Antibiofilm Activity of Extract and a Compound Isolated from Triumfetta welwitschii against Pseudomonas aeruginosa

Abstract

Triumfetta welwitschii has been used as a traditional medicine in Africa. It is documented as a rich source of phytochemicals with antibacterial activities. To further explore the antibacterial potential of these phytochemical components, the phytochemical profile of the dichloromethane: methanol leaf extract from T. welwitschii was investigated using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Compounds were isolated from the extract using column chromatography and thin-layer chromatography. Compound B1 was isolated from the fraction eluted by 90 hexane:10 ethyl acetate using column chromatography. The antibacterial activity of B1 against Pseudomonas aeruginosa was evaluated in vitro using the broth microdilution method and the iodonitrotetrazolium (INT) colorimetric assay. The antibiofilm activities of the extract and B1 against P. aeruginosa were determined by quantifying the biofilms using crystal violet. The effect of the extract and B1 on capsular polysaccharide and extracellular DNA content of biofilm formed by P. aeruginosa was determined using phenol-sulphuric acid and propidium iodide, respectively. A total of 28 peaks were detected and identified using UPLC-MS/MS. The three most abundant phytochemicals identified were catechin, umbelliferone, and a luteolin derivative. B1 showed antibacterial activity against P. aeruginosa with a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) value of 25 μg/ml. Only 38% and 6% of the biofilms were formed in the presence of the extract and B1, respectively. The extract and B1 reduced the capsular polysaccharide content in biofilms formed in P. aeruginosa by 40% and 65%, respectively. The extract and B1 significantly reduced the extracellular DNA content of biofilms by 29% and 72%, respectively. The results of this study provide evidence of the antibacterial and antibiofilm activities of B1 and leaf extracts from T. welwitschii. Future work should identify the chemical structure of B1 using nuclear magnetic resonance and mass spectrometry.

Anti-Biofilm and Associated Anti-Virulence Activities of Selected Phytochemical Compounds against Klebsiella pneumoniae

“…A similar trend was observed for the inhibition of mature biofilm, where the biofilms had accumulated biomass. These findings are in tandem with results obtained in a study carried out by Mombeshora et al [ 5 ], where the compound tested did not have any disruptive effect on mature (72 h) biofilms of P. aeruginosa , a Gram-negative bacterium like K. pneumoniae . This can also be attributed to the opinion of Kelmanson et al [ 49 ], who noted that more resistance to external agents is often shown once biofilms have been fully established; therefore, the disruption of mature biofilms tends to require higher doses of disrupting agents than those needed to destroy planktonic cells.…”

“…Klebsiella pneumoniae , a Gram-negative bacterium belonging to the family Enterobacteriaceae , has been reported to form biofilms that often adhere to surfaces such as lungs, livers, and central venous catheters which are implicated in prominent nosocomial and community-acquired infections [ 5 ]. These infections include pneumonia, urinary tract infections (UTIs), bloodstream infections, necrotizing fasciitis, pyogenic liver abscess, endophthalmitis, and meningitis, among others, subsequently affecting the morbidity and mortality rate, particularly in critically ill and immunocompromised patients [ 6 ].…”

Preferential disruption of E. coli biofilm via ratiometric detection and targeting of extracellular matrix using graphene-oxide-conjugated red-emitting fluorescent copper nanoclusters

“…Carbohydrate content was evaluated by performing phenol sulfuric acid (PSA) assay and measuring the absorbance of furfural compound at ∼490 nm wavelength by taking glucose as a standard. 23 Similarly, protein content was evaluated by performing bicinchoninic acid (BCA) assay, measuring the absorbance at ∼562 nm. In the same manner, the eDNA content was also evaluated by purifying the eDNA with proteinase K, and RNase.…”

“…Environmental Science: Nano Paper by taking glucose as a standard. 23 Similarly, protein content was evaluated by performing bicinchoninic acid (BCA) assay, measuring the absorbance at ∼562 nm. In the same manner, the eDNA content was also evaluated by purifying the eDNA with proteinase K, and RNase.…”

Anti-Biofilm, Anti-Quorum Sensing, and Anti-Proliferative Activities of Methanolic and Aqueous Roots Extracts of <i>Carica papaya</i> L. and <i>Cocos nucifera</i> L.

“…The Petri dishes were incubated for 24 hours at 37˚C. The CMB was visibly deduced as being the first dish devoid of bacteria [17].…”