Modulation of Quorum Sensing and Biofilms in Less Investigated Gram-Negative ESKAPE Pathogens

Abstract

Pathogenic bacteria have the ability to sense their versatile environment and adapt by behavioral changes both to the external reservoirs and the infected host, which, in response to microbial colonization, mobilizes equally sophisticated anti-infectious strategies. One of the most important adaptive processes is the ability of pathogenic bacteria to turn from the free, floating, or planktonic state to the adherent one and to develop biofilms on alive and inert substrata; this social lifestyle, based on very complex communication networks, namely, the quorum sensing (QS) and response system, confers them an increased phenotypic or behavioral resistance to different stress factors, including host defense mechanisms and antibiotics. As a consequence, biofilm infections can be difficult to diagnose and treat, requiring complex multidrug therapeutic regimens, which often fail to resolve the infection. One of the most promising avenues for discovering novel and efficient antibiofilm strategies is targeting individual cells and their QS mechanisms. A huge amount of data related to the inhibition of QS and biofilm formation in pathogenic bacteria have been obtained using the well-established gram-positive Staphylococcus aureus and gram-negative Pseudomonas aeruginosa models. The purpose of this paper was to revise the progress on the development of antibiofilm and anti-QS strategies in the less investigated gram-negative ESKAPE pathogens Klebsiella pneumoniae, Acinetobacter baumannii, and Enterobacter sp. and identify promising leads for the therapeutic management of these clinically significant and highly resistant opportunistic pathogens.

Original Contributions to the Chemical Composition, Microbicidal, Virulence-Arresting and Antibiotic-Enhancing Activity of Essential Oils from Four Coniferous Species

“…The results are represented as the minimum biofilm eradication concentration (MBEC) values in Table 2. These results show the promising potential of these EOs to appropriately address the challenges of biofilm-associated infections diagnosis and treatment, often remaining unresolved with the present approaches [43,44].…”

Fabrication and Characterization of Thymol‐Loaded Chitosan Nanogels: Improved Antibacterial and Anti‐Biofilm Activities with Negligible Cytotoxicity

“…Pathogenic bacteria including Staphylococcus aureus, Acinetobacter baumanii, Pseudomonas aeruginosa can cause many life-threatening infectious diseases, especially nosocomial infections. [1] Recently, due to the indiscriminate use of antibiotics, these bacteria have become resistant to many antimicrobial agents, and antimicrobial resistance (AMR) is one of the threats to public health. [2,3] Prevalence of AMR leads to the development of multi-drug resistant (MDR) characteristics, common antibiotics are not effective and lead to a limited number of medical options.…”

Peptidomimetics as Potential Anti-Virulence Drugs Against Resistant Bacterial Pathogens

“…Quorum sensing systems are signaling networks that regulate bacterial behavior and virulence genes expression ( LaSarre and Federle, 2013 ). These communicational systems are intimately linked to bacterial biofilm development since they influence several stages of the biofilm life cycle ( Lazar et al, 2021 ; Mahto et al, 2021 ). Therefore, interference with quorum-sensing systems is one of the explored strategies to overcome biofilm development by pathogenic bacteria ( Brackman and Coenye, 2015 ; Paluch et al, 2020 ; Fu et al, 2021 ).…”