Now working as a regulatory affairs specialist, early in my career I worked across programs in food safety, animal and plant health, and seed certification, using molecular based evidence in research and technology development, and in technical program support to enhance regulatory compliance and enforcement activities under the Canadian Food Inspection Agency.
Control of insect pests in both public health and agriculture is coming under increasing pressure... more Control of insect pests in both public health and agriculture is coming under increasing pressure due to the accelerated prohibition of pesticide chemistries, increasing resistance to chemistries that are authorised and limited discovery of novel active ingredients. Additionally, consumers, food producers and governments are seeking non-chemical or integrated solutions for insect pest pressures which are more aligned with environmental protection goals such as the reduced use of chemical controls. Biological control using self-limiting genetics represents a new paradigm for pest insect management and is especially advantageous where those pests are or have become resistant to chemical insecticides. However, insect biological control agents as part of Integrated Pest Management (IPM) strategies in agriculture, or Integrated Vector Management (IVM) in public health may be subject to a spectrum of regulatory oversight depending on the regulatory status of the insect. For example, non-genetically modified exotic species are subject to regulation under phytosanitary regimes and undergo a pest risk analysis (PRA) to determine if the organism is a pest and should be regulated, whereas genetically modified organisms generally have the regulatory trigger of the production process. In order for society to benefit from these innovations in agriculture and vector management it is important that new technologies such as self-limiting insects for biological control are regulated similarly and ideally by the characteristics of the self-limiting insect itself. It is currently not the case as genetically modified insects are subject to unjustifiably onerous oversight by regulators, as well as scrutiny in the public domain based on the technology used to produce the end product (genetic modification-GM). Insect pests present significant challenges to both public health and agriculture, and promising solutions using self-limiting genetics in release programs are now available or well in the development pipeline. Government policy makers and regulators must recognise that fully embracing solutions which can contribute to achieving broader government policy objectives in the areas of public health and agriculture requires adaptive approaches to regulatory oversight in risk assessment of living modified organisms (LMO's) such as self-limiting insects.
Blais, B.W., Turner, G., Sooknanan, R. et al. Biotechnol Tech (1996) 10: 189.
A NASBA system am... more Blais, B.W., Turner, G., Sooknanan, R. et al. Biotechnol Tech (1996) 10: 189.
A NASBA system amplifying specific sequences of the Listeria monocytogenes hlyA gene and an immunoenzymatic assay for the detection of amplimers was developed. The immunoenzymatic assay utilized a simple microtiter plate format and an anti-RNA:DNA hybrid antibody for the detection of NASBA product (predominantly RNA) hybridized to an immobilized DNA probe. This highly sensitive isothermal amplification and detection system was reactive with genomic DNA from various L. monocytogenes isolates but not with other Listeria or non-Listeria species.
I.B. Lambert C. Carroll N. Laycock L. Duval J. Whiteway I. Lawford G. Turner R. Booth S. D... more I.B. Lambert C. Carroll N. Laycock L. Duval J. Whiteway I. Lawford G. Turner R. Booth S. Douville M.R. Nokhbeh
Mutagenesis (1998) 13 (1): 9-18.
We have examined the mutational specificity of 1-nitroso-6-nitropyrene (1,6-NONP), an activated metabolite of the carcinogen 1,6-dinitropyrene, in the lacI gene of Escherichia coli strains which are deficient in nucleotide excision repair (strain NR6113, ΔuvrB; strain CM6114, ΔuvrB, plasmid pKM101). Separate collections of lacI– mutations and dominant lacI–d mutations, which contain DNA sequence alterations in the region of the lacI gene that encodes the DNA binding domain of the lacI repressor, were made following 1,6-NONP treatment The DNA sequence of 418 mutations was determined, of which 228 were lacI– mutations and 190 were lacI–d mutations. Ninety three percent of the induced point mutations occurred at G:C residues. –(G:C) frameshifts were the dominant mutational class in the lacI– collections of both NR6113 and CM6114, and in the lacI–d collection of NR6113. The frameshift mutations occurred preferentially in runs of guanine residues and their frequency increased markedly with the length of the reiterated sequence. In strain CM6114, which contained the plasmid pKM101, there was a marked stimulation in the frequency of G:C→T:A transversions that was articularly apparent in the lacI–d collection. We discuss models which might account for the apparent differences in mutational specificity resulting from the presence of the UmuD/C and MucA/B proteins. The results suggest that major classes of mutation are recovered in both the lacI– and lacI–d collections. However, the proportions of the major classes of mutations within the two collections can differ significantly. Depending on the genetic background of the host strain, the relative ratios of base substitutions to frameshift mutations in the lacI–d target can differ by almost an order of magnitude as compared with the lacI– target This is primarily a function of the relative mutational target size of the different classes of mutation.
