title: Fluorescently labeled bacteria provide insight on post-mortem microbial transmigration.
abstract: Microbially mediated mechanisms of human decomposition begin immediately after death, and are a driving force for the conversion of a once living organism to a resource of energy and nutrients. Little is known about post-mortem microbiology in cadavers, particularly the community structure of microflora residing within the cadaver and the dynamics of these communities during decomposition. Recent work suggests these bacterial communities undergo taxa turnover and shifts in community composition throughout the post-mortem interval. In this paper we describe how the microbiome of a living host changes and transmigrates within the body after death thus linking the microbiome of a living individual to post-mortem microbiome changes. These differences in the human post-mortem from the ante-mortem microbiome have demonstrated promise as evidence in death investigations. We investigated the post-mortem structure and function dynamics of Staphylococcus aureus and Clostridium perfringens after intranasal inoculation in the animal model Mus musculus L. (mouse) to identify how transmigration of bacterial species can potentially aid in post-mortem interval estimations. S. aureus was tracked using in vivo and in vitro imaging to determine colonization routes associated with different physiological events of host decomposition, while C. perfringens was tracked using culture-based techniques. Samples were collected at discrete time intervals associated with various physiological events and host decomposition beginning at 1h and ending at 60 days post-mortem. Results suggest that S. aureus reaches its highest concentration at 5-7 days post-mortem then begins to rapidly decrease and is undetectable by culture on day 30. The ability to track these organisms as they move in to once considered sterile space may be useful for sampling during autopsy to aid in determining post-mortem interval range estimations, cause of death, and origins associated with the geographic location of human remains during death investigations.
authors.affiliation: Department of Biological Sciences, Mississippi State University, Starkville, MS, USA. Electronic address: zmb50@msstate.edu.
authors.forename: Z M
authors.initials: ZM
authors.lastname: Burcham
authors.affiliation: Department of Biological Sciences, Mississippi State University, Starkville, MS, USA. Electronic address: jah842@msstate.edu.
authors.forename: J A
authors.initials: JA
authors.lastname: Hood
authors.affiliation: Department of Entomology, Michigan State University, East Lansing, MI, USA. Electronic address: pechalje@msu.edu.
authors.forename: J L
authors.initials: JL
authors.lastname: Pechal
authors.affiliation: Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City, KS, USA. Electronic address: kkrausz@kumc.edu.
authors.forename: K L
authors.initials: KL
authors.lastname: Krausz
authors.affiliation: Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City, KS, USA. Electronic address: jbose@kumc.edu.
authors.forename: J L
authors.initials: JL
authors.lastname: Bose
authors.affiliation: Department of Pathology, University of Michigan, MI, USA. Electronic address: cjschmidt@earthlink.net.
authors.forename: C J
authors.initials: CJ
authors.lastname: Schmidt
authors.affiliation: Department of Entomology, Michigan State University, East Lansing, MI, USA; Department of Osteopathic Medical Specialties, Michigan State University, East Lansing, MI, USA. Electronic address: benbow@msu.edu.
authors.forename: M E
authors.initials: ME
authors.lastname: Benbow
authors.affiliation: Department of Biological Sciences, Mississippi State University, Starkville, MS, USA. Electronic address: jordan@biology.msstate.edu.
authors.forename: H R
authors.initials: HR
authors.lastname: Jordan
mesh_terms: D000818:Animals; D018988:Bacterial Translocation / Q000502:physiology*; D003016:Clostridium perfringens / Q000502:physiology*; D015169:Colony Count, Microbial; D005453:Fluorescence; D049429:Forensic Pathology; D008812:Mice, Hairless; D023421:Models, Animal; D011180:Postmortem Changes; D013211:Staphylococcus aureus / Q000502:physiology*; D051598:Whole Body Imaging
keywords: Clostridium perfringens; Decomposition; Forensics; Necrobiome; Staphylococcus aureus