Marco Berning

Effects of 16S rRNA Gene Mutations on Tetracycline Resistance in Helicobacter pylori

ABSTRACT The triple-base-pair 16S rDNA mutation AGA926-928→TTC mediates high-level tetracycline resistance in Helicobacter pylori. In contrast, single- and double-base-pair mutations mediated only low-level tetracycline resistance and decreased growth rates in the presence of tetracycline, explaining the preference for the TTC mutation in tetracycline-resistant H. pylori isolates.

Detection of high‐level tetracycline resistance in clinical isolates of Helicobacter pylori using PCR‐RFLP

Tetracycline is one of four antibiotics commonly used for the treatment of Helicobacter pylori infection, but its effectiveness is decreasing as the incidence of tetracycline resistance is increasing. In five Brazilian tetracycline-resistant (Tet(R)) H. pylori isolates, high-level tetracycline resistance is mediated by the triple-base-pair substitution AGA(926-928)-->TTC in both 16S rRNA genes, as was previously observed in two independent high-level Tet(R) H. pylori strains. A polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) assay was developed for the detection of the AGA(926-928)-->TTC substitution, and confirmed the presence of the aforementioned triple-base-pair substitution in all five Brazilian Tet(R) isolates. This PCR-RFLP-based approach distinguishes the high-level Tet(R) isolates from low-level Tet(R) and Tet(S) H. pylori strains and thus allows the direct detection of Tet(R) H. pylori isolates.

Real-Time PCR Screening for 16S rRNA Mutations Associated with Resistance to Tetracycline in Helicobacter pylori

ABSTRACT The effectiveness of recommended first-line therapies for Helicobacter pylori infections is decreasing due to the occurrence of resistance to metronidazole and/or clarithromycin. Quadruple therapies, which include tetracycline and a bismuth salt, are useful alternative regimens. However, resistance to tetracycline, mainly caused by mutations in the 16S rRNA genes (rrnA and rrnB) affecting nucleotides 926 to 928, are already emerging and can impair the efficacies of such second-line regimens. Here, we describe a novel real-time PCR for the detection of 16S rRNA gene mutations associated with tetracycline resistance. Our PCR method was able to distinguish between wild-type strains and resistant strains exhibiting single-, double, or triple-base-pair mutations. The method was applicable both to DNA extracted from pure cultures and to DNA extracted from fresh or frozen H. pylori-infected gastric biopsy samples. We therefore conclude that this real-time PCR is an excellent method for determination of H. pylori tetracycline resistance even when live bacteria are no longer available.

Randomized trial on 14 versus 7 days of esomeprazole, moxifloxacin, and amoxicillin for second-line or rescue treatment of Helicobacter pylori infection.

Background:  Triple therapy with a proton pump inhibitor, moxifloxacin, and amoxicillin has been proven effective in first‐line treatment of Helicobacter pylori infection.

Moderne Helicobacter-pylori-Therapien in Zeiten zunehmender Antibiotikaresistenz@@@Modern Helicobacter Pylori Therapies in Times of Increasing Anti biotic Resistance

ZusammenfassungDie Empfehlungen zu Diagnostik und Therapie der Helicobacter pylori Infektion sind in aktuellen, nationalen und internationalen Leitlinien definiert. In Deutschland gilt die Protonenpumpeninhibitoren(PPI)-basierte Tripeltherapie mit Clarithromycin und Metronidazol oder Amoxicillin als Standard der Primärbehandlung. Allerdings sind die Erfolgsraten dieser Standardtherapien in den letzten Jahren aufgrund zunehmender Antibiotikaresistenzen gesunken, insbesondere bei Patienten aus dem südeuropäischen Raum. Zudem kommt es nach Versagen der Primärtherapie zu einem dramatischen Anstieg der Resistenzraten, die einen erneuten Einsatz der Standardantibiotika praktisch unmöglich macht. Vor diesem Hintergrund ist eine regelmäßige kritische Prüfung und ggf. auch Anpassung der therapeutischen Optionen sowohl in der Primärbehandlung als auch in der Reservesituation erforderlich. Dieser Artikel gibt eine praxisrelevante Übersicht über den aktuellen Stand der therapeutischen Optionen der Helicobacter pylori Infektion vor dem Hintergrund zunehmender Antibiotikaresistenzen.AbstractRecommendation for the diagnosis and treatment of Helicobacter pylori Infection are defined in recent national and international guidelines. In Germany, proton pump inhibitor-based triple therapy with clarithromycin and metronidazole or amoxicillin is still the standard in first line therapy. However, success rates have decreased substantially during the last years due to increasing antibiotic resistance, particularly in patients from Southern Europe. In addition, antimicrobial resistance rates against the standard antibiotics further increases dramatically after failure of first line therapy deeming the repeated use of these antibiotics basically impossible. Against this background, a critical appraisal and eventaully adaption of therapeutic options both in first line and rescue treatment appears necessary. This paper gives an overview on the current status of therapeutic options and developments in the treatment of H. pylori infection in the light of increasing antibiotic resistance.

