Method for detecting the presence or absence of biological particles

A method for detecting the presence or absence of at least one first inhibition zone comprised by a culture of biological particles on a culture medium in the presence of a chemical agent, said method of detection comprising

• a first step of seeding the culture medium with the biological particles,
• a second step in which the culture medium receives a support impregnated with the chemical agent, and
• a third step of incubation of the culture medium, wherein
• the method of detection comprises
• a fourth step of measurement comprising:
• a first phase of taking an image of the culture medium by ombroscopy so as to generate a two-dimensional intensity image of the culture medium in which the first inhibition zone is darker than a proliferation zone of the biological particles,
• an analysis of the two-dimensional intensity image in which the presence of the first inhibition zone is detected,
• measuring a diameter of the first inhibition zone and a distance between the impregnated support and an edge of the first inhibition zone, and
• at least one operation of estimating a minimum inhibitory concentration based on determination of an abscissa of the referenced minimum inhibitory concentration, to determine sensitivity of the biological particles to the chemical agent;
• wherein the first phase, the analysis, the measuring and the at least one operation of estimating are implemented by a detecting device including a processor comprising a calculating means configured to implement the fourth step of measurement.