Prevalence of Helicobacter Pylori Infections Among Patients Attending Endoscopy Unit of Tribhuvan University Teaching Hospital and Antibiotic Susceptibility Pattern of the Isolates to Contemporary Antibiotics

Abstract

ABSTRACT Helicobacter pylori (H. pylori), a flagellate gram negative rod, infects over half of the world’s population and plays a pivotal role in the etiology of a number of gastroduodenal diseases and development of gastric malignancy. The total of 300 gastric biopsy specimens (3 samples from each subject) and 100 serum samples of the patients attending endoscopy unit of Tribhuvan University Teaching Hospital were collected from May to October, 2009. Biopsy specimens were processed for rapid urease test, histology and culture respectively. Serum samples were used for detecting H. pylori IgG, IgA and IgM antibodies using commercially available kit (HEXAGON H. PYLORI, Germany). Bacterial isolates were identified by standard microbiological techniques and biochemical tests. The confirmed H. pylori isolates were subcultured and subjected to antibiotic susceptibility test by disk diffusion method. Of them 32 (32%) subjects were positive by rapid urease test, 47 (47%) by histology and 32 (32%) by culture. The prevalence of H. pylori infection among 100 subjects was 36 (36%) considering at least two of the three tests gave positive results and the seroprevalence was 63%. Statistically serological test was associated with other diagnostic tests. The male to female ratio for H. pylori infection was 1.22:1. H. pylori infection rate was higher in the age group of 20-29 years and the infection rate was higher in duodenal ulcer cases. Among 32 culture positive cases, only 30 of the bacterial isolates were subcultured and further processed for antibiotic susceptibility test. Among them 16 bacterial isolates (53.3%) were resistant to metronidazole, 8 bacterial isolates (26.6%) were resistant to amoxycillin, 4 bacterial isolates (13.3%) were resistant to clarithromycin and 2 bacterial isolates (6.6%) were resistant to tetracycline while resistant to levofloxacin was not observed. Five bacterial isolates (16.6%) were resistant to both amoxycillin and metronidazole, 2 bacterial isolates (6.6%) were resistant to both clarithromycin and metronidazole while 2 bacterial isolates (6.6%) were resistant to amoxycillin, clarithromycin, metronidazole and tetracycline. In this way the H. pylori infections assessed by four diagnostic tests revealed the prevalence to be 36%, taking at least two of the three diagnostic tests (rapid urease test, culture and histology) positive while seroprevalence was 63 % among the 100 patients. Prevalence of resistance was optimal for metronidazole, followed by amoxycillin, clarithromycin and tetracycline. Few multi drug resistant cases were also noticed. Levofloxacin was found to be sensitive in all cases.