Prevalence and evolution of Helicobacter pylori resistance to 6 antibacterial agents over 12 years and correlation between susceptibility testing methods

Boyanova, Lyudmila; Gergova, Galina; Nikolov, Rossen; Davidkov, Lubomir; Kamburov, Victor; Jelev, Christo; Mitov, Ivan

doi:10.1016/j.diagmicrobio.2007.11.008

Cited by 71 publications

(46 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The gradual increase in levels of resistance is probably also related to the widespread use of macrolides to treat other diseases, particularly respiratory tract infections in Belgium, and the introduction of new macrolides around 1995, such as CLR and azithromycin (7). In contrast with our findings, a decrease in rates of CLR r was observed in the Netherlands between 1997 and 2002 (22), rates of CLR r did not change over the period of 1994 to 2005 for French children (23), and they did not decrease between 1996 and 2007 for Bulgarian children (5,6).…”

Section: Discussioncontrasting

confidence: 54%

Multicenter Survey of Routine Determinations of Resistance of Helicobacter pylori to Antimicrobials over the Last 20 Years (1990 to 2009) in Belgium

et al. 2011

View full text Add to dashboard Cite

We analyzed the rates of antimicrobial resistance of Helicobacter pylori strains isolated from patients from 1990 to 2009 and identified risk factors associated with resistance. Gastric biopsy specimens were collected from several digestive disease centers in Brussels, Belgium. We routinely performed antimicrobial susceptibility testing for clarithromycin (CLR), metronidazole, amoxicillin, tetracycline, and ciprofloxacin. Evaluable susceptibility testing was obtained for 9,430 strains isolated from patients who were not previously treated for Helicobacter pylori infection (1,527 isolates from children and 7,903 from adults) and 1,371 strains from patients who were previously treated (162 isolates from children and 1,209 from adults). No resistance to amoxicillin was observed, and tetracycline resistance was very rare (<0.01%). Primary metronidazole resistance remained stable over the years, with significantly lower rates for isolates from children (23.4%) than for isolates from adults (30.6%). Ciprofloxacin resistance remained rare in children, while it increased significantly over the last years in adults. Primary clarithromycin resistance increased significantly, reaching peaks in 2000 for children (16.9%) and in 2003 for adults (23.7%). A subsequent decrease of resistance rates down to 10% in both groups corresponded to a parallel decrease in macrolide consumption during the same period. Multivariate logistic regression revealed that female gender, age of the patient of 40 to 64 years, ethnic background, the number of previously unsuccessful eradication attempts, and the different time periods studied were independent risk factors of resistance to clarithromycin, metronidazole, and ciprofloxacin. Our study highlights the need to update local epidemiological data. Thus, the empirical CLR-based triple therapy proposed by the Maastricht III consensus report remains currently applicable to our population.

show abstract

Section: Discussioncontrasting

confidence: 54%

Multicenter Survey of Routine Determinations of Resistance of Helicobacter pylori to Antimicrobials over the Last 20 Years (1990 to 2009) in Belgium

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Isolation, identification and susceptibility testing of H. pylori strains were performed as described previously (Boyanova et al 2008). Briefly, a susceptibility testing was performed by limited agar dilution method with 3-4 consecutive concentrations of antibacterials (Boyanova et al 2008). Antibiotic susceptibility tests were carried out in duplicate.…”

Section: Methodsmentioning

confidence: 99%

Association of iceA and babA genotypes in Helicobacter pylori strains with patient and strain characteristics

Boyanova

Yordanov

Gergova

et al. 2010

Antonie van Leeuwenhoek

Self Cite

View full text Add to dashboard Cite

Data on the geographic prevalence of Helicobacter pylori iceA and babA alleles in Eastern Europe are still relatively scant. The aim of this study was to evaluate the prevalence of iceA and babA genotypes in Bulgarian symptomatic patients. The iceA and babA genotypes were evaluated by PCR with pure cultures in strains from 196 and 181 patients, respectively. Mixed infections were found in 10.2% of all 196 patients. Prevalence of H. pylori genotypes in patients with single-strain infections was 69.3% for iceA1, 30.7% for iceA2, 82.4% for cagA(+), 89.2% for vacA s1, 10.8% for vacA s2, 39.8% for vacA m1, 60.2% for vacA m2 and 48.8% for babA2. Within the iceA1 positive strains, 94.3% and 88.5% were also vacA s1a and cagA positive, respectively. Of the babA2 positive strains, 100.0%, 92.4% and 72.2% were also vacA s1a, cagA and iceA1 positive, respectively. Ulcer patients had more often strains with cagA positive status and vacA s1a allele. Although neither iceA1 nor babA2 were more common in ulcer patients, the combination of both alleles was more frequent (48.1%) in the ulcer patients than in the rest (28.7%). Clarithromycin susceptible strains had more often iceA1 allele (74.4%) than the resistant strains (55.3%). In conclusion, the results demonstrated a high prevalence of virulent H. pylori in Bulgaria. Both iceA1 and babA2 genotypes were associated with other virulence factors of H. pylori and, in addition, the iceA1 allele was associated with the strain susceptibility.

