Difference between revisions of "Team:Tongji China/P.A."

Now, we are concerning about the spices and strain of the bacteria involved in our project. We choose Pseudomonas aeruginosa in the strain of PAK-JΔ9 which is an attenuated strain, for it has many advantages varies from efficiency and safety. To be specific, we will introduce the course of searching for this ideal strain step by step to you.



At the first time, we decided to use Type III secretion system (T3SS) to activate the patient’s immune system, because it seems to be a practical way. We already knew that T3SS is one of the features that belong to the Gram-negative bacteria, and there are significant differences between every species. As a result, some important speices which are wildly used in attenuated vaccine such as Listeria Monocytogenes are out of the range because of its classification. Then, referring to a large number of articles, we discovered that Pseudomonas aeruginosa has a distinctive ability of T3SS among common gram-negative spices (Because its T3SS shows little differences associated with the change of pH value a distinct feature showed in intestinal environment, while others’ items don’t.).

Pseudomonas aeruginosa is one of the ubiquitous gram-negative rods which we can see in many environments. It is also called hospital-acquired infections because it has multidrug-resistance which ensures its survival state. Also, P. aeruginosa is an opportunistic extracellular pathogen to human, because this bacterium is responsible for some diseases such as acute infections with burn wound and its primary hazard is the infections during surgery.



So, such a dangerous pathogen won’t do harm to patients in their oral way? Of course not. Description before this paragraph is for the wild-type P. aeruginosa, while the bacteria we use is modified to ensure its safety. This strain is called PAK-JΔ9, an advance type comparing to PAK-JΔ8, which add the feature that makes it a kind of auxotrophic bacterium. P. aeruginosa Δ8 is a genetically engineered attenuated strain, belonging to the fourth species level with the lowest degree of damage, which is the same level as the vaccine for human body use. The strain is an attenuated strain constructed by deleting all its virulence factors by genetic manipulation on the basis of P. aeruginosa . The biosafety laboratory level required for the experimental activities of this species is BSL-1/ABSL-1 (laboratory/animal laboratory), the lowest biosafety level. According to the classification and packaging requirements of ICAO document Doc9284 "Technical Specifications for the Safe Transport of Dangerous Goods", the species belongs to Class B transport requirements, and the corresponding UN number is UN 3373 for packaging and transportation. The μA gene of this strain is mutated so they cannot live without the presence of D-Glutamate. But the human body does not contain D-Glutamate, so this P. aeruginosa strain cannot be amplified in the human body and survive for a long time, nor can they survive in the natural environment.
To know more about the safety of the P.A., you go to the Safety-P.A.

Return to the Background Overview
Go to the Background Neoantigen
Go to the Background T3SS