AIM To determine the genetic basis and types of beta-lactamase encountered among enterobacterial isolates of wild pets from the animal exhibit. MATERIALS AND METHODS A total of 17 beta-lactamase-producing enterobacteria recovered from fecal samples of wild pet animals were analyzed for a selected beta-lactamase gene by polymerase chain reaction. RESULTS Molecular analysis identified one or ...

Abstract Invited for the cover of this issue are Jesús Ferrando‐Soria, Donatella Armentano, Antonio Leyva‐Pérez, Emilio Pardo and co‐workers at University Valencia, Technical Valencia Calabria. The image depicts crystal structure a novel Zn II biological metal–organic framework that mimics β‐lactamase enzymes. Read full text article 10.1002/chem.202301325 .

background beta-lactam resistance in gram-negative bacteria, especially escherichia coli, is a main clinical problem. it is often caused by the co-production of β-lactamases, particularly extended-spectrum β-lactamases (esbls) and ampc enzymes. it may lead to a problem for diagnosis via recommended phenotypic tests by the clinical and laboratory standards institute (clsi). conversely, β-lactama...

AmpC β-lactamase enzymes confer resistance to a wide variety of β-lactam antibiotics, except carbapenems. AmpC β-lactamase-producing bacteria are known to be causative pathogens of nosocomial infections, which are difficult to be treated. Hence, this study was aimed out to determine the prevalence of AmpC β-lactamase enzyme production among Gram-negative bacteria. A total of 500 multidrug-resis...

Ceftaroline is a new cephalosporin with broad-spectrum activity against Gram-positive and -negative organisms. The prodrug of ceftaroline, ceftaroline fosamil, combined with the β-lactamase inhibitor avibactam (formerly NXL104), was tested against Enterobacteriaceae strains producing Ambler class A, B, C, and D enzymes, including strains producing multiple enzymes, as well as Pseudomonas aerugi...

Mox-1 is a unique plasmid-mediated class C β-lactamase that hydrolyzes penicillins, cephalothin, and the expanded-spectrum cephalosporins cefepime and moxalactam. In order to understand the unique substrate profile of this enzyme, we determined the X-ray crystallographic structure of Mox-1 β-lactamase at a 1.5-Å resolution. The overall structure of Mox-1 β-lactamase resembles that of other AmpC...

carbapenemase producing bacteria frequently possess resistance mechanisms to a wide-range of antibacterial agents, and are associated with high mortality and morbidity rates. some enzymes like extended-spectrum β-lactamase (esbl), new delhi metallo-beta-lactamase-1 (ndm-1), klebsiella pneumoniae carbapenemase (kpc), and oxa-producing enterobacteriaceae are very important in frequently isolated ...

Production of chromosome-encoded β-lactamases confers resistance to β-lactams in many Gram-negative bacteria. Some inducible β-lactamases, especially the class C β-lactamase AmpC in Enterobacteriaceae, share a common regulatory mechanism, the ampR-ampC paradigm. Induction of ampC is intimately linked to peptidoglycan recycling, and the LysR-type transcriptional regulator AmpR plays a central ro...

The hydrolysis of β-lactam antibiotics by β-lactamases is one of the major bacterial defense systems. These enzymes generally hydrolyze a variety of antibiotics including the latest generation of cephalosporins, cephamycins and imipenem. In this paper, the effect of cephalosporins-based antibiotics on the peroxynitrite-mediated nitration of protein tyrosine is described. Although some of the an...

β-Lactam resistance in Acinetobacter baumannii presents one of the greatest challenges to contemporary antimicrobial chemotherapy. Much of this resistance to cephalosporins derives from the expression of the class C β-lactamase enzymes, known as Acinetobacter-derived cephalosporinases (ADCs). Currently, β-lactamase inhibitors are structurally similar to β-lactam substrates and are not effective...