Has anyone intentionally inoculated their cell culture medium with bacteria and fungi to understand what its bactericidal or growth promoting capabilities are? Using antibiotics in cell culture media is widely accepted as a preventative measure, but this may not be necessary if you have evidence that the medium is already antimicrobial. If you understand your risk points (even if just a select few microorganisms), then you can tailor your prevention measures. Gathering data to see if anyone has also asked this question and has experience and insight through testing, keeping in mind the media formulations for each application may be very unique.
https://safety.fsu.edu/.../Understanding%20and%20Managing%20Cell%20Culture%20...
Hi Rebecca Jordan , depending on the area you are in, especially the pharmaceutical and food area, it is important to validate the culture media through productivity and selectivity tests (ecométric method), what type of medium are you using?
Hi, to clarify, the goal is not to validate media beyond its intended capabilities (cell culture). Goal is to measure probability of different organisms contaminating the media based on their ability to survive and grow in it. Some medias may promote growth, while some may inhibit it. It is widely accepted that media is generally growth promoting, but has anyone actually demonstrated/challenged this, using a variety of different bacteria and fungi?
Generalist microorganisms (such as Bacillus and Enterobacteriaceae) seem to grow well in tissue culture medium (although note that some serum might have traces of antibiotics in it from the animals it came from). Some intracellular pathogens will not grow in tissue culture medium (for instance, Legionella and Coxiella -- need special medium for axenic growth), and some grow poorly in it (for instance, some species of Brucella).
So best not to rely on the medium for preventing microorganisms from growing, but use good sterile technique, including making sure that your gloves do not touch the mouths of the tissue culture vessels. We routinely grow mammalian cells without antibiotics because we do infection experiments, and contamination only occurs around once per year, with the most common cause identified being accidental contact of gloves with the mouths of flasks.
Fantastic discussion thank you all! If anyone is interested in conducting this type of study in parallel, let me know and we can share results. I'm really interested to see survival rates for spore-forming organisms.
Study update:
We found that Bacillus (2 species - subtilis and fumigatus) growth was inhibited in cell culture media, still evaluating whether it was bacteriostatic or bactericidal.
Is there something unique to Bacillus which would inhibit its growth in culture media? Same result at aerobic 33C, and 37C with 5% CO2 control. It grew fine on TSA verification plates and in TSB control. Traci L Testerman any insight? You have been super helpful so far! Thanks for all the responses so far.
Very interesting findings. Wanted to share this article that also supports Traci's theory. Article Human Transferrin Confers Serum Resistance against Bacillus anthracis
Although we didn't test B. anthracis, there is likely a similar interaction going on.
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