Development of A new method for using hand microbiota in identification of people

The most important part of the forensic research is the crime scene investigation. The investigation is clarified by the evidence obtained at the scene. If the evidence is corrupted or there is insufficient evidence, the investigation cannot be concluded. However, the fact that forensic sciences are a multidisciplinary field often provides the opportunity to associate evidence with crime. In forensic microbiology which is one of the sub-branches of forensic sciences, it is very substantial to identify microorganisms in order to determine the culprit. In cases where DNA and fingerprint which are the most important findings of incidence is not sufficient, microorganisms as invisible evidence can be identified and clarification can be provided. Recently, researches on microbiota indicate that all regions have a microbiota of their own and that the hand microbiota also has characteristic features. The hand microbiota forms a personal profile, despite the factors that may affect it such as lifestyle, geography, profession, or antiseptic use. Therefore, hand microbiota plays a critical role in distinguishing individuals who have samples on environmental surfaces. In our project, ribotyping of 16S, 23S gene regions and VNTR analysis of S.epidermidis in microbiota obtained from 10 different individuals collected for 10 days were evaluated. Similarity ratios in the distinction, clustering in common study areas, ability to identify people in contact with inanimate surfaces were evaluated. In order to increase the power of discrimination, 12 clusters were obtained. However, the rate of interpersonal similarity was found to be 77.143%, while the least similarity rate was 31.746%. In addition, two different groups of people with hand-held microbiota examples of their work environment compatible with two different groups can be distinguished. Our study showed that hand microbiota samples retain their core attributes in spite of factors such as life style, occupation and hand washing characteristics, and they carry these traces in the environment and contact surfaces. It has been shown that personal and unalterable hand microbiota is valuable in identifying crime-related persons in forensic sciences and contributing to coverage/exclusion.