Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017536 (giardiasis)
 1,714 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The lack of a quick, simple, and inexpensive diagnostic test has limited the ability of public health officials to rapidly assess and control outbreaks of Giardia lamblia in child day-care centers. We evaluated the performance of a commercially available enzyme-linked immunosorbent assay (ELISA) for the detection of a G. lamblia-associated antigen in stool. Stool specimens were collected from the diapers of 426 children attending 20 day-care centers, fixed in 10% Formalin and polyvinyl alcohol, and examined by microscopy by Formalin concentration and trichrome staining techniques. Specimens were also tested visually and spectrophotometrically by ELISA. Of 99 tests positive by microscopy, 93 were visually positive by ELISA (sensitivity, 93.9%). Of 534 tests negative for G. lamblia by microscopy, 32 (6.0%) were ELISA positive. However, on the basis of examination of multiple specimens from the same child, none of these could be considered false-positive ELISAs; the specificity of the ELISA was therefore 100%. The sensitivity of both microscopy and ELISA improved as the number of specimens per child increased. An optical density value of greater than 0.040 was 98.0% sensitive and 100% specific for G. lamblia. This ELISA, which appeared to be more sensitive for G. lamblia than did microscopic examination of stool, should be useful as an epidemiologic tool, particularly in day-care settings, and may also have a role in confirming clinical diagnoses of giardiasis.
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PMID:Evaluation of a commercially available enzyme-linked immunosorbent assay for Giardia lamblia antigen in stool. 186 30

A commercially available enzyme immunoassay for the diagnosis of giardiasis was evaluated in a clinical trial. The ProSpecT/Giardia diagnostic test (Alexon, Inc., Mountain View, Calif.) was compared with the standard ova and parasite (O&P) microscopic examination. Additionally, several widely used stool fixatives and a commonly used transport medium were assessed for compatibility with the immunoassay. A total of 325 stool specimens were collected and used to evaluate assay performance. Of those, 93 specimens were collected from symptomatic Giardia O&P-positive patients and 232 specimens were randomly collected from patients as part of a routine health screening procedure. All 93 Giardia O&P-positive stool specimens were strongly positive by visual and spectrophotometric examination using the immunoassay. Of the 232 randomly collected specimens, 16 were positive by O&P examination and immunoassay, 6 were negative by O&P examination but positive by immunoassay, and 1 was positive by O&P examination and negative by immunoassay. There was substantial supportive evidence that indicated that the six immunoassay-positive, O&P-negative specimens were true-positives. When these six specimens were accepted as true-positives, the immunoassay detected almost 30% more cases of Giardia infection than did O&P examination. Its sensitivity and specificity were 96 and 100%, respectively, while the sensitivity and specificity of O&P examination were 74 and 100%, respectively. The immunoassay also performed well on specimens treated with 10% neutral Formalin, sodium acetate-Formalin fixative, and Cary-Blair transport medium. However, the test was not compatible with polyvinyl alcohol-treated specimens. Overall, the ProSpecT/Giardia test was a sensitive, specific immunoassay which was easy to run and interpret. It offers a simple solution to traditional difficulties encountered in diagnosing Giardia infection.
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PMID:Stool diagnosis of giardiasis using a commercially available enzyme immunoassay to detect Giardia-specific antigen 65 (GSA 65). 267 96

We recently reported the isolation and identification of a Giardia lamblia-specific antigen (GSA 65) that is shed in the stool of giardiasis patients. In the present study, this antigen was affinity purified from sonic extracts of axenically cultured G. lamblia trophozoites and characterized to better understand its biological function and its potential usefulness in the design of coprodiagnostic assays for giardiasis. GSA 65 was resistant to proteolytic digestion with trypsin, chymotrypsin, and protease but was sensitive to treatment with NaIO4 as assessed by Western blotting. This antigen was also stable during prolonged storage at 4 and -20 degrees C in 10% Formalin or distilled H2O as assessed by counterimmunoelectrophoresis. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing gel banding patterns, in conjunction with protein and carbohydrate assays and lectin binding studies, confirmed that this antigen is a highly glycosylated glycoprotein. The resistance of GSA 65 to proteolytic degradation, together with previous immunofluorescence data that indicate the antigen is an integral part of the G. lamblia cyst wall, suggests that this molecule may play a role in maintaining the integrity of the cyst in vivo. The ability of GSA 65 to maintain its antigenic structure under a wide variety of conditions makes it an ideal antigen around which to design sensitive immunodiagnostic assays for giardiasis.
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PMID:Physical and chemical characterization of a Giardia lamblia-specific antigen useful in the coprodiagnosis of giardiasis. 353 98

