There are a lot of microorganisms present in the environment that are not visible to the naked eye. Therefore we are more prone to the diseases and harmful effects caused by these microorganisms. And because of this peculiar feature of microorganisms, they have made their way in the category of criminal threats successfully leading to nuisance of biocrimes and bioterrorism.
Biocrimes is the intentional release of biological agents (bacteria, virus, fungi or toxins) causing harm to an individual. On the other hand, bioterrorism is the intentional release of biological agents to harm a large population.
Biothreats gained attention in 2001 because of the anthrax letter attacks in the US. An anthrax (Bacillus anthracis) laden letter was sent to many politicians and prominent personalities in the USA, killing 5 people and sending 22 people to the hospital while forcing the evacuation of congressional office building, offices of New York governor, television network headquarters, and a tabloid newspaper office.
To combat the biothreats a field called microbial forensics has been evolved. In general, Microbial forensics is the investigation of biothreats (biocrimes/bioterrorism/biowarfare) caused by biological weapons.
According to Budowle et al. 2003, microbial forensics is defined as “the scientific discipline dedicated to analyzing evidence from a bioterrorism act, biocrime, or inadvertent microorganism/toxin release for attribution purposes.”
Microbial forensics combines the practices of epidemiology with the characterization of microbes related evidence to assist in determining the specific source of the sample, as individualized as possible, and/or the methods, means, processes and locations involved to determine the identity of the perpetrator(s) of an attack.
What Microbial Forensics Do?
Microbial forensics seek to establish the specific identity of a microorganism threat, discover the source of the threat and to estimate the impact of such a threat.
Since microorganisms are present all around the environment therefore they are trackable. Once the biothreat samples are available, unleashing their identity is often relatively simple by performing biological tests to determine the exact strain of microorganism. Tools used in microbial forensics include both genetic and non-genetic based assays.
Traditional microbiology methods and features do have forensic value. These methods include culture, phage sensitivity, staining and microscopy as well as fatty acid analysis and serotyping.
Advances in technologies such as massive parallel sequencing, atomic force microscopy, mass spectroscopy and bioinformatics have enabled high-level microbial characteristization.
Nucleic acid based detection and identification technologies provide the ability to examine the genetic as well as structural information associated with a pathogen.
Microbiome analysis can be used in combination with traditional DNA analysis techniques such as short tandem repeats (STRs) sequencing and single nucleotide polymorphism analysis to provide more robust results in cases where people are suspected of having been involved with bioterrorism or biocrime.
Polymerase Chain Reaction
Polymerase Chain reaction or PCR may be performed to amplify the quantity of DNA or RNA available from a small sample. Enzyme-linked immunosorbent assay(ELISA) can be used to identify the presence of particular proteins that are unique to some bacteria or viruses.
Common staining and microscopic assay can be used to identify the microorganisms.
Massive Parallel Sequencing (MPS), also referred to as next-generation or high-throughput sequencing, offers substantially increased speed and throughput compared with previous techniques. MPS combined with power bioinformatics techniques can identify any microbe and can even be used to characterize genetically engineered pathogens.
Mass spectrometry is also useful in identifying many non-nucleic acids (proteins, carbohydrates, lipids, peptides, inorganic metals and organic metabolites) that may provide clues to microbial identity, origins and production processes.
Challenges in Microbial Forensics
Researches have shown that although there are a lot of advancements in the technologies in microbial forensics, there is still scope of improvements in certain areas. These can be:
- Developing techniques to obtain sufficient information about the microorganisms and also distinguishing between accidental, intentional or natural microbial outbreaks.
- The efforts made in the field of microbial forensics and public health should be leveraged to improve worldwide accessibility to molecular diagnostic methods and to fine tune the bioinformatics and statistical techniques used to assess evidence.
- Shortening the duration of the identification process by creating more rapid, cost effective, and robust sequencing methods, implementing technical training more widely and compiling all information on protocols that are currently in place along with the details of their validation status.
Microbial forensics is an emerging field that combines microbiology and forensic science. The combination of both the fields provides means for investigation against biothreats.
The sophisticated analytical tools and knowledge of microbial forensics can provide investigative leads and help determine the responsible individual(s) for the biocrime, the source of the bio weapon, and how and where the bio weapon was produced.
Though many advanced techniques are present for investigating biothreats, a lot more research and improvements are required in this field to protect the world from biothreats.