Burton W. Blais and Geoff Turner 2001
Food Microbiology Protocols
Volume 14 of the series Methods... more Burton W. Blais and Geoff Turner 2001 Food Microbiology Protocols Volume 14 of the series Methods in Biotechnology pp 67-83
The rapid detection of foodborne pathogens such as Listeria monocytogenes requires ultrasensitive techniques that give measurable responses with low numbers of the target bacteria in food samples or enrichment cultures. Although a number of approaches are possible for detection of low levels of target bacteria, including enzyme immunoassay (EIA) and nucleic acid probe hybridization, perhaps the most efficient approach from the viewpoint of detectability and specificity are the nucleic acid amplification techniques. Nucleic acid amplification targets specific nucleotide sequences within the bacterial genome and raises the number of copies of the region of interest to levels that are detectable by conventional means (e.g., agarose gel electrophoresis, DNA probes). A well-known example is the polymerase chain reaction (PCR) technique, which amplifies target DNA sequences by a mechanism involving hybridization of two oligonucleotide primers to opposite strands flanking the target region, followed by a repetitive series of cycles involving template denaturation, primer annealing, and the extension of primers by a DNA polymerase, typically the thermostable Taq polymerase, which enables the use of an automated thermal cycling device in this process. The amplification in a typical PCR process can result in a million-fold increase in the number of target sequence copies after 20 cycles (1).
Control of insect pests in both public health and agriculture is coming under increasing pressure... more Control of insect pests in both public health and agriculture is coming under increasing pressure due to the accelerated prohibition of pesticide chemistries, increasing resistance to chemistries that are authorised and limited discovery of novel active ingredients. Additionally, consumers, food producers and governments are seeking non-chemical or integrated solutions for insect pest pressures which are more aligned with environmental protection goals such as the reduced use of chemical controls. Biological control using self-limiting genetics represents a new paradigm for pest insect management and is especially advantageous where those pests are or have become resistant to chemical insecticides. However, insect biological control agents as part of Integrated Pest Management (IPM) strategies in agriculture, or Integrated Vector Management (IVM) in public health may be subject to a spectrum of regulatory oversight depending on the regulatory status of the insect. For example, non-genetically modified exotic species are subject to regulation under phytosanitary regimes and undergo a pest risk analysis (PRA) to determine if the organism is a pest and should be regulated, whereas genetically modified organisms generally have the regulatory trigger of the production process. In order for society to benefit from these innovations in agriculture and vector management it is important that new technologies such as self-limiting insects for biological control are regulated similarly and ideally by the characteristics of the self-limiting insect itself. It is currently not the case as genetically modified insects are subject to unjustifiably onerous oversight by regulators, as well as scrutiny in the public domain based on the technology used to produce the end product (genetic modification-GM). Insect pests present significant challenges to both public health and agriculture, and promising solutions using self-limiting genetics in release programs are now available or well in the development pipeline. Government policy makers and regulators must recognise that fully embracing solutions which can contribute to achieving broader government policy objectives in the areas of public health and agriculture requires adaptive approaches to regulatory oversight in risk assessment of living modified organisms (LMO's) such as self-limiting insects.
Blais, B.W., Turner, G., Sooknanan, R. et al. Biotechnol Tech (1996) 10: 189.
A NASBA system am... more Blais, B.W., Turner, G., Sooknanan, R. et al. Biotechnol Tech (1996) 10: 189.
A NASBA system amplifying specific sequences of the Listeria monocytogenes hlyA gene and an immunoenzymatic assay for the detection of amplimers was developed. The immunoenzymatic assay utilized a simple microtiter plate format and an anti-RNA:DNA hybrid antibody for the detection of NASBA product (predominantly RNA) hybridized to an immobilized DNA probe. This highly sensitive isothermal amplification and detection system was reactive with genomic DNA from various L. monocytogenes isolates but not with other Listeria or non-Listeria species.
I.B. Lambert C. Carroll N. Laycock L. Duval J. Whiteway I. Lawford G. Turner R. Booth S. D... more I.B. Lambert C. Carroll N. Laycock L. Duval J. Whiteway I. Lawford G. Turner R. Booth S. Douville M.R. Nokhbeh
Mutagenesis (1998) 13 (1): 9-18.
