Resistance to beta-lactam antibiotics Proteus strains

Area of Science:

• Microbiology
• Bacterial genetics
• Antimicrobial resistance

Background:

• Proteus species are significant opportunistic pathogens.
• Understanding their antibiotic susceptibility is crucial for effective treatment.
• Beta-lactam antibiotics are commonly used but face resistance challenges.

Purpose of the Study:

• To assess the susceptibility of clinical Proteus isolates to penicillins and cephalosporins.
• To investigate the role of beta-lactamase production in antibiotic resistance.
• To explore mechanisms of resistance, including permeability barriers and plasmid transfer.

Main Methods:

• Testing susceptibility of 218 Proteus strains to penicillins and cephalosporins.
• Examining beta-lactamase production in 36 strains.
• Plasmid transfer experiments using E. coli K12 as a recipient.

Main Results:

• Proteus mirabilis showed higher susceptibility to cephalosporins than penicillins.
• Indole-positive Protei were resistant to most penicillins and cephalosporins, except carbenicillin.
• A correlation was observed between beta-lactamase activity and resistance patterns.
• 37% of strains transferred ampicillin resistance to E. coli.
• Plasmid-mediated beta-lactamase activity was higher in E. coli than in Proteus donors.

Conclusions:

• Antibiotic resistance in Proteus involves beta-lactamase production and potentially permeability issues.
• Plasmid-mediated resistance is a significant factor, with efficient transfer observed.
• Resistance patterns differ between Proteus species and indole-positive strains.