Genital Microorganisms May Help Identify Sexual Offenders



During sexual intercourse, there is a transfer of bacterial species between individuals that allows the identification of each person's genital microbiome, or 'sexome', according to a study that suggests that this could be used to identify sexual offenders.


The work was carried out by scientists at Murdoch University in Australia, who say the results show there may be microbial markers that detect sexual contact even when a condom is used.


The analysis could be useful in forensic areas, especially in cases where human DNA cannot be detected, the authors highlighted, who, however, admit that definitive application in cases of sexual assault is still far away and more research is needed, the Efe news agency reported on Wednesday.


The research, published in the Cell group's journal iScience, is based on the forensic concept that every contact leaves a trace, explained Brendan Chapman.


Researchers have confirmed that both men and women have unique populations of bacteria in their genital areas.


For the study they recruited 12 monogamous heterosexual couples to investigate whether these genital microorganisms --- which they dubbed the 'sexome' --- are transferred during sexual intercourse, even when a condom is used.


At the beginning of the study, each participant collected samples of their genital microbiome using cotton swabs. The researchers used genetic sequencing to determine which bacterial strains were present and identified each participant's microbial signatures.


The couples were then asked to abstain from sexual intercourse for varying periods of time (2 to 14 days) and then had sexual intercourse. Samples of the genital microbiome from each individual were collected again.


The analysis showed that a participant's unique bacterial signature could be identified in their sexual partner's sample after intercourse.


Three couples reported using condoms. The analysis found that while this had some impact on the transfer of microbial content, it did not completely inhibit it.


For the researcher, "the development is promising as a means of analyzing the aggressor after the assault and means that there may be microbial markers that detect sexual contact even when a condom has been used."


The researchers also looked at whether the men were circumcised and whether the participants had pubic hair, and found that neither factor appeared to affect the transfer of bacterial species.


However, they noted that the composition of the vaginal microbiome changed during menstruation, which the authors said could affect the results.


"The application of the 'sexome' to sexual assault cases is still in its early stages," said Dixon, who also believes it is "important to fully understand the external factors that may impact microbial diversity in men and women."