Philip M Kurpiel1, Nancy D Hanson. 1. Center for Research in Anti-Infectives and Biotechnology, Creighton University School of Medicine, Creighton University, 2500 California Plaza, Omaha, Nebraska 68127, USA.
Abstract
OBJECTIVE: To characterize a unique tandem bla(CMY-2) gene arrangement found in two non-identical clinical strains of Escherichia coli. METHODS: Both plasmid and chromosomal DNA were evaluated using PFGE, restriction digest analysis, plasmid profiling and Southern hybridization. bla(CMY-2) gene expression and gene copy number were evaluated by real-time PCR. Susceptibilities to selected β-lactam antibiotics were determined by agar dilution. RESULTS: A tandem arrangement for bla(CMY-2) was identified in both isolates and was the only arrangement for bla(CMY-2) observed. These isolates had distinct PFGE and plasmid profiles. Each strain exhibited 2-fold higher bla(CMY-2) mRNA expression and up to 8-fold lower β-lactam susceptibility compared with a strain with a single copy of bla(CMY-2). CONCLUSION: This is the first report of IS5 being associated with tandem bla(CMY-2). IS5 has previously been associated with antibiotic resistance through tandem gene amplification. The unique tandem arrangement provides a mechanism for increased bla(CMY-2) expression.
OBJECTIVE: To characterize a unique tandem bla(CMY-2) gene arrangement found in two non-identical clinical strains of Escherichia coli. METHODS: Both plasmid and chromosomal DNA were evaluated using PFGE, restriction digest analysis, plasmid profiling and Southern hybridization. bla(CMY-2) gene expression and gene copy number were evaluated by real-time PCR. Susceptibilities to selected β-lactam antibiotics were determined by agar dilution. RESULTS: A tandem arrangement for bla(CMY-2) was identified in both isolates and was the only arrangement for bla(CMY-2) observed. These isolates had distinct PFGE and plasmid profiles. Each strain exhibited 2-fold higher bla(CMY-2) mRNA expression and up to 8-fold lower β-lactam susceptibility compared with a strain with a single copy of bla(CMY-2). CONCLUSION: This is the first report of IS5 being associated with tandem bla(CMY-2). IS5 has previously been associated with antibiotic resistance through tandem gene amplification. The unique tandem arrangement provides a mechanism for increased bla(CMY-2) expression.
Authors: Norman Hembach; Ferdinand Schmid; Johannes Alexander; Christian Hiller; Eike T Rogall; Thomas Schwartz Journal: Front Microbiol Date: 2017-07-11 Impact factor: 5.640
Authors: Matej Medvecky; Costas C Papagiannitsis; Ethan R Wyrsch; Ibrahim Bitar; Max L Cummins; Steven P Djordjevic; Monika Dolejska Journal: mSphere Date: 2022-07-05 Impact factor: 5.029