Liposomal-lipopolysaccharide vaccine extracted from Proteus mirabilis induces moderate TLR4 and CD14 production

Novel antimicrobial agents for combating antibiotic-resistant bacteria

Antibiotic therapy has become increasingly ineffective against bacterial infections due to the rise of resistance. In particular, ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) have caused life-threatening infections in humans and represent a major global health threat due to a high degree of antibiotic resistance. To respond to this urgent call, novel strategies are urgently needed, such as bacteriophages (or phages), phage-encoded enzymes, immunomodulators and monoclonal antibodies. This review critically analyses these promising antimicrobial therapies for the treatment of multidrug-resistant bacterial infections. Recent advances in these novel therapeutic strategies are discussed, focusing on preclinical and clinical investigations, as well as combinatorial approaches. In this 'Bad Bugs, No Drugs' era, novel therapeutic strategies can play a key role in treating deadly infections and help extend the lifetime of antibiotics.

Role of lipopolysaccharides in potential applications of nanocarrier systems

BACKGROUND

Lipopolysaccharides (LPS) are considered the main molecular component in the outer membrane of gram-negative bacteria. The LPS molecule in the bacterial cell wall acts as a primary physical barrier and protects gram-negative bacteria from the surrounding environment. LPS (endotoxins) show immunomodulatory therapeutic properties as well as toxicity to the host cell, whereas potential applications encompass.

OBJECTIVE

This review article aims to describe the recent developments of lipopolysaccharides in nanocarrier systems for various applications such as vaccination, cancer chemotherapy and immune stimulants action. Different nanocarriers like cubosomes, niosomes, dendrimers and metal nanoparticles used in the delivery of actives are employed to decorate lipopolysaccharide molecules superficially.

METHODS

A narrative review of all the relevant papers known to the author was conducted.

CONCLUSION

Commercially available lipid nanoparticles contribute to many advances as promising nanocarriers in cancer therapy and are used as a vaccine adjuvant by improving the immune response due to their properties such as size, shape, biocompatibility, and biodegradability. Whereas lipopolysaccharide-decorated nanoparticles change the host's tolerability and increase the effectiveness of molecule in cancer immunotherapy. These nanoconjugate systems enhance overall immunogenic response and effectiveness in vaccine immunotherapy and targeted therapy, not only limited to humans application but also for poultry and aquaculture. Newer opportunities using lipopolysaccharides for the treatment and management of diseases with unique characteristics like the presence of lipoprotein that act as an alternative for bacterial infections over conventional dosage forms.

Pulling the Brakes on Fast and Furious Multiple Drug-Resistant (MDR) Bacteria

Life-threatening bacterial infections have been managed by antibiotics for years and have significantly improved the wellbeing and lifetime of humans. However, bacteria have always been one step ahead by inactivating the antimicrobial agent chemically or by producing certain enzymes. The alarming universal occurrence of multidrug-resistant (MDR) bacteria has compelled researchers to find alternative treatments for MDR infections. This is a menace where conventional chemotherapies are no longer promising, but several novel approaches could help. Our current review article discusses the novel approaches that can combat MDR bacteria: starting off with potential nanoparticles (NPs) that efficiently interact with microorganisms causing fatal changes in the morphology and structure of these cells; nanophotothermal therapy using inorganic NPs like AuNPs to destroy pathogenic bacterial cells; bacteriophage therapy against which bacteria develop less resistance; combination drugs that act on dissimilar targets in distinctive pathways; probiotics therapy by the secretion of antibacterial chemicals; blockage of quorum sensing signals stopping bacterial colonization, and vaccination against resistant bacterial strains along with virulence factors. All these techniques show us a promising future in the fight against MDR bacteria, which remains the greatest challenge in public health care.