Modern Helicobacter pylori therapies in times of increasing anti biotic resistance

ZusammenfassungDie Empfehlungen zu Diagnostik und Therapie der Helicobacter pylori Infektion sind in aktuellen, nationalen und internationalen Leitlinien definiert. In Deutschland gilt die Protonenpumpeninhibitoren(PPI)-basierte Tripeltherapie mit Clarithromycin und Metronidazol oder Amoxicillin als Standard der Primärbehandlung. Allerdings sind die Erfolgsraten dieser Standardtherapien in den letzten Jahren aufgrund zunehmender Antibiotikaresistenzen gesunken, insbesondere bei Patienten aus dem südeuropäischen Raum. Zudem kommt es nach Versagen der Primärtherapie zu einem dramatischen Anstieg der Resistenzraten, die einen erneuten Einsatz der Standardantibiotika praktisch unmöglich macht. Vor diesem Hintergrund ist eine regelmäßige kritische Prüfung und ggf. auch Anpassung der therapeutischen Optionen sowohl in der Primärbehandlung als auch in der Reservesituation erforderlich. Dieser Artikel gibt eine praxisrelevante Übersicht über den aktuellen Stand der therapeutischen Optionen der Helicobacter pylori Infektion vor dem Hintergrund zunehmender Antibiotikaresistenzen.AbstractRecommendation for the diagnosis and treatment of Helicobacter pylori Infection are defined in recent national and international guidelines. In Germany, proton pump inhibitor-based triple therapy with clarithromycin and metronidazole or amoxicillin is still the standard in first line therapy. However, success rates have decreased substantially during the last years due to increasing antibiotic resistance, particularly in patients from Southern Europe. In addition, antimicrobial resistance rates against the standard antibiotics further increases dramatically after failure of first line therapy deeming the repeated use of these antibiotics basically impossible. Against this background, a critical appraisal and eventaully adaption of therapeutic options both in first line and rescue treatment appears necessary. This paper gives an overview on the current status of therapeutic options and developments in the treatment of H. pylori infection in the light of increasing antibiotic resistance.

Moderne Helicobacter-pylori-Therapien in Zeitenzunehmender Antibiotikaresistenz

ZusammenfassungDie Empfehlungen zu Diagnostik und Therapie der Helicobacter pylori Infektion sind in aktuellen, nationalen und internationalen Leitlinien definiert. In Deutschland gilt die Protonenpumpeninhibitoren(PPI)-basierte Tripeltherapie mit Clarithromycin und Metronidazol oder Amoxicillin als Standard der Primärbehandlung. Allerdings sind die Erfolgsraten dieser Standardtherapien in den letzten Jahren aufgrund zunehmender Antibiotikaresistenzen gesunken, insbesondere bei Patienten aus dem südeuropäischen Raum. Zudem kommt es nach Versagen der Primärtherapie zu einem dramatischen Anstieg der Resistenzraten, die einen erneuten Einsatz der Standardantibiotika praktisch unmöglich macht. Vor diesem Hintergrund ist eine regelmäßige kritische Prüfung und ggf. auch Anpassung der therapeutischen Optionen sowohl in der Primärbehandlung als auch in der Reservesituation erforderlich. Dieser Artikel gibt eine praxisrelevante Übersicht über den aktuellen Stand der therapeutischen Optionen der Helicobacter pylori Infektion vor dem Hintergrund zunehmender Antibiotikaresistenzen.AbstractRecommendation for the diagnosis and treatment of Helicobacter pylori Infection are defined in recent national and international guidelines. In Germany, proton pump inhibitor-based triple therapy with clarithromycin and metronidazole or amoxicillin is still the standard in first line therapy. However, success rates have decreased substantially during the last years due to increasing antibiotic resistance, particularly in patients from Southern Europe. In addition, antimicrobial resistance rates against the standard antibiotics further increases dramatically after failure of first line therapy deeming the repeated use of these antibiotics basically impossible. Against this background, a critical appraisal and eventaully adaption of therapeutic options both in first line and rescue treatment appears necessary. This paper gives an overview on the current status of therapeutic options and developments in the treatment of H. pylori infection in the light of increasing antibiotic resistance.

Effect of 16S rRNA gene mutations on tetracycline resistance in Helicobacter pylori

The triple-base-pair 16S rDNA mutation AGA(926-928)-->TTC mediates high-level tetracycline resistance in Helicobacter pylori. In contrast, single- and double-base-pair mutations mediated only low-level tetracycline resistance and decreased growth rates in the presence of tetracycline, explaining the preference for the TTC mutation in tetracycline-resistant H. pylori isolates.