female out-patients with inflammation of genitourinary tract was detected. Among 18.57% positive cases, the effective rates of the gonorrhea (26.07%) and urethritis (23.73%) were higher than those of the Condyloma acuminatum (CA) (17.73%), vaginitis (17.70%), and cervicitis (11.54%)(P< 0.01), indicating that there were various degrees of NG infection in genitourinary tract diseases. Moreover, Ureaplasma urealyticum (UU), Chlamydia trachomatis (CT), NG, and human papilloma viruses (HPV) were also detected in 8329 patients with vaginitis. Among 20.01% positive cases, the positive rate of UU was 39.95%, CT 21.36%, NG 17.70%, and HPV 16.40%. Variance analysis showed that significant differences existed in the vaginitis caused by different pathogens ( P <0.01); namely, four kinds of pathogens were present in the patients with vaginitis.

Adult↗

PubMed1995

Detection and differentiation of the gene for toxin co-regulated pili (tcpA) in Vibrio cholerae non-O1 using the polymerase chain reaction.

The polymerase chain reaction has been used to differentiate the gene which encodes the toxin co-regulated pili (tcpA) of the El Tor and classical biotypes of Vibrio cholerae O1. The same PCR primers were applied to strains belonging to non-O1 serogroups that produced cholera toxin. The size of fragment amplified was either identical to the tcpA of biotype El Tor (471 bp) or to the tcpA of biotype classical (617 bp). All strains belonging to the novel epidemic serogroup O139 generated a 471-bp fragment identical to El Tor tcpA. The present study suggests that there may be an association between non-O1 serogroup and tcpA type.

Bacterial Outer Membrane Proteins↗

PubMed1998

Analysis of infectious laryngotracheitis virus isolates from Ontario and New Brunswick by the polymerase chain reaction.

The polymerase chain reaction (PCR) was used to amplify DNA of infectious laryngotracheitis virus (ILTV) isolates obtained from field specimens. The examined 47 samples included 37 isolates representing 35 cases of infectious laryngotracheitis from Ontario and 10 isolates originating from 10 field cases in New Brunswick. The viruses were grown in either embryonated chicken eggs or cell culture, the DNA extracted and amplified using primers designed from the sequence information of a 1.1 kb BamHI fragment of the Ontario 1598 ILTV strain. Thirty-four of the Ontario isolates and all of the New Brunswick isolates were amplified successfully. This suggests that the selected primers would be useful for the majority of the isolates encountered in outbreaks of ILTV.

Animals↗

PubMed1991

Detection of methicillin-resistant Staphylococcus aureus (MRSA) using polymerase chain reaction amplification.

Polymerase chain reaction (PCR) was applied for the detection of methicillin-resistant Staphylococcus aureus (MRSA). This procedure amplified a segment of MRSA-PBP (penicillin-binding protein) gene of DNA extract from the clinical isolates of S. aureus. A 1339-base-pair fragment of MRSA-PBP gene in DNA from S. aureus (MIC of methicillin, greater than or equal to 16 micrograms/ml) was amplified and detected by a specific oligonucleotide probe. Moreover, a 4.3 kb HindIII fragment containing MRSA-PBP gene was detected by using the same oligonucleotide probe. On the other hand, no PCR-amplified product was detected in DNA from methicillin-sensitive S. aureus (MIC of methicillin, less than 16 micrograms/ml).

Base Sequence↗

PubMed1991

Detection of herpes simplex virus DNA sequences in corneal transplant recipients by polymerase chain reaction assays.

Polymerase chain reaction (PCR) assays were used to amplify herpes simplex virus type 1 (HSV-1) thymidine kinase (TK) sequences in DNA extracted from formalin-fixed, paraffin embedded corneas of patients undergoing corneal transplantation. PCR reamplification with an internal (nested) set of primers was required for detection in 10 of the 12 positive corneas indicating very low abundance of viral sequences. Three of the positive corneal samples were from failed corneal grafts. Overall, TK sequences were detected in 8 of 11 corneas from subjects with a past history of herpes keratitis and in 4 of 11 corneas from subjects with no past history of herpetic eye disease.

Adult↗

PubMed1994

Rapid detection of bovine herpesvirus 1 (BHV 1) using the polymerase chain reaction.

A polymerase chain reaction (PCR) assay based on primers from the viral gI glycoprotein gene detected 3 fg pure BHV-1 DNA, 0.1-1.0 TCID50 or a single infected cell. No amplification was observed with DNA from BHV-2, BHV-3, BHV-4, OHV-1 or OHV-2. However, a fragment of the correct size was amplified using DNA from herpesviruses isolated from reindeer, red deer and goats. The PCR assay was able to detect virus in nasal swabs up to 14 days after experimental infection of cattle and there was a good correlation when PCR was compared with virus isolation for the detection of BHV-1 in clinical field samples. Detection of BHV-1 in fetal bovine serum and semen samples was also successful.

