Confers resistance to the different beta-lactams antibiotics (penicillin, cephalosporin and carbapenem) via the hydrolysis of the beta-lactam ring. Does not confer resistance to the polymixin colistin or the fluoroquinolone ciprofloxacin. a beta-lactam + H2O = a substituted beta-amino acid Binds 2 Zn(2+) ions per subunit. Inhibits by captopril, thiorphan, dimercaprol and tiopronin (PubMed:25815530). This enzyme is not susceptible to inactivation by the beta-lactamase-blocking agents clavulanic acid (PubMed:19770275). No activity detected against the monobactam aztreonam. Monomer. Enterobacteriaceae carrying this gene (identified by PCR) have been isolated in Sweden, India, Pakistan, Bangladesh, England, Scotland, Northern Ireland, Australia and the USA. The organisms they were identified in were K.pneumoniae, Enterobacter cloacae, E.coli, Proteus spp, Citrobacter freundii, Morganella morganii, Providencia spp and Klebsille oxytoca. In India most isolates were from community-acquired infections rather than hospital-acquired infections, indicating the gene is widespread in the environment. Belongs to the metallo-beta-lactamase superfamily. Class-B beta-lactamase family. Transfer of a plasmid encoding this gene has been detected between bacteria within a patient (between K.pneumoniae and E.coli). Additionally the gene may be encoded within a transposon.