Different penicillin-binding protein profiles in amoxicillin-resistant Helicobacter pylori

Area of Science:

• Microbiology
• Antibiotic Resistance
• Bacterial Physiology

Background:

• Beta-lactam antibiotics inhibit bacterial peptidoglycan synthesis.
• Amoxicillin-resistant Helicobacter pylori strains lacking beta-lactamase were identified.
• Penicillin-binding proteins (PBPs) are targets for beta-lactams, and their alterations are linked to resistance.

Purpose of the Study:

• To investigate the potential role of altered penicillin-binding proteins (PBPs) in amoxicillin resistance in Helicobacter pylori.
• To compare PBPs between amoxicillin-sensitive and amoxicillin-resistant H. pylori strains.

Main Methods:

• Five amoxicillin-resistant and three sensitive H. pylori strains were analyzed.
• Penicillin-binding proteins (PBPs) were extracted and labeled in vivo with 3H-benzylpenicillin.
• Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and fluorography were used to analyze PBPs.

Main Results:

• Four main PBPs were identified in amoxicillin-sensitive H. pylori strains.
• Amoxicillin-resistant strains exhibited only three of the four main PBPs.
• A specific PBP, designated PBP D (30-32 kD), was absent in resistant strains.

Conclusions:

• The absence or alteration of PBP D is implicated in the amoxicillin-resistant phenotype of beta-lactamase-negative H. pylori.
• PBP D is a potential key factor in amoxicillin resistance in H. pylori.
• Further research into PBP D function is warranted to understand amoxicillin resistance.