ACTIVITY OF AUGMENTIN(R) AGAINST 998 STRA INS OF ESCHERICHIA-COLI ISOLATED IN 4 FRENCH HOSPITALS IN 1992

In a multicenter study, we analysed the in vitro activity of 7 betalac tam antibiotics, including 2 combined with clavulanate (amoxicillin an d ticarcillin) against 998 strains of Escherichia coli isolated in 199 2. The datas were analysed by the CERIB multifactorial analysis packag e which yields to homogeneous populations. The percentage of wild-type isolates was 56 %, with a mean Augmentin(R) (AMC) inhibition zone dia meter of 24,7 mm. Strains with a penicillinase phenotype accounted for 39,7 % (n = 397) of the isolates and were broken down as follows : st rains with a low-level penicillinase phenotype (n = 229); 75 % of thes e strains were susceptible to AMC (mean inhibition zone diameter : 21, 7 mm), strains with high-level penicillinase phenotype (n = 114), whic h had a mean AMC inhibition zone diameter of 15.1 mm, strains with an ''inhibitor-resistant'' penicillinase phenotype (n = 54), which were n ormally susceptible to cefalotin and resistant to AMC (TRI or OXA enzy me). Strains with a cephalosporinase hyperproduction phenotype and tho se with combined cephalosporinase hyperproduction and penicillinase ph enotypes represented 1,3 % and 0,8 % of isolates, respectively. Strain s with an extended-spectrum betalactamase (ESBL) phenotype represented 0,3 % of isolates. The proportion of isolates susceptible, intermedia te and resistant to AMC were 70, 23 and 7 % respectively. Susceptibili ty to the ticarcillin/clavulanic acid (TCC) combination was higher (78 .5 %) than for AMC.