Animals↗

PubMed1991

Survey of urine from transplant recipients for polyomaviruses JC and BK using the polymerase chain reaction.

Using polymerase chain reaction (PCR), we examined 108 urine specimens from 39 post transplant patients for polyomaviruses JC (JCV) and BK (BKV). Urine sediments were collected and subjected to 30 cycles of amplification. PCR products were resolved by agarose gel electrophoresis, transferred to nylon membranes by Southern blot, and hybridized with radiolabelled probes. Polyomavirus DNA was found in urine specimens from 17 out of 39 patients (44%). Both viruses were detected in specimens from nine patients, JCV alone in five, and BKV alone in three. In comparison, polyomavirus was detected in only five of 22 PCR positive specimens by shell vial cell culture assay. Our results show a high prevalence of polyomavirus shedding after transplantation and suggest a higher rate of JC viruria than previously reported.

DNA, Viral↗

PubMed1995

Diagnosis of Mycoplasma pneumoniae pneumonia in pediatric patients by polymerase chain reaction (PCR).

Polymerase chain reaction (PCR) testing was performed on respiratory tract specimens obtained by throat swab in 21 children admitted to the hospital with suspected Mycoplasma pneumoniae pneumonia. Of 13 patients with a clinical condition compatible with mycoplasma infection and an immunological response to M. pneumoniae, 11 were positive by PCR. Eight patients were negative by serology and/or had a clinical condition not compatible with mycoplasma infection, and all were negative by PCR. The antibody response to M. pneumoniae was delayed for a week or more in 3 (23%) of the 13 patients with documented mycoplasma infection. These results suggest that PCR performed on a respiratory tract specimen obtained by a throat swab may be useful in the initial evaluation of children with suspected M. pneumoniae pneumonia, especially in patients in whom the serological response is delayed.

Adolescent↗

PubMed2001

Rapid and specific identification of nitrile hydratase (NHase)-encoding genes in soil samples by polymerase chain reaction.

A polymerase chain reaction (PCR) protocol was developed for the specific detection of genes coding nitrile hydratase (NHase). Primer design was based on the highly conserved sequences found in the coding region of the alpha-subunit gene corresponding to the metal-binding site. Purified genomic DNA from bacterial strains or directly from soil can serve as the target for the PCR, thus affording a simple and rapid method for screening NHase genes. The primer pairs, NHCo1/NHCo2 and NHFe1/NHFe2 yield PCR products corresponding to a partial coding sequence of cobalt and iron NHase genes, respectively. Using the PCR method, both types of iron- and cobalt-NHase-encoding genes were detected in DNA from pure cultures and soil samples. Furthermore consensus primers allowed rapid cloning and expression of novel NHases in Escherichia coli.

Amino Acid Sequence↗

PubMed1991

No evidence of HTLV-I infection in French patients with multiple sclerosis using the polymerase chain reaction.

The polymerase chain reaction (PCR), using three primer pairs in the pol, tax, and env regions of the HTLV-I genome, was unable to detect HTLV-I in the blood samples of 54 caucasian subjects with multiple sclerosis who were seronegative for HTLV-I/II. Seventeen HTLV-I/II seropositive (by ELISA and Western blot) subjects used as positive controls were positive with the three primer pairs. The PCR was negative in 47 healthy HTLV-I/II seronegative (by ELISA) subjects at low risk of HTLV-I infection used as negative controls. These results suggest that there is no association between the occurrence of HTLV-I sequences and the development of multiple sclerosis.

Adult↗

PubMed1991

Rapid screening for toxigenic Corynebacterium diphtheriae by the polymerase chain reaction.

The polymerase chain reaction (PCR) was used to discriminate between toxigenic and non-toxigenic isolates of Corynebacterium diphtheriae. Primers specific to the diphtheria toxin gene were used to amplify a toxin gene fragment from simple boiled-cell preparations. Eight recent clinical isolates and four reference strains were tested. The result of the PCR agreed with the traditional toxigenicity assays (the Elek test and guinea pig inoculation) in all cases. PCR has several advantages over the Elek test: it gives a same-day result, it works on colonies taken from selective media, and it detects the toxin gene in mixed cultures. One potential drawback is that the PCR might give a false positive result with the occasional isolate carrying an inactive toxin gene. The good predictive value of a negative PCR result, however, should make it a valuable screening test.

Base Sequence↗