Validation of a Fluorescence In Situ Hybridization Method Using Peptide Nucleic Acid Probes for Detection of Helicobacter pylori Clarithromycin Resistance in Gastric Biopsy Specimens

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Cerqueira, L. (Author) FEUP; Ricardo M. Fernandes (Author) Other; Rui M. Ferreira (Author) Other; Mónica Oleastro (Author) Other; Fátima Carneiro (Author) FMUP; Catarina Brandão (Author) Other; Pedro Pimentel Nunes (Author) FMUP; Mário Dinis Ribeiro (Author) FMUP; Céu Figueiredo (Author) FMUP; Charles W. Keevil (Author) Other; Maria J. Vieira (Author) Other; Nuno F. Azevedo (Author) FEUP

Journal

Title: Journal of Clinical Microbiology

Vol. 51 No. 6

Pages: 1887-1893

ISSN: 0095-1137

Publisher: American Society for Microbiology

Indexing

ISI Web of Knowledge - 39 Citations

Scopus - 49 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

Associated Projects

DNA mimics - Desenvolvimento e aplicação de mímicos de DNA para a rápida identificação de microrganismos patogénicos

Other information

Authenticus ID: P-005-095

DOI: 10.1128/jcm.00302-13

Abstract (EN): Here, we evaluated a previously established peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) method as a new diagnostic test for Helicobacter pylori clarithromycin resistance detection in paraffin-embedded gastric biopsy specimens. Both a retrospective study and a prospective cohort study were conducted to evaluate the specificity and sensitivity of a PNA-FISH method to determine H. pylori clarithromycin resistance. In the retrospective study (n = 30 patients), full agreement between PNA-FISH and PCR-sequencing was observed. Compared to the reference method (culture followed by Etest), the specificity and sensitivity of PNA-FISH were 90.9% (95% confidence interval [CI], 57.1% to 99.5%) and 84.2% (95% CI, 59.5% to 95.8%), respectively. In the prospective cohort (n = 93 patients), 21 cases were positive by culture. For the patients harboring clarithromycin-resistant H. pylori, the method showed sensitivity of 80.0% (95% CI, 29.9% to 98.9%) and specificity of 93.8% (95% CI, 67.7% to 99.7%). These values likely represent underestimations, as some of the discrepant results corresponded to patients infected by more than one strain. PNA-FISH appears to be a simple, quick, and accurate method for detecting H. pylori clarithromycin resistance in paraffin-embedded biopsy specimens. It is also the only one of the methods assessed here that allows direct and specific visualization of this microorganism within the biopsy specimens, a characteristic that allowed the observation that cells of different H. pylori strains can subsist in very close proximity in the stomach.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7