title: Colorimetric detection of Helicobacter pylori DNA using isothermal helicase-dependent amplification and gold nanoparticle probes.
abstract: This study describes a nanodiagnostic method using thermophilic helicase-dependent isothermal amplification (tHDA) and gold nanoparticle probes for colorimetric detection of Helicobacter pylori DNA. The primers targeting ureC gene were used for the amplification of bacterial DNA by the isothermal tHDA reaction, resulting in the accumulation of DNA amplicons. The amplicons were hybridized with specific gold nanoparticle probes. The hybrids were colorimetrically detected by the assembly of gold nanoparticles. Using this method, we detected as little as 10 CFU mL(-1) of H. pylori within less than 1 h. Results obtained from the gastric biopsy samples showed 92.5% and 95.4% of sensitivity and specificity, respectively, in comparison with culture results, and 100% and 98.8% of sensitivity and specificity, respectively, in comparison with those of the histologic studies. Owing to its ease of operation, this assay significantly reduces the time and cost needed for the molecular diagnosis of H. pylori and has the potential to facilitate early detection of this pathogen.
authors.affiliation: Department of Nanobiotechnology, Faculty of Basic Sciences, Tarbiat Modares University, Tehran 14115-175, Iran. pooriagill@yahoo.com
authors.forename: Pooria
authors.initials: P
authors.lastname: Gill
authors.forename: Amir-Houshang
authors.initials: AH
authors.lastname: Alvandi
authors.forename: Hossein
authors.initials: H
authors.lastname: Abdul-Tehrani
authors.forename: Majid
authors.initials: M
authors.lastname: Sadeghizadeh
mesh_terms: D001706:Biopsy; D003124:Colorimetry / Q000379:methods; D015342:DNA Probes; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification; D006046:Gold; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D053768:Metal Nanoparticles; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D013270:Stomach / Q000382:microbiology; D014510:Urease / Q000235:genetics
chemical_list: D015342:DNA Probes; D004269:DNA, Bacterial; D006046:Gold; D014510:Urease