AIM: Helicobacter pylori can be diagnosed by invasive or non-invasive tests but to obtain bacteria for culture and antibiotic susceptibility testing, an upper GI endoscopy is often required. The string test may be a minimally-invasive alternative method of obtaining H. pylori samples. This study evaluates the sensitivity and specificity of the string test in the diagnosis of H. pylori in comparison with endoscopic means of diagnosis. METHODS: This was a prospective open comparative study of patients with dyspepsia with endoscopy-based tests as gold standard (defined as a positive CLO test and antral histology). Fasting patients swallowed the encapsulated-string (Entero-test Hp), which was withdrawn after 1 hour. The gastric juice from the string was plated onto H. pylori-selective media for culture. Helicobacter pylori was identified by typical colony morphology, gram stain and biochemical test results. RESULTS: Thirty dyspeptic patients were recruited of whom 21 (70 %) were positive for H. pylori according to the gold standard. The sensitivity, specificity, positive predictive value, and negative predictive value for the string test were 38 %, 100 %, 100 % and 41 % respectively, and for endoscopic biopsies 81 %, 100 %, 100 %, 69 % respectively (P=0.004). Logistic regression showed that only abundant growth density from endoscopic biopsy cultures to be a predictor of a positive string test (P=0.018). CONCLUSION: The string test is an alternative method to endoscopy in obtaining H. pylori but has a low sensitivity compared to endoscopic biopsies.
AIM: Helicobacter pylori can be diagnosed by invasive or non-invasive tests but to obtain bacteria for culture and antibiotic susceptibility testing, an upper GI endoscopy is often required. The string test may be a minimally-invasive alternative method of obtaining H. pylori samples. This study evaluates the sensitivity and specificity of the string test in the diagnosis of H. pylori in comparison with endoscopic means of diagnosis. METHODS: This was a prospective open comparative study of patients with dyspepsia with endoscopy-based tests as gold standard (defined as a positive CLO test and antral histology). Fasting patients swallowed the encapsulated-string (Entero-test Hp), which was withdrawn after 1 hour. The gastric juice from the string was plated onto H. pylori-selective media for culture. Helicobacter pylori was identified by typical colony morphology, gram stain and biochemical test results. RESULTS: Thirty dyspeptic patients were recruited of whom 21 (70 %) were positive for H. pylori according to the gold standard. The sensitivity, specificity, positive predictive value, and negative predictive value for the string test were 38 %, 100 %, 100 % and 41 % respectively, and for endoscopic biopsies 81 %, 100 %, 100 %, 69 % respectively (P=0.004). Logistic regression showed that only abundant growth density from endoscopic biopsy cultures to be a predictor of a positive string test (P=0.018). CONCLUSION: The string test is an alternative method to endoscopy in obtaining H. pylori but has a low sensitivity compared to endoscopic biopsies.
Authors: D E Roth; B Velapatiño; R H Gilman; W W Su; D E Berg; L Cabrera; E Garcia Journal: Trans R Soc Trop Med Hyg Date: 2001 Jul-Aug Impact factor: 2.184
Authors: M G Domínguez-Bello; C Cienfuentes; R Romero; P García; I Gómez; V Mago; N Reyes; P Gueneau de Novoa Journal: FEMS Microbiol Lett Date: 2001-04-20 Impact factor: 2.742
Authors: Richard N Arboleda; Barbara G Schneider; Luis E Bravo; Judith Romero-Gallo; Richard M Peek; Robertino M Mera; Maria Clara Yepez; Cristina Campo; Pelayo Correa Journal: J Pediatr Gastroenterol Nutr Date: 2013-08 Impact factor: 2.839
Authors: Andreas Leodolter; Kathlen Wolle; Ulrike von Arnim; Stefan Kahl; Gerhard Treiber; Matthias-P Ebert; Ulrich Peitz; Peter Malfertheiner Journal: World J Gastroenterol Date: 2005-01-28 Impact factor: 5.742
Authors: Sophie A Fillon; J Kirk Harris; Brandie D Wagner; Caleb J Kelly; Mark J Stevens; Wendy Moore; Rui Fang; Shauna Schroeder; Joanne C Masterson; Charles E Robertson; Norman R Pace; Steven J Ackerman; Glenn T Furuta Journal: PLoS One Date: 2012-09-05 Impact factor: 3.240