Mechanism of action of secondary metabolites from marine-derived Streptoymces on bacterial isolates by membrane permeability. (December 2020)

• Record Type: Journal Article
• Authors: Igbinosa, Etinosa O.; Beshiru, Abeni; Igbinosa, Isoken H.
• Is Part Of: Microbial pathogenesis. Volume 149(2020)
• Publication Date: 2020-12
• Subjects: Antibacterial activity -- Streptomyces -- Secondary metabolite -- Cell membrane; Pathogenic microorganisms -- Periodicals; Pathology, Molecular -- Periodicals; Communicable Diseases -- microbiology -- Periodicals; Communicable Diseases -- parasitology -- Periodicals; Micro-organismes pathogènes -- Périodiques; Pathologie moléculaire -- Périodiques; Electronic journals; 616.9041
• DOI: 10.1016/j.micpath.2020.104532
• Languages: English
• ISSNs: 0882-4010

Abstract

Abstract: This study was designed to further investigate the potential mechanism of action of our previously characterized and identified marine-derived Streptomyces extracts (ESC003 and ESC012) on selected bacterial isolates from our culture bank. Time-kill kinetics, protein and lipid leakages assay, cell membrane permeability, phosphate and potassium ions efflux assay, extracellular adenosine triphosphate (ATP) concentration and membrane potential (MP) were all carried out using the marine-derived Streptomyces extract to determine and understand the probable mode of action at which the extract inhibit or kill bacterial cell. The MIC of ESC003 and ESC012 ranged from 0.16 to 6.25 mg/mL while the MBC ranged from 1.25 to >10 mg/mL. On the time-kill kinetics, a reduction in mean viable cell amount was detected at respective time studied. For the impermeability of the bacterial isolates, the relative electric conductivity increased with increase in concentration and time interval of exposure. As regards the protein leakage, lipid leakage, 260 nm absorbing materials leakage, phosphate and potassium ions efflux; considerable amount of these products were leaked with increase in concentration and time of exposure to the bacterial isolates. The extracellular ATP concentration from respective bacterial isolates increased appreciably with increased concentration of exposure with a simultaneous decrease in membrane potential. Findings from this study revealed that the Streptomyces extracts revealed a significant breakthrough against susceptible bacterial isolates via the permeability of the bacterial cell membrane, and thus resulted in the outflow of ATP, electrolytes, DNA materials, and proteins. These changes lead to disruption, and eventually cell death, which were proportional to a concurrent decrease in the viability of the bacterial cell. Highlights: The degree at which the extracts eliminated the cells increases with the contact time intervals and concentration. Intensification in the electrolytes leakage showed the interference of the penetrability barrier. Persistent increase of these extracts concentrations along with persistent elongation in contact time resulted in nucleotides loss from the respective bacterial cells. The level of external ATP amount exposed to Streptomyces extracts emerge as a result of damage in integrity of cell membrane of the bacterial isolates. Bacterial membrane potential was directly correlated with the fluorescence intensity.