Primary resistance to clarithromycin in clinical strains of Helicobacter pylori isolated from children in Poland

Dzierżanowska-Fangrat, Katarzyna; Rozynek, E; Jóźwiak, Paulina; Celińska-Cedro, D; Madaliński, K; Dzierżanowska, D

doi:10.1016/s0924-8579(01)00421-6

Cited by 23 publications

(20 citation statements)

References 10 publications

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“…Only a few groups have studied mutations involved in clarithromycin resistance in strains obtained from children, and their results are similar to those obtained in our study (5,13,29).…”

supporting

confidence: 87%

High Prevalence of Clarithromycin Resistance and cagA , vacA , iceA2 , and babA2 Genotypes of Helicobacter pylori in Brazilian Children

Garcia¹,

Aranda²,

Gonçalves

et al. 2010

J Clin Microbiol

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We isolated 45 Helicobacter pylori strains from 217 child patients. Resistance to clarithromycin, metronidazole, amoxicillin, and tetracycline was detected in 27%, 13%, 4%, and 0% of strains, respectively. The A2143G mutation was the most prevalent (67%) among clarithromycin-resistant strains. In addition, strain genotyping revealed a significant association between gastritis severity and the simultaneous presence of cagA, vacA s1m1, iceA2, and babA2 genes.Helicobacter pylori infection is found worldwide and constitutes a public health concern in many countries. Previous epidemiological studies have shown a high prevalence of H. pylori infection in Brazil (2,20,24). H. pylori infection, generally acquired in childhood, persists asymptomatically for decades in most individuals.Amoxicillin, tetracycline, metronidazole, and clarithromycin are frequently used, combined with proton pump inhibitors or bismuth salts, for the treatment of H. pylori infections (25). However, antibiotic resistance is frequently associated with eradication failure (3, 16). Resistance to metronidazole and clarithromycin is population dependent, and several studies suggest that clarithromycin resistance is higher in strains isolated from children than in strains isolated from adults (10). In Brazil, the prevalence of clarithromycin-resistant strains in adults is reported to be from 7 to 10% (15, 18). However, little is known about the prevalence of clarithromycin-resistant H. pylori infection in Brazilian children.The primary aims of this study were to determine the prevalence of clarithromycin-resistant H. pylori strains in children, to identify those isolates via rapid methodology, and to examine the severity of gastritis caused by the antibiotic-resistant H. pylori isolates. Metronidazole, amoxicillin, and tetracycline resistance was also studied. Furthermore, the study aimed to genotype the vacA and iceA genes and to detect the cagA gene in gastric biopsy specimens, since recent studies found a high frequency of cagA-positive and iceA2-positive strains as well as a strain with the vacA signal region genotype s1 and middle region sequence m1 among pediatric H. pylori isolates in Brazil (6,7,11,23). This is also the first investigation of babA2 gene prevalence in Brazilian children.A total of 217 consecutive child patients, aged 1 to 18 years (mean age, 10 years) (105 girls and 112 boys), who underwent Gastric biopsy specimens were processed for histological examination and evaluated according to the updated Sydney system of classification and grading of gastritis (4).Antral gastric specimens were transported in sodium thioglycolate broth (Difco, Detroit, MI) in an ice bath and ground before submission to DNA extraction and PCR-restriction fragment length polymorphism (PCR-RFLP) analysis with primers specific to the H. pylori 23S rRNA gene (17). The QIAmp tissue kit (Qiagen) was used for DNA extraction. Point mutations related to clarithromycin resistance in the 23S rRNA amplicon were investigated in all H. pylori isolates by PCR-RFLP usin...

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“…Only a few groups have studied mutations involved in clarithromycin resistance in strains obtained from children, and their results are similar to those obtained in our study (5,13,29).…”

supporting

confidence: 87%

High Prevalence of Clarithromycin Resistance and cagA , vacA , iceA2 , and babA2 Genotypes of Helicobacter pylori in Brazilian Children

