Abstract
Objective: Most of the microbial infection in the body is through biofilm formation. Quorum sensing (QS) is the key regulator in the biofilm formation in both Gram-negative and Gram-positive bacteria. Therefore, interfering with QS is the current strategy to prevent bacterial infection.
 Methods: In this study, the effect of various extracts of freshwater microalgae – Chlorella vulgaris on the growth of clinical pathogens – Pseudomonas aeruginosa and Staphylococcus aureus which were studied using minimum inhibitory concentration (MIC), antibiofilm activity, and (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay using 96-well flat bottom microtiter plates. The phytochemical analysis of C. vulgaris was also carried using standard procedure.
 Results: The petroleum ether, dichloromethane, chloroform, ethyl acetate, and methanolic and acetone extract of C. vulgaris showed the presence of carbohydrates, amino acids, proteins, steroids, flavonoids, alkaloids, saponins, and phenolic compounds. The MIC value of methanolic extract of C. vulgaris was found to be 1 mg/ml. The highest inhibition of 82.5% and 88.0% was shown by methanolic extract at a concentration of 1 mg/ml for P. aeruginosa and S. aureus, respectively. The antibiofilm activity by crystal violet and MTT assay confirmed the reduction of biofilm formation in both pathogenic organisms. 
 Conclusion: The present results suggested the possible use of C. vulgaris in attenuation of QS and biofilm formation to control pathogenic bacteria – P. aeruginosa and S. aureus.
Highlights
Bacterial biofilms are sessile communities of bacteria encased in a self-synthesized exopolysaccharide matrix [1]
Bacteria in biofilms show distinct features from their free-living planktonic cells, such as different physiology and high resistance to the immune system and antibiotics that make the biofilm a source of chronic and persistent infections [2]. It is necessary for the development of drugs to prevent bacterial infections because of increasing emergence in the multidrug resistance among pathogens for antibiotics
quorum sensing (QS) controlled virulence factors, and biofilm formation is vital for the development of acute and chronic diseases of P. aeruginosa and S. aureus
Summary
Bacterial biofilms are sessile communities of bacteria encased in a self-synthesized exopolysaccharide matrix [1]. Bacteria in biofilms show distinct features from their free-living planktonic cells, such as different physiology and high resistance to the immune system and antibiotics that make the biofilm a source of chronic and persistent infections [2] It is necessary for the development of drugs to prevent bacterial infections because of increasing emergence in the multidrug resistance among pathogens for antibiotics. Bacteria in biofilms show distinct features from their free-living planktonic cells, such as different physiology and high resistance to the immune system and antibiotics that make the biofilm a source of chronic and persistent infections [10]. There is a need for the search of potential anti-QS and antibiofilm compounds from natural sources to prevent bacterial infections because of increasing emergence in the multidrug resistance among pathogens for antibiotics
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
