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 ...

To determine the prevalence and genotype of an extended-spectrum beta-lactamase and new chromosomal AmpC beta-lactamases among clinical isolates of Enterobacter species, we performed antibiotic susceptibility testing, pI determination, induction tests, transconjugation, enterobacterial repetitive consensus (ERIC) PCR, sequencing, and phylogenetic analysis. Among the 51 clinical isolates collect...

There are currently no standardized phenotypic methods for the screening and detection of AmpC enzymes. This study aimed to evaluate different methods to detect AmpC enzymes in Escherichia coli, Klebsiella spp., and Proteus spp., comparing the results from two disk-based methods and an agar dilution method. AmpC activity was determined for 255 clinical isolates by use of a three-dimensional enz...

Background and Objective: A large group of genes associated with extended-spectrum beta-lactamases (ESBL) and AmpC expression is involved in inducing antibiotic resistance in various bacteria. Identifying these genes and assessing their harboring will be crucial in determining the pattern of antibiotic resistance. This study aimed to characterize genetic variants in extended-spectrum beta-lacta...

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...

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...

background: extended spectrum β-lactamases (esbls) and ampc β-lactamases enzyme are major sources of resistance to β-lactam antibiotics especially in enterobacteriaceae such as escherichia coli and klebsiella pneumoniae. increasing frequency of the co-existence of esbls with ampc-β-lactamases in bacteria is a serious threat for treating bacterial infections. conclusions: outbreak of isolates co...

background :   ampc beta lactamases play a significant role in creating resistance to third generation cephalosporins worldwide. they mostly express on chromosome of enterobacteriaceae especially escherichia coli and cause consequential problem in clinical treatment and lead to failure in diagnosis and phenotypic test recommended by clinical and laboratory standards institute.   methods : total...

Cloacal swabs from carcasses of Dutch wild birds obtained in 2010 and 2011 were selectively cultured on media with cefotaxime to screen for the presence of extended-spectrum β-lactamase (ESBL)/AmpC-producing Escherichia coli. Subsequently, all cefotaxime-resistant E. coli isolates were tested by broth microdilution and microarray. The presence of ESBL/AmpC and coexisting plasmid-mediated quinol...