title: Detection of diverse aquatic microbes in blood and organs of drowning victims: first metagenomic approach using high-throughput 454-pyrosequencing.
abstract: Current 454-pyrosequencing technology enables massive parallel sequencing. We used this technology to investigate the diversity of aquatic microbes in 14 specimens (blood and organs) of two drowning victims and in two water samples taken from the discovery sites. The 16S ribosomal RNA (rRNA) genes of microbes, which are often used to identify species (or genera), have nine highly variable regions (V1-V9), each of which is surrounded by conserved regions. Some parts within the conserved regions are common over domains of microbes, such as between bacteria and algae (16S rRNA genes on algal chloroplast genomes). We therefore simultaneously amplified the target regions (V7 and V8) of various microbes in the blood and organs of drowning victims using PCR with custom-designed primers that were based on the conserved regions. We then exhaustively analyzed the PCR products by pyrosequencing using the Genome Sequencer FLX Titanium system (Roche-454 Life Sciences). This approach identified a wide array of bacteria including cyanobacteria and algae including Bacillariophyceae (diatom), Cryptophyceae, Dictyochophyceae, Chrysophyceae and Trebouxiophyceae in the blood and organs of the victims and water at discovery sites. Our data further indicated that when conventional diatom testing of lungs yielded insufficient evidence of water aspiration, the detection of various exogenous microbes by 454-pyrosequencing is very useful to support a conclusion of death by drowning. To the best of our knowledge, this is the first attempt to use a new generation sequencer to investigate diverse aquatic microbes in the blood and closed organs of drowning victims.
authors.affiliation: Division of Legal Medicine, Department of Social Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan. eijik@med.miyazaki-u.ac.jp
authors.forename: Eiji
authors.initials: E
authors.lastname: Kakizaki
authors.forename: Yoshitoshi
authors.initials: Y
authors.lastname: Ogura
authors.forename: Shuji
authors.initials: S
authors.lastname: Kozawa
authors.forename: Sho
authors.initials: S
authors.lastname: Nishida
authors.forename: Taketo
authors.initials: T
authors.lastname: Uchiyama
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hayashi
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Yukawa
mesh_terms: D000328:Adult; D001419:Bacteria / Q000235:genetics* / Q000302:isolation & purification*; D058893:DNA Barcoding, Taxonomic; D004269:DNA, Bacterial / Q000235:genetics; D017377:Diatoms / Q000302:isolation & purification; D004332:Drowning / Q000175:diagnosis*; D005260:Female; D049429:Forensic Pathology; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006801:Humans; D007668:Kidney / Q000382:microbiology; D008099:Liver / Q000382:microbiology; D008168:Lung / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000032:analysis
chemical_list: D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S