The goal of this study was to determine if the interpretations of extended-spectrum and advanced-spectrum cephalosporins (ESCs and ASCs, respectively) for isolates of Enterobacteriaceae would be impacted by the results of aminophenylboronic acid (APBA) testing. Fifty-three isolates of Escherichia coli, 21 Klebsiella species, and 6 Proteus species that were resistant to at least one ESC were tes...

Here we describe the presence of two very similar but unusual variants of AmpC cephalosporinase in each Cronobacter sakazakii and C. malonaticus isolates conferring resistance exclusively to first generation cephalosporins. During a survey on the antibiotic resistance patterns of C. sakazakii and C. malonaticus strains isolated from a milk powder production facility, originally two different ph...

BACKGROUND We investigated the prevalence of plasmid-mediated quinolone resistance and its association with extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase in Enterobacteriaceae. METHODS A total of 347 non-duplicated isolates of Enterobacteriaceae were collected between August and October 2006 from 2 hospitals. Qnr determinant screening was conducted using PCR amplification, a...

This work describes a simple and practical double synergy differential test (DSDT) that couples the detection of ESBLs and AmpC-type enzymes by means of a combo-disk approach using cefotaxime and ceftazidime as indicator substrates, and clavulanate and boronic acid as enzyme inhibitors. The DSDT was tested with a collection of 118 Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis st...

Detection of AmpC-mediated resistance in Gram negative organisms poses a problem due to misleading results in phenotypic tests. There are no recommended guidelines for detection of this resistance mechanism and there is a need to address this issue as much as the detection of extended spectrum beta lactamases (ESBLs) since both may co-exist and mask each other. Several methods have been used to...

Beta-lactamases hydrolyze beta-lactam antibiotics and are the leading cause of bacterial resistance to these drugs. Although beta-lactamases have been extensively studied, structures of the substrate-enzyme and product-enzyme complexes have proven elusive. Here, the structure of a mutant AmpC in complex with the beta-lactam cephalothin in its substrate and product forms was determined by X-ray ...

Nghiên cứu đã thực hiện tại bệnh viện đa khoa thành phố Cần Thơ và tiến hành mẫu xét nghiệm MEDLATEC thơ từ tháng 1 năm 2022 đến 12 2022. Thiết kế nghiên cứu: mô tả cắt ngang, chọn thuận tiện, số chủng thu thập được là 262 mẫu. Kết quả: các Klebsiella pneumoniae có AmpC (+)/ESBL (-) tỷ lệ kháng cao nhất trên nhóm beta-lactam cả sinh phối họp chất ức chế beta-lactam, Ampicillin Amox- Clavulanate...

AmpC beta lactamase producing Gram-negative bacteria have emerged worldwide. It is important to distinguish plasmid mediated AmpC β lactamases from chromosomally mediated enzymes for surveillance, epidemiology and hospital infection control as plasmid mediated genes can spread to other organisms. Occurrence of blaCMY-1 AmpC β-lactamase, a plasmid mediated cephamycinase was studied in 100 consec...

Introduction: Proteus mirabilis is an important pathogen isolated from both community-acquired and health-care associated infections. Acquired AmpC-type beta-lactamases represent an important mechanism of resistance to extended-spectrum cephalosporins and are emerging in several European countries. The objective of this work was to know the prevalence of acquired AmpC beta-lactamase producing P...

Two-hundred consecutive, single patient isolates of Enterobacter spp., Serratia spp., Citrobacter spp., and Pseudomonas aeruginosa were evaluated for AmpC production using a variety of inducer-substrate antibiotic combinations in a disk approximation format. The combinations examined included cefoxitin-piperacillin, imipenem-cefotaxime, imipenem-ceftazidime, imipenem-piperacillin-tazobactam, an...