Filamentation is the anomalous growth of certain
bacteria, such as
E. coli, in which cells continue to elongate but do not divide (no
septa formation). The cells that result from elongation without division have multiple chromosomal copies. Bacterial filamentation is often observed as a result of bacteria responding to various stresses, including
DNA damage or inhibition of replication. This may happen, for example, while responding to extensive DNA damage through the
SOS response system. Nutritional changes may also cause bacterial filamentation. Some of the key genes involved in filamentation in E.coli include
sulA and
minCD. The following genes have been connected to virulence using the G. mellonella infection model: BCR1,FLO8, KEM1, SUV3 and TEC1. These genes are required for biofilm development from filamentation. Filamentation properties are argued to be necessary in virulence. The biofilm of bacteria is also connected to the organism’s virulence. Filamentation is a survival strategy that protects bacteria from stressors such as host effectors and protist predators. The strategy of filamentation is known to protect bacteria from antibiotic medicines taken by the host.