A novel LEN-derived β-lactamase from Klebsiela pneumoniae

β-lactam antibacterial agents are the most commonly used antibiotics in clinic. The production of β-lactamases is the important mechanism for resistance to β-lactam antibiotics in Gram-negative bacteria. As a result of the generous use of β-lactam antibiotics, mutations of β-lactamases gene in bacteria are frequently developed to oppose against attack from antibiotics, novel β-lactamases were found one after another, among them SHV-28, CTX-M-11 and CTX-M-22 β-lactamases were first found by Chinese researchers.