ABSTRACT
The proteolytic activity (PA) of some microorganisms is an important pathogenic factor during tissue invasion. However, its role in Helicobacter pylori infection is not clear. Due to the importance of the immunological response to inhibit pathogenic factors of microorganisms, this study aims to establish an in vitro system to detect inhibitory antibodies to the PA of H. pylori in mouse serum. We obtained mouse sera from animals immunized by oral and intraperitoneal inoculations with the raw bacterial extract (BE) of H. pylori, in which we had previously detected PA. The degradation of azocasein subtract for BE was inhibited in 49.23 and 22.6 using 5 micrograms/ml of serum proteins (SP) from oral and intraperitoneal inoculation, respectively. However, when using more than 25 micrograms/ml of SP of immune serum, PA was inhibited in a similar way than with control serum. In conclusion we present a methodology for the detection of inhibitory antibodies to PA of H. pylori in the serum of the immunized mouse.