CALCULATION OF INTERMICROBIAL INTERACTIONS OF ORAL BIOTOPE
Authors: Zaitsev A.V. , Kotelevskaya N.V. , Boychenko O.M. , Nikolishin A.K. 
Published: June 2021

A large number of applied and theoretical questions of various sciences are solved with the help of mathematics. Mathematical methods are used in the biological sciences, in particular in medicine. They can describe both quantity and quality, ie function. The aim of the work is to consider the possibility of presenting the relationship between the associates of the oral habitat using mathematical analysis. The materials were the following: the studies of the Department of Therapeutic Dentistry, Department of Microbiology and Virology with Immunology UMSA, sources of literature related to the study of microflora. Such methods as bibliosemantic analysis, mathematical methods, online calculator were used. Based on the results of the study of the microbiocenosis of the oral cavity in young people with different values of the CPV index, graphs were obtained. The curves that reflect the changes in the number of representatives of the oral microbiocenosis at different values of the CPV index coincide with the growth fragments of biological objects (Pearl curve). The study of antagonistic activity (AA) of the oral habitat concerned several microorganisms with different growth phases. To calculate the relationship between microbial relationships, representatives of the normoflora were selected: corynebacteria, Str. mutans as well as fungi of the genus Candida. These microorganisms belong to different groups of effects on the human body. Corynebacteria form vitamin K - the growth factor of many bacteria. They are able to reduce the redox potential, thus creating conditions for the growth of anaerobes. But under certain conditions, these microorganisms can cause meningitis, brain abscesses, peritonitis, endocarditis, infections of the upper and lower respiratory tract, skin lesions, sepsis and others. Str. mutans, which belongs to Str. γ-haemolyticus, is an antagonist of putrefactive bacteria and also produces substances that inhibit the increase in other streptococci and actinomycetes. Under certain conditions, it becomes cariogenic. Yeast-like fungi Candida synthesize vitamins needed to increase lactobacilli. They are also an etiological factor of candidiasis of the oral mucosa. The calculation was performed according to the formula adapted by us on the online calculator.

According to calculations, AA corynebacteria decreases with increasing CPV, ie their activity is suppressed. A completely different situation concerns Str. γ-haemolyticus, AA which increases with increasing CPV. That is, with increasing caries intensity, this type of microorganism begins to dominate some members of the oral microbiota. For fungi of the genus Candida, the error at CPV ≤ 6 is due to the fact that at CPV = 0 they are absent in the biocenosis. Further, with increasing CPV, Candida activity also increases. It is much more pronounced than AA Str. γ-haemolyticus. This fact indicates favorable conditions for this and the suppression of yeast-like fungi of other associates microbiota.

Conclusions. Mathematical methods can be used in medicine to characterize the relationship between the biotope of the human oral cavity. Symbiotic relationships within the oral biocenosis can manifest themselves in the form of antagonism. Antagonistic activity between oral habitats can be characterized by an indicator. This technique can be used to study the function of the microbiome of the oral cavity. The calculation indicates that not one associate of the microbiocenosis, but rather several representatives are to prone for the increase in the intensity of caries. We propose to use the calculation of AA in the treatment of caries by means of influencing the oral microbiocenosis. Also, calculated AA data may have prognostic value.