Biofilms as Battlefield Armor for Bacteria against Antibiotics: Challenges and Combating Strategies

Abstract

Bacterial biofilms are formed by communities, which are encased in a matrix of extracellular polymeric substances (EPS). Notably, bacteria in biofilms display a set of ‘emergent properties’ that vary considerably from free-living bacterial cells. Biofilms help bacteria to survive under multiple stressful conditions such as providing immunity against antibiotics. Apart from the provision of multi-layered defense for enabling poor antibiotic absorption and adaptive persistor cells, biofilms utilize their extracellular components, e.g., extracellular DNA (eDNA), chemical-like catalase, various genes and their regulators to combat antibiotics. The response of biofilms depends on the type of antibiotic that comes into contact with biofilms. For example, excessive production of eDNA exerts resistance against cell wall and DNA targeting antibiotics and the release of antagonist chemicals neutralizes cell membrane inhibitors, whereas the induction of protein and folic acid antibiotics inside cells is lowered by mutating genes and their regulators. Here, we review the current state of knowledge of biofilm-based resistance to various antibiotic classes in bacteria and genes responsible for biofilm development, and the key role of quorum sensing in developing biofilms and antibiotic resistance is also discussed. In this review, we also highlight new and modified techniques such as CRISPR/Cas, nanotechnology and bacteriophage therapy. These technologies might be useful to eliminate pathogens residing in biofilms by combating biofilm-induced antibiotic resistance and making this world free of antibiotic resistance.

Role of Biofilm Formation in the Drop of Bacterial Resistance to Antibiotics after Animal Therapy with Silver Nanoparticles

“…Bacteria employ quorum sensing, a process involving chemical signaling molecules, to coordinate biofilm formation and antibiotic resistance based on population density and environmental cues . The intricate interplay among antibiotic concentration, bacterial genetics, environmental factors, and communication systems within bacterial populations contributes to the variability observed in biofilm production following antibiotic exposure …”

“…51 The intricate interplay among antibiotic concentration, bacterial genetics, environmental factors, and communication systems within bacterial populations contributes to the variability observed in biofilm production following antibiotic exposure. 2 This variability highlights the complexity of managing biofilm-related infections and underscores the need for a comprehensive approach to combat antibiotic resistance. 52 AgNP therapy may be one such approach, as in this study, they have shown the capacity to mitigate biofilm formation.…”

“…1 A biofilm consists of a community of bacteria enclosed within a self-produced polymer matrix composed of polysaccharides, proteins, and DNA. 2 Bacterial biofilms lead to enduring infections because they exhibit increased resistance to antibiotics, disinfectants, and the body's immune system. 3 Biofilms are formed when bacteria adhere to surfaces and gather within a moist macromolecule structure.…”

Salmonella exploits the reactive oxygen species generated by the plant immune system to enhance colonization

“…Bacteria encased in a matrix are known as biofilm 16 . The matrix protects the bacteria from chemical assaults and, as such, poses a serious challenge for antibiotic treatment 17 . Biofilm formation is essential for root colonization 15,18 .…”