Antibacterial resistance in Helicobacter pylori strains isolated from Bulgarian children and adult patients over 9 years

Abstract

The aim of this study was to evaluate the primary, combined and post-treatment antibacterial resistance rates in 1205 Helicobacter pylori strains from non-treated (786 adults, 282 children) and treated (109 adults, 28 children) patients in Bulgaria. Susceptibility was tested by the limited agar dilution method. Overall primary resistance rates to metronidazole, clarithromycin, amoxicillin, tetracycline and both metronidazole and clarithromycin were respectively 15?0, 12?5, 1?5, 3?4 and 4?7 % in children and 25?6, 12?6, 0?8, 5?2 and 4?9 % in adults. Primary metronidazole resistance in adults was more common than in children, but the differences for other agents tested were not significant. Primary resistance rates were in the range of those reported worldwide. There was no significant increase in primary resistance rates from 1996/1999 to 2003/2004; however, clarithromycin resistance rates exhibited a slight tendency to increase. Post-treatment resistance to amoxicillin was detected in 1?6 % of 63 strains. Post-treatment resistance to metronidazole was common (81?6 %) and that to clarithromycin was considerable (36 %). Alarming emergence of strains with triple resistance to amoxicillin, metronidazole and clarithromycin was found in two non-treated and three treated patients. The results motivate a larger and continuing surveillance of H. pylori resistance in Bulgaria and worldwide.

Alaska Sentinel Surveillance Study of Helicobacter pylori Isolates from Alaska Native Persons from 2000 to 2008

“…An increase in the multidrug resistance of H. pylori isolates to commonly prescribed antibiotics has been previously documented (5,6,20,28). In this study, persons infected with isolates resistant to metronidazole were more likely to have isolates resistant to clarithromycin as well.…”

Characterization of 23S rRNA gene mutation in primary and secondary clarithromycin-resistant Helicobacter pylori strains from East China

“…The Maastricht-3 consensus guidelines recommend that antibiotics be chosen based on local resistance levels, therefore knowing the levels of clarithromycin resistance is essential for clinicians to develop treatment plans. The prevalence of primary and secondary clarithromycin resistance is lower in East China than Italy (12), while the prevalence is similar to that reported in Bulgaria (13). As clarithromycin is a member of the macrolide family, which has well documented cross resistance between all macrolide family members (14).…”

Antibiotics resistance ofHelicobacter pyloriand treatment modalities in children withH. pyloriinfection

“…This discrepancy might be due to differences in the prescription of antibiotics to patients by the medical doctors of these areas. In Jinju, the rate of amoxicillin resistance increased from 19.0% between 1990 and 1994 to 24.2% between 2005 and 200922), and has been estimated at more than 50% in Iran18). These findings suggest that administration of a course of amoxicillin is ineffective for the management of H. pylori infection.…”

“…In some countries, antimicrobial resistance has evolved with the use of antibacterial agents3,16). Table 1 shows recent the rates of H. pylori resistance to antimicrobials that are commonly administered to children in 10 countries17,18,19,20,21,22,23,24,25,26,27). The E-test has been established as a reliable modality for measuring antibiotic resistance to all antimicrobials, except for metronidazole for which it overestimates resistance.…”