The Antimicrobial Susceptibility of Helicobacter pylori Strains Isolated from Children and Adults with Primary Infection in the Lower Silesia Region, Poland.

Abstract

The resistance of microorganisms to antibiotics has become a serious issue in recent years in the therapy of bacterial infections. This problem also concerns the treatment of infections caused by Helicobacter pylori strains. The aim of this study was to evaluate the frequency of primary resistance of H. pylori strains isolated from children and adults. The subject of the research was 105 strains of H. pylori isolated from children and 60 strains from adults in the Lower Silesia Region in the years 2008-2011. Antimicrobial susceptibility to the following antibiotics was assessed: amoxicillin (AC), clarithromycin (CH), metronidazole (MZ), tetracycline (TC), levofloxacin (LEV) and rifabutin (RB). Among the strains isolated from children, 33.3% were resistant to CH, 44.8% to MZ whereas 1.9% of strains were resistant simultaneously to CH, MZ and LEV. Among 60 strains isolated from adults, 23.3% were resistant to CH, 66.7% to MZ, and 6.7% to LEV. Moreover, 16 multidrug resistant strains were isolated from adults, including 12 resistant to CH and MZ, 3 to MZ and LEV, and 1 to CH, MZ and LEV. All examined strains were susceptible to AC, TC and RB. The high incidence of resistance to CH and MZ suggests that standard triple therapies may not be useful as first-line treatment in Poland without earlier susceptibility testing.

Increasing metronidazole and rifampicin resistance of Helicobacter pylori isolates obtained from children and adolescents between 2002 and 2015 in southwest Germany

“…44 Using the same breakpoint for rifabutin as we used for rifampicin, that is, 1 mg/L, Seo and colleagues reported resistance rates to rifabutin of 8.6% for 1990-1994 and 6.1% for 2005-2009 in South Korea, 45 while all 105 pediatric isolates were rifabutin susceptible in a recent Polish study. 46 Thus, dependent on the population studied and the breakpoint concentration applied, there may be a substantial proportion of pediatric H. pylori isolates resistant to rifampicin or rifabutin. bly be due to a higher prescription rate of this drug, for example, for parasitic infections, in this small subpopulation of patients than in the other patients.…”

Frequency of infection with Helicobacter pylori isolates of different antimicrobial profiles in children and adolescents: A preliminary study

“…The isolation and identification of strains were performed as described previously. 11 After obtaining a positive culture, 6 single colonies of H. pylori were isolated from each medium (with special attention to differences in the size of colonies) and transferred to new plates with Columbia agar supplemented with 7% of hemolyzed horse blood which were incubated for 3-4 days in microaerophilic conditions. Of the 15 positive cultures, 6 single H. pylori colonies were isolated from each primary medium, making a total of 90 isolates.…”

“…Susceptibility of strains to the antibiotics amoxicillin (AC), clarithromycin (CH), and metronidazole (MZ) was determined by gradient diffusion (E-test, BioMerieux) on Mueller-Hinton agar (Oxoid) supplemented with 10% horse blood under microaerophilic conditions. 11 The strains were considered resistant to AC, CH and MZ when the minimum inhibitory concentration (MIC) values were > 0.12, > 0.5 and > 8 mg/mL, respectively. 11 DNA isolation and determination of the cagA gene and vacA alleles in isolated strains were performed as described elsewhere.…”

The effect of virulence genotypes of Helicobacter pylori on eradication therapy in children

“…At present, the most common resistance to antibiotics worldwide among affected children involve metronidazole and clarithromycin, whereas the resistance rate of amoxicillin is lower. [ 15 16 ] In China, the rates of resistance to metronidazole and clarithromycin were increased among children infected with H. pylori with resistance rates of 49.2% and 34.9%, respectively. The amoxicillin resistance rate was 6.2%.…”