Phenotypic and enzymatic comparative analysis of the novel KPC variant KPC-5 and its evolutionary variants, KPC-2 and KPC-4.

A novel Klebsiella pneumoniae carbapenemase (KPC) variant, designated bla(KPC-5), was discovered in a carbapenem-resistant Pseudomonas aeruginosa clinical isolate from Puerto Rico. Characterization of the upstream region of bla(KPC-5) showed significant differences from the flanking regions of other bla(KPC) variants. Comparison of amino acid sequences with those of other KPC enzymes revealed that KPC-5 was an intermediate between KPC-2 and KPC-4, differing from KPC-2 by a single amino acid substitution (Pro(103)-->Arg), while KPC-4 contained Pro(103)-->Arg plus an additional amino acid change (Val(239)-->Gly).

Carbapenem-resistant Escherichia coli and Klebsiella pneumoniae isolates from Turkey with OXA-48-like carbapenemases and outer membrane protein loss.

Treatment options are limited in infections caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, with carbapenems generally preferred. Disturbingly, however, carbapenem-resistant strains are emerging worldwide. Here we report two clinical isolates, one Escherichia coli and one Klebsiella pneumoniae, each with high-level carbapenem resistance (imipenem minimum inhibitory concentration of 32 microg/mL).

Ertapenem resistance among Klebsiella and Enterobacter submitted in the UK to a reference laboratory.

The emergence of carbapenem resistance in Enterobacteriaceae represents a major public health concern. We investigated ertapenem-resistant clinical isolates of Klebsiella spp. and Enterobacter spp.

Wide geographic spread of diverse acquired AmpC beta-lactamases among Escherichia coli and Klebsiella spp. in the UK and Ireland.

Objectives: To determine the distribution of acquired AmpC beta-lactamases in 173 isolates of Escherichia coli and Klebsiella spp. submitted to the UK's national reference laboratory for antibiotic resistance.

Methods: MICs were determined and interpreted according to BSAC guidelines.

Outbreak of Klebsiella pneumoniae producing a new carbapenem-hydrolyzing class A beta-lactamase, KPC-3, in a New York Medical Center.

From April 2000 to April 2001, 24 patients in intensive care units at Tisch Hospital, New York, N.Y., were infected or colonized by carbapenem-resistant Klebsiella pneumoniae.

Nosocomial outbreak of carbapenem-resistant Pseudomonas aeruginosa with a new bla(IMP) allele, bla(IMP-7).

Pseudomonas aeruginosa isolates from an outbreak in Canada were highly resistant to carbapenems and ceftazidime but not piperacillin. They produced a novel integron-associated metallo-beta-lactamase, designated IMP-7, with 91% identity to IMP-1. bla(IMP-7) was not detected with standard bla(IMP)-specific primers, owing to mismatches in the forward primer.