The Distribution of ESBL-Producing Enterobacteriaceae: Leicestershire UK Compared to Worldwide| Biomed Grid

Beta-lactam antibiotics are the most frequently used antibiotic worldwide, therefore, bacterial resistance has continued to rise since their introduction due to a permanent selective force for resistance mechanisms [1,2]. Extended-spectrum β-lactamases (ESBLs) are mainly plasmid-encoded enzymes that are able to inactivate a variety of β-lactam antibiotics, including penicillins, 2nd-, 3rd- and 4th-generation cephalosporins and monobactams (e.g. aztreonam) [3] . However, ESBLs are generally susceptible to clavulanic acid (a beta-lactamase inhibitor), sulbactam and tazobactam [4] . There are two distinct classification systems for beta-lactamases: the Ambler molecular classification and the Bush– Jacoby–Medeiros functional classification. The protein homology of the beta-lactamases is used to determine the Ambler scheme of four classes [4] . The four classes can then be differentiated further, classes A, C and D are serine beta-lactamases and class B are metallo-beta-lactamases. In contrast, the Bush–Jacoby–Medeiros functional scheme takes advantage of the functional properties of the beta-lactamase enzymes to classify them, for example, their substrate and inhibitor profiles [4] . The Ambler Scheme shall be used from here onwards.