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Resistance to beta-lactam antibiotics Proteus strains
Abstract:
A total of 218 Proteus strains isolated from clinical sources were tested for their susceptibility to three penicillins and two cephalosporins. The ability to beta-lactamase production was examined in 36 of these strains. Proteus mirabilis strains were generally more susceptible to cephalosporins than to penicillins, whereas indole-positive Protei were almost uniformely resistant to cephalosporins as well as to ampicillin and benzylpenicillin but susceptible to carbenicillin. Fairly good correlation was found between the amount and hydrolytic soectryn if beta-lactamase activity and the pattern of resistance to penicillins and cephalosporins in the strains examined. Some observations indicate, however, that the resistance of Proteus bacilli to this group of antibiotics is partly related to permeability barriers in bacterial cell. About 37% of Proteus strains transferred their ampicillin resistance to E. coli K12. Beta-lactamase activities mediated by R plasmids in E. coli cultures were 1.5 to 5 times higher than in respective Proteus donors.
Insights
This study investigated Proteus antibiotic resistance, finding that beta-lactamase production and permeability barriers contribute to resistance. Some strains transferred ampicillin resistance to E. coli, highlighting plasmid-mediated resistance concerns.
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.