Plasmid-encoded AmpC beta-lactamases: how far have we gone 10 years after the discovery?.
10.3349/ymj.1998.39.6.520
- Author:
Adolf BAUERNFEIND
1
;
Yunsop CHONG
;
Kyungwon LEE
Author Information
1. Max von Pettenkofer Institut fur Hygiene und Medizinische Mikrobiologie der Ludwig-Maximilians-Universitat Munchen, Munchen, Germany. Adolf.Bauernfeind@mvp-bak.med. uni-muenchen.de
- Publication Type:Review
- Keywords:
AmpC beta-lactamases;
plasmid-encoded beta-lactamases;
CMY-1;
CMY-2;
molecular evolution of beta-lactamases
- MeSH:
Microbiology/trends;
Plasmids/genetics*;
Structure-Activity Relationship;
Tissue Distribution;
beta-Lactamases/metabolism;
beta-Lactamases/genetics*
- From:Yonsei Medical Journal
1998;39(6):520-525
- CountryRepublic of Korea
- Language:English
-
Abstract:
The dogma that ampC genes are located exclusively on the chromosome was dominant until about 10 years ago. Since 1989 over 15 different plasmid-encoded AmpC beta-lactamases have been reported from several countries. Most of these enzymes evolved in two clusters. The major cluster includes several enzymes with a high similarity to CMY-2, which is the closest related chromosomal AmpC enzyme of Citrobacter freundii. A second cluster centers around CMY-1. It is less homogeneous and not closely related chromosomal AmpC enzymes. Molecular diversification by amino acid substitutions does not usually translate into a change in the resistance phenotype. At this time, CMY-2 appears to be the most prevalent and widely distributed. Further global increase of prevalence and diversity of plasmidic AmpC beta-lactamases have to be anticipated in the next millenium.
