Hamid Abdollahi - Microbiology Department, Medical School, Kerman University of Medical Sciences, Kerman, Iran
Omid Tadjrobehkar - Microbiology Department, Medical School, Kerman University of Medical Sciences, Kerman, Iran and Basic Sciences Department, Medical School , Zabol University of Medical Sciences, Zabol , Iran

Objective(s) Motility plays a major role in pathogenicity of Helicobacter pylori, yet there is  scarce data regarding its chemotactic behaviour. The present study was designed to investigate the chemotactic responses of local isolates of H. pylori towards various sugars, amino acids, as well as some other chemical substances. Materials and Methods Chemotaxis was assayed by a modified Adler’s method. We used solutions of sugars, amino acids as well as urea, sodium chloride, sodium and potassium bicarbonate, sodium deoxycholate and keratin at ۱۰ mM concentrations. Results Despite some small differences, tested H. pylori isolates generally had a positive chemotaxis towards the tested sugars (P< ۰.۰۵).  Among amino acids, phenylalanine, aspartic acid, glutamic acid, isoleucine and leucine showed a positive chemotaxis (P< ۰.۰۵) ; however, tyrosine showed negative chemotaxis (repellent) (P< ۰.۱۵). Urea, sodium chloride, sodium and potassium bicarbonate showed to be attractants (P< ۰.۰۵), but sodium deoxycholate was repellent (P< ۰.۰۵). Conclusion It seems that, sugars and many amino acids by their attraction for H.pylori, many amino acids, may enhance the activity of this bacterium and probably aggravate the symptoms of its infection. However, those like      L-tyrosine, may possibly be employed as deterrents for H. pylori and thus can control its infections. However, we suggest that further investigations on chemotactic behaviour of many more strains of H. pylori should be carried out before a final conclusion.

Amino acids, Bicarbonates, Chemotaxis, Helicobacter pylori, Urea