These data should help the users to choose the kit the most appropriate to their goals.

In vitro, Helicobacter pylori converts from a bacillary to a full coccoid form via an intermediate U-shaped form. Organisms with a full coccoid form keep a double membrane system, a polar membrane, and invagination structures. Western blots (immunoblots) of sera from colonized patients show that some high-molecular-mass antigenic fractions are expressed only in coccoids. Conversely, fractions of 30 and 94 kDa were more intensively detected in the bacillary forms. These results suggest that (i) coccoid conversion is not a degenerative transformation and (ii) antigens specific to the coccoid forms are expressed in vivo.

SUMMARYAim: To compare the efficacy of different regimens in patients in whom previous Helicobacter pylori eradication therapy has failed. Methods: In this study named StratHegy patients (n ¼ 287) were randomized to receive one of three empirical triple therapy regimens or a strategy based on antibiotic susceptibility. The empirical regimens were omeprazole, 20 mg b.d., plus amoxicillin, 1000 mg b.d., and clarithromycin, 500 mg b.d., for 7 days (OAC 7 ), clarithromycin, 500 mg b.d., for 14 days (OAC 14 ) or metronidazole, 500 mg b.d., for 14 days (OAM 14 ). In the susceptibility-based strategy, patients with clarithromycin-susceptible strains received OAC 14 , whilst the others received OAM 14 . The 13 C-urea breath test was performed before randomization and 4-5 weeks after eradication therapy.Results: In the intention-to-treat analysis, the eradication rates for empirical therapies were as follows: OAC 7 , 47.4% (27/57); OAC 14 , 34.5% (20/58); OAM 14 , 63.2% (36/57); it was 74.3% (84/113) for the susceptibilitybased treatment (P < 0.01 when compared with OAC 7 and OAC 14 ). In patients receiving clarithromycin, the eradication rates were 80% for clarithromycin-susceptible strains and 16% for clarithromycin-resistant strains; in patients receiving OAM 14 , the eradication rates were 81% for metronidazole-susceptible strains and 59% for metronidazole-resistant strains. Conclusions: Eradication rates of approximately 75% can be achieved with second-line triple therapy based on antibiotic susceptibility testing. If susceptibility testing is not available, OAM 14 is an appropriate alternative.

We developed a single-vessel multiplex real-time PCR assay that detects Helicobacter pylori infection and identified the four existing alleles of the 23S rRNA genes of H. pylori-the wild-type sequence and the three mutations conferring clarithromycin resistance-using allele-specific Scorpion primers directly on biopsy specimens. The Scorpion primers combine a primer and a probe in a single molecule and are able to distinguish single-nucleotide polymorphism. Fluorescent signals, produced when the probes are annealed, are read in four channels by a SmartCycler thermocycler. The assay was first applied successfully on 4 reference and 61 clinical strains. MICs of clarithromycin were determined by the Etest method. A perfect concordance was obtained between Etest and Scorpion PCR. Mixed populations were better detected by Scorpion PCR. We examined 259 biopsies from 229 patients by culture, PCR-restriction fragment length polymorphism (RFLP), and Scorpion PCR. One biopsy, positive for culture, exhibited inhibitors for both PCR-RFLP and Scorpion PCR. Twelve biopsies were positive for PCR-RFLP and Scorpion PCR but negative for culture with concordant determination of mutations in the 23S rRNA genes by the two PCR assays. Three biopsies were positive for Scorpion PCR only. Compared to culture, the sensitivity of Scorpion PCR was 98.3% and the specificity was 92.5%. The Scorpion PCR assay provides a highly accurate, rapid, and precise method for the detection and determination of mutations conferring clarithromycin resistance to H. pylori.