SHV-27, a novel cefotaxime-hydrolysing beta-lactamase, identified in Klebsiella pneumoniae isolates from a Brazilian hospital

From a collection of cefotaxime-resistant Klebsiella pneumoniae isolated fr om neonatal blood culture specimens in a maternity hospital in Aracaju, Bra zil, two isolates (strains KPBRZ-842 and -843, indistinguishable by pulsed- field gel electrophoresis) were found to produce beta -lactamases with isoe lectric points (pl) of 5.4 and 8.2, respectively. Using a gel overlay metho d, cefotaxime hydrolysis was shown to be associated with the pI 8.2 protein . Nucleotide sequencing of the gene encoding the pI 8.2 beta -lactamase rev ealed a bla(SHV-ESBL)-type gene differing from the gene encoding SHV-1 by t hree silent point mutations, and a fourth that resulted in an amino acid su bstitution, aspartate for glycine, at position 156. This novel SHV-type ext ended-spectrum beta -lactamase is designated SHV-27.