In a 3-month period in 1998, 79 consecutive isolates of Enterobacteriaceae
producing an extended-spectrum beta -lactamase (ESBL) were collected. ESBLs
were predominantly TEM derivatives (74 of 79): TEM-24-like (40 isolates),
TEM-3-like (29 isolates), TEM-21 (3 isolates), and TEM-4 and TEM-52 (1 isol
ate each). Four isolates produced SHV derivatives SHV-4 (three isolates) an
d SHV-5 tone isolate), and one strain produced a CTX-M-3 enzyme. The high p
roportion of TEM-24-like-producing Enterobacter aerogenes isolates (36 of 7
9) suggests the occurrence of an epidemic strain in France.