Enhancement of antimicrobial activities of whole and sub-fractionated white tea by addition of copper (II) sulphate and vitamin C against Staphylococcus aureus; a mechanistic approach

Article English OPEN
Holloway, Andrew C ; Gould, Simon WJ ; Fielder, Mark D ; Naughton, Declan P ; Kelly, Alison F (2011)
  • Publisher: BioMed Central
  • Journal: BMC Complementary and Alternative Medicine, volume 11, pages 115-115 (eissn: 1472-6882)
  • Related identifiers: pmc: PMC3239241, doi: 10.1186/1472-6882-11-115
  • Subject: alliedhealth | Research Article | Complementary and alternative medicine

Background Enhancement of antimicrobial plant products e.g. pomegranate extract by copper (II) sulphate is known. Such combinations have applications in various settings, including the identification of novel compositions to study, treat and control infection. Methods A combination of white tea (WT) (made allowing 10 minutes infusion time at 100°C) was combined with 4.8 mM copper (II) sulphate and tested for antimicrobial effect on the viability of Staphylococcus aureus NCTC 06571. Comparisons were made with green (GT) and black (BT) teas. A WT sub-fraction (WTF < 1000 Da) was tested with copper (II) sulphate and 4.8 mM vitamin C. pH measurements of samples were taken for controls and to observe any changes due to tea/agent interaction. Catalase was used to investigate hydrogen peroxide release. UV-vis. was used to compare WT and WTF. Results A 30 minute incubation at room temperature of copper (II) sulphate alone and combined with WT reduced the viability of S. aureus NCTC 06571 by c.a 1 log10 cfu mL-1. GT and BT with copper (II) sulphate negated activity to buffer values. Combined with copper (II) sulphate, vitamin C, WTF and, vitamin C plus WTF all reduced the viability of S. aureus NCTC 06571 by c.a. 3.5 log10 cfu mL-1. Independent experiments showed the results were not due to pH effects. Adding WT or WTF to copper (II) sulphate resulted in increased acidity. Copper (II) sulphate alone and combined with WT required c.a 300 μg mL-1 (final concentration) catalase to restore S. aureus viability, WTF with copper (II) sulphate and added vitamin C required c.a 600 μg mL-1. WT and WTF UV-visible spectra were similar. Conclusions WT showed no efficacy in the combinations tested. WTF was enhanced with copper (II) sulphate and further with vitamin C. WT and WTF increased acidity of copper (II) sulphate possibly via the formation of chemical complexes. The difference in WT/WTF absorbance possibly represented substances less concentrated or absent in WTF. Investigations to establish which WTF component/s and in what proportions additives are most effective against target organisms are warranted.
  • References (41)
    41 references, page 1 of 5

    1. European Antimicrobial Resistance Surveillance System Annual Report 2008. [http://www.ecdc.europa.eu/en/activities/surveillance/EARS-Net/ Documents/2008_EARSS_Annual_Report.pdf].

    2. Nieuwdorp M, van Nood E, Speelman P, van Heukelem HA, Jansen JM, Visser CE, Kuijper EJ, Bartelsman JFWM, Keller JJ: Treatment of recurrent Clostridium difficile-associated diarrhoea with a suspension of donor faeces. Ned Tijdschr Geneeskd 2008, 152:1927-1932.

    3. Franco W, Hsu WY, Simmone AH: Survival of Salmonella and Staphylococcus aureus in Mexican Red Salsa in a Food Service Setting. J Food Prot 2010, 73:1116-1120.

    4. Parsonnet J, Hansmann NA, Seymour JL, Delaney ML, DuBois AM, Modern PA, Jones MB, Wild JE, Onkerdonk AB: Persistence survey of Toxic Shock Syndrome toxin-1 producing Staphylococcus aureus and serum antibodies to this antigen in five groups of menstruating women. BMC Infect Dis 2010, 10:249.

    5. Humphreys H: New technologies in the prevention and control of healthcare-associated infection. J R Coll Physicians Edinb 2010, 40:161-164.

    6. Gordon N, Wareham DW: Antimicrobial activity of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) against clinical isolates of Stentrophomonas maltophilia. Int J Antimicrob Agents 2010, 36:129-131.

    7. Yi SM, Zhu JL, Fu LL, Li JR: Tea polyphenols inhibit Pseudomonas aeruginosa through damage to the cell membrane. Int J Food Microbiol 2010, 144:111-117.

    8. Chou CC, Lin LL, Chung KT: Antimicrobial activity of tea as affected by the degree of fermentation and manufacturing season. Int J of Food Microbiol 1999, 48:125-130.

    9. Si W, Gong J, Tsao R, Kalab M, Yang R, Yin Y: Bioassay-guided purification and identification of antimicrobial components in Chinese green tea extract. J Chromatogr A 2006, 1125:204-210.

    10. Tiwari RP, Bharti HD, Kaur RP, Dikshit RP, Hoondal GS: Synergistic antimicrobial activity of tea and antibiotics. Indian J Med Res 2005, 122:80-84.

  • Metrics
    No metrics available
Share - Bookmark