Aims: To identify whether a duck egg yolk was viable substitute lecithin source for chicken egg yolk agar as a culture medium in identification of lecithinase positive bacteria.
Study Design: In this study, experimental method was used by the researchers.
Place and Duration of the study: Daniel Mercado Medical Center and Mary Mediatrix Medical Center between September 2018 to October 2018.
Methodology: The examination of bacteria was evaluated through macroscopic morphology. The duck egg yolk infused in nutrient agar was used in the attempt at growing Bacillus cereus. Then it was planted and incubated. Observation of the growth of the organism was done after incubationg 24-48 hours.
Results: Lecithinase positive B. cereus was planted in different concentrations of duck egg yolk emulsion: 5ml, 10ml and 15ml. Each of them demonstrated a visible formation of opaque halo around the test organisms. Adding more volume will further improve the quality of the opaque halo.
Conclusion: The egg yolk can be used as an alternative for chicken egg in the presumptive identification of lecithinase-producing organisms. It is more cost-efficient to use duck egg yolk instead of using chicken yolk when preparing egg yolk agar.