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

Abstract

Background. Helicobacter pylori (H. pylori) infection can occur as a mixed infection caused by several strains of H. pylori. Objectives. The aim of the study was to determine the frequency of colonization of the gastric mucosa by strains of H. pylori with different susceptibility to antimicrobial agents. Material and methods. The study was carried out on gastric biopsies taken from 54 previously untreated Polish children and adolescents. Of the 15 positive cultures, from each primary medium, 6 single H. pylori colonies were isolated, making a total of 90 isolates, and the susceptibility to metronidazole (MZ), amoxicillin (AC) and clarithromycin (CH) was determined by E-test method. The presence of the cagA gene and vacA alleles (s1, s2, m1, m2) was determined by PCR. Results. Positive culture for H. pylori was noted in 15/54 (27.7%) of patients. All H. pylori isolates were susceptible to AC, 27.8% were resistant to MZ and 38.9% to CH. The results showed 7/15 (46.7%) of children were infected with H. pylori strains with antibiotic heteroresistance, resistant to CH (5/15, 33.3%) and to MZ (2/15, 13.3%). The cagA + vacA s1/m2 combination was predominant genotype among detected H. pylori strains. The isolates possessing different antimicrobial susceptibility profiles in the same patient were identified. Conclusions. Microbiological analyses confirmed the presence of isolates possessing different antimicrobial susceptibility profiles in 47% of examined children with H. pylori infection. Different antimicrobial susceptibility profiles of H. pylori isolates detected in the same patient may influence the success of eradication therapy.

In Vitro Activity of 3-Bromopyruvate, an Anticancer Compound, Against Antibiotic-Susceptible and Antibiotic-Resistant Helicobacter pylori Strains

“…The study was conducted using 52 H. pylori strains (50 clinical strains, isolated during previous studies [50,51], and two reference strains, Tx30a (ATCC 51932) and J99 (ATCC 700824)) (Table 1). The strains were categorized as susceptible or resistant to antibiotics based on the EUCAST recommendations, i.e., amoxicillin (AMX, R > 0.125 μg/mL), clarithromycin (CLR, R > 0.5 μg/mL), tetracycline (TET, R > 1 μg/mL), and metronidazole (MTZ, > 8 μg/mL) [52].…”

Helicobacter pylori infection in children

“…4 In the studies reviewed in children within the last 5 years, we observed that in most of them the resistance rates to CLA and MET exceed 20%, with CLA resistance prevailing and with very little resistance to amoxicillin (AMO) and levofloxacin. [27][28][29] Multidrug resistance was a problem. 27 28 30 Resistance increases considerably in treatment failures.…”

“…28 31 The hetero-resistance in strains was described in children. 27 Studies demonstrated that triple therapy with PPI-AMO-CLA offers acceptable eradication rates when the strains are sensitive, and the resistance to MET does not significantly influence eradication. [32][33][34] Authors reported patients with susceptibilityguided treatment with adherence >90% of treatment achieved acceptable rates of eradication, 30 35 the rates were significantly higher in those receiving sequential therapy.…”

“… 27–29 Multidrug resistance was a problem. 27 28 30 Resistance increases considerably in treatment failures. 28 31 The hetero-resistance in strains was described in children.…”

Secretion of outer membrane vesicles as a mechanism promoting H. pylori infections

“…Rozprzestrzenianie genów oporności w procesie HGT udowodniono również u H. pylori. Stwierdzono istnienie silnego związku między infekcją mieszaną H. pylori (zakażenie kilkoma szczepami bakterii) u pacjentów a opornością tych bakterii na antybiotyki [7,16]. W doświadczeniu Cellini i wsp.…”