Inhibitory effect of probiotic and non-probiotic micro-organisms against Helicobacter pylori clinical isolates

Abstract number: 1734_49

Diaz-Regañon J., Alarcon T., Domingo D., Monclus D., Moreno M.J., Lopez-Brea M.

Objective: To determine the effect of 15 probiotic, and 17 non-probiotic (8 Gram-positive and 9 Gram-negative microorganisms) against Helicobacter pylori clinical isolates.

Material and Methods:H. pylori strains were isolated from 35 gastric biopsies and processed by standard microbiological methodology. Several probiotic and non-probiotic bacteria were obtained from several specimens following standard microbiological procedures and were identified by Gram stain and MicroScan (Dade–Behring). The following bacteria were tested: probiotics: 3 Lactobacillus spp., 2 Lactococcus lactis lactis, 4 Streptococcus spp., 2 Bacillus spp., 3 Enterococcus spp. and 1 Saccharomyces cerevisiae, and non-probiotics: 8 Staphylococcus sp., 2 E. coli, 2 Klebsiella spp., 1 P. aeruginosa, 1 Salmonella GDF9, 1 A. baumannii, 1 E. cloacae and 1 S. maltophilia.

The effect of these microorganisms on H. pylori was determined by the ``drop'' method: A blood agar plate was completely inoculated with H. pylori and a drop was deposited containing 10 mL of the microorganism after 0.5 McFarland concentrations. Plates were incubated at 37°C under microaerobic atmosphere for 3–5 days. Lecture was made by the diameter of the inhibition zone observed after incubation.

Results: Among probiotics 2 LactoBacillus spp. showed inhibitory activity against 5 and 6 out of the 30 H. pylori strains tested, Bacillus spp. inhibited 11 out of 27 tested, 1 E. faecium inhibited 1 out of 27 tested and S. cerevisiae inhibited 7 out of 27 H. pylori strains tested. Staphylococcus spp. showed inhibitory effect against H. pylori strains: S. hominis against 5 out of 35, 1 S. auricularis against 7 out of 27, 1 S. auricularis against the 37 strains tested, 2 S. epidermidis against the 27 and 35 strains tested, S. warneri against 1 out of 35, S. cohni-cohni against 1 out of 35 and S. aureus against 6 out of 35. Among Gram-negative bacteria one E. coli strain was able to inhibit the growth of 1 out of 25 H. pylori clinical isolate tested. K. pneumoniae, A. baumannii and Salmonella GDF9 were able to inhibit the growth of 4 out 25 strains each. E. cloacae and S. maltophilia were able to inhibit the growth of 14 out 25 H. pylori isolates each.

Conclusions:Staphylococcus spp. strains (1 S. auricularis and 2 S. epidermidis) were able to inhibit the growth of all H. pylori strains tested. Several probiotic and non-probiotics bacteria were able to inhibit some H. pylori strains.

Acknowledgement: The study was supported by FIS PI 052442.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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