Antibacterial mode of action of violacein from Chromobacterium violaceum UTM5 against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA)

Abstract

Violacein, violet pigment produced by Chromobacterium violaceum, has attracted much attention recently due to its pharmacological properties including antibacterial activity. The present study investigated possible antibacterial mode of action of violacein from C. violaceum UTM5 against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) strains. Violet fraction was obtained by cultivating C. violaceum UTM5 in liquid pineapple waste medium, extracted, and fractionated using ethyl acetate and vacuum liquid chromatography technique. Violacein was quantified as major compound in violet fraction using HPLC analysis. Violet fraction displayed bacteriostatic activity against S. aureus ATCC 29213 and methicillin-resistant S. aureus ATCC 43300 with minimum inhibitory concentration (MIC) of 3.9 μg/mL. Fluorescence dyes for membrane damage and scanning electron microscopic analysis confirmed the inhibitory effect by disruption on membrane integrity, morphological alternations, and rupture of the cell membranes of both strains. Transmission electron microscopic analysis showed membrane damage, mesosome formation, and leakage of intracellular constituents of both bacterial strains. Mode of action of violet fraction on the cell membrane integrity of both strains was shown by release of protein, K, and extracellular adenosine 5'-triphosphate (ATP) with 110.5 μg/mL, 2.34 μg/mL, and 87.24 ng/μL, respectively, at 48 h of incubation. Violet fraction was toxic to human embryonic kidney (HEK293) and human fetal lung fibroblast (IMR90) cell lines with LC value of 0.998 ± 0.058 and 0.387 ± 0.002 μg/mL, respectively. Thus, violet fraction showed a strong antibacterial property by disrupting the membrane integrity of S. aureus and MRSA strains. This is the first report on the possible mode of antibacterial action of violet fraction from C. violaceum UTM5 on S. aureus and MRSA strains.

Anti-listeria Activities of Linalool and Its Mechanism Revealed by Comparative Transcriptome Analysis

“…Recently, more and more studies have shown the presence of mesosomes in bacteria cells after treatment with antimicrobial drugs, suggesting mesosomes may be important to bacteria for responding to and surviving exposure to antibiotics. Several antibiotic efficacy studies have been performed with S. aureus and/or MRSA, including retinoids (Kim et al, 2018), violacein (Aruldass et al, 2018), defensins (Shimoda et al, 1995), trimethoprim (Nishino et al, 1987), rifampin (Gottfredsson et al, 1993), cationic peptides (Friedrich et al, 2000), tetrabromobisphenol A (Wang et al, 2018), antimicrobial peptides (Hartmann et al, 2010), photodynamic therapy (Iluz et al, 2018), porphyrins (Malik et al, 1988), silver nanoparticles (Krychowiak et al, 2018). In addition, imipenem has been studies with P. aeruginosa (Gottfredsson et al, 1993) and rifampicin has been studies with Xanthomonas campestris (Li et al, 2008) and E. coli (Xin et al, 2014).…”

Chromobacterium violaceum delivers violacein, a hydrophobic antibiotic, to other microbes in membrane vesicles

“…B. As expected based on the known activities of violacein (Choi et al ., ; Im et al ., ; Aruldass et al ., ), the purified sample was very potent towards this bacterium, with 3.1 mg/l significantly reducing both its bioluminescence (99.8% loss; Figs B, C and Supporting Information S6) and viability (6‐log reduction; Fig. D) by 6 h. The wild‐type MVs were also bactericidal towards this strain of S. aureus , with the same concentration causing a 90.7% loss in bioluminescence and an 85% loss in viability.…”

Engineering oleaginous yeast Yarrowia lipolytica for violacein production: extraction, quantitative measurement and culture optimization

“…Most strikingly, CaCO 3 was found to be a superior supplement to buffer media pH. The carbonate group (CO 3 2-) will effectively neutralize the organic acids accumulated during the fermentation. At the end of the fermentation, 70.04 mg/L violacein and 5.28 mg/L deoxyviolacein were produced from the yeast culture supplemented with CaCO 3 , with violacein purity up to 86.92%.…”

“…Violacein and deoxyviolacein belong to bisindol pigments with deep purple color, which are derived from tryptophan biosynthetic pathway and naturally produced by a number of marine bacteria such as Janthinobacterium lividum [1,2], Chromobacterium violaceum [3][4][5], Pseudoalteromonas luteoviolacea [6], et al Clinical trials and biomedical studies indicate both compounds possess strong antibacterial [7,8], anticancer [9], antiviral [10], trypanocidal [11] and antiprotozoal [12] properties. These characteristics make violacein a superior chemical scaffold and drug candidate for the development of clinically active agents.…”

“…At present, most of the reported violacein-producing host are gram-negative bacteria with human pathogenicity. For example, both C. violaceum [3][4][5], and J. lividum [1,2] have been related with serious skin infection in immune-compromised people, and both strain have been classified as biosafety level II bacteria. Although the native host represents some advantage to produce violacein, the pathogenicity significantly limited their industrial application.…”