hi, i'm assessing the effect of dead bacteria on viability of fibroblast.
Both control bacteria alone and cells alone don't show any change in medium color but the co-culture become yellow.
The cells appear highly stressed and less in number, pointing to dead or at least stop in replication. Also the morphology becomes highly uneven.
I can't figure out why the medium is acidified though.
Any idea to explain it?
Hello Alexander Bontempo
The release of bacterial toxins from dead bacteria regardless of when they are released, results in the disruption of metabolic pathways in the fibroblast cells. These metabolic pathways include damaging cell membranes, disrupting protein synthesis and other important cellular mechanisms needed for the survival of cells. So, the fibroblast cells appear highly stressed and begin to die turning the culture medium yellow as the cell debris start to accumulate.
In case of controls, bacteria alone, there are no fibroblast cells on which the bacterial toxins could act and therefore no change in medium color, while in cells alone, there are no dead bacteria (bacterial toxins) to act on the cells and so no change in medium color.
Best.
i'm not sure cell debris acidify medium. i used to do cell selection with antibiotics. i used to have 90 or more % of death cells, but never observed shift in medium color due to acidification. actually was the contrary, due to high cell death medium remain pink indefinitely. we used the pinky medium color to estimate if the antibiotic was working just by eyesight.
Are you sure that you are using 100 percent dead bacteria for coculture? Even if some bacteria are viable they may multiply in the medium and contribute to acidification.
Regarding viability of fibroblasts, I agree with Nobre, even dead bacteria or cell debris can be toxic to cells.
live bacteria co-culture should make your medium pinking, i.e., alkaline/
bead bacteria co-culture not making pink is correct that dead bacteria are not metabolizing media component
Fibroblasts are not in good shape due to dead bacterial culture, since dead bacteria will have endotoxins
Solution: reduce the bacterial number in both co-cultures
good luck
Thank you guys. Yes sure they are dead. Actually we assessed viability colturing them on bacterial medium. What i was looking for is if exist any cell response to bacteria that cause the acidification. Some kind of defense mechanism immune cells independent.
yes we tried with bacteria supernatant, but now we were looking for not soluble factors.
- Badges
- Science topic