R-factor mediated trimethoprim resistance: result of two three-month clinical surveys.

R-factor mediated trimethoprim resistance: result of two three-month clinical surveys.

All urinary tract isolates were monitored in the Whittington Hospital, London for trimethoprim resistance over a three-month period in 1975; this survey was repeated 18 months later in 1977. In the later survey the incidence of trimethoprim resistance had increased significantly, and the proportion of strains carrying R-factors conferring trimethoprim resistance had nearly doubled. The pattern ...

Increasing importance of plasmid-mediated trimethoprim resistance in enterobacteria: two six-month clinical surveys.

All clinical isolates of enterobacteria received at the laboratory were monitored for trimethoprim resistance over six months in 1978. The survey was repeated in 1979 and the incidence of trimethoprim resistance showed a slight decrease, but the proportion of resistant strains owing their trimethoprim resistance to transferable R plasmids had almost trebled. There was also a large increase in t...

Mechanism of R factor-mediated chloramphenicol resistance.

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...

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...