For this project, we chose the pneumoccal strain TIGR4. This specific strain was isolated from an invasion infection - an infection that spred to the blood of the patient. Also, as mentioned in the section "Bad Bacterium", this was the first strain ever to be sequenced. Moreover, the genome was manually annotated by a group of experts. Many of the following sequenced genomes have been automatically annotated.

For many scientists, TIGR4 is used as a reference organism, and it is one of the most widely used streptococcal strains for research. Overall, there is not much difference in the cellular machinery between the many strains. It is mostly the surface proteins that vary. Therefore, we reasoned that the TIGR4 strain would be a natural choice for this review.