Biotech, infectious diseases fueling growth of biological laboratories
01/01/2001
by Richard C. Knudsen, Ph.D.
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Those of us living in modern industrialized nations may forget that the world of infectious diseases can be a dangerous world. Infectious diseases are the leading cause of death worldwide, and infectious diseases in the U.S. account for 25 percent of all visits to physicians each year. Furthermore, anti-microbial agents are the second most frequently prescribed class of drugs.
When it is necessary to study or diagnose infectious agents we must work in biocontainment laboratories that are specially designed and operated to protect the worker against infection with the agent during the work process.
Among the most distinguishing characteristics of these laboratories are the use of single passage air; negative pressure differentials in rooms to drive the directional air flow; the liberal use of HEPA filters in HVAC units; and biosafety cabinets to remove microbes from the air.
Moving target
As we attempt to control and treat infectious diseases in our society, and diagnose and study them in our laboratories, we find that we are dealing with a moving target—the world of infectious diseases is continually changing and expanding.
This changing and expanding world is due to the continuing emergence of new infectious diseases as well as the reemergence of old ones, the possible use of infectious agents for bioterrorism, and the growth of the field of biotechnology.
Emerging infectious diseases are those where incidence in humans has increased within the past two decades or which threaten to increase in the near future.
There are a number of ways in which new diseases may emerge. The first is through mutation or acquiring new genetic elements. For example, harmless micro-organisms, such as the gut bacterium Escherichia coli, may acquire harmful genetic elements that change it into a toxin producing strain, such as E. coli O157:H7, that has been shown to be the cause of serious foodborne disease.
Another way involves diseases such as West Nile fever virus, which is normally found in Africa and other mideastern countries, spreading to new geographic areas and populations such as New York City.
Additionally, previously undescribed microorganisms may infect humans who live or work in changing ecologic conditions that increase their exposure to insect vectors, animal reservoirs or novel sources of human pathogens. The identification of a new virus, now named Sin Nombre virus, as the causative agent of 17 deaths in the southwestern United States several years ago is one example.
A recent scientific publication listed 42 new viruses and four new rickettsia discovered since 1988. As we study diseases previously thought to be non-infectious in origin, we find that some may actually be caused by an infectious agent. For example, Helicobacter pylori has been identified as a causative agent of stomach ulcers.
Re-emerging infectious diseases may also occur because of the development of antimicrobial resistance in existing infectious bacteria (e.g. gonorrhea, malaria, pneumococcal disease) or breakdowns in various public health measures for controlling infections (e.g. cholera, tuberculosis, pertussis).
Fifty years ago the development and use of infectious agents for biological warfare was a technologically complex and costly process that could be performed only within well financed and staffed government laboratories.
Advances in technology have dramatically simplified some of these microbiological requirements resulting in the possibility of growing these agents in the basements of our homes. Information on the Internet provides "how to" instructions, which are available to terrorist groups.
As a result biological agents of animals, plants and humans are now perceived as possible "poor man's weapons" for terrorizing our domestic populations.
The growth of the field of genetic engineering also raises the specter of developing new bioterrorist agents by genetically modifying micro-organisms to enhance their deadliness.
Advances in understanding the basic biology of the cell and the genetic code, as well as the means for manipulating genetic information, have spawned the new, but explosively growing field of biotechnology.
We can transfer genes into a variety of cell types, both in vivo and in vitro, resulting in cells with beneficial and therapeutic characteristics. We can maintain, grow and manipulate many types of human and other cells in vitro. After in vitro treatment, some types of human cells may be reimplanted into the patient for therapeutic purposes. It may soon be possible to grow new organs from a few cells, and transplant these into needy patients.
What to expect
Infectious diseases, bioterrorism and biotechnology will fuel the growth of biological laboratories and their supporting "cleanroom" infrastructure in the foreseeable future.
We can expect many new biocontainment laboratories to be built and aging biocontainment facilities to be renovated, updated and upgraded to deal with new infectious disease threats. The biotechnology industry will need new laboratories, equipment and procedures that will ensure that in vitro treated biological materials intended for in vivo use will be free from hitch-hiking infectious agents or genes.
We can expect new and renovated laboratories to install new digital HVAC control systems, to adopt improved versions of HEPA filters and their housings and to use new generations of biosafety cabinets, gloves, safety eye wear, protective clothing and suits, respirators, safety centrifuges and specially designed workstations and animal caging. We can expect that the growth of biological laboratories will also stimulate interest in cleanroom technologies because of the many features that they share.
Richard C. Knudsen, Ph.D., is a microbiologist with a teaching, research and safety background in infectious diseases. He is the Biological Safety Officer and Chief of the Laboratory Safety Branch, Office of Health and Safety at the Centers for Disease Control and Prevention (CDC; Atlanta, GA), which oversees the biological, chemical and radiological laboratory safety programs at CDC. Knudsen is also a Past President of the American Biological Safety Association and is the Editor of the Journal of the American Biological Safety Association.