Sangeeta Singh

By Princy Choudhary, Sangeeta Singh and Vishnu Agarwal

Biofilms are the aggregation of microbial cells, which are associated with the surface in almost an irreversible manner. It exists in variety of forms like dental plaque, pond scum, or the slimy build up in sink. Biofilm formation involves sequence of steps like conditioning, attachment, metabolism, and detachment. Biofilm consists of water channels, EPS (Exopolysaccharide), and eDNA (Environmental DNA), which plays an important role in nutrient circulation, its development, and structure stabilization. Resistance of planktonic bacteria against antimicrobial agents gets increased on the formation of biofilm, which may be the presence of diffusive barrier EPS or neutralizing enzyme, cells undergoing starvation, or due to spore formation. There are numerous factors, which affects biofilm formation such as substratum effects, conditioning film on substratum, hydrodynamics, characteristics of the aqueous medium, cell characteristics, and environmental factors. Biofilm can cause industrial, medical, and household damage and is a reason for loss of billions of dollars every year. Development of biofilm on catheters, medical implants, and devices is a major cause of infections and diseases in humans. Examples include Plaque, Native Valve Endocarditis, Otitis media, Prostatitis, Cystic fibrosis, Periodontitis, Osteomyelitis, and many more.

Part of the book: Bacterial Biofilms

By Tanu Singh, Princy Choudhary and Sangeeta Singh

Antimicrobial peptides (AMPs) are a diverse class of small peptides that are found in most life forms ranging from microorganisms to humans. They can provoke innate immunity response and show activity against a wide range of microbial cells which includes bacteria, fungi, viruses, parasites, and even cancer cells. In recent years AMPs have gained considerable attention as a therapeutic agent since bacterial resistance towards conventional antibiotics is accelerating rapidly. Thus, it is essential to analyze the mechanism of action (MOA) of AMPs to enhance their use as therapeutics. The MOA of AMPs is classified into two broad categories: direct killing and immunological regulation. The direct killing action mechanism is categorized into membrane targeting and non-membrane targeting mechanisms. There are several models and biophysical techniques which determine the action mechanism of antimicrobial peptides.

Part of the book: Insights on Antimicrobial Peptides