Uncovering the essential building blocks which bacteria use to make long, hair–like filaments could lead to new drugs to fight infection.

Bacteria use long, trailing hairs called pili for a number of functions, including movement and swapping DNA with other cells.

One of the most important functions of these filaments, however, is helping microbes stick to surfaces. In harmful, or ‘pathogenic’, bacteria this helps the bugs to colonise their host, an essential early step in infections.

Previous research has revealed that microbes use up to 15 proteins to make the most universal and multipurpose filaments, called type IV pili (TFP).

Now, a group led by researchers at Imperial College London has uncovered that just eight of these proteins are essential to the assembly process, without which bacteria cannot form the filaments.

According to Dr Vladimir Pelicic, from the MRC Centre for Molecular Bacteriology and Infection at Imperial, who led the research, TFPs are like a “Swiss Army Knife for bacteria”.

They carry out a variety of roles, including helping the cells to move, stick to surfaces and sense changes to their environment. Crucially, the filaments are used by bacteria to pick up new DNA from their surroundings, including genes which can make them more harmful to hosts, or more resistant to antibiotics.

The study, which included researchers from University College London and the University of Wisconsin Madison, and was published in the journal Proceedings of the National Academy of Sciences, used E.coli bacteria to uncover the crucial proteins needed for making filaments.