Culturing Mouse-Adapted H. pylori Strains

A mouse-adapted strain of H. pylori SS1 strain57 (link), was provided by the H. pylori Research Laboratory, University of Western Australia. J99 strain was from Amerian Type Culture Collection (ATCC, Rockwille, MA)59 (link) while 298 strain was derived from a local clinical isolate, UM032, as previously described60 (link). Bacteria was grown on chocolate agar plate supplemented with 7% laked horse blood (Oxoid, Basingstoke, UK) under microaerophilic conditions at 10% CO₂, 37 °C in a humidified incubator and were subcultured every 3 days. For infection, H. pylori was harvested in brain heart infusion (BHI) broth and quantified by a spectrophotometer (OD_650 nm of 1 = 1 × 10⁸ cells/ml). Viable cell count was predetermined by calculating colony forming units after serially diluted bacteria were drop plated onto chocolate agar plate.