BACKGROUND Nosocomial infections caused by Pseudomonas aeruginosa presenting resistance to beta-lactam drugs are one of the most challenging targets for antimicrobial therapy, leading to substantial increase in mortality rates in hospitals worldwide. In this context, P. aeruginosa harboring acquired mechanisms of resistance, such as production of metallo-beta-lactamase (MBLs) and extended-spect...

The prevalence and molecular types of extended-spectrum beta-lactamases (ESBLs) were determined during a 1-year period in unselected clinical nonduplicate isolates of Escherichia coli (n = 1,738), Klebsiella pneumoniae (n = 436), and Klebsiella oxytoca (n = 208), cultured at the University Medical Centre Nijmegen, The Netherlands. Isolates identified as ESBL producer by the Phoenix automated sy...

OBJECTIVES To investigate the occurrence and the diversity of Ambler class A ESBLs among Enterobacteriaceae from different Portuguese clinical settings over a 2 year period (2002-04). METHODS One hundred and nine extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae isolates from five geographically distant health institutions in Portugal were studied. ESBLs were characterized ...

BACKGROUND The beta-lactamase landscape is changing radically, with CTX-M types now the most prevalent extended-spectrum beta-lactamases (ESBLs) worldwide, except maybe in the USA. In addition, there are growing numbers of Enterobacteriaceae with KPC and metallo-carbapenemases. We examined whether combinations of oxyimino-cephalosporins with NXL104, a novel non-beta-lactam beta-lactamase inhibi...

BACKGROUND Resistance to beta-lactams in Haemophilus influenzae is mostly due to the presence of TEM beta-lactamases. beta-Lactamase-negative ampicillin resistance (BLNAR) also occurs as a result of PBP3 modifications. BLNAR strains are particularly common in Japan and France, and strains with combined mechanisms of altered PBP3 and beta-lactamase (BLPACR) are emerging. Although the prevalence ...

Extended-spectrum beta-lactamases (ESBLs), e.g., ESBLs of the TEM or SHV type, compromise the efficacies of expanded-spectrum cephalosporins. An SHV non-ESBL that hydrolyzes only narrow-spectrum cephalosporins can be converted into an SHV ESBL through substitutions at three amino acid positions, 179, 238, or 238--240. In order to improve detection of SHV ESBLs, a novel method, based on real-tim...

AIM During 2010-2011, six Providencia spp. (five Providencia stuartii and one Providencia rettgeri) urine isolates with unusual resistance phenotype were collected from various hospital units at the University Hospital Split in Croatia. The aim of the study was to analyze the mechanisms of resistance to expanded-spectrum cephalosporins. METHODS The antimicrobial susceptibility to a wide range...

BACKGROUND AND OBJECTIVE Nowadays, the presence of extended-spectrum β-lactamases (ESBLs) producing strains in Serratia genus causes the emergence of resistance to many antibiotics. So, the lack of proper diagnosis of ESBLs strains can lead to failure in the treatment. The objective of the present study was to investigate ESBLs production in Serratia strains isolated from the clinical blood sam...