0:09
You know, microorganisms have a lot of characteristics that tend to
make evidence valuable.
I, and by that I mean, one, microorganisms are basically everywhere.
And, you can compare that to other forms of physical evidence that
are really helpful, like soils and hairs, and fibers.
One of their values as evidence is that
0:35
people come into contact with these things a lot.
And, you know, recently we're learning that we as humans not only come into
contact with micro-organisms as we're out in the world, but we're
carrying around a lot of micro-organisms with us during life anyway.
Another aspect of microbes that I think gives them real value as physical
evidence is that, they tend to respond rapidly to disturbance.
So, if, if somebody dies and starts to decompose you could refer to that as a,
a disturbance in an ecosystem, where all of a sudden that habitat has
been introduced to a really high quality organic resource.
And microbes naturally are just going to respond to that because it
represents a large nutrition food source for them.
Microbiology actually has a really long history in forensic science even though,
now a days, you don't hear about it much or
possibly don't even think about it much if you're a forensic scientist.
1:37
Really I have publications going back to the,
the early 20th century about post-mortem microbiology.
And most of the time,
the goal of those investigations is to figure out is a microorganism
associated with the cause of death through some type of microbial infection.
And that's really what the definition of postmortem microbiology was for 100 years.
You know, taking biological samples, whether it's fluids during an autopsy or
pieces of tissue, and
seeing if a microorganism made some contribution to that person's desk.
Where post-mortem microbiology really got hung up along the way was,
it had this reliance totally on culturing techniques.
So you'd have a pathologist conducting an autopsy, taking samples, and
sending samples off for a microbiological study to be done.
And what that postmortem microbiologist would do was take those samples and,
and see what they could culture from it.
Well, the problem with that is, when you try and
culture something from an environmental or an autopsy sample.
Your taking that bit of resource and putting it
in a completely different habitat that it is during life or during death.
And what that does it often times,
it selects for different organisms that you wouldn't be finding there.
Anyway, and so there's a lot of pathologists out there that
haven't got a lot of value out of postmortem microbiology because it's very
difficult to culture some of those pathogenic microbes because they get
outcompeted by other microbes when they're in the culture medium.
3:27
Just in the last decade, we've seen a real opportunity for
postmortem microbiology to advance because we, there's been a great advancement
in our ability to sequence and identify none culturable micro-organisms.
So, now what a pathologist could do is send off a sample and
then a microbiologist could sequence the microbial community and
be able to see everything that's there.
Not just what they're able to culture in their laboratory.
And I think these capabilities are going to be opening up areas of research,
areas of application in postmortem microbiology that will completely
revolutionize this field and I, I think probably 10, 20 years from now, when you
talk about postmortem microbiology, or even forensic microbiology,.
There will be areas of knowledge that are completely new to what we're doing today.
Rob KnightProfessor
Dr. Jessica L. MetcalfSenior Research Associate
Dr. Katherine R. AmatoPostdoctoral Research Associate
