Inhibitory effects of probiotics on H. pylori by co-culture method

The antibiotic resistance and also harmful side effects of treatments processes are among the most fundamental reasons of treatment failures. Therefore the global efforts are focused on subsidiary and more successful treatment protocols. The aim of this study was to assess inhibitory effect of one probiotic regime on H. pylori isolated from peptic ulcer patients. Forty species of H. pylori were isolated from stomach biopsy samples from 140 patients with gastritis. After culturing biopsy samples in brucella blood agar and identification of the bacteria by standard complementary tests, antibiotic sensitivity test was performed by disk diffusion and E-Test methods. Antibiotic resistance to metronidazole, claritromycin, amoxicillin, and tetracycline was checked for all H. pylori isolates. H. pylori species were cultured in brucella broth medium and then the isolates were co-cultured with L acidophilus for assessment of antagonistic effect of L acidophilus on H. pylori growth. Among 45 species, 25 (55.5%) showed antibiotic resistance. The resistance rates to metronidazole, claritromycin, amoxicillin and tetracycline were (65 %), (33%), (22%) and (20%) respectively. Lacto bacillus acidophilus prevented growth of 26 (57.7%) H. pylori- species among which, 68% were antibiotic sensitive and 31.8% antibiotic resistant. Although growth of half of H.pylori isolates were inhibited by Lactobacilli species, the proportion of unaffected isolates is considerable. The results of this study were almost compatible with those of other studies. Checking more isolates under standard laboratory conditions is necessary to determine the exact inhibitory effect of lactobacillus. At the present time the inhibitory effect of lactobacillus on some enteric pathogens has been recognized, but more studies are required to understand the mechanism and factors involved in such inhibitory effect.