Triple therapy with high-dose proton-pump inhibitor, amoxicillin, and doxycycline is useless for Helicobacter pylori eradication: a proof-of-concept study.

INTRODUCTION: Helicobacter pylori resistance to antibiotics is steadily increasing and multidrug-resistant strains are common and difficult to eliminate, mainly in countries where bismuth, tetracycline, furazolidone, and rifabutin are unavailable. AIM: To evaluate the efficacy and safety of a triple therapy with proton-pump inhibitor (PPI), amoxicillin, and doxycycline in patients with multidrug-resistant H. pylori. PATIENTS AND METHODS: This prospective study involved 16 patients (13 females; mean age - 50 ± 11.3 years) infected by H. pylori with known resistance to clarithromycin, metronidazole, and levofloxacin, but susceptibility to amoxicillin and tetracycline. All patients were previously submitted to upper endoscopy with gastric biopsies for H. pylori culture and susceptibility testing by Etest. Mutations in 23S rRNA and gyrA genes were determined by real-time PCR. A 10-day eradication regimen with PPI (double-standard dose b.i.d.), amoxicillin (1000 mg b.i.d.), and doxycycline (100 mg b.i.d.) was prescribed after pretreatment with PPI during 3 days. Eradication success was assessed by (13) C-urea breath test 6-10 weeks after treatment. Compliance and adverse events were determined through phone contact immediately after treatment and specific written questionnaires. RESULTS: Only one patient did not complete treatment due to adverse events. Another four patients experienced mild side effects not affecting compliance. The control (13) C-urea breath test was positive in all patients. Per-protocol and intention-to-treat eradication rates were 0%. CONCLUSIONS: Although safe, a triple-therapy protocol with high-dose PPI, amoxicillin, and doxycycline is useless for multidrug-resistant H. pylori eradication.

Prevalence and molecular epidemiology of imipenem-resistant Pseudomonas aeruginosa carrying metallo-beta-lactamases from two central hospitals in Portugal.

Metallo-beta-lactamases (MBLs) can confer broad-spectrum beta-lactam resistance, including carbapenems. The aim of this work was to document the occurrence of MBLs in 122 imipenem-resistant Pseudomonas aeruginosa isolates collected in two Portuguese central hospitals, to determine their antimicrobial susceptibility, and to observe if there were intra- and interhospital epidemic spread. About 20.5% of these isolates presented blaVIM-2, which was found to be widespread in both hospitals. Clonal diversity was observed within hospitals, and no interhospital spread was observed. Ten of the blaVIM-2-positive isolates (44%), from both hospitals, presented one or two class 1 integrons. Two of those contained a VIM-2 gene, one from each hospital, which is indicative for the possibility of MBL gene transfer. No interhospital spread of integrons was observed. Regular screening and surveillance is needed to prevent spread of this worrisome resistance determinant.