title: Molecular identification of vaginal fluid by microbial signature.
abstract: The discrimination of body fluids in forensic examinations can play an important role in crime scene reconstruction. Conventional methods rely on the detection of antigens or enzymatic activity, limiting detection sensitivity and specificity, particularly on old forensic samples. Methods based on human RNA analysis are not easily applicable to samples exposed to harsh and degrading environments. An alternative approach based on the identification of prokaryotic genomes was developed. Specific bacterial communities are characteristic typical of different human non-sterile body fluids: the molecular characterization of a microbial signature, and not the typing of single bacterial species, can effectively lead to univocal identification of these fluids. A multiplex real time PCR assay was developed using oligonucleotide mixtures targeting genomes specific for a selected group of bacteria. Microflora DNA (mfDNA) was extracted from vaginal, oral and fecal clinical swabs. In addition forensic samples were processed. Vaginal samples showed a strong specific signal for bacteria of the female genital tract. Oral samples clearly showed signal for bacteria present in saliva, and in fecal samples the main signal was from Enterococcaceae. Vaginal casework samples showed results comparable to freshly collected ones; moreover the DNA extracted was successfully used for STR typing. Also mixtures of body fluids were analyzed, providing a microbiological signature compatible with the presence of microbes of oral, fecal and vaginal origin. The presented method can be useful in identifying biological fluids, and it is based on DNA technologies already available in forensic laboratories and feasible for further high throughput automation.
authors.affiliation: University of Rome Foro Italico, Unit of Public Health, P.zza L. De Bosis, 6, 00135 Roma, Italy.
authors.forename: Saverio
authors.initials: S
authors.lastname: Giampaoli
authors.forename: Andrea
authors.initials: A
authors.lastname: Berti
authors.forename: Federica
authors.initials: F
authors.lastname: Valeriani
authors.forename: Gianluca
authors.initials: G
authors.lastname: Gianfranceschi
authors.forename: Antonio
authors.initials: A
authors.lastname: Piccolella
authors.forename: Laura
authors.initials: L
authors.lastname: Buggiotti
authors.forename: Cesare
authors.initials: C
authors.lastname: Rapone
authors.forename: Alessio
authors.initials: A
authors.lastname: Valentini
authors.forename: Luigi
authors.initials: L
authors.lastname: Ripani
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Romano Spica
mesh_terms: D001483:Base Sequence; D001826:Body Fluids / Q000378:metabolism*; D017931:DNA Primers; D004269:DNA, Bacterial / Q000235:genetics*; D005260:Female; D006801:Humans; D018895:Microsatellite Repeats / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D014621:Vagina / Q000378:metabolism* / Q000382:microbiology
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial