The characterization of AmpC-type beta-lactamases was performed in a collection of 32 clinical Pseudomonas aeruginosa isolates with intermediate susceptibility or resistance to imipenem and ceftazidime. Twenty-one out of those 32 isolates overexpressed AmpC beta-lactamase, and the MICs of ceftazidime and imipenem were reduced after cloxacillin addition. Cloning and sequencing identified 10 AmpC...

In two recently published articles, Wachino et al. designated a novel ceftazidime-hydrolyzing class A extended-spectrum -lactamase (ESBL) (GES-a) as GES-3 (4), and a new cephamycin-hydrolyzing and inhibitor-resistant class A ESBL (GESb) as GES-4 (5). In actuality, their articles are fraught with misleading nomenclature of GES-type ESBLs and controvertible conclusions on the relationship between...

1. Clinical and Laboratory Standards Institute. Performance Standards for Antimicrobial Susceptibility Testing: Sixteenth Informational Supplement M100-S16. CLSI, Wayne, PA, USA, 2006. 2. Arpin C, Dubois V, Coulange L et al. Extended-spectrum b-lactamase-producing Enterobacteriaceae in community and private health care centers. Antimicrob Agents Chemother 2003; 47: 3506–14. 3. De Gheldre Y, Ave...

background urinary tract infections (uti) caused by resistant bacteria are becoming more prevalent. the spread of extended-spectrum beta-lactamase (esbl)-producing bacteria worldwide has become a serious public health issue among healthcare centers and in the community. drugs and many secondary metabolites from medicinal plants have proved to be economical and effective against many pathogens. ...