Helicobacter pylori antimicrobial resistance rates in the central region of Portugal

Abstract

Helicobacter pylori resistance to antimicrobial agents is steadily increasing. It is extremely important to be aware of the local prevalence of antibiotic resistance so as to adjust treatment strategies. During this single-centre, prospective study, we aimed to determine primary and secondary resistance rates of H. pylori to antibiotics as well as host and bacterial factors associated with this problem. Overall, 180 patients (131 female; mean age 43.4±13.5 years; primary resistance 103; secondary resistance 77) with positive (13) C-urea breath test were submitted to upper endoscopy with gastric biopsies. Helicobacter pylori was cultured and antimicrobial susceptibility was determined by Etest and molecular methods. Clinical and microbiological characteristics associated with resistance were evaluated by logistic regression analysis. Among the 180 isolates 50% were resistant to clarithromycin (primary 21.4%; secondary 88.3%), 34.4% to metronidazole (primary 29.1%; secondary 41.6%), 33.9% to levofloxacin (primary 26.2%; secondary 44.2%), 0.6% to tetracycline and 0.6% to amoxicillin. Being female was an independent predictor of resistance to clarithromycin and metronidazole. Previous, failed, eradication treatments were also associated with a decrease in susceptibility to clarithromycin. History of frequent infections, first-degree relatives with gastric carcinoma and low education levels determined increased resistance to levofloxacin. Mutations in the 23S rRNA and gyrA genes were frequently found in isolates with resistance to clarithromycin and levofloxacin, respectively. This study revealed that resistance rates to clarithromycin, metronidazole and levofloxacin are very high and may compromise H. pylori eradication with first-line and second-line empiric triple treatments in Portugal.

Detection of virulence gene belonging to cag pathogenicity island in Helicobacter pylori isolates after multiple unsuccessful eradication therapy in Northwest Croatia

“…This is in agreement with some studies which consider cagE to be a better marker of cagI region than cagA (9, 36). We did not find any association between cagE and endoscopic diagnosis and pathohistological lesions which is in agreement with the results from a study conducted in Portugal where cagE is more prevalent than cagA (27). Modena at al.…”

“…Prevalence of cagA positive strains differs between the countries and is the highest in East Asia (90%), Japan (100%) (21) and Bulgaria (84.9%) (22). The moderate prevalence was found in Iran (62%) (23), Slovenia (61%) (24), Columbia (64%) (21), Turkey (49%) (25), Equador (46%) (26) and Portugal (31.8%) (27). The previous studies on H. pylori in Croatia reported the prevalence of serum antibodies However, some studies did not find any significant relationship between cagA positivity and H. pylori density, neutrophil activity, lymphoid aggregation in lamina propria and glandular atrophy in the biopsies, but significant association was detected with severe chronic gastritis (23).…”

Twelve-day quintuple regime containing four antibiotics as a rescue therapy for Helicobacter pylori eradication in the central region of Portugal

“…The main limitation of our study is the lack of data with regard to antibiotic resistance, even though resistance rates may be extrapolated from regional data (4,5). A very high resistance rate is expected in studies that analyze rescue regimens as these patients have already been treated with several antibiotics.…”

“…Therefore, there is a growing need for an effective eradication strategy in patients who failed previous therapies. Resistance to clarithromycin is worrisome in Mediterranean countries and others worldwide (4,5), and commonly used regimens such as triple therapy with amoxicillin and clarithromycin have shown disappointing results and are considered to be obsolete (6). Despite achieving acceptable results in regions with low quinolone resistance, the currently recommended second-line levofloxacin-based triple therapy has shown unacceptable results if the H. pylori resistance rates to quinolones are higher than 15% (7)(8)(9).…”

“…Thus, the latest Consensus in Spain with regard to H. pylori infection and the Maastricht V conference is to add bismuth to a levofloxacin rescue therapy, or even extend the treatment to 14 days (10,11). In the central Portugal region and in others worldwide, primary resistance rates to levofloxacin, clarithromycin and metronidazole have surpassed 15%, 25% and 35%, respectively (4,5,12,13). Furthermore, due to the current use of suboptimal first-line regimens, secondary resistance to these antibiotics has also reached the alarming figure of 60% in several countries (14,15).…”