Trends in beta-lactam resistance among Enterobacteriaceae.
beta-Lactam resistance among Enterobacteriaceae is related primarily to the emergence of novel beta-lactamases. The class A extended-spectrum beta-lactamases hydrolyze extended-spectrum beta-lactams and are inhibited by clavulanic acid. These beta-lactamases are divided in two groups: TEM and SHV derivatives and non-TEM and non-SHV extended-spectrum beta-lactamases (CTX-M1, CTX-M2, MEN-1, PER-1, PER-2, TOHO-1, and VEB-1). The plasmid-mediated cephalosporinases (MIR-1, FOX-1, MOX-1, BIL-1, CMY-1, CMY-2, and LAT-1) hydrolyze extended-spectrum cephalosporins and cephamycins and are not inhibited by clavulanic acid. They have been reported in Europe and in the United States. The 15 inhibitor-resistant penicillinases are TEM derivatives (except for SHV-10) and plasmid mediated, and they are mainly from Escherichia coli isolates. The carbapenemases noted among Enterobacteriaceae are either the chromosomally located penicillinases (Sme-1, NmcA, IMI-1) found in rare Enterobacter cloacae or Serratia marcescens isolates or the plasmid-mediated metalloenzyme IMP-1 that is widespread in Japan. The incidence of resistance among Enterobacteriaceae related to the other more common beta-lactam-resistance mechanisms has continued to rise worldwide.
Nordmann
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Hôpitaux de Bicêtre et Antoine Bécleère, Hôpitaux de Paris, Faculté Médecine Paris-Sud, France.
D000818:Animals; D015780:Carbapenems / Q000494:pharmacology; D002510:Cephalosporinase / Q000494:pharmacology; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000201:enzymology; D006801:Humans; D010957:Plasmids; D018440:beta-Lactam Resistance / Q000235:genetics / Q000502:physiology; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism
D015780:Carbapenems; D065093:beta-Lactamase Inhibitors; D002510:Cephalosporinase; D001618:beta-Lactamases