A family of dinuclear iron cluster-containing oxygenases that catalyze β-hydroxylation tailoring reactions in natural product biosynthesis by nonribosomal peptide synthetase (NRPS) systems was recently described [Makris, T. M., Chakrabarti, M., Münck, E., and Lipscomb, J. D. (2010) Proc. Natl. Acad. Sci. U.S.A. 107, 15391-15396]. Here, the 2.17 Å X-ray crystal structure of the archetypal enzyme...

To the Editor: The New Delhi metallo-β-lactamase (NDM-1) was fi rst characterized in 2009 from Kleb-siella pneumoniae and Escherichia coli isolated from a patient in Sweden who had received medical care in New Delhi, India (1). Further studies have shown broad dissemination of this β-lactamase gene (bla NDM-1) in India, Pakistan, Bangladesh, and the United Kingdom (2). Additional isolates have ...

BACKGROUND AND OBJECTIVES The rapid emergence and dissemination of carbapenemase-producing Klebsiella pneumoniae strains and other members of the Enterobacteriaceae poses a considerable threat to the care of hospitalized patients and to public health. The aim of this study was to determine the frequency of metallo-β-lactamases (MBL) and VIM-1 gene in multidrug-resistant strains of K. pneumoniae...

Background and Objectives New Delhi metallo-ß-lactamase (NDM) is a newly emerging metallo-ß-lactamases, which can destroy all β-lactams including carbapenems. Therefore, this study aimed at evaluating New Delhi metallo-ß-lactamase-1-production in clinical isolates of Klebsiella pneumoniae in Kashan, Iran. Materials and Methods In a cross-sectional study, 181 K. pneumoniae isolates were collec...

The widespread use of tracheal intubation and mechanical ventilation to support the critically ill patients increases the risk of development of tracheobronchitis and bronchopneumonia. This cross-sectional study was conducted with an aim to isolate and identify bacterial pathogens from tracheal aspirates producing extended-spectrum β -lactamase (ESBL), AmpC β -lactamase, and metallo- β -lactama...

The veterinary cephalosporin drug ceftiofur is rapidly degraded in the bovine intestinal tract. A cylinder-plate assay was used to detect microbiologically active ceftiofur, and high-performance liquid chromatography-mass spectrometry analysis was used to quantify the amount of ceftiofur remaining after incubation with bovine intestinal anaerobic bacteria, which were isolated from colon content...

Metallo-beta-lactamases are zinc enzymes able to hydrolyze the four-membered ring of beta-lactam antibiotics, representing one of the latest generations of beta-lactamases. These enzymes belong to the zinc metallo-hydrolase family of the beta-lactamase fold. Enzymes belonging to this family have a bimetallic active site whose structure varies among different members by point substitutions of th...

To the Editor: Extended-spectrum β-lactamase–producing Enter-obacteriaceae strains have emerged as a major public health problem throughout the world, particularly in India and Pakistan. The widespread use of carbapenems, the only agents reliably active against these bacteria, resulted in the emergence of a new resistance mechanism. New Delhi metallo-β-lactamase (NDM-1) was fi rst detected in a...