agar and Dyspepsia

Rapid urease tests (RUTs) are used commonly as a convenient method to detect Helicobacter pylori infection. New rapid tests have been commercially available with promotional literature suggesting enhanced utility. We compared CLOtest to a new reagent strip RUT, PyloriTek.. Gastric antral mucosal biopsy specimens were obtained from 102 patients for comparison between CLOtest and PyloriTek (204 specimens). Biopsy specimens obtained from a nearby area were stained using the Genta stain for determination of H. pylori status. The RUT to be used first was selected randomly.. Sixty-five of the 102 patients had peptic ulcer disease, two had gastric cancer, and 35 had dyspepsia; 61 patients had active H. pylori infection. There were one false-negative and three false-positive CLOtest results, compared with one false-negative and 13 false-positive PyloriTek results (p < 0.02 for incorrect categorization with PyloriTek). Sensitivity and specificity were 98 and 92% compared with 98 and 68% for CLOtest and PyloriTek, respectively. An erroneous categorization of H. pylori status occurred in 3.9% (95% confidence interval [CI]: 1-9.7%) with CLOtest compared with 13.7% (95% CI: 7.7 -22%) with PyloriTek. When the PyloriTek was scored at 1 h (0-1 h) after obtaining the specimen, the accuracy improved; erroneous categorization of H. pylori status occurred in only 2.9% (95% CI: 0.6-8.3%).. Used according to manufacturer instructions, the new reagent strip RUT PyloriTek has too many false-positive results for use in a clinical situation. In contrast, when the test was interpreted within 1 h, accuracy was comparable to that of CLOtest.

Topics: Adult; Agar; Aged; Biopsy; Coloring Agents; Confidence Intervals; Dyspepsia; False Negative Reactions; False Positive Reactions; Female; Gastric Mucosa; Gastroesophageal Reflux; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Peptic Ulcer; Prospective Studies; Pyloric Antrum; Reagent Strips; Sensitivity and Specificity; Stomach Neoplasms; Urease

The aim of the present study was to compare six media, three selective and three nonselective media, to determine the best combination of media for the primary isolation of Helicobacter pylori. Over a period of 8 months, mucosal antral biopsy specimens were obtained from 97 dyspeptic patients undergoing endoscopy. Biopsy samples were plated in parallel on all six media. Egg yolk emulsion agar (EYE), Skirrow's medium and modified Thayer-Martin medium were used as selective media; modified chocolate agar (MCHOC), Triptycase Soy Agar (TSA) and brain heart infusion agar were used as nonselective media. Overall, by using these six media, H. pylori were recovered from biopsy specimens from 48 of 97 patients, yielding an isolation rate of 49%. Comparison of all possible combinations of the six media showed that the highest rate of isolation of H. pylori was 100% (48 of 48) with EYE-MCHOC, followed by 97% (47 of 48) when EYE-SK was used. Conversely, it was found that none of the media used alone yielded a 100% rate of recovery (the maximum recovery rate was 92%, which was achieved with EYE). These results indicate that the association of EYE and MCHOC yielded the maximum recovery of H. pylori from gastric biopsy specimens. Therefore, the use of selective and nonselective media in parallel offers optimal recovery rates with only a slight increase in costs.

Topics: Agar; Animals; Biopsy; Caseins; Cell Culture Techniques; Culture Media; Dyspepsia; Egg Yolk; Endoscopy; Female; Gastric Mucosa; Helicobacter pylori; Humans; Male; Protein Hydrolysates; Time Factors

Topics: Agar; Dyspepsia; Escherichia coli; Humans; Precipitins