Clarithromycin and Amoxicillin Susceptibility of Helicobacter pylori Strains Isolated from Adult Patients with Gastric or Duodenal Ulcer in Italy

Abstract

Helicobacter pylori strains, isolated from 100 gastric biopsies from 49 previously untreated adult patients with endoscopy and histology-confirmed gastric or duodenal ulcer, were tested for in vitro antimicrobial susceptibility. Strains were isolated from biopsies of 75.5% (37 of 49) patients before therapy and of 13.5% after therapy. Clarithromycin and amoxicillin susceptibility testing was performed on pretreatment and posttreatment strains by using the agar disk diffusion method and E-test, a quantitative technique for the minimal inhibitory concentration (MIC) determination. All strains (n = 53) were susceptible to amoxicillin by the two methods. Three strains of 34 (8.8%) patients were resistant to clarithromycin: two by both methods and one by E-test (MIC > 2 microg/ml). E-test, although more expensive than the disk diffusion method, is easy to perform and is a reliable method for testing H. pylori susceptibility to antimicrobial agents in the clinical microbiology laboratory.

Prevalence of <em>Helicobacter pylori</em> among patients with different gastrointestinal disorders in Saudi Arabia

“…The isolation rate of H. pylori among dyspeptic patients by culture and rapid urease test was inconsistence with Franzin et al 16 who reported that 75.5% of dyspeptic patients were H. pylori positive. On the other hand, our findings were higher than the percentage in the study obtained by Matsukura et al 12 Studies performed at Ismailia (Egypt), 66% and 68%, respectively of dyspeptic patients were H. pylori positive.…”

High levels of dual resistance to clarithromycin and metronidazole and in vitro activity of levofloxacin against Helicobacter pylori isolates from patients after failure of therapy

“…In contrast, somewhat more reassuring figures have emerged from studies conducted in northern Italy. Primary resistance to CLA was documented in only 1.8% of the H. pylori isolates recovered in the Northeast [33] and in 8.8% of those examined in a northwestern region of the country [34]. Figures from different areas of the world obviously vary widely: relatively low or moderate rates have also been reported in Lebanon (4%) and in Israel (8%) [19,20], while in North America [18], Europe [10,11,17], and Asia [14,15], resistance has been observed in up to 12, 15 and 13% of isolates, respectively.…”

In vitro anti‐Helicobacter pylori activity of diallyl sulphides and protocatechuic acid

“…The clinical combination of a proton pump inhibitor and antimicrobial agents such as clarithromycin or metronidazole is the most favoured treatment (Franzin et al, 2000;Megraud, 2004). However, the increasing use of these antibiotics causes the development of clinical isolates of H. pylori resistant to commonly used antibiotics.…”