Helicobacter pylori (H. pylori) infection is found in 50% of humans and can result in a group of disorders of the upper gastrointestinal tract involving principally stomach and the most proximal portion of the duodenum. Marshall and Warren in 1983, first reported the presence of gram negative spiral bacillus from a patient suffering from gastritis, since then over whelming evidence has become available that H. pylori plays an important role in the pathogenesis of gastrodudenal disease ( 1 ).

Since that time, this bacterium has been hotly debated both in the medical press and by the media. Later, in 1975 Steer showed the association of this spiral bacteria in 80% of patients suffering from gastritis, isolated from gastric resection specimens ( 2 ). Pathologically, it is claimed that there are etiologic association of H. pylori infection with an increasing number of some associated disorders such as cardiovascular diseases, metabolic syndrome and as an independent carcinogen ( 3 ).

The international agency for research on cancer working group WHO defined H. pylori as a grade-1 or definite human carcinogen ( 4 ). Helicobacter pylori bacterium (Helicobacter: a spiral rod, pylori: gate keeper), is S-shaped or curved gram negative rod, measuring 0.5- 0.9 µm wide by 2-4 µm long with rounded ends and spiral periodicity, micro-aerophilic, non-sporing, with 4-7 sheathed, unipolar flagella with rapid drating motility, coccal transformation occurs when exposed to air for about 2 hours ( 5 , 6 ). The biochemical testing showed that it is non-saccharolytic, oxidase positive, catalase positive and urease positive. Growth was seen after 3-5 days incubation at 37oC under microaerophilic conditions with sufficient humidity ( 1 ). Interestingly, Sensitivity pattern of H. pylori to antibiotics in vitro differs from that in vivo due to the effects of the conditions into gastric mucus epithelium.

The most successful used antibiotics in vivo are amoxicillin, clarithromycin and tinidazole, but these antibiotics are subject to lose their effectiveness due to mutations of H. pylori since plasmids have been detected inn about 50% of H. pylori strains ( 7 , 8 ). The major modes of transmission of H. pylori are still uncertain, with oral-oral,gastro-oral, and faecal-oral routes all possibilities ( 9 , 10 ). The prevalence of H. pylori in the world vary widely based on the geographical differences, However the majority of patients suffering from H. pylori infection were found living in poor hygienic conditions as well as poor countries ( 11 ). There are different of method for diagnosis of H. pylori infection, they are generally grouped as being “invasive” meaning that they require gastric tissue or mucus, or “non-invasive” requiring only blood, breath or stool analysis ( 12 ).

The aim of this study was to compare and to know if this bacterium could be identified by at least two of the four diagnostic methods used which are: Rapid urease test, direct gram’s stain smear examination, culturing and IgG ELISA.

Samples were collected at Department of Gastroenterology, JJM medical College Hospital, India. Prior of sample collection, the ethical Considerations were followed Purpose and benefits of the survey were explained to patients and consent has obtained. Patients suffering from gastroduodental diseases were endosopied after 12 hours of fasting. The endoscope with biopsy forceps were rinsed thoroughly with water and soaked in 2% glutaraldehyde for 20 minuets, then rinsed with physiological saline just before insertion. Three samples from the ulcer site was taken from each patient under aseptic precautions. The specimen from the biopsy forceps was picked up by sterile disposable needle (about 1mm in diameter of tissue). The first specimen was taken in stuarts transport medium for culturing. The second specimen was inoculated into urease broth. The third specimen was used for imprint smear by placing it on sterile slide and pressing it gently with another slide. Also, serum was collected from the patient for IgG estimation by ELISA.

A total of 100 cases (study group) suffering from gastroduodenal disease were endoscopied and specimen were collected and another 20 cases from apparently healthy individuals endoscopied and served as control group, the maximum number of cases located between age 26 to 50 years and males, male and female ratio is approximately 3:1, respectively. Findings of different laboratory tests are summarized in ( Table-1 ), showing that rapid urease test recorded high positive result (62%), compared to gram staining and culturing.

According to Table-2, it can be inferred that H. pylori infection was observed in more number of antral gastritis cases and duodenal ulcers, followed by gastric ulcers, gastroduodenitis and carcinoma stomach, respectively.

As shown in Table-3 , there is gradual increase in the seropositivity with increasing age and gradual decline is seen after 50 years of age. Interestingly, in comparison between non-invasive and invasive tests, it can be inferred that seropostitive cases also give maximum positive number (non-invasive), while the maximum positive number of invasive tests was rapid urease, followed by gram’s stain and culture, respectively.

The discovery of H. pylori by Warren and Marshall in 1982 not only introduced a new group of bacteria but also revolutionized our concept of gastroduodenal pathology. This study highlights the role of H. pylori in chronic antral gastritis, duodenal ulcer, gastric ulcer, gastroduodenitis and gastric cancer. Now, H. pylori infection is the leading cause of gastric cancer worldwide ( 14 ). Currently, the diagnosis of H. pylori is based upon endoscopic biopsy and/or rapid urease, gram’s staining and culture. For invasive tests, not every patient complaining from syptoms of gastroduodenal disease are subject to these tests, particularly in developing countries. On the other hand, non–invasive serology based test detecting IgG antibodies are available commercially. The findings of current study assumed that none of them (non-invasive or invasive) are 100% accurate.

The findings of this study correlates with that of Maimooma et al. ( 15 ) who stated that rapid urease test was the best choice, detects H.pylori highly and accurately. Rapid urease test is cheap and simple test that is frequently used in clinical practice ( 12 ). The rapidity with which the test becomes positive was probably related to the number of H.pylori percent in biopsy material ( 16 ). Due to patchy distribution of H.pylori in gastric mucosa, false negativity can also be possible ( 17 ). The gram’s staining is an important test for detection of H. pylori in biopsy material which is 100% sensitive and 96% with low false positivity ( 18 ).

In our study, the use of diluted carbolfuchsin as counter stain facilitated easy identification of this organism under microscope. The current study suggests that detection of H. pylori by culturing is highly specific but it is relatively expensive, time consuming, technically demanding and may be unnecessary unless antibiotic sensitivity required. Accordingly, the easiest was to diagnose H. pylori infection is by serological testing for IgG antibodies using ELISA ( Table-3 ). Notably, The maximum number of intection occurred between age groups 26 to 50 years old and less common among children and elder people.

More studies should be carried out regarding the prevalence of H. pylori among different ages. May be some conditions may play role in spreading of this disease such as low socio-economic status, housing tenure, overcrowding, occupation, area of residence and geographical variation. It was published that the prevalence of H. pylori varies widely by age, race, ethnicity and geographic area, the developing countries appeared higher rates, with most of the infections occurring during childhood, and decreasing of this infection is associated with the improvements in hygiene practices ( 19 ).

Based on the findings of the present study, it may be appropriate to conclude that for detection of H. pylori infection among symptomatic individuals it is necessary to use more than one test. The usage of rapid urease test with detection of H. pylori antibodies stands better chance in establishing laboratory diagnosis.