Bacterial biofilms and their resistance mechanisms: a brief look at treatment with natural agents

Biofilm is a complex community of microorganisms residing within a polysaccharide and/or protein matrix. Biofilm can be produced by several microorganisms, including various bacteria and fungi. Nowadays, the resistance of biofilm-growing cells to antimicrobials originated from the structural nature of biofilms, and phenotypic alteration of sessile cells is becoming a global issue. Bacterial biofilms are important in various aspects of human health, including chronic infections, dental plaque, and infection of indwelling medical devices such as catheters. They are also a major problem in other industries, including oil recovery, drinking water distribution, papermaking, metalworking, and food processing. Estimates indicate that more than 80% of infectious diseases are biofilm-derived. The aim of this study is to describe mechanisms of antibiotic resistance to provide a better perspective on how to manage it. Moreover, the current strategies for biofilm inhibition were described. Considering that plants are a valuable source of abundant natural chemicals to create prophylactic and therapeutic medicines against biofilm-based infections, significant natural compounds with anti-biofilm properties were highlighted. Finally, natural anti-biofilm compounds under clinical trial evaluation were summarized to provide a background for more extensive researches and assist in opening a new window to novel treatments.