2.3 Transformation

In contrast to conjugation, the process of transformation allows bacteria to take up DNA from their environment (for example, from a lysed bacterium) across the cell wall. This DNA can then be incorporated into the genome of the bacterium (Figure 8).

Transformation occurs naturally between some bacteria, such as Streptococcus pneumoniae and Haemophilus influenza. When antibiotic resistance genes in the environment are transformed into a new bacterial type, they can be incorporated into that bacterium’s genome. They are then transmitted to the next generation by binary fission, establishing a newly resistant population of bacteria.