Nine types of bacteria associated with drug-resistant superbugs were discovered by scientists during tests on the Tube- and the Victoria line is the capital’s dirtiest.

A new study carried out by microbiologists at London Metropolitan University found 22 different types of bacteria were present on the line, which runs from Walthamstow to Brixton.

Of those, three potentially-fatal strains of bacteria, Staphylococcus Aureus, E.coli and Klebsiella Pneumoniae, were picked up in swabs taken from seats, doors and handrails.

An outbreak of Klebsiella Pneumoniae at a hospital in Manchester in 2014 was linked to the death of 14 people- and the superbug is resistant to 26 different types of antibiotic.

Dr Paul Matewele, a microbiologist at London Metropolitan University, said: “The Klebsiella Pneumoniae infection is a superbug that antibiotics cannot fight and can be extremely harmful.”

“The bacteria doesn’t usually affect healthy people. It’s mainly a problem if transmitted between sick patients in hospitals and between people with weakened immune systems.

“But, not only did we find potentially life threatening bacteria which behaved like superbugs when tested against antibiotics, but other forms of mould and bacteria that can be harmful to humans.”

The research, funded by taxi insurance firm Staveley Head, discovered 121 types of bacteria living in trains, buses and cabs across the capital, including nine antibiotic-resistant superbugs.

Some 16 different strains were found on the Central line, which serves areas of Waltham Forest, Redbridge and Epping Forest.

The cleanest Tube line on the London Underground network was the Metropolitan line, where just 11 different types of bug were found.

The study found the average London cab is home to 14 different types of bacteria, with traces of faeces and salmonella also detected in some of the vehicles tested.

However, it was buses that the research suggested are London’s cleanest form of public transport, with just 37 different bacteria found on board those tested.