We have examined the mutational specificity of 1-nitroso-6-nitropyrene (1,6-NONP), an activated metabolite of the carcinogen 1,6-dinitropyrene, in the lacI gene of Escherichia coli strains which are deficient in nucleotide excision repair (strain NR6113, ΔuvrB; strain CM6114, ΔuvrB, plasmid pKM101). Separate collections of lacI– mutations and dominant lacI–d mutations, which contain DNA sequence alterations in the region of the lacI gene that encodes the DNA binding domain of the lacI repressor, were made following 1,6-NONP treatment The DNA sequence of 418 mutations was determined, of which 228 were lacI– mutations and 190 were lacI–d mutations. Ninety three percent of the induced point mutations occurred at G:C residues. –(G:C) frameshifts were the dominant mutational class in the lacI– collections of both NR6113 and CM6114, and in the lacI–d collection of NR6113. The frameshift mutations occurred preferentially in runs of guanine residues and their frequency increased markedly with the length of the reiterated sequence. In strain CM6114, which contained the plasmid pKM101, there was a marked stimulation in the frequency of G:C→T:A transversions that was articularly apparent in the lacI–d collection. We discuss models which might account for the apparent differences in mutational specificity resulting from the presence of the UmuD/C and MucA/B proteins. The results suggest that major classes of mutation are recovered in both the lacI– and lacI–d collections. However, the proportions of the major classes of mutations within the two collections can differ significantly. Depending on the genetic background of the host strain, the relative ratios of base substitutions to frameshift mutations in the lacI–d target can differ by almost an order of magnitude as compared with the lacI– target This is primarily a function of the relative mutational target size of the different classes of mutation.
Burton W. Blais and Geoff Turner 2001
Food Microbiology Protocols
Volume 14 of the series Methods... more Burton W. Blais and Geoff Turner 2001 Food Microbiology Protocols Volume 14 of the series Methods in Biotechnology pp 67-83
The rapid detection of foodborne pathogens such as Listeria monocytogenes requires ultrasensitive techniques that give measurable responses with low numbers of the target bacteria in food samples or enrichment cultures. Although a number of approaches are possible for detection of low levels of target bacteria, including enzyme immunoassay (EIA) and nucleic acid probe hybridization, perhaps the most efficient approach from the viewpoint of detectability and specificity are the nucleic acid amplification techniques. Nucleic acid amplification targets specific nucleotide sequences within the bacterial genome and raises the number of copies of the region of interest to levels that are detectable by conventional means (e.g., agarose gel electrophoresis, DNA probes). A well-known example is the polymerase chain reaction (PCR) technique, which amplifies target DNA sequences by a mechanism involving hybridization of two oligonucleotide primers to opposite strands flanking the target region, followed by a repetitive series of cycles involving template denaturation, primer annealing, and the extension of primers by a DNA polymerase, typically the thermostable Taq polymerase, which enables the use of an automated thermal cycling device in this process. The amplification in a typical PCR process can result in a million-fold increase in the number of target sequence copies after 20 cycles (1).
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A NASBA system amplifying specific sequences of the Listeria monocytogenes hlyA gene and an immunoenzymatic assay for the detection of amplimers was developed. The immunoenzymatic assay utilized a simple microtiter plate format and an anti-RNA:DNA hybrid antibody for the detection of NASBA product (predominantly RNA) hybridized to an immobilized DNA probe. This highly sensitive isothermal amplification and detection system was reactive with genomic DNA from various L. monocytogenes isolates but not with other Listeria or non-Listeria species.
Mutagenesis (1998) 13 (1): 9-18.
We have examined the mutational specificity of 1-nitroso-6-nitropyrene (1,6-NONP), an activated metabolite of the carcinogen 1,6-dinitropyrene, in the lacI gene of Escherichia coli strains which are deficient in nucleotide excision repair (strain NR6113, ΔuvrB; strain CM6114, ΔuvrB, plasmid pKM101). Separate collections of lacI– mutations and dominant lacI–d mutations, which contain DNA sequence alterations in the region of the lacI gene that encodes the DNA binding domain of the lacI repressor, were made following 1,6-NONP treatment The DNA sequence of 418 mutations was determined, of which 228 were lacI– mutations and 190 were lacI–d mutations. Ninety three percent of the induced point mutations occurred at G:C residues. –(G:C) frameshifts were the dominant mutational class in the lacI– collections of both NR6113 and CM6114, and in the lacI–d collection of NR6113. The frameshift mutations occurred preferentially in runs of guanine residues and their frequency increased markedly with the length of the reiterated sequence. In strain CM6114, which contained the plasmid pKM101, there was a marked stimulation in the frequency of G:C→T:A transversions that was articularly apparent in the lacI–d collection. We discuss models which might account for the apparent differences in mutational specificity resulting from the presence of the UmuD/C and MucA/B proteins. The results suggest that major classes of mutation are recovered in both the lacI– and lacI–d collections. However, the proportions of the major classes of mutations within the two collections can differ significantly. Depending on the genetic background of the host strain, the relative ratios of base substitutions to frameshift mutations in the lacI–d target can differ by almost an order of magnitude as compared with the lacI– target This is primarily a function of the relative mutational target size of the different classes of mutation.
