Prevention of nitroimidazole resistance in Campylobacter pylori by coadministration of colloidal bismuth subcitrate: clinical and in vitro studies.

Abstract

SUMMARY One hundred patients with duodenal ulceration and Campylobacter pylori in their stomach were entered into a double blind placebo controlled prospective study. Treatment schedules were cimetidine and placebo, or cimetidine and tinidazole, or colloidal bismuth subcitrate (CBS) and placebo, or CBS and tinidazole. Seventeen per cent of isolates of C pylori obtained at the first endoscopy were resistant to tinidazole and 70% of the second isolates from patients given cimetidine and tinidazole became tinidazole resistant. Suspensions of nitroimidazole sensitive cultures of C pylori showed that three of 22 isolates had a nitroimidazole resistant subpopulation. In patients who healed and remained free of C pylori after treatment ulcers recurred less often than in patients who healed but retained C pylori (23% v 73% over 12 months, p < 0-001).The spiral bacteria first cultured from the gastric mucosa of patients with histologically confirmed gastritis at Royal Perth Hospital in 1982' were originally named Campylobacter pyloridis,2 but the revised name is now Campylobacter pylori.3 Cpylori is highly susceptible to many antibiotics.245 We recently concluded a double blind, placebo controlled, prospective study ofpatients with duodenal ulceration and C pylori in their stomach, which included the nitroimidazole drug (tinidazole), given in addition to standard prophylaxis. We report the development of tinidazole resistance in a high proportion of the patients given tinidazole and cimetidine; the full clinical details of the study will be reported elsewhere. Some patients remained unhealed after 10 weeks of treatment and were then entered into an open study of various antibacterial regimens. Colloidal bismuth subcitrate (CBS) has a powerful bactericidal action against C pylori; the minimum inhibitory concentration of bismuth of C pylori is 8 mg/I,5 and ultrastructural studies of the gastric mucosa 75 minutes after administration of CBS have shown that most bacteria seem to have been killed.

Susceptibility of Helicobacter pylori isolates to metronidazole, clarithromycin and amoxycillin in vitro and in clinical treatment in Japan

“…11,12 Primary and acquired resistance to antibiotics is an important factor in treatment failure, resulting in an altered cure rate. 12,13 The purposes of the present study were (i) to assess the susceptibility of H. pylori isolates in Japan to MNZ, CLAR and AMOX, (ii) to examine the in¯uence of primary antibiotic resistance to H. pylori treatment, and (iii) to evaluate the prevalence of acquired antibiotic resistance in H. pylori treatment failure.…”

A new 1‐week therapy for Helicobacter pylori eradication: rani‐ tidine bismuth citrate plus two antibiotics

“…18 Bismuth preparations have an effective topical action which can markedly reduce the bacterial load and then favour the elimination of the remaining organisms by the associated antibiotics. 19 There is also evidence that the use of bismuth may prevent the development of acquired resistance to nitroimidazoles 20 and, in vitro, ranitidine bismuth citrate has been shown to signi®cantly reduce the emergence of H. pylori strains spontaneously resistant to metronidazole and clarithromycin. 21 These features may be of help in overcoming the major disadvantage of triple therapies containing both nitroimidazoles and clarithromycin, which are the two antibiotics most frequently shown to develop H. pylori resistance.…”

Effectiveness of different treatment regimens in helicobacter pylori eradication: Ten-year experience of a single institution

“…Osato et al had shown a synergy between RBC and clarithromycin with a decrease of RBC minimal inhibitory concentrations (MICs) from more than 8 mg/L to less than 2 mg/L in 8 of 10 clarithromycin-resistant Hp strains (26). RBC can release bismuth, which has also been shown to have moderate anti-Hp activity in the gastric mucosa (27). The level of bismuth concentration achieved in the mucosa is very important and markedly higher than the MIC.…”