Beta‐lactam antibiotics: from antibiosis to resistance and bacteriology

Abstract

SUMMARYThis review focuses on the era of antibiosis that led to a better understanding of bacterial morphology, in particlar the cell wall component peptidoglycan. This is an effort to take readers on a tour de force from the concept of antibiosis, to the serepidity of antibiotics, evolution of betalactam development, and the molecular biology of antibiotic resistance. These areas of research have culminated in a deeper understanding of microbiology, particularly in the area of bacterial cell wall synthesis and recycling. In spite of this knowledge, which has enabled design of new even more effective therapeutics to combat bacterial infection and has provided new research tools, antibiotic resistance remains a worldwide health care problem.

Morphological and ultrastructural changes in bacterial cells as an indicator of antibacterial mechanism of action

“…The β-lactam induced formation of spheroplasts and protoplasts occurs, not just in E. coli, but in many species of Gram-negative [36, 53,74,[79][80][81][82][83] and Gram-positive bacteria [69,84]. However, because PBP nomenclature is species-dependent [85,86], and because relatively few studies have determined the affinity of their test β-lactam(s) for the PBPs of their test species, the relationship between spheroplast formation and inhibition of a specific PBP is less clearly defined for these species than E.…”

“…The β-lactam induced formation of ovoid cells has been reported, not just in E. coli and P. aeruginosa, but in many species of Gram-negative bacteria including Acinetobacter baumanii [102], Klebsiella pneumoniae [54], Proteus mirabilis [54,111], and Serratia marcescens [54]. Again however, because PBP nomenclature is species-dependent [86], and because relatively few studies have determined the affinity of their test β-lactam(s) for the PBPs of their test organism(s), ovoid cell formation has not been attributed to inhibition of a specific PBP in these organisms.…”

“…In β-lactam-treated cells of E. coli and P. aeruginosa, this change has been attributed to inhibition of PBP3 [75,119]. PBP3 crosslinks peptidoglycan at the septal wall but not the lateral wall, so inhibition of this enzyme results in cell elongation without division [58,86]. Cefuroxime and ceftazidime, which have a higher affinity for PBP3 than PBPs 1a, 1b or 2 [76,120], cause E. coli and P. aeruginosa to form filaments relatively quickly (within 3-4 hours) at low antibiotic concentrations (0.008xMIC to 1xMIC), with spheroplast formation or lysis becoming observable at 0.5xMIC and increasing at higher concentrations [54,76,120].…”

Loop-Mediated Isothermal Amplification untuk Mendeteksi Gen blaTEM Sebagai Penyandi Extended-Spectrum Beta-Lactamase pada Isolat Enterobacteriaceae

“…1 Penisilin dan juga sefalosporin merupakan antibiotik betalaktam yang paling sering digunakan. Keduanya mempunyai kesamaan, yaitu strukturnya yang tersusun dari cincin beta-laktam.…”

Pesquisa de genes de resistência a antimicrobianos em filés de tilápia comercializados no município de São Paulo-SP

“…Ao realizar o estudo, observou que, não havia crescimento de colônias, sugerindo a existência de substância na secreção responsável por inibir o crescimento bacteriano. Essa substância foi denominada lisozima, enzima que age na parede celular de microorganismos resultando na lise de bactérias (KONG et al, 2009).…”