Garcia¹,

Aranda²,

Gonçalves

et al. 2010

J Clin Microbiol

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“…Some papers showed that A2142G was the most frequently detected (48 or 52.5%) (20,23), although some others found that A2143G was more prevalent (55.6 or 56.5%) (5,18). Only a few groups had studied the mutation involved in clarithromycin resistance in strains obtained from children; however, they found results similar to those obtained in our study (8,14,25).…”

supporting

confidence: 87%

“…In some countries resistance is higher in children than in adults (9), although not in others (21). An increase of resistance to clarithromycin and metronidazole in children has also been described elsewhere (3,8,15).…”

mentioning

confidence: 95%

Clarithromycin Resistance among Helicobacter pylori Strains Isolated from Children: Prevalence and Study of Mechanism of Resistance by PCR-Restriction Fragment Length Polymorphism Analysis

et al. 2003

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Clarithromycin and metronidazole resistance was 29.1 and 23.9%, respectively, in 96 Helicobacter pylori strains obtained from pediatric patients. No resistance to amoxicillin was observed. Resistance according to patients' ages to clarithromycin and metronidazole was 45.4 and 18.2% in 22 patients from 4 to 8 years old, 30.2 and 20.7% in 53 patients from 9 to 13 years old, and 9.5 and 38.1% in 21 patients from 14 to 18 years old, respectively. The A2143G mutation was the most prevalent (82.1%) among clarithromycin-resistant strains.Helicobacter pylori is a gram-negative microaerophilic rod found in the human gastric mucosa associated with different digestive diseases, such as peptic ulcer, gastritis, and mucosaassociated lymphoid tissue lymphoma (7), and it is considered a risk factor in the development of gastric cancer (24). H. pylori infection is frequently acquired during childhood, and symptoms such as vomiting and epigastric or recurrent abdominal pain are associated with H. pylori infection (6).Amoxicillin, tetracycline, metronidazole, and clarithromycin are frequently used, combined with proton pump inhibitors or bismuth salts, for the treatment of H. pylori infections (22). However, side effects, poor compliance, and resistance to antibiotics are causes of treatment failure (4, 16). Resistance to metronidazole and clarithromycin is population dependent, and several studies suggest that clarithromycin resistance is higher in strains obtained from children than in those from adults (9).The aim of this study was to determine the rate of resistance to clarithromycin in H. pylori strains obtained from pediatric patients according to the age of the patients. Metronidazole and amoxicillin resistance was also studied. The mutation involved in clarithromycin resistance was detected by PCR-restriction fragment length polymorphism analysis.Ninety-six pediatric patients, aged from 4 to 18 years (mean age Ϯ standard deviation, 10.86 Ϯ 3.3 years), attending the Gastroenterology Unit at the Hospital del Niño Jesus during 1999 and 2000, were included in this study. Patients were referred for endoscopy due to different symptoms, with epigastric pain (74.2%), vomiting (33.3%), and recurrent abdominal pain (25.8%) being the most prevalent. Parents signed an informed consent form for the endoscopy, and the Ethical Committee supervised the study. Patients previously treated for H. pylori infections were not included. Strains were grouped according to the age of the patient at the time of endoscopy.Only culture-positive patients were included. H. pylori clinical isolates were obtained from gastric biopsy specimens according to standard procedures.Clarithromycin was obtained from Abbott Laboratories SA, Madrid, Spain, and metronidazole and amoxicillin were obtained from Sigma-Aldrich, Madrid, Spain. MICs were determined by an agar dilution technique with Mueller-Hinton agar plus 7% horse blood according to NCCLS recommendations (17). Plates with twofold dilutions of each antibiotic were inoculated with 1 to 2 l of 10 9 CFU/ml ...

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“…The trend of the decline in rates of primary CLR r observed during the last years of the study (particularly in 2008 and 2009, with a mean value of 10.5% resistant strains) contrasts with the constant increases observed for other European countries, such as Austria, Bulgaria, France, and Italy (6,12,15). The observed decrease in rates of primary resistance may be mul- (20).…”

Section: Discussionmentioning

confidence: 95%

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

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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.

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Primary resistance to clarithromycin in clinical strains of Helicobacter pylori isolated from children in Poland

Cited by 23 publications

References 10 publications

High Prevalence of Clarithromycin Resistance and cagA , vacA , iceA2 , and babA2 Genotypes of Helicobacter pylori in Brazilian Children

High Prevalence of Clarithromycin Resistance and cagA , vacA , iceA2 , and babA2 Genotypes of Helicobacter pylori in Brazilian Children

Clarithromycin Resistance among Helicobacter pylori Strains Isolated from Children: Prevalence and Study of Mechanism of Resistance by PCR-Restriction Fragment Length Polymorphism Analysis

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

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