Mechanism of R factor-mediated chloramphenicol resistance

Mechanism of R factor-mediated chloramphenicol resistance.

Mechanism of Chloramphenicol Resistance in Staphylococcus epidermidis.

The mechanism of chloramphenicol resistance in several multiple-resistant Staphylococcus epidermidis strains has been studied and shown to be due to the presence of the enzyme, chloramphenicol acetyltransferase. As with S. aureus, the inactivating enzyme in S. epidermidis appears to be the product of a structural gene on the chloramphenicol plasmid because resistance and enzyme activity are con...

Gentamicin resistance in Pseudomonas aeruginosa: R-factor-mediated resistance.

By disk diffusion antimicrobial susceptibility testing, 11% of 313 consecutive strains of Pseudomonas aeruginosa, examined during July to October 1973, were resistant to gentamicin (minimal inhibitory concentration 12.5 to >100 mug/ml), and a further 31% were moderately resistant (6.25 to 12.5 mug/ml) to gentamicin at the University of Alberta Hospital in Edmonton, Canada. Of 45 gentamicin-resi...

Plasmid-mediated chloramphenicol resistance in Haemophilus influenzae.

A clinical isolate of Haemophilus influenzae HC234 was found to be resistant to chloramphenicol and tetracycline. It was shown that both resistance markers are tranferable as one unit to other Haemophilus influenzae strains and also to Escherichia coli. Data are presented which indicate that conjugation is the most likely mechanism of resistance transfer. HC234 was shown to carry a single plasm...

R factor-mediated antibiotic resistance in Serratia marcescens.

Nineteen of 39 multiresistant strains of Serratia marcescens isolated from clinical sources transferred antibiotic resistance to Escherichia coli or Klebsiella pneumoniae recipients. Marcesins and/or phage prevented effective resistance transfer to E. coli and attempts to select marcescin-resistant mutants of the E. coli recipient strain were unsuccessful. Transfer of resistance was demonstrate...