Hai,
I am working on methicillin-resistant Staphylococcus aureus. I have often encountered a serious problem is reviving the strains. Could you please suggest a proper protocol for MRSA preservation?
I use to preserve in 40% glycerol mixed with overnight grown culture in 1:1 ration (20% final concentration) without antibiotics. I particularly said "without antibiotics" because certain articles suggests to add sub-lethal concentration of oxacillin to the culture.
There is no particular system for preserving MRSA in my opinion. AS I have previously worked on MRSA and used STGG media, did not find any problem after reviving the culture using tryptone soy broth( with or without 1% blood). I have used mecA gene for PCR confirmation of the MRSA and cefoxitin disc diffusion method for phenotypic identification. I worked bacteria preserving for three years in -80C.
I've also never had any issues with MRSA banking in -80C. I don't even use glycerol. Basically just MRSA in the media (I forget what I used).
It regrows in both broth and plate culture...
Colonies exhibiting the typical morphological characteristic of MRSA were purified on Baird-Parker agar without supplement at 35°C for 24 h and preserved on Tryptic Soy Agar-YE at 4°C with 0.02% of thiomersal solution. For a long preservation period up to 6 months, purified colonies were preserved inTryptic Soy broth -YE with 20% medical glycerin at deep freezing.
See the following RG link:
Article Antibacterial effect of ozonated water against methicillin-r...
It is my pleasure Muneeb Hamza , Actually, I am professional in this bacteria and I have much research about it as well as my MSC thesis also about it. So, I provide you my personal experience with it.
Maintain good hand and body hygiene. Clean hands often, and clean your body regularly, especially after exercise. Keep cuts, scrapes, and wounds clean and covered until healed. Avoid sharing personal items such as towels and razors.
There is no specific way for MRSA. In our lab we preserve ourbacteria under 80 C
The simplist methods for maintaining bacterial cultures is one of the old methods, an agar stab. Prepare your normal media, or MSA or NA, and sterilize it in glass culture tubes. Use a 'needle' and stick it into an active colony, then stab the needle deep into the agar (in the middle). I prefer making it a slant as that is easier to stab. Allow about 12-24 hrs for growth, and then refrigerate. A screw top tube is best as that reduces drying. Bacteria may be kept alive in this manner for weeks to months and it is easy to recover them by stabbing right down in the same area. Doing the stab every month or so keeps the sulture alive, but do check how long they live using your strain and your growth medium to determine how often you should transfer them. This method is easy, cheap, effective and for those of us without a -80 freezer available it is effective. The growth medium may also be made with lower percent nutrients for slower growth and longer survival.
There's still no specific way to preserve Methicillin-resistant Staphylococcus aureus other than storing it under 80 C like other bacteria.
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