PMC:6599329 / 19035-21252 JSONTXT

{"project":"2_test","denotations":[{"id":"31253082-17020544-12221365","span":{"begin":430,"end":432},"obj":"17020544"},{"id":"31253082-21761944-12221366","span":{"begin":434,"end":436},"obj":"21761944"},{"id":"31253082-22096200-12221367","span":{"begin":680,"end":682},"obj":"22096200"},{"id":"31253082-15633107-12221368","span":{"begin":1642,"end":1644},"obj":"15633107"},{"id":"31253082-24035282-12221369","span":{"begin":2210,"end":2212},"obj":"24035282"},{"id":"31253082-25403660-12221369","span":{"begin":2210,"end":2212},"obj":"25403660"},{"id":"31253082-30271935-12221369","span":{"begin":2210,"end":2212},"obj":"30271935"}],"text":"Stress response factors and protein folding\nSeveral proteins involved in stress response including universal stress protein (10.69 fold), and General stress protein (3.42 fold) were identified to be steadily increased in biofilm stages. Similarly, universal stress proteins were found to be upregulated in Porphyromonas gingivalis and Sulfolobus solfataricus biofilms and showed impaired biofilm upon inactivation of these genes [18, 19]. Signaling pathways for inducing stress response within the biofilm are cell-density dependent quorum sensing and the starvation–activated stringent response where the latter helps bacteria in adapting to nutrient deprivation. Nguyen et al. [20] identified the role of this stringent response in protecting bacteria within the biofilm from antimicrobial stress. It also activates the production of catalase and superoxide dismutase in stress condition. Enhanced expression of GTPase ObgE (1.53 fold) suggested the tendency of biofilm cells to attain the persistence nature in response to nutrient deprivation as suggested by previous findings [21]. Similarly, proteins like DPS family protein (5.41 fold), Thioredoxin family protein (4.75 fold), Alkyl hydroperoxide reductase (2.33 fold) and H2O2 scavenging proteins (9.11 fold) involved in reactive oxygen stress were also found to be over synthesized. It was also noticed that Gls24 is overexpressed by 9.2 fold in biofilm cells, suggesting its role in Enterococcal biofilm which is in accordance with the previous reports. Gls24 was found to be related to the stress and virulence of E. faecalis and was considered as a possible immunotherapy target [22].\nChaperonins and chaperones including GroL (1.63 fold), GroS (3.49 fold), several heat shock proteins, etc. were also found to be relatively abundant in SK460 biofilm. Enhanced levels of chaperones ensure the proper protein folding which enables E. faecalis to thrive within the biofilm. Clp proteases involved in the degradation of misfolded proteins also showed elevated expression in biofilm stages. Several studies have proved the role of chaperone DnaK in curli-dependent biofilm formation and are considered as a potential target for anti-biofilm compounds [23–25]."}