A novel enzyme immunoassay for the direct detection of H. pylori antigens in stool

Abstract Objective Prompt diagnosis of Helicobacter pylori infection is essential for proper treatment and eradication of the pathogen because prolonged infection could lead to gastric cancer. Sensitive and cost effective diagnostic methods are key to guiding treatment options that will reduce mortality. This study was aimed at detecting H. pylori from biopsies of peptic ulcer patients. Real-time PCR using TaqMan and EvaGreen assays targeting 16S rRNA and ureA genes were used to detect H. pylori DNA extracted from 40 biopsy samples comprising 20 biopsies obtained from the antrum and 20 from the corpus of 20 patients undergoing endoscopy for duodenal ulcer investigation in Lagos, Nigeria. Results H. pylori was detected in 80% of the biopsy samples by combined cycle threshold (Ct) and melting temperature (Tm) values. Mean Ct value for ureA gene ranged from 21.40 to 37.53 and 22.71 to 35.44 for 16SrRNA gene. Average melting temperatures (Tm) of 81.57 and 82.90 °C among amplicons of ureA and 16S rRNA were observed respectively. H. pylori DNA was generally detected in biopsies collected from antrum and corpus. Real-time PCR in the diagnosis of H. pylori can be considered a simple, low cost and efficient alternative or addition to the gold standard.

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Efficacy of immunohistochemical staining in detecting Helicobacter pylori in Saudi patients with minimal and atypical infection

European Journal of Histochemistry ◽

10.4081/ejh.2021.3222 ◽

2021 ◽

Vol 65 (3) ◽

Author(s):

Mohammed Akeel ◽

Ahmed Elhafey ◽

Atef Shehata ◽

Erwa Elmakki ◽

Thanaa Aboshouk ◽

...

Keyword(s):

Helicobacter Pylori ◽

Chronic Gastritis ◽

Direct Detection ◽

Giemsa Staining ◽

Pcr Analysis ◽

Qrt Pcr ◽

Urease Test ◽

Gastric Biopsies ◽

Polymerase Chain ◽

H Pylori

Gastric Helicobacter pylori infection is diagnosed based on histopathological evaluation of gastric mucosal biopsies, urease test, urea breath test, H. pylori culturing, or direct detection using polymerase chain reaction (PCR). This study aimed to evaluate the efficacy of immunohistochemical (IHC) staining in detecting H. pylori in gastric biopsies from patients with chronic gastritis and minimal or atypical infection. Gastric biopsies from 50 patients with chronic gastritis were subjected to routine haematoxylin and eosin (H&E), modified Giemsa, and IHC staining. The results of staining were compared with those of quantitative real-time PCR (qRT-PCR). The qRT-PCR analysis identified 32 (64%) H. pylori-positive cases, whereas IHC, H&E, and modified Giemsa staining identified 29 (58%), 27 (54%), and 21 (42%) positive cases. The sensitivity of IHC staining (87.50%) was higher than that of H&E (59.38%) and modified Giemsa (43.75%) staining. The specificity of H&E, modified Giemsa, and IHC staining was 55.56%, 61.11%, and 94.44%, respectively. IHC staining exhibited the highest diagnostic accuracy (90%), followed by H&E (58%) and modified Giemsa (50%) staining. Active gastritis, intestinal metaplasia, and lymphoid follicles were detected in 32 (64%), 4 (8%), and 22 (44%) cases, respectively, and all of these cases were H. pylori positive. In contrast to routine H&E and modified Giemsa staining, IHC allows for the accurate H. pylori detection in cases with minimal or atypical infection. Moreover, IHC can be an alternative diagnostic method to qRT-PCR for detection of H. pylori in such cases.

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Detection of Helicobacter pylori in Stool Specimens by PCR and Antigen Enzyme Immunoassay

Journal of Clinical Microbiology ◽

10.1128/jcm.36.9.2772-2774.1998 ◽

1998 ◽

Vol 36 (9) ◽

pp. 2772-2774 ◽

Cited By ~ 118

Author(s):

Athanasios Makristathis ◽

Eva Pasching ◽

Kurt Schütze ◽

Margit Wimmer ◽

Manfred L. Rotter ◽

...

Keyword(s):

Helicobacter Pylori ◽

Enzyme Immunoassay ◽

Eradication Therapy ◽

Diagnostic Tools ◽

Pcr Assay ◽

Highly Sensitive ◽

Stool Specimens ◽

H Pylori ◽

Seminested Pcr

A highly sensitive seminested PCR assay to detectHelicobacter pylori DNA in feces was developed. PCR with stool specimens and a novel antigen enzyme immunoassay (EIA) forH. pylori detection in feces were evaluated as diagnostic tools and in follow-up with samples from 63 infected and 37 noninfected persons. Infected individuals received eradication therapy followed by endoscopic follow-up 35 days after the start of treatment. At that time, a second stool specimen was obtained from 55 of these patients. Before eradication, the sensitivity of PCR was 93.7% and that of EIA 88.9%. Specificities were 100 and 94.6%, respectively. Of the 55 follow-up specimens, 41 originated from patients from whom H. pylori had been eradicated. Of these, 21 were still positive by PCR and 13 were positive by EIA, indicating that 1 month may be too short a period for follow-up evaluation of stool specimens by these tests.

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Direct detection of influenza virus antigen in nasopharyngeal specimens by direct enzyme immunoassay in comparison with quantitating virus shedding.