show abstract

“…Non-selective Mueller-Hinton blood agar plates were used as a control of the viability of the strains. Breakpoints for resistance were: .8 mg metronidazole ml -1 , ¢1 mg clarithromycin ml -1 , .1 mg ciprofloxacin ml -1 and .4 mg tetracycline ml -1 (Mégraud & Lehours, 2007;Boyanova et al, 2008;CLSI, 2010). Strain susceptibility was tested in duplicate.…”

Section: Methodsmentioning

confidence: 99%

“…The susceptibility of the strains was evaluated by a breakpoint susceptibility test, as described previously (Boyanova et al, 2008). Briefly,~30-60 ml H. pylori suspension, corresponding to a density of McFarland turbidity standard 2-3, was inoculated on Mueller-Hinton blood agar plates (National Centre of Infectious and Parasitic Diseases, Sofia, Bulgaria) containing one of the following drug concentrations: 8, 16 or 32 mg metronidazole ml -1 ; 0.25, 0.5, 1 or 2 mg clarithromycin ml -1 ; 1 mg ciprofloxacin ml -1 ; and 4 mg tetracycline ml -1 .…”

Section: Methodsmentioning

confidence: 99%

Numerous risk factors for Helicobacter pylori antibiotic resistance revealed by extended anamnesis: a Bulgarian study

Boyanova

Ilieva

Gergova

et al. 2012

Journal of Medical Microbiology

Self Cite

View full text Add to dashboard Cite

The aim of this study was to assess risk factors for primary Helicobacter pylori antibiotic resistance by an extended anamnesis. In total, 519 H. pylori strains from untreated symptomatic adults who answered a questionnaire were evaluated. Strain susceptibility was assessed by a breakpoint susceptibility test. Primary resistance rates were 29.5 % for metronidazole, 17.9 % for clarithromycin, 7.3 % for metronidazole+clarithromycin, 4.0 % for tetracycline and 10.8 % for ciprofloxacin. On multivariate analysis, younger (¡65 years) age was an independent predictor for metronidazole resistance. To our knowledge, for the first time, being a member of the health-care profession was revealed as a risk factor for H. pylori resistance to metronidazole and both metronidazole and clarithromycin. Respiratory and urinary tract infections were independent predictors of clarithromycin and ciprofloxacin resistance, respectively. The presence of co-infections was an independent risk factor for clarithromycin, metronidazole and ciprofloxacin resistance. Surprisingly, female sex was the only predictor for tetracycline resistance. The antibiotic resistance rates were not associated with disease type, place of residence, birthplace, educational level, non-steroidal anti-inflammatory drug or proton pump inhibitor use, smoking or dietary factors, such as consumption of coffee, yogurt, green tea, raw garlic, raw onion, honey or meat. There was a trend for higher metronidazole resistance in strains from diabetic patients. In conclusion, the extended anamnesis of H. pylori-positive patients should include data on patient age, sex, whether they are in the health-care profession, co-infections and possibly diabetes to improve the choice of empiric therapy. Tailored treatment based on the extended anamnesis is suggested, and susceptibility testing of the strains is recommended for patients at risk for antibiotic resistance, especially to clarithromycin, fluoroquinolones or both metronidazole and clarithromycin.

show abstract

Prevalence and evolution of Helicobacter pylori resistance to 6 antibacterial agents over 12 years and correlation between susceptibility testing methods

Cited by 71 publications

References 26 publications

Multicenter Survey of Routine Determinations of Resistance of Helicobacter pylori to Antimicrobials over the Last 20 Years (1990 to 2009) in Belgium

Multicenter Survey of Routine Determinations of Resistance of Helicobacter pylori to Antimicrobials over the Last 20 Years (1990 to 2009) in Belgium

Association of iceA and babA genotypes in Helicobacter pylori strains with patient and strain characteristics

Numerous risk factors for Helicobacter pylori antibiotic resistance revealed by extended anamnesis: a Bulgarian study

Contact Info

Product

Resources

About