Among 99 clinical Klebsiella pneumoniae isolates resistant to cefoxitin and extended-spectrum cephalosporins, coexistence of AmpC (DHA-1, CMY-2, or CMY-8) and extended-spectrum beta-lactamases (CTX-M and/or SHV) was detected in a total of 35. The remainder produced AmpC (n = 42), extended-spectrum beta-lactamases (n = 9), metallo-beta-lactamases (n = 2), or none of these enzymes (n = 11). Pheno...

In a collection of 43 indole-positive Klebsiella clinical isolates, which were initially identified as Klebsiella oxytoca, there were 18 isolates which exhibited a pattern characteristic of extended-spectrum beta-lactamase (ESBL) resistance. This study aimed to confirm their identity by biochemical tests and by PCR and to determine the genetic basis for their resistance to the beta-lactams and ...

Pseudomonas aeruginosa is an opportunistic pathogen which is naturally resistant to a large range of antibiotics like lots of Beta–Lactams (penicillins, cephalosporins and carbapenems) and may cause additional resistance after unsuccessful treatment. The understanding of beta-lactamase identification and detection in these bacteria is very valuable. In recent years a number of variety of new be...

Two isolates of Klebsiella pneumoniae possessing both TEM-1 and SHV-2 beta-lactamases were isolated from patients at the Cleveland Clinic in 1988. The beta-lactamases were discriminated and identified by using substrate hydrolysis data and an isoelectric focusing procedure in which the gel was overlaid with beta-lactamase inhibitors.

In the past 3 decades, classical extended-spectrum beta-lactamases (ESBLs) have probably been the main contributors to gram-negative antimicrobial resistance in Singapore. These appear to be being replaced by the newer CTX-M ESBLs. Metallo-beta-lactamases are found in Pseudomonas aeruginosa but do not seem to have spread widely in Acinetobacter spp. and Enterobacteriaceae. Carbapenem-hydrolysin...