Background: Community-acquired infections by multidrug-resistant (MDR), extended-spectrum β-lactamase (ESBL) producing Klebsiella species (Klebsiella spp.) is of major concern worldwide. Antibiotic resistance, production of extended-spectrum β-lactamases (ESBLs), and carbapenemases, as well as the presence of classes 1, 2, and 3 integrons in outpatient isolates of Klebsiella collected from Yazd...

Escherichia coli (328 isolates), Klebsiella pneumoniae (296), Klebsiella oxytoca (44), and Proteus mirabilis (33) isolates collected during 2012 from the nine U.S. census regions and displaying extended-spectrum-β-lactamase (ESBL) phenotypes were evaluated for the presence of β-lactamase genes, and antimicrobial susceptibility profiles were analyzed. The highest ESBL rates were noted for K. pne...

Background & objective: Beta-lactam antibiotics resistance specifically Imipenem and Meropenem, the last choices of treatment, causes fatal events in patients with P.aeruginosa infection. The aim of this study was to detect the VIM and IMP of metallo-beta-lactamase genes in 103 isolates of P. aeruginosa in two Iranian hospitals. <strong...

background and objectives: β-lactamase production is the predominant mechanism for resistance to β-lactams in enterobacteriaceae. the producing isolates are often multidrug resistant and are major hosts for extended spectrum β-lactamases. this study was designed to determine the prevalence of extended-spectrum β-lactamase producing isolates of escherichia coli and klebsiella pneumoniae and thei...

Limited information is available regarding AmpC β-lactamase (ABL)-producing Enterobacteriaceae compared to extended-spectrum β-lactamase-producing enterobacteria. Since ABL-producing organisms are often resistant to multiple antimicrobial agents, therapeutic options against these pathogens are limited. Among 230 clinical Enterobacteriaceae isolates, 64 (27.8%) were found to produce ABL in our s...

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...

Background: β-lactamase mediated resistance is the most common mechanism which renders the β-lactam antibiotics ineffective against bacteria including Escherichia coli. The development of resistance has led to the widespread empirical use of higher generation cephalosporins and it is likely that the third generation cephalosporins are also losing their efficacy by the same mechanism. The presen...

Increasing frequency of infections caused by antibiotic resistant Escherichia coli strains producing extended-spectrum β-lactamase (ESBL) needs to be addressed by continuous surveillance and accurate detection of specific ESBLs genes for more effective treatment. A total of 71 β-lactam drug resistant isolates (26 phenotypically ESBL-producing and 45 non-ESBLproducing) were observed to carry app...

Pseudomonas aeruginosa is one of the most important causes of nosocomial infection and it has increasing resistance to many antimicrobial agents. β-lactamase production is the most frequent mechanism for β-lactam resistance in P. aeruginosa. We evaluated the prevalence of β-lactamase genes in P. aeruginosa for classes A, C, and D by polymerase chain reaction, and investigated clonal diversity b...