Prevalence of beta-lactamases among 1,072 clinical strains of Proteus mirabilis: a 2-year survey in a French hospital.
beta-Lactam resistance was studied in 1,072 consecutive P. mirabilis clinical strains isolated at the Clermont-Ferrand teaching hospital between April 1996 and March 1998. The frequency of amoxicillin resistance was 48.5%. Among the 520 amoxicillin-resistant isolates, three resistance phenotypes were detected: penicillinase (407 strains [78.3%]), extended-spectrum beta-lactamase (74 strains [14. 2%]), and inhibitor resistance (39 strains [7.5%]). The penicillinase phenotype isolates were divided into three groups according to the level of resistance to beta-lactams, which was shown to be related to the strength of the promoter. The characterization of the different beta-lactamases showed that amoxicillin resistance in P. mirabilis was almost always (97%) associated with TEM or TEM-derived beta-lactamases, most of which evolved via TEM-2.
Chanal
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C
Laboratoire de Bactériologie, Faculté de Médecine, 63001 Clermont-Ferrand Cedex, France. CHANAL@u-clermont1.fr
Bonnet
R
R
De Champs
C
C
Sirot
D
D
Labia
R
R
Sirot
J
J
D000658:Amoxicillin / Q000494:pharmacology; D005602:France; D005787:Gene Frequency; D006784:Hospitals, Teaching; D006801:Humans; D008826:Microbial Sensitivity Tests; D010403:Penicillin Resistance / Q000235:genetics; D010405:Penicillinase / Q000378:metabolism; D010406:Penicillins / Q000494:pharmacology; D010641:Phenotype; D011513:Proteus mirabilis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D018440:beta-Lactam Resistance; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000032:analysis* / Q000235:genetics
D010406:Penicillins; D065093:beta-Lactamase Inhibitors; D000658:Amoxicillin; D010405:Penicillinase; D001618:beta-Lactamases