Patho-Biotechnology; Using Bad Bugs to Make Good Bugs Better

By Sleator, Roy D.; Hill, Colin | Science Progress, Spring 2007 | Go to article overview

Patho-Biotechnology; Using Bad Bugs to Make Good Bugs Better


Sleator, Roy D., Hill, Colin, Science Progress


ABSTRACT

Given the increasing commercial and clinical relevance of probiotic cultures, improving their stress tolerance profile and ability to overcome the physiochemical defences of the host is an important biological goal. Pathogenic bacteria have evolved sophisticated strategies to overcome host defences, interact with the immune system and interfere with essential host systems. We cool the term 'patho-biotechnology' to describe the exploitation of these valuable traits in biotechnology and biomedicine. This approach shows promise for the design of more technologically robust and effective probiotic cultures with improved biotechnological and clinical applications as well as the development of novel vaccine and drug delivery platforms.

Keywords: patho-biotechnology, probiotics, pathogen, Listeria, virulence factor, stress, infection, drug delivery, vaccination

Introduction

"Trust not yourself, but your defects to know. Make use of every friend and every foe"

Alexander Pope (1688-1744)

Pathogenic bacteria, with lifecycles oscillating between the host and external milieu, have evolved sophisticated stress management strategies allowing them to succeed and thrive in both environments (1-4). We coined the term 'Patho-biotechnology' to describe the commercial exploitation of these valuable traits in biotechnology, food and medicine (5). This concept encompasses three broad areas; firstly, the use of selected bacterial pathogens (e.g., Listeria monocytogenes) as effective vaccine and drug delivery platforms (6,7) either through the generation of conditional auxotrophic mutants (8) or by the selective elimination of key virulence factors (9). The second approach involves the isolation and purification of pathogenspecific immunogenic proteins (e.g., listeriolysin) for direct application (10-12), thus removing the necessity for potentially harmful bacterial carrier platforms. The third area, and the primary focus of this review, provides an alternative to using either the attenuated pathogen or pathogen-derived proteins for disease prevention or therapy. This approach involves equipping non-pathogenic bacteria with the genetic elements necessary to survive the many stresses encountered outside the host (e.g. spray and freeze drying; experienced during product formulation (13,14) as well as the myriad of antimicrobial hurdles faced during host transit and/or colonisation (e.g. gastric acidity, bile, low iron and elevated osmolarity (15)).

Pathogenic and probiotic bacteria face an almost identical set of challenges from the host physico-chemical defences (Figure 1) and must also be able to interact with or modulate the host immune system in order to have an impact on human health (16) (either positively or negatively). Thus we can conceive of employing well characterised pathogenic species as a reservoir for stress and virulence associated genes to significantly improve the clinical effectiveness and technological robustness of potentially probiotic strains. The ability to confer additional stress tolerance on what are often process sensitive cultures may be an important first step in the development and delivery of viable probiotics with maximal efficacy (17).

[FIGURE 1 OMITTED]

Rational design of improved probiotics

The human gut contains more bacteria than there are eukaryotic cells in the body (18). Collectively, this gut flora represents a virtual organ with a metabolic activity m excess of that of the liver (19) and a microbiome (total genome of constituent microorganisms) more diverse than that of the human genome (20). Some members of this commensal flora, defined as probiotics (21), have been demonstrated to beneficially affect the host by influencing the composition of the gut microflora (22) and by providing a health promoting or immunomodulatory challenge to the host (23). Indeed, certain bacteria, when administered perorally, have been shown to stimulate the mucosal immune system (24,25), attenuate inflammation and reduce neoplastic lesions associated with auto immune disease states such as Crohn's disease and ulcerative colitis (6), as well as providing a potentially viable alternative for the treatment of chronic gut associated bacterial infections such as Clostridium difficile (27). …

The rest of this article is only available to active members of Questia

Sign up now for a free, 1-day trial and receive full access to:

  • Questia's entire collection
  • Automatic bibliography creation
  • More helpful research tools like notes, citations, and highlights
  • Ad-free environment

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Patho-Biotechnology; Using Bad Bugs to Make Good Bugs Better
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Full screen

matching results for page

Cited passage

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.