MODIFICATION BY ANALGESICS OF THE SUSCEPTIBILITY TO ANTIBIOTICS IN SERRATIA-MARCESCENS

The influence of analgesics at low concentrations on permeability and beta-lactamase expression have been studied ''in vitro''. The effect o f these drugs on major outer membrane proteins and the lipopolysacchar ide was evaluated. Acetylsalicylate and paracetamol induced modificati ons in susceptibility to a large variety of antibiotics when tested at therapeutic concentrations. The results suggested that when analgesic s and antibiotics are administered simultaneously, the interaction bet ween both kinds of drugs can alter the response of microorganisms to a ntibiotics.