Journal of Clinical Microbiology ◽

10.1128/jcm.30.4.866-869.1992 ◽

1992 ◽

Vol 30 (4) ◽

pp. 866-869 ◽

Cited By ~ 24

Author(s):

G Döller ◽

W Schuy ◽

K Y Tjhen ◽

B Stekeler ◽

H J Gerth

Keyword(s):

Influenza Virus ◽

Enzyme Immunoassay ◽

Direct Detection ◽

Virus Antigen ◽

Virus Shedding

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Efficacy of immunohistochemical staining in detecting Helicobacter pylori in Saudi patients with minimal and atypical infection

10.21203/rs.3.rs-63601/v1 ◽

2020 ◽

Author(s):

Mohammed Abdulraheem Akeel ◽

Ahmed Elhafey ◽

Atef Shehata ◽

Erwa Elmakki ◽

Thanaa Aboshouk ◽

...

Keyword(s):

Helicobacter Pylori ◽

Diagnostic Accuracy ◽

False Positive ◽

Direct Detection ◽

Giemsa Staining ◽

Pcr Analysis ◽

Qrt Pcr ◽

Urease Test ◽

Gastric Biopsies ◽

H Pylori

Abstract Background Gastric Helicobacter pylori infection is diagnosed based on histopathological evaluation of gastric mucosal biopsies, urease test, urea breath test, H. pylori culturing, or direct detection using polymerase chain reaction (PCR). This study aimed to evaluate the efficacy of immunohistochemical (IHC) staining in detecting H. pylori in gastric biopsies from dyspeptic patients with minimal and/or atypical infection. Gastric biopsies from 50 patients with chronic gastritis were subjected to routine haematoxylin and eosin (H&E), modified Giemsa, and IHC staining. The results of staining were compared with those of quantitative real-time PCR (qRT-PCR). Results The qRT-PCR analysis identified 32 (64%) H. pylori-positive cases, whereas IHC, H&E, and modified Giemsa staining identified 29 (58%), 27 (54%), and 21 (42%) positive cases. The false-positive rates of H&E and modified Giemsa staining were 16% and 14%, respectively. The sensitivity of IHC staining (87.50%) was higher than that of H&E (59.38%) and modified Giemsa (43.75%) staining. The specificity of H&E, modified Giemsa, and IHC staining was 55.56%, 61.11%, and 94.44%, respectively. IHC staining exhibited the highest diagnostic accuracy (90%), followed by H&E (58%) and modified Giemsa (50%) staining. Active gastritis, intestinal metaplasia, and lymphoid follicles were detected in 32 (64%), 4 (8%), and 22 (44%) cases, respectively, and all of these cases were H. pylori positive. Conclusions H. pylori can be detected using routine H&E or modified Giemsa staining. However, the high sensitivity, specificity, and diagnostic accuracy of IHC staining minimise the false-positive/negative results and enable H. pylori detection in cases with minimal or atypical infection. Moreover, IHC can be an alternative diagnostic method to qRT-PCR for detection of H. pylori in such cases.

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Detection of Helicobacter pylori Antibodies in a Pediatric Population: Comparison of Three Commercially Available Serological Tests and One In-House Enzyme Immunoassay

Journal of Clinical Microbiology ◽

10.1128/jcm.37.10.3328-3331.1999 ◽

1999 ◽

Vol 37 (10) ◽

pp. 3328-3331 ◽

Cited By ~ 18

Author(s):

Bengt Sunnerstam ◽

Torbjörn Kjerstadius ◽

Lillemor Jansson ◽

Johan Giesecke ◽

Mats Bergström ◽

...

Keyword(s):

Helicobacter Pylori ◽

Enzyme Immunoassay ◽

Reference Method ◽

False Positives ◽

Serological Response ◽

Serum Samples ◽

False Negatives ◽

Serological Tests ◽

Predictive Values ◽

H Pylori

A serum immunoglobulin G enzyme immunoassay (EIA) forHelicobacter pylori antibodies already in use in adults was evaluated with 99 pediatric serum samples to determine its usefulness for the study of H. pylori disease in children. The reference method used was either the 13C-urea breath test or a biopsy culture of gastric mucosa. In children, an EIA cutoff of 0.35 absorbancy unit yielded sensitivity, specificity, and positive and negative predictive values of 93, 97, 93, and 97%, respectively. The cutoff recommended when this EIA was published for use in adults was 0.70 absorbancy unit (H. Gnarpe, P. Unge, C. Blomqvist, and S. Mäkitalo, APMIS 96:128–132, 1988). Another subset of 169 serum samples taken from children was analyzed by four serological tests in order to compare the performance of the in-house EIA with the Pyloriset, HM-CAP, and Helico-G kits. For the 169 samples, 10 (5.9%) false-positives and no false-negatives occurred with the Helico-G, 3 (1.8%) false-positives and no false-negatives occurred with the Pyloriset, and 3 (1.8%) false-positives and 1 (0.6%) false-negative occurred with the HM-CAP. For the 169 samples, 1 (0.6%) false-positive and no false-negatives occurred with the in-house EIA. Serological detection of H. pylori antibodies with our EIA seems to be valuable in diagnosing H. pylori infection in children, but only if a lowered, specific pediatric cutoff is established. The commercial kits, particularly the Helico-G, seem to overdiagnose pediatric H. pylori infection. A positive serological test for H. pylori infection, particularly for children, needs to be confirmed by a reference method because of the possibility of spontaneous eradication of infection, with a lingering serological response.

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