Application of a Petri dish with a millimeter ruler

The development of the team of authors relates to veterinary microbiology, namely, to laboratory equipment for the cultivation of colonies of microorganisms. The most effective use of a Petri dish with a millimeter ruler is to establish the degree of growth retardation of microorganisms when determining their antibiotic sensitivity. The industry produces contact Petri dishes, and also produces stickers with a grid for Petri dishes. However, these large-cell counting grids are intended only for counting the number of colonies of microorganisms inside their cells, and not for obtaining the size of the growth retardation zone of microorganisms when determining their sensitivity to antibiotics, expressed in millimeters. When working with such counting grids that are not designed to determine the size of the growth retardation zone of microorganisms when determining their sensitivity to antibiotics, it is impossible to obtain reliable results. It is unacceptable when analyzing the sensitivity of microorganisms to antibiotics, carried out in order to prescribe timely and effective antibiotic therapy to animals. The purpose of modifying the Petri dish is to eliminate these shortcomings and perform accurate laboratory tests for determining the microorganisms antibiotic sensitivity in various time periods (hours, days) at the stage of their cultivation. The use of a modified Petri dish with a millimeter ruler allows: to conduct an early and step-by-step study of the growth retardation of microorganisms when determining their antibiotic sensitivity at the stage of their cultivation; to visualize the place of the beginning and completion of the inspection of the growth retardation of colonies of microorganisms in a Petri dish with a millimeter ruler; to eliminate the need for repeated studies; to increase the accuracy of research results.