Related Experiment Video
Updated: Aug 11, 2026
Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
Status of membrane-filter procedure in the examination of water and milk for Staphylococcus aureus
1Dairy Research Laboratory, National Research Center, Dokki, Cairo, Egypt.
Abstract:
A comparative study was carried out to assess the performance of four selective media, namely Baird-Parker (B-P), Mannitol-Salt Agar (M.S.A.), Staphylococcus-110 (S-110), and Chapman-Stone (C.S) in solid and liquid forms for recovery of Staphylococcus aureus from water and milk, using membrane filter technique. The descending order of efficiency for demonstrating the presence of inoculated S. aureus from unsterilized Nile water was (B-P)--(M.S.A) + (S-110) and (C.S) medium in solid form and changed to (S-110)--(M.S.A)--(C.S) when used in the liquid form. With sterile Nile water, the descending order of efficiency of the tested media was (B-P) + (M.S.A)--(S-110) and (C.S) medium in the solid form and (M.S.A) + (S-110) and (C.S) in the liquid form. In testing the inoculated milk using solid media, (S-110) and (M.S.A) tend to show similar results and took intermediate position between (B-P) and (C.S). When liquid media were used, the descending order of productivity was (S-110)--(M.S.A) and (C.S).
Insights
This study compared four selective media for detecting Staphylococcus aureus in water and milk. Baird-Parker medium showed the best performance in solid form for unsterilized water, while Staphylococcus-110 excelled in liquid media for milk samples.
Area of Science:
- Microbiology
- Food Safety
- Environmental Science
Background:
- Staphylococcus aureus is a significant pathogen in food and water.
- Accurate detection methods are crucial for public health.
- Selective media are commonly used for isolating S. aureus.
Purpose of the Study:
- To compare the efficacy of four selective media (Baird-Parker, Mannitol-Salt Agar, Staphylococcus-110, Chapman-Stone) in solid and liquid forms.
- To evaluate their performance in recovering Staphylococcus aureus from water and milk samples.
Main Methods:
- Comparative analysis of four selective media: Baird-Parker (B-P), Mannitol-Salt Agar (M.S.A.), Staphylococcus-110 (S-110), and Chapman-Stone (C.S).
- Media were tested in both solid and liquid formulations.
- Membrane filter technique was employed for recovery of S. aureus from inoculated water (sterilized and unsterilized Nile water) and milk samples.
Main Results:
- For unsterilized Nile water, solid media efficiency: B-P > M.S.A = S-110 = C.S; liquid media: S-110 > M.S.A > C.S.
- For sterilized Nile water, solid media efficiency: B-P = M.S.A > S-110 = C.S; liquid media: M.S.A = S-110 = C.S.
- For inoculated milk, solid media: S-110 ≈ M.S.A (intermediate) between B-P and C.S; liquid media: S-110 > M.S.A = C.S.
Conclusions:
- The optimal selective medium for Staphylococcus aureus recovery varies depending on the sample type (water vs. milk) and medium form (solid vs. liquid).
- Baird-Parker medium was most effective for solid-phase detection in unsterilized water.
- Staphylococcus-110 and Mannitol-Salt Agar demonstrated strong performance in liquid media, particularly for milk samples.
