An Overview of Extended Spectrum Beta Lactamases and Metallo Beta Lactamases

Abstract

Antibiotic resistant β-lactamases are diverse and complex enzymes produced by most of the Gram-negative bacteria that are mediated by number of plasmids. The impact of these enzymes has posed a major threat to the health sectors and has challenged the available treatment options for both community and hospital acquired infections. These include the uncomplicated most severe life-threatening infections. Moreover, with resistance to the cephalosporin drugs these MDR strains exhibit co-resistance patterns with different class of antibiotics which is a cause of concern that leads to narrow the limited treatment options. It is alarming situation since there is a steep rise in MDR—Beta lactamase pathogens mainly in Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumanii and Pseudomonas aeruginosa. Currently, the clinical detection of Extended Spectrum of β-Lactamases (ESβL) and MβL producing pathogens are carried out by antibiotic sensitivity test on the guidelines of Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards) since, the other methods being too expensive. The choice of antimicrobial treatment for infections should rely on the clinical data and the tests (AST) in asymptomatic and mild cases. However, this does not imply for critical infections. The last resorts of treatment for ESβL pathogens are carbapenem and nevertheless, resistances have also been reported for the same. With increasing resistance rate to the antibiotics, it’s very essential to follow the guidelines for detection, implementation of antibiotic rotation to reduce these pathogens, followed by the efficient infection control practices and strategies to avoid such outbreaks.