Effect of pH on the activity of erythromycin against 500 isolates of gram-negative bacilli.

V. Lorian, L. D. Sabath

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


Erythromycin was found to be a more effective inhibitor of gram-negative bacilli in alkaline medium than in neutral or acid medium. A definite effect was noted with all of 500 recent clinical isolates of Escherichia coli, Klebsiella-Enterobacter, Pseudomonas aeruginosa, and Proteus mirabilis studied, but it was most striking with E. coli. At pH 8.5 all strains, except for 14% of those of P. mirabilis, were inhibited by concentrations of erythromycin readily achieved in urine with common therapeutic doses.
Original languageUndefined/Unknown
Pages (from-to)754-756
Number of pages3
JournalApplied Microbiology
Issue number5
StatePublished - 1970


  • Bacteriuria/dt [Drug Therapy]
  • Drug Resistance, Microbial
  • Enterobacteriaceae/de [Drug Effects]
  • Erythromycin/ad [Administration & Dosage]
  • Erythromycin/pd [Pharmacology]
  • Humans
  • Hydrogen-Ion Concentration
  • Microbial Sensitivity Tests
  • Pseudomonas aeruginosa/de [Drug Effects]

Cite this