Publications by authors named "Cassandra L Chatwin"

β-Lactams are the most widely used antibiotics for the treatment of bacterial infections because of their proven track record of safety and efficacy. However, susceptibility to β-lactam antibiotics is continually eroded by resistance mechanisms. Emerging multidrug-resistant (MDR) strains possessing altered alleles (encoding PBP2) pose a global health emergency as they threaten the utility of ceftriaxone, the last remaining outpatient antibiotic.

View Article and Find Full Text PDF

A major antimicrobial resistance mechanism in Gram-negative bacteria is the production of β-lactamase enzymes. The increasing emergence of β-lactamase-producing multi-drug-resistant "superbugs" has resulted in increases in costly hospital Emergency Department (ED) visits and hospitalizations due to the requirement for parenteral antibiotic therapy for infections caused by these difficult-to-treat bacteria. To address the lack of outpatient treatment, we initiated an iterative program combining medicinal chemistry, biochemical testing, microbiological profiling, and evaluation of oral pharmacokinetics.

View Article and Find Full Text PDF

There is an urgent need for oral agents to combat resistant Gram-negative pathogens. Here, we describe the characterization of VNRX-5236, a broad-spectrum boronic acid β-lactamase inhibitor (BLI), and its orally bioavailable etzadroxil prodrug, VNRX-7145. VNRX-7145 is being developed in combination with ceftibuten, an oral cephalosporin, to combat strains of expressing extended-spectrum β-lactamases (ESBLs) and serine carbapenemases.

View Article and Find Full Text PDF

As shifts in the epidemiology of β-lactamase-mediated resistance continue, carbapenem-resistant (CRE) and carbapenem-resistant (CRPA) are the most urgent threats. Although approved β-lactam (BL)-β-lactamase inhibitor (BLI) combinations address widespread serine β-lactamases (SBLs), such as CTX-M-15, none provide broad coverage against either clinically important serine-β-lactamases (KPC, OXA-48) or clinically important metallo-β-lactamases (MBLs; e.g.

View Article and Find Full Text PDF