Storage at low temperature of Helicobacter pylori by cyanobacterial extract

STEGE, P. W.; VEGA, A. E.; CORTIÑAS, T. I.; SILVA, H. J.

Uspallata, Mendoza

Congreso; Annual Scientific Meeting of biology; 2005

Sociedad de biología de cuyo

Helicobacter pylori is a microaerophilic, gram-negative spiral bac­terium that is currently recognized as a pathogenic microorganism; it is associated with peptic ulcer, malignant lymphoma, and gastric cancer. There is continued interest in morphological, physiological and genetic studies in order to better characterize the prevalence of infection, as well as the natural history and transmission mode of the infection. One problem has been the long term storage of H. pylori strains. For this reason we evaluated the feasibility of using a cyanobacterial extract (CE) to conserve H. pylori at low tem­perature. Three H. pylori strains were stored in CE plus 20% glyc­erol (CE-20%) and broth tripticase soy plus 20% glycerol (BTS­20%, standard medium), at -80°C for six months. The recuperation index (IR = ufc/ml recovered /ufc/ml initial inoculum X 100) was used to evaluate the ability of the CE to maintain viability of H.pylori strains. Our results showed an important increase of recov­ered cells with the CE-20%. The RIs for CE-20% were 100%, 71.4% and 26.6%; while, the RIs for BTS-20% were 66.6%, 8.57% and 3.6%, respectively. We concluded that the CE can successfully replace the standard storage medium for the conservation of H. py­lori strains at low temperatures. Although we observed variations in the IR between the strains stored with CE-20% 01- BTS-20%, this can be attributed to different abilities of the strains to survive under these conditions.