Evaluation of the egg yolk enriched columbia agar for isolation of Helicobacter pylori from gastric biopsy specimens

Helicobacter pylori is the first known carcinogenic bacterium and cause of several gastroduodenal disorders. Therefore, detection and treatment of H. pylori infection is very important. The aim of this study was to evaluate egg yolk enriched columbia agar for isolation of H. pylori from gastric biopsy specimens of patients suffering from gastroduodenal disorders referring to Imam Khomeini Hospital, Kermanshah and comparison with rapid urease test. The study was an analytic descriptive cross-sectional survey that was carried out on 192 patients referred to Imam Khomeini Hospital in Kermanshah in 2013. Two gastric antrum biopsies and two corpus biopsies were taken from each patient and H. pylori infection was detected using rapid urease test and culture on egg yolk enriched columbia agar supplemented with antibiotics. After culture gram staining method and biochemical tests were used to detect identification of H. pylori. Data were analyzed using kappa calculator and SPSS software to calculate sensitivity and specificity. The rates of diagnosis of H. pylori infection in 192 biopsy specimens taken from patients with gastroduodenal diseases by rapid urease test and culture were 51.10% and 45.31% respectively. The sensitivity, specificity, and positive and negative predictive values of the culture were 76.5%, 87.2%, 86.2, and 78.0% respectively. The results showed that the test accuracy (effectiveness) of the method was 81%. This study indicates that egg yolk enriched columbia agar is an appropriate medium with high sensitivity, specificity and efficiency for isolation of H. pylori that is a low-cost and available culture medium.