Antibiotic susceptibility and mechanisms of beta-lactam resistance in 1310strains of Pseudomonas aeruginosa: a French multicentre study (1996)

A total of 1310 consecutive strains of Pseudomonas aeruginosa were collecte d in 11 French hospitals in 1996. The percentages of susceptible isolates m easured by the agar dilution method were: ticarcillin (53%), piperacillin ( 69%) (MIC less than or equal to 16 mg/L), ceftazidime (77%), cefepime (55%) , cefpirome (40%), aztreonam (57.5%), imipenem (81.5%) (MIC less than or eq ual to 4 mg/L), amikacin (64.5%) (MIC less than or equal to 8 mg/L) and cip rofloxacin (58%) (MIC less than or equal to 1 mg/L), Resistance to beta-lac tams was linked to the production of transferable beta-lactamases (30%), ov erproduction of cephalosporinase (29%) and to non-enzymic mechanisms (38%).