I've just realized that I haven't told you what exactly am I doing to deserve 3-year PhD fellowship abroad financed by the Ministry of Science (aka FCT) from Portugal.
I can't believe I'm actually going to do my best to justify the ~35000€ that my government spends with my PhD EVERY Year, but I'll try.
Most of the times I think there's no plausible justification for this but then again the ministers themselves do even less and they keep fucking the country at their will every single day... and at least I try to elevate the name of my country as higher as I possible can!
I basically spend my days in front a of a computer trying to figure out why some types of plasmids are more successful than others in certain scenarios and not in others. Aren't lost yet? Let me help with some background information:
Plasmids are extra-chromosomal DNA molecules that can replicate
autonomously and some can also transfer themselves among bacteria. The transfer process also known as "sex in bacteria" is carried out through a mating bridge that allows the passage of one strand of plasmid DNA between the donor and the recipient cells. Moreover, they
often carry various genes for antibiotic resistance which allows pathogenic bacteria to escape antibiotic treatments.
However, in situations where the genes encoded by the plasmid aren't advantageous for its host, the cost of carrying this extra piece of DNA that relies on the host's resources to replicate and transfer can be high.
Plasmids with the ability of infecting and replicating in very different hosts (e.g. RK2 plasmid can replicate and transfer in both E. coli from the gut and P. putida found in soil) are named Broad-Host Range (BHR). They are expected to confer a high metabolic burden to their host since the frequent swapping between hosts should not allow enough time for co-evolution between plasmid and host. Other plasmids that can only be maintained in a small group of related hosts (e.g. F plasmid can only replicate in E. coli) are known as Narrow-Host Range (NHR) plasmids, and since they are well-adapted to their hosts the metabolic burden they impose is very small.
Previous studies have showed that higher transfer rates tend to be observed in dense microbial communities such as biofilms, i.e., aggregate of cells growing on a surface. In contrast, in a well-mixed bulk liquid environment plasmid-bearing cells are quickly outcompeted by plasmid-free cells unless the transfer rate at which the plasmid infects the population overcomes the fitness costs associated with its carriage.
And... to simulate all these events I use an Individual-based model, iDynoMiCS, but also standard mass action models based on differential equations simulated with Matlab.
And then the result looks somewhat like this:
And.. that's it for today... I can assure you there's more to this...! lol Still, not yet enough to save the world from Humanity!...
