Filamentation

Filamentation is the anomalous growth of certain <a href="/facts/Bacteria/wC8xSCsU">bacteria</a>, such as <a href="/facts/Escherichia_coli/nR4Gvl56">Escherichia coli</a>, in which cells continue to elongate but do not divide (no <a href="/facts/Septum/lPNxGG9u">septa</a> formation). The cells that result from elongation without division have multiple chromosomal copies.
In the absence of <a href="/facts/Antibiotic/sF1kIfxg">antibiotics</a> or other <a href="/facts/Stressor/Jn39oeN7">stressors</a>, filamentation occurs at a low frequency in bacterial populations (4–8% short filaments and 0–5% long filaments in 1- to 8-hour cultures). The increased cell length can protect bacteria from <a href="/facts/Protozoa/JczTf25H">protozoan</a> <a href="/facts/Predation/JEGdrX3f">predation</a> and <a href="/facts/Neutrophil/KL6oTt8b">neutrophil</a> <a href="/facts/Phagocytosis/eBrv2XKV">phagocytosis</a> by making <a href="/facts/Ingestion/VIsgnlnA">ingestion</a> of cells more difficult. Filamentation is also thought to protect bacteria from antibiotics, and is associated with other aspects of bacterial <a href="/facts/Virulence/TYmX1Fa6">virulence</a> such as <a href="/facts/Biofilm/zg93x2w4">biofilm</a> formation.
The number and length of filaments within a bacterial population increases when the bacteria are exposed to different physical, chemical and biological agents (e.g. <a href="/facts/Ultraviolet/kncBUqn5">UV light</a>, <a href="/facts/DNA_synthesis/ywV1plto">DNA synthesis</a>-inhibiting antibiotics, <a href="/facts/Bacteriophage/L2Ll0T3q">bacteriophages</a>). This is termed conditional filamentation. Some of the key genes involved in filamentation in E. coli include sulA, minCD and damX.

Filamentation open-in-new

Filamentation