Isolation, biochemical characterization and comparative study of diagnostic methods for Helicobacter pylori infection from dyspepsia patients

The success of any therapy especially against H. pylori depends upon the prompt and authentic diagnosis. This research was designed to study the patients with dyspepsia for possible H. pylori infection and to compare different commonly used diagnostic techniques. Ninety-Six gastrointestinal biopsies and blood samples were collected after obtaining an informed consent having gastro duodenal symptoms. The obtained samples were tested and compared by using different invasive and non-invasive diagnostic tests. The results showed that 40 (41.67%) subjects were positive for H. pylori in RUT and histopathology. Contrariwise, 46 subjects were positive for ELISA test against anti-IgA and IgG. Culture tests showed 18 biopsies against the bacteria. On the other side, tests like endoscopic examination, urease, catalase and oxidase further confirmed the findings. A high resistance was observed to antibiotics like kanamycin (77.78%), amoxicillin (88.89%) and polymyxin B (100%) respectively. A gene ( Cag A ) was also detected by using molecular technique and 18 subjects emerged as positive. Sensitivity/specificity (%) of used diagnostic method was 95/77 for histology, 100/83.5 for rapid urease, 85.7/90 for gram staining, 100/66.6 for IgG serology, 100/79.5 for IgA serology, 100/75.0 for PCR, 100/79.04 for a combination of RUT and IgG serology and 100/92.4 for a combination of RUT, gram staining and IgG serology. It is concluded that PCR appeared the most reliable test among different diagnostic methodologies. However, the higher sensitivity and specificity values were also observed for other tests. Hence, comparative detection methods should be used for accurate detection rather than a single methodology.