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Box 6: Possible links between genetic engineering biotechnology and the recent resurgence of infectious diseases
- Unregulated Hazards ‘Naked’ and ‘Free’ Nucleic Acids


  1. Horizontal gene transfer is responsible for creating new viral and bacterial pathogens and for spreading drug and antibiotic resistance
  2. Experimental evidence of horizontal gene transfers, some between very distant species, has been obtained in all natural environments and in the gut. Thesewere all accomplished with artificially constructed vectors used in genetic engineering.
  3. Genetic engineering makes extensive use of antibiotic resistance genes as selectable markers, thereby increasing the spread of antibiotic resistance genes.
  4. Antibiotics increases the frequency of horizontal gene transfer 10 to 10000 fold, thereby enhancing the spread of disease-causing genes as well as antibiotic resistance genes.
  5. Genetically ‘crippled’ strains of bacteria, supposed to be ‘biological contained’, are nevertheless found to survive in the environment, and to swap genes with other bacteria.
  6. DNA released from dead as well as live cells are not entirely broken down in the environment, nor in the gut, where it may be taken up and incorporated into the genomes of bacteria.
  7. DNA from viruses is more infectious than the intact virus itself.
  8. Routine chemical inactivation of genetically engineered microorganisms prior to disposal in the general environment may be ineffective, leaving a substantial proportion of viruses and bacteria in an infective state.
  9. Current legal limits of ‘tolerated releases’ of genetically engineered microorganisms from contained use vastly exceed the minimal infective dose of pathogens and potential pathogens.
  10. Non-pathogens are transformed into pathogens by horizontal gene transfer of unit blocks of virulence genes.
  11. Horizontal gene transfers are bi-directional. Released non-pathogens can be readily converted into pathogens in one step, by acquiring unit-blocks of virulence genes.


  1. Genetic engineering is based on facilitating horizontal gene transfer between distant species by constructing artificial vectors that break down species barriers.
  2. The artificial vectors constructed for genetic engineering are combinations of viral pathogens and other invasive genetic elements that can generate new cross-species viral pathogens.
  3. The artificial vectors and other constructs for genetic engineering are inherently unstable and prone to recombination, thereby enhancing horizontal gene transfer and recombination.
  4. Special ‘shuttle vectors’ made by genetic engineering are essentially unstoppable, as they contain signals for transfer and replication in different species; and helper functions for mobilization and transfer can be supplied by viruses and other genetic parasites which occur naturally in bacteria in all environments.



The accelerated emergence of infectious diseases and of drug and antibiotic resistance coincide with the development of commercial genetic engineering biotechnology. Many horizontal gene transfer events responsible for the spread of virulenc and antibiotic resistance are recent, as inferred from the high degree (>99%) of similarity in sequences of genes found in unrelated species.

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