Synthetic Biology | Risk assessment and risk management
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Risk
Group
Biosafety Level
Laboratory Type
Laboratory Practices
Safety Equipment
1
basic
Biosafety
Level 1
basic teaching,
research
GMT
none;
open
bench work
2
basic
Biosafety
Level 2
primary health
services,
diagnostic
services,
research
GMT plus protective
clothing, biohazard
sign
open bench plus BSC
for potential aerosols
3
containment
Biosafety
Level 3
Special
diagnostic
services,
research
as Level 2 plus
special
clothing,
controlled
access,
directional airflow
BSC
and/or
other
primary devices for all
activities
4
maximum
containment
Biosafety
Level 4
dangerous
pathogen units
as Level 3 plus airlock
entry, shower exit,
special
waste
disposal
class
III
BSC,
or
positive pressure suits
in conjunction with
class II BSCs, double-
ended
autoclave
(through the wall),
filtered air
Table 6: Relation of risk groups to biosafety levels, practices and equipment (NIH 2013)
GMT….good microbiological techniques
BSC….biosafety cabinet
It is important to realise that the risk group classification scheme is to be used only for laboratory work.
However, this classification provides a convenient basis and starting point for a comprehensive risk assessment
of BioBrick™ devices and viable constructs.
The assignment of an agent to a risk group is based upon a thorough risk assessment process considering the
following issues (WHO 2004):
1)
Pathogenicity of the agent and infectious dose
2)
Potential outcome of exposure
3)
Natural route of
infection
4)
Other routes of infection, resulting from laboratory manipulations (parenteral, airborne, ingestion)
5)
Stability of
the agent in the environment
6)
Concentration of the agent and volume of concentrated material to be manipulated
7)
Presence of a suitable host (human or animal)
8)
Information available from animal studies and reports of laboratory-acquired infections or clinical
reports
9)
Laboratory activity planned (sonication, aerosolisation, centrifugation, etc.)
10)
Any genetic manipulation of the organism that may extend the host range of
the agent or alter the
agent’s sensitivity to known, effective treatment regimens
11)
Local availability of effective prophylaxis or
therapeutic interventions
The assignment of biosafety levels takes the following issues into account:
Organism (pathogenicity of the potential host/agent)
Facilities available
Equipment
Synthetic Biology | Risk assessment and risk management
60
Practices and procedures to conduct work safely in the
laboratory
Beginning in 2008, iGEM acknowledged these issues and started to request mandatorily the answering of a
questionnaire relating to the biosafety aspects of the submitted projects from the competitors (Guan et al.
2013). Risk assessment of BioBrick™ constructs under the auspices of iGEM is predominantly based upon self-
evaluation by the involved researchers in combination with incentives to involve local biosafety committees
and open to scrutiny by the public.
On the level of BioBrick™ basic and composite parts risk assessment is quite straight forward: A combination of
a strong constitutive viral promoter with a known pathogenicity determinant (e.g. adhesion-, invasion factors,
toxins, insufficiently characterised proteins etc…) intended to be applied in a human or animal environment
has to be treated in a different way compared to a system relying on an inducible promoter assembled to a
well-known housekeeping gene (e.g. glycerinaldehyd-3-phosphat-dehydrogenase, ribosomal proteins etc.).
All items deposited in the Registry Repository maintained by iGEM are accompanied by a detailed description
of their function and origin. This information is open for public and scientific scrutiny. The potential risk
mediated by a single part may, therefore, be readily assessed before the constructs are actually synthesised,
because usually sufficient information concerning biosafety aspects is available. This open source/open access
strategy followed by the iGEM consortium allows streamlining of the risk assessment process and facilitates a
first estimation of the potential risk mediated by the designed construct. On the level of BioBrick™ devices risk
assessment relevant information obtained for basic and composite parts provide a valuable basis and starting
point for a full scale risk assessment procedure for a product which is intended for deliberate release or for
commercial purposes as the cellular context comes into play.
A “self-evaluation” of iGEM projects in the years 2008 - 2011 by the executing researchers revealed four major
categories of risk they conceived concerning their application of principles for Synthetic Biology (Guan et al.
2013):
No risk: The project posed no risk at all
Minor biosafety problems: There were minor problems to be expected which the researchers were
confident to solve
Major biosafety problems: Difficult problems were to be expected during the course of the project
which were assumed
to be difficult to solve
Major biosafety problems: no solution provided
The most common observed safety issues were related to:
Known toxicity of chemicals used during the execution of the project (e.g. ethidium bromide, IPTG,
phenol, etc.)
Hazardous physical agents (e.g. ultraviolet light)
Biological waste disposal
Environmental
pollution
As insurmountable safety related problems i) horizontal gene transfer, ii) unpredictable mutations in the
designed construct in the living cell, iii) unknown and/or pleiotropic effects of the bacterial modification, iv)
misuse of the product and v) antibiotic resistance were identified.
In order to mitigate the risk of biosynthetic products appropriate biosafety laboratory trainings and
cooperation with local/institutional biosafety committees who oversaw the biosafety laboratory rules were
proposed.
Biosafety questions in the area of BioBricks™ which have to be primarily considered are: