It is well known that in the oral cavity, there are many bacterial species, both aerobic and anaerobic and the most common pathological phenomena in the oro-dental sphere (caries and periodontal disease) have bacterial aetiology. Therefore, a first step in diagnosing oro-dental bacterial infections is collecting pathological products and identifying existing bacteria. There are two categories of methods that can be used: classical methods (which use taxonomic criteria) and modern (multitest systems, which use biochemical measures, with increased stiffness and accuracy). The best known fast systems for Gram-positive bacteria are those in the API category (API 20C, API 20E). In this case, the harvested biological products are taken from the oro-dental sphere: the pus from the periodontal pouch and the softened dentin from dental caries. The multitest system used for identification is API 20 Strep. The mechanism underlying the identification of isolated pathogenic bacteria is an enzymatic, specific biochemical process (fermentation of carbohydrates, for example, which takes place in dental plaque). Fermentation tests are inoculated with bacteria in the enriched culture medium that rehydrates the sugar substrates. A change in pH and colour detects carbohydrate fermentation. The reactions are read according to the reading table, and the identification is obtained by referring to the analytical profile index or using the identification software. Upon completion of the identification process, it was observed that the identified bacteria are part of the genus Streptococcus, namely Streptococcus mutans and Streptococcus oralis. Both are species known for their essential role in plaque formation, tooth decay and periodontal disease.

Acknowledgements: “The work of the first author is supported by the project ANTREPRENORDOC, in the framework of Human Resources Development Operational Programme 2014-2020, financed from the European Social Fund under the contract number 36355/23.05.2019 HRD OP /380/6/13 – SMIS Code: 123847. The work of the second author was carried out in the framework of the research project DREAM (Dynamics of the REsources and technological Advance in harvesting Marine renewable energy), supported by the Romanian Executive Agency for Higher Education, Research, Development and Innovation Funding – UEFISCDI, grant number PN-III-P4-ID- PCE-2020-0008.”