VIDEO. Subway bar, door handle, toilet flush, are these objects so dirty?

“There is no dirt in the bacteria”. For Geneviève Héry-Arnaud, the bacteria that are part of our daily lives are not unsuitable. According to her, we must accept that they are part of our environment. A teacher-researcher in bacteriology, her job is to determine bacteria, their characteristics and their names. And for Brut, she lent herself to the game of examining a few everyday objects.

“The vast majority of bacteria are neutral on us”

A few days after making contact with the objects, circles, corresponding to bacterial colonies, formed. Whether on a door handle, a toilet flush or a subway bar, most of the bacteria found by Geneviève Héry-Arnaud come from our natural environment. On the subway bar, there are “gram-positive cocci”, probably staphylococcus that comes from the palms of the hands of passengers who have used the subway bar. “There was an article that caused quite a stir because they had discovered Yersinia pestis on the subway in New York. They had made headlines saying: ‘Plague in the New York subway!’ Except that their technique was not quite perfect yet. And, there are several species of Yersinia, but it wasn’t a Yersinia pestis, it was a Yersinia enterocolitica. Well, it’s not a very friendly germ, it gives gastroenteritis, but it’s still nothing to do with the plague. So they went a bit fast”, continues Geneviève Héry-Arnaud.

For her, bacteria are, in the majority, neutral on us. “The vast majority of bacteria are totally, at least, neutral on us, or even better, they do positive things to us for our health. So, the ones that make us really sick, they can be counted on the fingers of one hand”, adds Geneviève Héry-Arnaud.