OBJECTIVES The objective of this study was to determine the occurrence of chromosomal and plasmid-mediated β-lactamases (AmpC) genes in a collection of Malaysian isolates of Enterobacter species. Several phenotypic tests for detection of AmpC production of Enterobacter spp. were evaluated and the agreements between tests were determined. METHODS Antimicrobial susceptibility profiles for 117 E...

An Escherichia coli strain exhibiting decreased susceptibility to carbapenems was isolated from a hospitalized patient in Greece. The strain carried a self-transferable plasmid coding for metallo-beta-lactamase VIM-1. bla(VIM-1), along with aacA7, dhfrI, and aadA, was included as a gene cassette in a novel class 1 integron. A Citrobacter freundii ampC-derived gene, not associated with the integ...

Selective pressures generated by the indiscriminate use of beta-lactam antibiotics have resulted in increased bacterial resistance across all beta-lactams classes. In particular, the use of third-generation cephalosporins has been associated with the emergence of extended-spectrum beta-lactamase-producing and AmpC beta-lactamase-producing Enterobacteriaceae and vancomycin-resistant enterococci....

background  and  objectives: pseudomonas  aeruginosa is responsible for devastating nosocomial infections among severely burn patients. class c of cephalosporinase (ampc-β-lactamases) is important cause of multiple β-lactam resistance in p. aeruginosa . the aim of this study was to detect the ampc-β-lactamases producing isolates among carbapenem resistant p.  aeruginosa isolated from burn patie...

LK-157 is a novel tricyclic carbapenem with potent activity against class A and class C beta-lactamases. When tested against the purified TEM-1 and SHV-1 enzymes, LK-157 exhibited 50% inhibitory concentrations (IC(50)s) in the ranges of the clavulanic acid and tazobactam IC(50)s (55 nM and 151 nM, respectively). Moreover, LK-157 significantly inhibited AmpC beta-lactamase (IC(50), 62 nM), as LK...

The phenotype of Klebsiella pneumoniae HEL-1 indicates a plasmidic cephamycinase gene (blaCMY-2). Its sequence shows one open reading frame coding for a protein of 381 amino acids. CMY-2 is classified as class C beta-lactamase that is closely related to the plasmidic enzymes BIL-1 and LAT-1 and the chromosomal AmpC of Citrobacter freundii. The blaCMY-2 gene possibly was translocated onto a plas...

In a UK survey of the occurrence of extended spectrum beta-lactamases, 96 hospitals submitted a total of 3951 non-selected, non-duplicate isolates of Enterobacteriaceae from 100 patients in each hospital, 206 of these cultures being mixed and, therefore, discarded. These isolates were initially screened for strains likely to produce extended-spectrum beta-lactamases (ESBLs) by MIC determination...

Aim: This was a prospective, multicenter, single-arm intervention, against historical controls, study of the efficacy vonoprazan-based 7-day triple regimen with metronidazole (VPZ-AMPC-MNZ) as first-line therapy for eradicating clarithromycin-resistant Helicobacter pylori (H. pylori). Methods: We enrolled 35 patients positive H. pylori, assessed by culture, without history eradication. These we...

Induction of ampC β-lactamase expression can often compromise antibiotic treatment and is triggered by several β-lactams (such as cefoxitin and imipenem) and by the β-lactamase inhibitor clavulanic acid. The novel β-lactamase inhibitor avibactam (NXL104) is a potent inhibitor of both class A and class C enzymes. The potential of avibactam for induction of ampC expression in Enterobacter cloacae...