Broilers and broiler meat products are highly contaminated with extended spectrum beta-lactamase (ESBL) or plasmid-mediated AmpC beta-lactamase producing Escherichia coli and are considered to be a source for human infections. Both horizontal and vertical transmission might play a role in the presence of these strains in broilers. As not much is known about the presence of these strains in the ...

AIM The study aimed at analyzing ESBL- and AmpC-positive Enterobacteriaceae in the gastrointestinal tracts of university hospital inpatients and persons from the Olomouc Region community, and comparing the results with data from 2007. METHODS Bacteria were isolated from rectal swabs inoculated onto the ChromID(TM) ESBL selective medium (bioMérieux). Production of ESBL-type beta-lactamases was...

In members of the family Enterobacteriaceae, ampC, which encodes a beta-lactamase, is regulated by an upstream, divergently transcribed gene, ampR. However, in Pseudomonas aeruginosa, the regulation of ampC is not understood. In this study, we compared the characteristics of a P. aeruginosa ampR mutant, PAOampR, with that of an isogenic ampR+ parent. The ampR mutation greatly altered AmpC produ...

results fifty isolates were positive on the screening test. among them, positive pcr reactions were identified in 35/221 and 12/77 isolates of e. coli and klebsiella spp., respectively, including 16 (34.0%) for cit only, 7 (14.8%) for dha only, and 24 (51.0%) for both dha and cit. no isolate was positive for fox or mox. no proteus organism was positive for ampc genes. conclusions currently, phe...

BACKGROUND Extended-spectrum AmpC (ESAC) β-lactamase enzymes, which are either chromosomally encoded or plasmid encoded, have minor structural changes that broaden their substrate hydrolysis profile. The derepressed AmpC enzyme found once in Enterobacter cloacae CHE was shown to contain a six residue deletion in the H-10 helix in close proximity to the active site. Avibactam is a non-β-lactam i...

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. Candidate isolates were those resistant to cefotaxime and/or ceftazidime, irrespective of addition of clavulani...

Sir, Resistance to third-generation cephalosporins such as ceftazidime and cefotaxime in Acinetobacter baumannii is often due to increased expression of an intrinsic ampC gene. Expression increases when the ISAba1 insertion sequence (IS) is present in the appropriate orientation upstream of the ampC gene, providing an outward-facing promoter that appears to be stronger than the intrinsic promot...

Two major hospitals in Kano, North West Nigeria have recorded increasing resistance of clinical pathogens to broad spectrum β lactams, mediated by extended spectrum β-lactamase (ESβL) and non ESBLs. A study was therefore undertaken to determine the occurrence and prevalence of plasmid and chromosomal mediated AmpC βL and carbapenemase in addition to already known ESBL due to increasing resistan...

Constitutive AmpC hyperproduction is the most frequent mechanism of resistance to the weak AmpC inducers antipseudomonal penicillins and cephalosporins. Previously, we demonstrated that inhibition of the β-N-acetylglucosaminidase NagZ prevents and reverts this mechanism of resistance, which is caused by ampD and/or dacB (PBP4) mutations in Pseudomonas aeruginosa. In this work, we compared NagZ ...