Background: Arcobacter is one of the most common bacteria in humans and livestock, leading to gastroenteritis in humans as well as genital and enteric diseases in animals. This bacterium is known to be the main cause of diarrhea. In molecular studies, the 16SrRNA gene was primarily used as the standard gene for the determination of the Arcobacter. The purpose of this study was to investigate the molecular detection of Arcobacter using glyA, atpA, and gyrA genes compared to16SrRNA. Methods: In this study, 61 samples of Arcobacter DNA isolated from fecal specimens of patients and healthy individuals in the sample bank were used. In order to detect Arcobacter, the intended primers for 16SrRNA as well as glyA, atpA, and gyrA genes were used for polymerase chain reaction (PCR). The products obtained from the PCR were sequenced. Results: The results of the proliferation reactions indicated the accuracy of the intended primers and the associated molecular experiments. Our results showed that 65. 57% of the cases were detected to be positive for Arcobacter among 61 samples using the glyA gene. This percentage was higher compared to 16SrRNA (42. 62%), gyrA (42. 62%), and atpA (24. 59%). The analysis was statistically significant. Conclusions: Given the presence of repetitive sequences in the 16SrRNA in most bacteria, the interpretation of the results is likely to be difficult for researchers. The results of this study showed more sensitivity and accurate diagnosis of Arcobacter using the glyA gene than other studied genes. In diagnostic studies of Arcobacter, the glyA gene is proposed as an alternative to the 16SrRNA.

Objective: Reliable non-invasive methods for detection of Helicobacter pylori (H. pylori) infection are required to investigate the incidence, transmission, and clearance of infection in childhood. Detecting bacterial antigens in Stool offer an alternative noninvasive diagnostic test. However its accuracy in developing countries is not well established. The aim of this study was to evaluate the performance of Stool antigen test for H pylori in Iranian children with recurrent abdominal pain necessitating endoscopy.Methods: One hundred three children enrolled in this study. Endoscopy and biopsy was done on all patients providing a criterion standard for validation of the H. pylori Stool antigen (HpSA) tests. The presence of H. pylori organisms in Stool was determined by an enzyme-linked immunosorbent assay using a commercially available polyclonal antibody. HpSA sensitivity, specificity, and positive and negative likelihood ratios were determined with reference to the results of cultures of gastric biopsy.Findings: Of the 103 children tested 41 (39.8%) and 39 (37.8%) were positive for H. pylori according to the results of cultures of gastric biopsy and HpSA, respectively. The sensitivity, specificity, and positive and negative likelihood ratios of HpSA were found to be 85%, 93%, 89.7%, and 90%, respectively.Conclusion: In this pilot study, a low-cost and rapid diagnostic technique, Stool antigen test proved to be highly sensitive and specific for detecting H pylori infection in children with recurrent abdominal pain. Our results are comparable to those reported elsewhere in children and demonstrate that the HpSA test can replace endoscopy and biopsy for detecting H. pylori infection.