FIG 6.

Loss of BabA expression in rhesus monkeys is not dependent on its capacity to bind Leb. Six monkeys were inoculated with the H. pylori babA-CL2 mutant, and output colonies from 2, 8, 14, and 20 weeks p.i. were examined. Amplification and sequencing of the 5′ region of the babA locus from multiple colonies were used to determine if the gene was babA (A) or babB (B) and if the CT repeat region was in frame (eight CT repeats, black bars) or out of frame (seven or nine CT repeats, hatched bars). By 20 weeks p.i., loss of BabA expression by phase variation (hatched bars) and gene conversion (black bars) occurred with approximately equal frequency.