Antibiotic resistance is an increasing global problem resulting from the pressure of antibiotic usage, greater mobility of the population, and industrialization. Many antibiotic resistance genes are believed to have originated in microorganisms in the environment, and to have been transferred to other bacteria through mobile genetic elements. Among others, β-lactam antibiotics show clinical eff...

Mackenzie, A., Studies on the Biosynthetic Pathways of Clavulanic Acid and Cephamycin C in Streptomyces clavuligerus. Doctoral dissertation. ISSN 1652-6880 ISBN 978-91-576-7318-3 The discovery of penicillin, a β-lactam antibiotic, changed the way humans thought about infectious disease. Unfortunately, the widespread use of antibiotics has lead to a concomitant increase in bacterial resistance t...

Pseudomonas aeruginosa is an opportunistic Gram-negative bacterial pathogen. A primary contributor to its ability to resist β-lactam antibiotics is the expression, following detection of the β-lactam, of the AmpC β-lactamase. As AmpC expression is directly linked to the recycling of the peptidoglycan of the bacterial cell wall, an important question is the identity of the signaling molecule(s) ...

β-Lactam resistance in Acinetobacter baumannii presents one of the greatest challenges to contemporary antimicrobial chemotherapy. Much of this resistance to cephalosporins derives from the expression of the class C β-lactamase enzymes, known as Acinetobacter-derived cephalosporinases (ADCs). Currently, β-lactamase inhibitors are structurally similar to β-lactam substrates and are not effective...

β-Lactamase-mediated resistance is a growing threat to the continued use of β-lactam antibiotics. The use of the β-lactam-based serine-β-lactamase (SBL) inhibitors clavulanic acid, sulbactam, and tazobactam and, more recently, the non-β-lactam inhibitor avibactam has extended the utility of β-lactams against bacterial infections demonstrating resistance via these enzymes. These molecules are, h...

Three types of phenotypic expression of β-lactam resistance have been reported in methicillin-resistant Staphylococcus aureus (MRSA): heterogeneous, homogeneous, and Eagle-type resistance. Heterogeneous-to-homogeneous conversion of β-lactam resistance is postulated to be caused by a chromosomal mutation (chr*) in addition to the expression of the mecA gene. Eagle-type resistance is a unique phe...