OBJECTIVE To determine the prevalence of extended spectrum b-lactamase at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia and to compare the ability of the disc diffusion, double disc potentiation methods and the extended-spectrum b-lactamase E test to detect exended-spectrum b-lactamase among enterobacteriaceae. METHODS This study was undertaken during the time period period...

The first betalactamases were identified in a species of E.coli in 1940 (1). However, the ability of bacteria to produce enzymes that destroy the b-lactam ring was noted even before penicillin was developed. In fact, many of the gram-negative bacteria possess chromosomally mediated blactamases, which help the bacteria find a niche when faced with competition from other bacteria that naturally p...

background and objective: organisms producing ctx-m β-lactamases are emerging as a source of resistance to oxyiminocefalosporins such as ceftriaxone and ceftazidime. however, the laboratory detection of these strains is not well defined. in this study, phenotypic assay for screening of extended-spectrum β-lactamases producing strains and molecular assay for the identification of ctx-m β-lactama...

Ligase chain reaction (LCR) is a recently developed technique that employs a thermostable ligase and allows for the discrimination of DNA sequences differing in only a single base pair. The method has been adapted and applied to differentiation of bla(SHV) genes. We have developed an LCR typing method to characterize point mutations in genes for SHV-derived extended-spectrum beta-lactamases wit...

In this study, 121 Escherichia coli samples isolated from clinical specimens obtained from Pakistan Institute of Medical Science, Islamabad, Pakistan, were analyzed for extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases using disk-diffusion assay and polymerase chain reaction. Of the isolates, 78 and 43 were identified as ESBL and AmpC producers, respectively. The highest resistance (...

The purpose of this study was to simultaneously screen for Extended-spectrum beta-lactamases (ESBL) and AmpC beta-lactamases in gram negative clinical isolates from four tertiary care hospitals and further to compare two detection methods three-dimensional extraction method and AmpC disk test for AmpC beta-lactamases. A total of 272 isolates were screened for ESBL and AmpC beta-lactamase by mod...

Enterobacteriaceae species are important human pathogens while increasing number of antibiotic resistant strains are detected worldwide. The most common antibiotic resistance in Enterobacteriaceae is observed against beta-lactams, fluoroquinolones, aminoglycosides while recently resistance to polymyxins has also appeared. Beta-lactam resistance is mainly conferred by beta-lactamases, capable to...

A clinical Providencia stuartii isolate SM662 was recovered from a patient hospitalized in the intensive care unit at the Military hospital, Tunisia. This isolate was resistant to penicillins, cephalosporins, aminoglycosides and fluoroquinolones. A marked in vitro synergy between ceftazidime or cefotaxime and amoxicillin-clavulanic acid on Mueller-Hinton agar plates suggested the presence of an...

Pseudomonas aeruginosa is an opportunistic pathogen that causes frequently nosocomial infections, currently becoming more difficult to treat due to the various resistance mechanisms and different virulence factors. The purpose of this study was to determine the risk factors independently associated with the development of bacteremia by carbapenem-resistant P. aeruginosa, the frequency of virule...

Background & Aims: Imipenem is a member of Carbapenem with stability against most -lactamases .It is of particular use in the treatment of infections associated with drug resistant gram negative bacteria harboring ESBL and AmpC genes. The aim of this study was to determine the imipenem resistance in gram negative bacteria causing nosocomial infections and the presence of metallo--lactamases (MB...