Micro-Organisms: An Investigative Tool in Forensic Science
On February 16th, 1934, India reported its first biological attack. Amarendra Chandra Pandey was murdered by a goon assigned by his brother Vinayendra Chandra Pandey via needle prick, which contained one of the most dangerous bacteria, Yersinia Pestis.
It was injected, and it further worsened into a plague; he fell into a coma on December 3rd and died on December 4th. The death of a completely healthy individual due to the plague caused quite a suspicion among the finest doctors of India.
They further did a research study that led to the investigation and trial of Vinayendra.
Microbial Forensics: An Emerging Tool in Crime Investigation
Over time various cases like the anthrax attack had proven how effortless it is to cause an attack using biological weapons. Micro-organisms are all around us. Due to its intrinsic features consisting of infectivity, virulence, toxicity, pathogenicity, transmission ease, etc. makes them the perfect weapon of attack.
The study of micro-organisms is called as microbiology. The application of microbiological studies in solving crimes or studying their investigations is covered under Microbial forensics. It lays its basic foundations upon classical sciences such as medicine, forensic genetics, epidemiology, molecular and evolutionary biology.
If we consider the biological attacks from Mongols to the recent Anthrax attack in the US, the organisms used to weaponize were mostly bacteria sharing oddly similar characteristics, such as rod-shaped. They first affected/caused the respective diseases in domestic animals.
This similarity was because, in this pattern, organisms were easily transferrable, like from domestic animals to humans, say while feeding them or petting them, and the shape and consistent characteristics making them easily dispersible.
Hence, these minute organisms can be heavily weaponized with the present and developing technologies, causing heinous spread among the people, which brings us to studying micro-organisms in microbial forensics, which will help the investigators be much more aware of the potential weapon and the crime that occurs.
Micro-Organisms and Trace Evidences
Microbial Forensics is not only restricted to analyze the use of bioweapons. It is said that humans often shed approximately thirty billion bacterial cells around them into the environment. Also, every individual has their unique HUMAN MICROBIOME, including identical twins!
There exist symbiotic microorganisms in every living body, which might even evolve slightly property-wise. However, the composition remains the same. This difference in the property and structure of the microbiome among different individuals is due to the host’s lifestyle, diet, travel pattern, occupation, pharmaceutical usage, etc.
This proves to be of great importance in forensics, considering the possibility of microorganisms becoming trace evidence from crime scenes to victims’ body that can potentially be a biome unique to the perpetrator itself. Hence the study of these human microbiomes can help in individualization.
The Human Microbiome Project (HMP) By the National Institutes of Health, US, was a research project aimed at studying the microbial flora of human beings and their effect on health and diseases.
Their first phase included studying the presence of naturally occurring micro-organisms in the human body, which they broadly classified under the biological group Bacteria, members of the domain Archae, yeasts, and single-celled eukaryotes, and various helminths, parasites, and viruses.
Even among these, a considerable portion of microbial flora exists that are unidentified. In the subject “Microbial Forensics,” microorganisms are studied the same way as that in microbiology.
It covers the method of collection and preservation of micro-organisms, their identification, sampling (into various culture plates), their culturing, followed by observing them and studying the characteristics that can relate them as a crucial bioweapon or trace evidence.
When it comes to viewing the organisms under microscopes from the cultures, staining techniques are fundamental, and they are studied on a large scale too.
The subtopic studied under microbial forensics is the analysis of toxins. This solely directs to the part where we can learn more about organisms as bioweapons. In most bio attacks, the organisms used tend to produce collective toxins that are extremely harmful.
The increasing usage of toxins in bio attacks is mainly due to easy production and quick mode of action. Simple culturing techniques can be followed to culture both bacteria and fungi. This followed by a simple extraction protocol, gives a ready usage of toxins.
Most microbial toxins affect the central nervous system (CNS), resulting in quick irreversible damage with minimal temporal window periods for countermeasures. One of the major toxins that can be a source of interest is Aflatoxins and their variants.
A group of mycotoxins is produced by Aspergillus species of fungi such as Aspergillus flavus or Aspergillus parasiticus. They can be of four types B1, B2, G1, and G2. Among these, Aflatoxin B1 is a potential carcinogen.
Aflatoxins are commonly linked with goodies produced in the tropic and sub-tropic areas, such as peanuts, cotton, spices, etc. Some other potential toxins can include Botulinum neurotoxins, Diphtheria toxins, etc.
Microbial toxins are better preferred than microorganisms (microbial cells) for biowarfare because; identification of toxins, especially on injection, is comparatively tricky as against bacterial or fungal cells. However, analysis of these toxins cannot be succeeded via PCR or other microbiological techniques.
Neither do they contain genetic material such as DNA, nor can they be grown in vitro conditions. Hence spectrometric methods, such as Mass spectrometry, are much preferred over traditional analysis for toxins.
From thriller TV series to mystery movies, forensic science has greatly influenced young minds. Budding up, these enthusiasts have now become focused on entire career revolving around forensic science.
Moreover, that thankfully has started to develop into a vast field of more inventions and technologies. Microbial forensics, a new topic in forensic science, can potentially be a fantastic evolution, making the best evidential support for any crime.
Of course, there is more interesting than those tiniest, beautiful creatures and to study about them?
By ADRA BALAGOPAL
Adra Balagopal has completed her Graduation in Forensic Science Honours from Jain University, Bangalore. Mysteries and Investigations has always fascinated her. It was quite accidental, bumping upon an elective Subject called microbial forensics back in her college days which inspired her a lot.