Frequency of inhibitor-resistant TEM beta-lactamases in Escherichia coli isolates from urinary tract infections in France.
Over a six-month period in 1993, 2972 non-duplicated isolates of Escherichia coli causing urinary tract infections were collected in a French teaching hospital (n = 785) and in three private laboratories (n = 2187). The resistance rate to amoxycillin-clavulanate combination (MIC > 16 mg/l) was 25.0% in the hospital isolates and 10.0% in the community isolates. Respectively, 27.5% and 45.0% of hospital and community isolates resistant to amoxycillin-clavulanate exhibited an unusual beta-lactam resistance pattern, suggesting inhibitor-resistant TEM (IRT) beta-lactamase production. These isolates were highly resistant to amoxycillin-clavulanate (MIC90 > 1024 mg/L), but were susceptible to cephalosporins (MIC < 32 mg/L). Enzyme extracts of these IRT-producing strains focused at pI 5.2 (n = 100) or 5.4 (n = 53). DNA-DNA hybridization confirmed that the beta-lactamases involved in this resistance mechanism were TEM-1 derived and contained variations in the altered positions described in IRT enzymes. This study shows a total frequency of 4.9% of IRT-producing isolates among E. coli isolated from urine specimens.
Henquell
C
C
Laboratoire de Bactériologie, Faculté de Médecine, Clermont-Ferrand, France.
Sirot
D
D
Chanal
C
C
De Champs
C
C
Chatron
P
P
Lafeuille
B
B
Texier
P
P
Sirot
J
J
Cluzel
R
R
D000658:Amoxicillin / Q000494:pharmacology; D019980:Amoxicillin-Potassium Clavulanate Combination; D002969:Clavulanic Acids / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology*; D014552:Urinary Tract Infections / Q000382:microbiology*; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases
D002969:Clavulanic Acids; D065093:beta-Lactamase Inhibitors; D019980:Amoxicillin-Potassium Clavulanate Combination; D000658:Amoxicillin; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1