b ackg r oun d : pseudomonas aeruginosa is one of the most important oppor- tunistic pathogens responsible for various types of infections. children suffer significant morbidity and mortality due to nosocomial infections. the aim of this study was to investigate the presence of class1 integron, blabel, blaper, blakpc, blavim, blaimp and blaoxagroup-1  genes among p. aeruginosa isolates at child...

The main objective is to study the genotypic and characterization of plasmid deoxyribonucleic acid content resistant isolates in Erbil city. A total 39 Acinetobacter baumannii were isolated from 102 diabetic foot ulcer patients, whose ages ranged 37 88 y, attending various medical wards hospitals city, Iraq, between May 2020 March 2021. Isolates tested for presence extended-spectrum beta-lactam...

Production of beta-lactamases, the enzymes that degrade beta-lactam antibiotics, is the most widespread and threatening mechanism of antibiotic resistance. In the past, extensive research has focused on the structure, function, and ecology of beta-lactamases while limited efforts were placed on the regulatory mechanisms of beta-lactamases. Recently, increasing evidence demonstrate a direct link...

INTRODUCTION The rising prevalence of extended-spectrum beta-lactamases in gram-negative bacillary pathogens is an important clinical problem resulting from the extensive use of broad-spectrum antibiotics. The emergence of the extended-spectrum beta-lactamases increases the possibility that traditional, empiric antimicrobial regimens may be ineffective. The aims of this study are: to determine ...

beta-Lactamases represent the major resistance mechanism of gram-negative bacteria against beta-lactam antibiotics. The amino acid sequences of these proteins vary widely, but all are located in the periplasm of bacteria. In this study, we investigated the translocation mechanism of representative beta-lactamases in an Escherichia coli model. N-terminal signal sequence analyses, antibiotic acti...

Objective: In addition to assessing the phenotypic development of biofilms and beta-lactamases, in current study, Pseudomonas aeruginosa isolates from intensive care units (ICU) patients with prevalent drug resistance are being evaluated. Methods: Standard CLSI recommended protocols were utilized detect beta-lactamases such as extended-spectrum β-lactamases (ESBL), metallo beta-lactamase (MBL),...

BACKGROUND Despite increasing importance of Acinetobacter baumannii in nosocomial infections and rapid development of multi-antimicrobial resistance in this strain, the resistance mechanisms of beta-lactam antimicrobials in A. baumannii were not clearly defined. In order to observe the resistance mechanisms against beta-lactams and carbapenem, we characterized the production of beta-lactamases ...

The in vivo activity and source of beta-lactamase in sputum samples from 43 patients with cystic fibrosis (CF) during a 2-week antipseudomonal treatment were studied. A colorimetric method, based on the conversion of nitrocefin, was used for quantitation of the sputum beta-lactamase activity. beta-Lactamases in sputum were characterized by isoelectric focusing and inhibition profile and were co...

Genes for two group 1 beta-lactamases, SRT-1 and SST-1, were sequenced. These beta-lactamases were produced by clinical isolates of Serratia marcescens, isolates GN16694 and GN19450, respectively. The resulting enzymes were 96% identical. SRT-1 hydrolyzed oxyimino cephalosporins, but SST-1 hardly hydrolyzed them. At residue 213 in the third motif, which is conserved among group 1 beta-lactamase...

A 1536-nucleotide-long sequence that carries the ampC beta-lactamase gene of the Escherichia coli K-12 chromosome has been determined. This gene codes for a protein of 377 amino acids, of which the first 19 amino acids form a signal peptide. The molecular weight of the mature enzyme was determined to be 39,600. The ampC beta-lactamase with a substrate specificity for cephalosporins showed no si...