As a part of a nationwide study in Spain, 15 clinical isolates of Acinetobacter genomic species 3 (AG3) were analyzed. The main objective of the study was to characterize the ampC genes from these isolates and to determine their involvement in beta-lactam resistance in AG3. The 15 AG3 isolates showed different profiles of resistance to ampicillin (range of MICs, 12 to >256 microg/ml). Nucleotid...

AIM the goal of this study is to understand the phenotype characteristic of beta-lactamase enzymes producing Enterobacteriaceae, such as ESBL, AmpC, and carbapenemase. METHODS three different methods are performed to confirm those phenotypic characteristics, namely double disk diffusion method to confirm ESBL, AmpC disk test (cefoxitin-based) to confirm AmpC, and modified Hodge test to confir...

BACKGROUND Pseudomonas aeruginosa is one of the most common causes of nosocomial infections. Resistance of P. aeruginosa to β-lactam antibiotics may be the result of acquired resistance through mutation and over production of various antibiotic inactivating enzymes. This research aimed to determine the prevalence of extended-spectrum β-lactamases (ESBL) and metallo β-lactamase (MBL) production ...

The characterization of AmpC-type beta-lactamases was performed in a collection of 32 clinical Pseudomonas aeruginosa isolates with intermediate susceptibility or resistance to imipenem and ceftazidime. Twenty-one out of those 32 isolates overexpressed AmpC beta-lactamase, and the MICs of ceftazidime and imipenem were reduced after cloxacillin addition. Cloning and sequencing identified 10 AmpC...

background: ampc type β-lactamases are commonly isolated from extended-spectrum cephalosporin-resistant gram-negative bacteria. also, resistance appeared in bacterial species not naturally producing ampc enzymes. therefore, a standard test for the detection of the plasmid-mediated ampc enzyme and new breakpoints for extended spectrum cephalosporins are urgently necessary. objectives: to detect ...

Environmental microorganisms represent the most relevant reservoir of resistance to antibiotics in the community, and this is due in part to the undue exposure of these organisms to antimicrobial agents. AmpC β-lactamases are clinically important cephalosporinases encoded on the chromosomes of bacteria in the Enterobacteriaceae family and some non-enteric bacteria including Pseudomonas aerugino...

Introduction Extended-spectrum β-lactamases (ESBLs), including the AmpC type, are important mechanisms of resistance among Klebsiella pneumoniae and Escherichia coli isolates. Objective The aim of the study was to investigate the occurrence of AmpC-type β-lactamase producers isolated from two hospitals in Tripoli, Libya. Methods All clinical isolates (76 K. pneumoniae and 75 E. coli) collec...

We investigated the occurrence and genetic basis of AmpC β-lactamase (AmpC)-mediated antibiotic resistance, by examining Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis isolates at a university hospital, from 2007 to 2010. The ampC genes were detected by multiplex AmpC PCR, and AmpC-positive strains were subjected to DNA sequencing. Extended-spectrum β-lactamase (ESBL) production...

AIM To characterize AmpC-beta lactamases among Enterobacteriaceae isolates from clinical samples at Mbarara Regional Referral Hospital. STUDY DESIGN Laboratory-based descriptive cross-sectional study. PLACE AND DURATION OF STUDY Microbiology Department, Mbarara Regional Referral Hospital and MBN clinical Laboratories, between May to September 2013. METHODOLOGY This study included 293 Ente...

b a ckground: quorum-sensing systems regulate expression of several virulence factors in pseudomonas aeruginosa . this study investigated the relation between expression of the las quorum-sensing system and expression of mexy and ampc in35 clinical isolates of p. aeruginosa . m e t hods: antibiotic susceptibility was determined by the disc diffusion method according to the clinical and laborato...