Melbourne: Scientists from Melbourne has begun a study to discover how much bacteria is living within the Australian city's public transport system. Melbourne, along with Sydney, are two of 58 cities participating in an international study based out of New York, which is aimed at developing an outline of the germs and bacteria found in major cities' public transport systems, Xinhua news agency reported on Wednesday. In Melbourne, the team will run tests inside and outside trains, trams and buses. In the study already completed in New York's subway system, scientists discovered that of the human bacterial DNA identified, 32 per cent was associated with the stomach and intestine area and 29 per cent was connected to the skin. Another 20 per cent of the bacteria was identified from the genital area and almost 10 per cent was associated with the simple act of breathing. The Melbourne team, led by Monash University science student Andrew Gray, said on Wednesday that each city is taking a "selfie of its microbiome", also known as its bacterium system. To create a snapshot of Melbourne's bacterium landscape, scientists and volunteers ran tests across seven of Melbourne's train stations, including key tourist spot, Flinders Street station, and the CBD's Southern Cross and Melbourne Central stations in June. The scientists swabbed the infrastructure around key transport hubs, including benches, vending machines, hand rails, escalators and bike racks near the stations. The swabs were then placed in a tube containing a mixture designed to keep the bacteria alive but inactive. "We really know very little about the bacteria that surround us," Gray said. The international experiment, which is partly being funded by the Bill and Melinda Gates Foundation in the US, will hopefully give researchers an understanding into any bacterial trends that develop in the major cities, as they aim to combat infectious disease. Of the data collected in New York, 48 per cent did not match any known living organism, showing how ambiguous and unknown the bacterium can be. The results of the Melbourne samples will be available within six months, as the tubes are currently being stored in a community science laboratory in Melbourne.