Detection of plasmid-mediated class C beta-lactamases.
Plasmid-mediated class C beta-lactamases are reported from Enterobacteriaceae with increasing frequency. They likely originate from chromosomal AmpC of certain Gram-negative bacterial species and subsequently are mobilized onto transmissible plasmids. There are reports of unfavorable clinical outcomes in patients infected with these organisms and treated with broad-spectrum cephalosporins. However, unlike class A extended-spectrum beta-lactamases (ESBLs), no screening and confirmatory tests have been uniformly established for strains that produce class C beta-lactamases. Reduced susceptibility to cefoxitin is a sensitive but not specific indicator of class C beta-lactamase production. Simple confirmatory tests including tests using boronic acid compounds as specific class C beta-lactamase inhibitors have recently been developed. Their utilization will enable clinical microbiology laboratories to report those strains producing plasmid-mediated class C beta-lactamases as being resistant to all broad-spectrum cephalosporins, thus allowing physicians to prescribe appropriate antimicrobial therapy.
Doi
Yohei
Y
Division of Infectious Diseases, University of Pittsburgh Medical Center, Falk Medical Building Suite 3A, 3601 Fifth Avenue, Pittsburgh, PA 15213, USA.
Paterson
David L
DL
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology*; D004755:Enterobacteriaceae / Q000187:drug effects / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D016133:Polymerase Chain Reaction; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000032:analysis* / Q000235:genetics
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D004791:Enzyme Inhibitors; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases