Resistance to 3rd generation cephalosporins in Salmonella has been attributed to the production of extended spectrum β-lactamases (ESBLs), but AmpC and KPC or metallo β-lactamase (MBL) mediated resistance have also been reported1. ESBLs reported in Salmonella spp. are the derivatives of TEM, SHV, CTX-M and PER type β-lactamase families1. We isolated Salmonella enterica ser. Typhimurium (B9903) ...

BACKGROUND Extended spectrum β-lactamases (ESBLs) and AmpC β-lactamases enzyme are major sources of resistance to β-lactam antibiotics especially in Enterobacteriaceae such as Escherichia coli and Klebsiella pneumoniae. Increasing frequency of the co-existence of ESBLs with AmpC-β-lactamases in bacteria is a serious threat for treating bacterial infections. OBJECTIVES The aim of this study wa...

BACKGROUND Emergence of extended-spectrum beta-lactamases (ESBLs) in Shigella species imparting resistance to third-generation cephalosporins is a growing concern worldwide. The aim of this study is to molecularly characterize the newly emerging beta-lactam resistant Shigella sonnei, specifically ESBLs in Lebanon, and compare them to beta-lactam sensitive isolates. METHODOLOGY We compared fiv...

Extended-spectrum-beta-lactamase (ESBL)-producing members of the Enterobacteriaceae are often resistant to multiple drug classes, making therapy of urinary infections with oral antibiotics difficult. Previously it was shown that amoxicillin-clavulanate can provide clavulanate inhibition of ESBLs and protect an oral cephalosporin present in combination when tested by broth microdilution. This st...

Four novel oxapenem compounds (i.e., AM-112, AM-113, AM-114, and AM-115) were investigated for their beta-lactamase inhibitory activity against a panel of isolated class A, C, and D enzymes, which included expanded-spectrum beta-lactamase enzymes (ESBLs). The oxapenems were potent beta-lactamase inhibitors. Activity varied within the group, with AM-113 and AM-114 proving to be the most active c...

Background & Aims: Organisms producing TEM-β-lactamase are emerging around the world as a source of resistance to β-lactam antibiotics such as three generation cephalosporins. In this study, we used a polymerase chain reaction (PCR) to identify genes TEM for Extended-spectrum β-lactamase (ESBLs) producing clinical isolates of Klebsiella pneumonia from hospitals of Boro...

Proteus mirabilis is a specific opportunistic pathogen of many infections including urinary tract (UTIs). Risk factors are linked with the acquisition multidrug-resistant (MDR) to 3 or more classes antimicrobials) strains. The resistance in extended-spectrum alpha-lactamase rare, but rising beta-lactamase (ESBL) producing strains matter concern. ?-lactamases and antibiotic modifying enzymes mai...

Ceftazidime-avibactam, aztreonam-avibactam, and comparators were tested by reference broth microdilution against 372 nonrepetitive Gram-negative bacilli (346 unselected plus 26 selected meropenem-nonsusceptible Enterobacteriaceae isolates) collected from 11 teaching hospitals in China in 2011 and 2012. Meropenem-nonsusceptible isolates produced extended-spectrum β-lactamases (ESBLs; e.g., CTX-M...

Twelve ceftazidime-resistant isolates of the family Enterobacteriaceae (11 Klebsiella pneumoniae isolates and 1 Escherichia coli isolate) were collected in 1995 from three Polish hospitals located in different cities. All were identified as producers of extended-spectrum beta-lactamases (ESBLs). Detailed analysis of their beta-lactamase contents revealed that six of them expressed SHV-5-like ES...