Bacterial biofilms: role of quorum sensing and quorum quenching

Abstract

Bacterial biofilms provide an adjustable strategy to manage themselves in the existing conditions. Biofilms of pathogenic bacteria act as a reservoir for various device and non-device related diseases which are tough to cure. Exposure to a high dose of antibiotics is not an appropriate solution to this problem as high antibiotic concentrations lead to the generation of Multi-drug resistant strains as well as affect the human body. So, it is needed to bypass the use of antibiotics to prevent bacterial biofilms. In this context, Quorum Sensing (QS) may be a potential target since biofilm formation is regulated by QS. N-acyl homoserine lactones (N-AHL) act as predominant QS signal molecules in Gram-negative bacteria. Counteraction of the QS-regulated activities using quorum quenching may be an alternative way to combat biofilm formation in bacteria. Quorum sensing inhibitors (QSIs) and QQ enzymes play a significant role in this regard either by interference with the signal generation, perception, or by degradation, and chemical modification, respectively. Many quorum quenching enzymes have been reported from bacteria. Extremophilic bacteria have also been reported to produce potent quorum quenching enzymes which can effectively break down N-AHLs.

Cepacian degrading Cytobacillus sp. strain Dbc1 with anti-biofilm activity potentiating antibiotic efficacy against Burkholderia cepacia biofilm development

“…In addition, these exopolysaccharides hold eDNA, proteins, enzymes and capsular polysaccharides (Sutherland, 2001;Matsukawa and Greenberg, 2004) targeting which, in turn, can minimize long-term medication and establishment of chronic infection. Moreover, biofilm disruption does not change any cellular function, so it neither imposes selective pressure on the bacterial growth nor promotes significant counteractive resistance mechanisms by them (Ghosh et al, 2022). Though there are several reports on enzymatic degradation of biofilm matrix components of pathogenic bacteria such as exopolysaccharides (Baker et al, 2016), proteins (Saggu et al, 2019) etc., reports on cepacian EPS degradation of B. cepacia is scanty.…”