The effect of the olive phenolic compound, oleuropein, on growth and enterotoxin B production by Staphylococcus aureus.
The presence of low concentrations (0.1% w/v) of oleuropein, a phenolic compound extracted from olives, delayed the growth of Staphylococcus aureus in NZ amine A and brain heart infusion media modified by the addition of growth factors and glucose (NZA+ and BHI+), as indicated by changes in conductance, whilst higher concentrations (0.4-0.6% w/v) inhibited growth completely. Intermediate concentrations of oleuropein (0.2%) prevented growth in BHI+ but allowed growth to occur in NZA+ despite an extended lag phase (30 h). Concentrations of oleuropein > 0.2% inhibited growth and production of enterotoxin B in both types of media. Lower levels (0.1%) did not affect the final viable count and production of toxin in BHI+ but decreased the number of viable organisms and reduced the toxin production in NZA+ by eightfold. An increase in the concentration of oleuropein resulted in a decrease in the amount of glucose assimilated and consequently the amount of lactate produced. In addition, oleuropein prevented the secretion of a number of exoproteins. Addition of oleuropein during the exponential phase appeared to have no effect on the growth of Staph. aureus in NZA+.
Tranter
H S
HS
Division of Biologics, PHLS Centre for Applied Microbiology and Research, Salisbury, Wilts, UK.
Tassou
S C
SC
Nychas
G J
GJ
D015169:Colony Count, Microbial; D003217:Conductometry; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004768:Enterotoxins / Q000096:biosynthesis*; D005947:Glucose / Q000378:metabolism; D057888:Iridoid Glucosides; D039823:Iridoids; D007773:Lactates / Q000096:biosynthesis; D019344:Lactic Acid; D011714:Pyrans / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
D003470:Culture Media; D004768:Enterotoxins; D057888:Iridoid Glucosides; D039823:Iridoids; D007773:Lactates; D011714:Pyrans; C002769:oleuropein; D019344:Lactic Acid; C031818:enterotoxin B, staphylococcal; D005947:Glucose