4 Plant and Microbial Forensics

Transcript

Hello!! welcome back to the fourth talk of the week that is Plant and microbial forensics. We already know that forensic science is applied to investigate a crime and the same principles applied for microbial forensics or forensics in plant pathology where a criminal approach is been investigated and the perpetrator of the crime is punished. So let us see how the forensic science in Plant Pathology works.

So, Microbial Forensics is defined as the application of scientific approaches to solve a crime that involves a microorganism. Its goal is to investigate and present unbiased scientific evidence useful for attributing the crime to a perpetrator recent programs intended to enhance general capabilities in microbial forensics there have included specific attention to plant pathogens. Compared to strategies employed by traditional plant disease diagnosticians forensic applications of plant pathogen diagnostics require usually high level of stringency, reliability and prior validation. These assays must be paired with forensic investigations for example court-defensible sampling methods, chain of custody and other traditional and non[1]traditional methods of forensic investigation.

Forensics in plant pathologists – have been deployed very recently. So, it’s a blend of disciplines of plant pathology and forensic science that supports the investigation of plant diseases and pathogens by providing unbiased scientific methodology and evidence for criminal attribution. Important to this effort are trace backs strategies for determining pathogen origin and movement pathways as well as the possible role of human intent. So this is very important whether there is any involvement of human in the microbial associated crime that needs to be investigated. Multidisciplinary teams including representatives of diagnostic regulatory and law enforcement communities must work in coordination to achieve the most effective response. More creative strategies for both vertical and horizontal communication among the involved biosecurity and law enforcement agencies are needed to solve certain issues.

Now, what is the difference between Forensics and Traditional Plant Disease Diagnosis – In traditional plant disease diagnosticians are multifaceted approaches to detect and identify diseases and the causal pathogens. Here the primary stakeholders include Farmers, Extension educators, crop consultants and regulatory officials and the primary goal is to identify the pathogen to recommend effective means of disease management. Whereas, in case of forensics it is the application of scientific methods and strategies to solve a crime with the primary goal of connecting the crime to a perpetrator for the purpose of criminal attribution. The major stakeholders for forensic science include members of the law enforcement, security, investigative and regulatory communities. So these are some of the basic differences between a traditional and a forensic plant disease diagnosis.

Why do we Need Plant Pathogen Forensics?

Then what is the necessity of forensics in plant pathology. The plant based resources for any nation that includes a forests, rangelands, crops raised for food and fiber, etc. are among the most critical components of its infrastructure and it contributes to a healthy environment and robust national and international market. So, any critical element of national infrastructure might become a target of those having a motive to harm a nation, region, company, person or other entity. And, that is why to protect this national resources one has to link plant disease diagnostics with forensics. Crimes are also always committed intentionally. Negative consequences can also result from unintentional actions. For example, if a grower purchases seed that is certified as disease free but later after losing the crop to disease learns that the order was filled inadvertently with pathogen contaminated scene there may be a cause for a lawsuit based on criminal negligence. So, it is not the grower who is responsible for such situations, but it is the packager who is basically can be charged for negligence. Other crimes may include multiple elements for example, smuggling of exotic plant material such as seeds, fruits, propagating plant parts is a frequent biocrime at airports and ports of entry, but if the smuggle material is contaminated with pathogens or other exotic microbes there may be an additional criminal charge for which forensic investigation is needed. So, biocrime is always a common problem in the port of entry, but if the biomaterial is associated with a quarantine pathogen or a new pathogen then the crime becomes more severe and it requires involvement of forensic specialists.

How we come to know that whether a crime has occurred or not?

The prerequisite to any forensic investigation is an informed judgment that a crime has been committed. It is important to know if the presence of a plant pathogen or the occurrence of plant disease may have resulted from criminal activity. So plant disease is a natural phenomenon but whether the occurrence of plant disease has any crime involved for example, it is an intentional by involvement of certain human beings disease development comes into the scenario of a crime. Since agricultural producers and consultants environmental specialists and plant disease diagnosticians are generally unused to considering the possibility of intentional intervention, a term normally called as ‘suspicion inertia’, it is important to consider what features of a plant disease even might prompt a contact that would lead to investigation. So it is very essential to determine whether there is any association of any crime and then if any investigation is required to be associated with the occurrence of that particular plant disease.

Sampling for Plant Pathogen Forensic

So, sampling for forensic science involves mostly two steps – collection of sample and chain of custody.

Assay Features

And Assay features include Pathogen Detection Assays as well as Pathogen Discrimination Assays. In the pathogen detection assays the detection methods used in microbial forensics include an array of serological and molecular detection assays, mass spectrometry, nucleic acid sequencing, and bioinformatics. Selection of the most appropriate methods depends on the type of pathogen, the tools available, and the scope of the screening. Whereas, pathogen discrimination assays involved since microbial forensics is often a question of fine-level “matching” of microbes found at a crime scene with those associated with a suspect, microbes may be subjected to molecular fingerprinting techniques such as restriction fragment level polymorphism (RFLP), multi-locus variable repeat analysis (MLVA), single nucleotide polymorphism (SNP) assays, single sequence repeat or inter-single sequence repeat (SSR and ISSR) assays that will discriminate among strains of a pathogen. So, it is not only detection of the pathogen but also it is important to establish the strain or biomire of the pathogen for which certain specific molecular tools have been deployed in forensic science because this is highly essential going for a criminal investigation.

Evidence Interpretation and Criminal Attribution – is another important aspect in forensic investigations. So forensic evidence is judged in the courtroom and the judgment is conferred by a jury panel. I n the investigation of a crime that may involve plant pathogens forensic plant pathologist must gather, safeguard, analyze and interpret a comprehensive package of information to be used by prosecutors or defendants as evidence in a court of law. In addition to diagnostic assays providing pathogen identification data with acceptable level confidence levels interpretation of field and laboratory tests must be done in consideration of other evidence such as the chain of sample custody, the history of disease site and crop, possible motives and access of individual other than the suspect and other relevant factors.

So as investigated in other human associated crime in forensic plant pathology also certain angles has to be looked upon during the court presentations. At times even a comprehensive package of evidence and court testimony is unlikely to result in hundred percent confidence in a world per day. So until and unless a full proof support system is there it is not necessarily that the perpetrator will be vindicated in the law of court if the evidences are not sufficient enough to prove the same. So with this we have seen that how important forensic plant pathology in current days and how it is helping us to stop or check certain human mediation in involvement of certain microbial associated crime and it is definitely a emerging branch on plant pathology.

So with this we have come to an end of this topic that plant and microbial forensics and in the last talk of the week we’ll be talking about Development and Implementation of Rapid Detection Techniques for plant disease diagnosis. Till then have a good time.

Thank you very much.