Are Uropathogenic Bacteria Living in Multispecies Biofilm Susceptible to Active Plant Ingredient—Asiatic Acid?

Abstract

Urinary tract infections (UTIs) are a serious health problem in the human population due to their chronic and recurrent nature. Bacteria causing UTIs form multispecies biofilms being resistant to the activity of the conventionally used antibiotics. Therefore, compounds of plant origin are currently being searched for, which could constitute an alternative strategy to antibiotic therapy. Our study aimed to determine the activity of asiatic acid (AA) against biofilms formed by uropathogenic Escherichia coli, Enterobacter cloacae, and Pseudomonas aeruginosa. The influence of AA on the survival, biofilm mass formation by bacteria living in mono-, dual-, and triple-species consortia as well as the metabolic activity and bacterial cell morphology were determined. The spectrophotometric methods were used for biofilm mass synthesis and metabolic activity determination. The survival of bacteria was established using the serial dilution assay. The decrease in survival and a weakening of the ability to create biofilms, both single and multi-species, as well as changes in the morphology of bacterial cells were noticed. As AA works best against young biofilms, the use of AA-containing formulations, especially during the initial stages of infection, seems to be reasonable. However, there is a need for further research concerning AA especially regarding its antibacterial mechanisms of action.

Centella asiatica and Its Metabolite Asiatic Acid: Wound Healing Effects and Therapeutic Potential

“…Asiatic acid showed in vitro anti-mycobacterial activity against Mycobacterium tuberculosis H37Ra, Mycobacterium bovis BCG and Mycobacterium smegmatis [ 105 ]. Bacteria causing urinary tract infections such as Escherichia coli , Enterobacter cloacae and Pseudomonas aeruginosa showed a decrease in survival and a weakened ability to create biofilms demonstrating significant effects of asiatic acid on bacterial cell survival [ 106 ]. Previously, this compound also increased the susceptibility of Pseudomonas aeruginosa biofilms to tobramycin [ 107 ].…”

Anti-Planktonic and Anti-Biofilm Properties of Pentacyclic Triterpenes—Asiatic Acid and Ursolic Acid as Promising Antibacterial Future Pharmaceuticals

“…Weak AA activity has been described for Gram-positive strains of E. faecalis [ 46 , 63 ] and S. aureus [ 63 ]. Gram-negative strains of E. coli , P. aeruginosa , and E. cloacae as well as Gram-positive S. aureus showed the lowest sensitivity to AA (MIC >128 mg/L) [ 9 , 63 , 64 ]. Among these strains were uropathogenic E. coli , for which the AA MIC ranged from 512 mg/L to >1024 mg/L [ 9 , 10 , 47 ].…”

“…The recent study of Sycz et al [ 9 ] revealed that AA decreased the survival and the ability to create single- and multi-species biofilms by uropathogenic E. coli CFT073, E. cloacae ATCC-BAA 2468, P. aeruginosa ATCC 25000 strains. AA also changed the morphology of these bacteria.…”

“…Therefore, in recent years, antimicrobial agents derived from natural sources have attracted great interest due to their potential activity against multidrug-resistant bacteria. Plant metabolites can be such effective antimicrobial compounds that act against planktonic and biofilms forms of pathogens [ 9 , 10 , 11 ]. Their antibacterial effects on the planktonic forms of bacteria may contribute to a reduced adherence of bacteria to the surface and biofilm formation.…”

Antibacterial Activity and Mechanism of Madecassic Acid against Staphylococcus aureus

“…As one of the most active constituents in Centella asiatica (L.) Urb, asiatic acid can show significant broad-spectrum antibacterial activity on Escherichia coli , Salmonella typhimurium , Pseudomonas aeruginosa , Enterococcus faecalis , S. aureus , etc. [ 13 , 14 , 15 , 16 ]. However, our research confirmed that another main compound in Centella asiatica (L.) Urb, MA, also showed significant antibacterial activity.…”