Food Microbiology Protocols
Volume 14 of the series Methods in Biotechnology pp 67-83
The rapid detection of foodborne pathogens such as Listeria monocytogenes requires ultrasensitive techniques that give measurable responses with low numbers of the target bacteria in food samples or enrichment cultures. Although a number of approaches are possible for detection of low levels of target bacteria, including enzyme immunoassay (EIA) and nucleic acid probe hybridization, perhaps the most efficient approach from the viewpoint of detectability and specificity are the nucleic acid amplification techniques. Nucleic acid amplification targets specific nucleotide sequences within the bacterial genome and raises the number of copies of the region of interest to levels that are detectable by conventional means (e.g., agarose gel electrophoresis, DNA probes). A well-known example is the polymerase chain reaction (PCR) technique, which amplifies target DNA sequences by a mechanism involving hybridization of two oligonucleotide primers to opposite strands flanking the target region, followed by a repetitive series of cycles involving template denaturation, primer annealing, and the extension of primers by a DNA polymerase, typically the thermostable Taq polymerase, which enables the use of an automated thermal cycling device in this process. The amplification in a typical PCR process can result in a million-fold increase in the number of target sequence copies after 20 cycles (1).
A NASBA system amplifying specific sequences of the Listeria monocytogenes hlyA gene and an immunoenzymatic assay for the detection of amplimers was developed. The immunoenzymatic assay utilized a simple microtiter plate format and an anti-RNA:DNA hybrid antibody for the detection of NASBA product (predominantly RNA) hybridized to an immobilized DNA probe. This highly sensitive isothermal amplification and detection system was reactive with genomic DNA from various L. monocytogenes isolates but not with other Listeria or non-Listeria species.
Mutagenesis (1998) 13 (1): 9-18.
We have examined the mutational specificity of 1-nitroso-6-nitropyrene (1,6-NONP), an activated metabolite of the carcinogen 1,6-dinitropyrene, in the lacI gene of Escherichia coli strains which are deficient in nucleotide excision repair (strain NR6113, ΔuvrB; strain CM6114, ΔuvrB, plasmid pKM101). Separate collections of lacI– mutations and dominant lacI–d mutations, which contain DNA sequence alterations in the region of the lacI gene that encodes the DNA binding domain of the lacI repressor, were made following 1,6-NONP treatment The DNA sequence of 418 mutations was determined, of which 228 were lacI– mutations and 190 were lacI–d mutations. Ninety three percent of the induced point mutations occurred at G:C residues. –(G:C) frameshifts were the dominant mutational class in the lacI– collections of both NR6113 and CM6114, and in the lacI–d collection of NR6113. The frameshift mutations occurred preferentially in runs of guanine residues and their frequency increased markedly with the length of the reiterated sequence. In strain CM6114, which contained the plasmid pKM101, there was a marked stimulation in the frequency of G:C→T:A transversions that was articularly apparent in the lacI–d collection. We discuss models which might account for the apparent differences in mutational specificity resulting from the presence of the UmuD/C and MucA/B proteins. The results suggest that major classes of mutation are recovered in both the lacI– and lacI–d collections. However, the proportions of the major classes of mutations within the two collections can differ significantly. Depending on the genetic background of the host strain, the relative ratios of base substitutions to frameshift mutations in the lacI–d target can differ by almost an order of magnitude as compared with the lacI– target This is primarily a function of the relative mutational target size of the different classes of mutation.
Food Microbiology Protocols
Volume 14 of the series Methods in Biotechnology pp 67-83
The rapid detection of foodborne pathogens such as Listeria monocytogenes requires ultrasensitive techniques that give measurable responses with low numbers of the target bacteria in food samples or enrichment cultures. Although a number of approaches are possible for detection of low levels of target bacteria, including enzyme immunoassay (EIA) and nucleic acid probe hybridization, perhaps the most efficient approach from the viewpoint of detectability and specificity are the nucleic acid amplification techniques. Nucleic acid amplification targets specific nucleotide sequences within the bacterial genome and raises the number of copies of the region of interest to levels that are detectable by conventional means (e.g., agarose gel electrophoresis, DNA probes). A well-known example is the polymerase chain reaction (PCR) technique, which amplifies target DNA sequences by a mechanism involving hybridization of two oligonucleotide primers to opposite strands flanking the target region, followed by a repetitive series of cycles involving template denaturation, primer annealing, and the extension of primers by a DNA polymerase, typically the thermostable Taq polymerase, which enables the use of an automated thermal cycling device in this process. The amplification in a typical PCR process can result in a million-fold increase in the number of target sequence copies after 20 cycles (1).