Premium
Comparison of solid‐phase cytometry and the plate count method for the evaluation of the survival of bacteria in pharmaceutical oils
Author(s) -
De Prijck K.,
Peeters E.,
Nelis H.J.
Publication year - 2008
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/j.1472-765x.2008.02464.x
Subject(s) - tea tree oil , bacteria , proteus mirabilis , antimicrobial , food science , melaleuca alternifolia , staphylococcus aureus , microbiology and biotechnology , biology , pseudomonas aeruginosa , chemistry , pseudomonas , essential oil , genetics
Aim: To compare the survival of four bacterial strains ( Escherichia coli , Proteus mirabilis , Staphylococcus aureus , Pseudomonas aeruginosa ) in pharmaceutical oils, including jojoba oil/tea tree oil, carbol oil, jojoba oil and sesame oil. Methods and Results: Oils were spiked with the test bacteria in a concentration of 10 4 CFU ml −1 . Bacteria were extracted from oils with phosphate‐buffered saline containing 0·5% Tween 20. Aliquots of the pooled water layers were analysed by solid‐phase cytometry and plate counting. Plate counts dropped to zero for all test strains exposed for 24 h to three of the four oils. In contrast, significant numbers of viable cells were still detected by SPC, except in the jojoba oil/tea tree oil mixture and partly in sesame oil. Conclusions: Exposure of bacteria for 24 h to the two oils containing an antimicrobial led to a loss of their culturability but not necessarily of their viability. The antibacterial activity of the jojoba oil/tea tree oil mixture supersedes that of carbol oil. Significance and Impact of the Study: These in vitro data suggest that the jojoba oil/tea tree oil mixture more than carbol oil inhibits bacterial proliferation when used for intermittent self‐catherization.