Here's the post with the harmful bacteria result from a product he doesn't name.
post from telegraham
The implication is that the bottle was contaminated. But he says he didn't use it on his tank, so it was likely purchased just for the testing, which narrows (but doesn't close) the window of contamination a bit.
there's enough info from that post plus these two to conclude that it likely was MB7 that was the tested product.
https://www.instagram.com/telegraham/p/C05YPGrL5Wj/?img_index=1
https://www.instagram.com/telegraham/p/C1QL_unrvcz/
It's quite an unusual result. The bacteria that is "harmful" is
serratia marcescens which is in the bacillus family and is known both as a pathogen of humans AND more recently found as a coral pathogen in the Caribbean. Even within a single species, there can be enough strain differences - that maybe the human-version doesn't acually infect corals and vice versa, or maybe not.
Usually in these results you see human bacteria or marine bacteria and the source is a bit more clear cut who the source was: the aquarium system or the humans involved.
This is clearly not a case of "MB7 infects aquarium corals" because frankly nobody reports that occurance. Lots of people use MB7 and nobody claims that the use of that product started unusual coral infections. And that's a conclusion that people would absolutely talk about if it happened a couple of times.
The likelier interpretation is that these products contain nutrients in the media and can grow any number of things that might be introduced. Either in the bottle if contaminated at the facility, or on the hobbyist end, or if preservatives are used in the product then after dilution growth is possible.
I once took a bunch of the popular hobby grunge-eating products (including MB7) and cultured them up individually on sterilized fish flakes in saltwater. (nothing grew in the controls)
I then bundled them all together in one aquabiomics sample - I wasn't trying to ID each product generally, just survey.
I got a lot of what you'd expect - lots of bacillus, some other bacteria known for nutrient roles, but the number one prominent species was in a genus that's a fish pathogen. (There was no
serratia marcescens)
anyway, my perspective is that most things in these bottles do not establish as part of the aquarium community (we have data to support that), and we should be glad for that because there's no guarantees of quality control of what strains might be in the bottle and what might grow once you open the bottles and expose to bacteria in your home aquarium environment.
Certainly don't try to "culture up" a bottle of heterotrophs on a random rich food environment because pathogens grow well in such environments and you have no guarantees of what you're growing.
What's to guarantee you wouldn't culture up a pathogen like I did?
(I except PNS products from this "don't culture up heterotrophs" rule, because their niche is selective enough that you can know what you are growing, and know if you've failed - distinctive color)
