Identification of hugZ , the isogenic mutant of hugZ in H. pylori 26695. (A) Cartoon description of hugZ knockout from the H. pylori 26695 chromosome. pBSKΔhugZ::cam is the recombinant vector constructed specifically to inactivate hugZ. hugZLA and hugZRA respectively indicate the left- and right- border of hugZ. A pair of specific primers (P-F &P-R) located adjacent to hugZ on both sides are indicated with blue arrows and used for PCR-detection of hugZ in the H. pylori 26695 genome. WT, wild type H. pylori 26695; ΔhugZ, an isogenic mutant of gene hugZ. (B) Multiple-PCR analysis of ΔhugZ. The PCR products were separated by electrophoresis on a 1.0% agarose gel stained with ethidium bromide (EB). P & H, the PCR product amplified with the P-F &P-R and H-F &H-R primers for hugZ. ΔhugZ has been replaced by CamRwithout affecting either boundary sequence (not shown). (C) RT-PCR analysis of ΔhugZ using hugZ1 & hugZ2 and gyrB1 & gyrB2 primers. RT-PCR products of hugZ and gyrB were separated by electrophoresis on a 2.0% agarose gel.