Antibiotic susceptibility patterns surveillance and clinical distribution of Enterobacteriaceae.

3700 strains of Enterobacteriaceae clinical isolates were tested by automated devices for susceptibility to several antimicrobial agents widely used in clinical practice. Amikacin demonstrated the greatest in vitro activity whereas ampicillin and mezlocillin were the least active. Finally gentamicin and nalidixic acid had a similar activity to recently introduced cephalosporins. The bacterial species widely isolated were grouped in three clusters according to the clinical body site of isolates: several discrepancies emerged from the study of antibiotic susceptibilities of strains obtained from different body site sources. Source could be correlated with bacterial pattern of resistance.