Giardia lamblia is recognized as one of the most common agents for diarrhea world wide. To date, microscopical examination of stool samples is the gold standard for giardiasis diagnosis. However, intermittence of the Giardia cycle and some medications may cause temporary disappearance of cysts from stools, thus giving false negative results. In the present study, we evaluated a commercially available enzyme immunoassay kit (GiardEIA) for the detection of Giardia copro-antigens and compared the results with those of the merthiolate-iodine-formaldehyde concentration (MIFC) microscopical examination technique. Sixty-nine fecal samples from children 2-12 years old were emulsified and allowed to react with a Giardia specific antibody, then with an enzyme conjugated antibody and the reaction was developed colorimetrically. Seventy-four percent of the parasitologically positive Giardia cases were also positive by GiardEIA while 26% of the microscopically negative cases were positive by the assay. GiardEIA gave negative results with 82% and 100% of stools with helminthic and protozoan (other than Giardia) infections, respectively. Similarly, no cross-reactivity was found with any of the bacterial agents including Shigella flexneri, pathogenic E. coli, Klebsiella spp. and Salmonella typhi. GiardEIA is a simple assay that can diagnose 24 samples in less than an hour without the need for any special equipment and can be useful in epidemiological surveys and in giardiasis outbreaks.
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PMID:Evaluation of GiardEIA kit for giardiasis diagnosis. 858 58

It is known that fecal examination to detect Giardia lamblia cysts or trophozoites produces a high percentage of false-negative results. A commercially available immunoenzymatic assay (ProSpecT Giardia Microplate Assay, Alexon, Inc., BIOBRAS) to detect G. lamblia specific coproantigen was evaluated for the first time in Brazil. A total of 90 specimens were tested. Each specimen was first tested as unpreserved stool, and then it was preserved in 10% Formalin to be tested 2 months later. The assay was able to identify all the 30 positive patients (sensitivity = 100.0%) by visual or spectrophotometric examination in the unpreserved specimens and was negative in 57 of the 60 patients without G. lamblia (specificity = 95.0%). The assay identified 27 of the 30 positive patients (sensitivity = 90.0%) and was negative in 59 of the 60 negatives (specificity = 98.3%) in the preserved stools according to both readings. A marked difference was observed in the optical densities in both groups, preserved and unpreserved stools, when the G. lamblia-positive specimens were compared to the negative or positive for other intestinal parasites than G. lamblia. The assay seems a good alternative for giardiasis diagnosis, especially when the fecal examination was repeatedly negative and the patient presents giardiasislike symptoms.
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PMID:Detection of a giardia lamblia coproantigen by using a commercially available immunoenzymatic assay, in belo horizonte, brazil 1052 32

Covalent loading or directional binding of biomolecules on gold nanoparticles (AuNPs) could lead to better results than simple direct adsorption for an enhanced ELISA application. The use of Mini-Parasep solvent-free (SF) without ether or ethyl acetate for the clean and efficient concentration of protozoa cysts, it is a single-use device for in vitro diagnostic use only. In this work, we used Mini-Parasep SF for the detection of giardia cysts in comparison to direct smear and Merthiolate-Iodine Formaldehyde Concentration (MIFC) technique in addition to its use in antigen detection by AuNPs biomolecule loading using rabbit polyclonal antibodies (pAb) against purified Giardia antigen (PGA). As a result, Mini-Parasep SF was the most effective method for Giardia cyst detection and regarding optimization of Mini-Parasep antigen detection, our data showed increased sensitivity and specificity of nano-sandwich ELISA to 92% and 94% respectively and increased positive predictive value (PPV) and negative predictive value (NPV) to 88.64% and 95.91% respectively. In conclusion, this research provides that Mini-Parasep SF concentrator enhanced Giardia cyst detection and improved antigen preparation for AuNPs sandwich ELISA in giardiasis diagnosis. The advantages of this method are the short assay time and the raised accuracy of antigen detection providing concentrated samples without the risk of solvent use and being a disposable Mini-Parasep it helps in giardia antigen purification as well as raising the sensitivity and specificity of ELISA through binding AuNPs.
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PMID:Combined Mini-Parasep SF and Nanogold Immunoassay Show Potential in Stool Antigen Immunodetection for Giardiasis Diagnosis. 3222 66