Phage Therapy: Difference between revisions

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==Delivery of the Phage==
==Delivery of the Phage==
<br>Phages, unlike many antibiotic molecules, are not diffusible across membranes and must therefore have a method of delivery to the target cells. Some researchers believe that the best delivery mechanism may lie in using other nonpathogenic species of bacteria to bring the phage to its pathogenic target.
<br>Phages, unlike many antibiotic molecules, are not diffusible across membranes and must therefore have a method of delivery to the target cells. Some researchers believe that the best delivery mechanism may lie in using other nonpathogenic species of bacteria to bring the phage to its pathogenic target.
A study by Broxmeyer et al (2002) investigated the effectiveness of phage treatment of an intracellular human pathogen by using a mouse model.  The study tested the ability of a mycobacteriophage delivered by a nonvirulent mycobacterium to kill <i>Mycobacterium avium</i> and <i>Mycobacterium tuberculosis</i>. These disease are common in sufferers of acquired immunodeficiency syndrome (AIDS), and though there have been some advancements in treatment in recent years, their effectiveness is limited by drug resistance and the fact that most of their modes of action require that the target is not in a dormant period.  The researchers used vacuoles within macrophages to deliver the phage and found that treatment of <i>M. avium</i>-infected and to an even greater extent <i>M. tuberculosis</i>- infected cells with the phage resulted in decreased bacterial numbers (Figure 1). They capitalized on the fact that infecting macrophages with both <i>M. avium</i> and <i>Mycobacterium smegmatis</i> (the delivery bacteria for the TM4 lytic phage) leads to fusion of the vacuoles of the two, which in turn results in delivery of the phage to the target pathogenic bacteria.
A study by Broxmeyer et al (2002) investigated the effectiveness of phage treatment of an intracellular human pathogen by using a mouse model.  The study tested the ability of a mycobacteriophage delivered by a nonvirulent mycobacterium to kill <i>Mycobacterium avium</i> and <i>Mycobacterium tuberculosis</i>. These disease are common in sufferers of acquired immunodeficiency syndrome (AIDS), and though there have been some advancements in treatment in recent years, their effectiveness is limited by drug resistance and the fact that most of their modes of action require that the target is not in a dormant period.  The researchers used vacuoles within macrophages to deliver the phage and found that treatment of <i>M. avium</i>-infected and to an even greater extent <i>M. tuberculosis</i>- infected cells with the phage resulted in decreased bacterial numbers (Figure 1). They capitalized on the fact that infecting macrophages with both <i>M. avium</i> and <i>Mycobacterium smegmatis</i> (the delivery bacteria for the TM4 lytic phage) leads to fusion of the vacuoles of the two, which in turn results in delivery of the phage to the target pathogenic bacteria. A decrease in <i>M. avium</i> number was seen when treated with the delivery bacteria, but a far greater decrease was seen when it was coinfected with the delivery bacteria plus the TM4 phage (Figure 1).
This study provides promising support to the potential for the use of other bacteria as a delivery mechanism for bacteriophages to treat pathogenic diseases.
This study provides promising support to the potential for the use of other bacteria as a delivery mechanism for bacteriophages to treat pathogenic diseases.
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Revision as of 19:33, 17 April 2010

Introduction

Electron micrograph of the Ebola Zaire virus. This was the first photo ever taken of the virus, on 10/13/1976. By Dr. F.A. Murphy, now at U.C. Davis, then at the CDC.


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Legend/credit: Electron micrograph of the Ebola Zaire virus. This was the first photo ever taken of the virus, on 10/13/1976. By Dr. F.A. Murphy, now at U.C. Davis, then at the CDC.
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Introduce the topic of your paper. What microorganisms are of interest? Habitat? Applications for medicine and/or environment?

Section 1


Include some current research, with at least one figure showing data.

Delivery of the Phage


Phages, unlike many antibiotic molecules, are not diffusible across membranes and must therefore have a method of delivery to the target cells. Some researchers believe that the best delivery mechanism may lie in using other nonpathogenic species of bacteria to bring the phage to its pathogenic target. A study by Broxmeyer et al (2002) investigated the effectiveness of phage treatment of an intracellular human pathogen by using a mouse model. The study tested the ability of a mycobacteriophage delivered by a nonvirulent mycobacterium to kill Mycobacterium avium and Mycobacterium tuberculosis. These disease are common in sufferers of acquired immunodeficiency syndrome (AIDS), and though there have been some advancements in treatment in recent years, their effectiveness is limited by drug resistance and the fact that most of their modes of action require that the target is not in a dormant period. The researchers used vacuoles within macrophages to deliver the phage and found that treatment of M. avium-infected and to an even greater extent M. tuberculosis- infected cells with the phage resulted in decreased bacterial numbers (Figure 1). They capitalized on the fact that infecting macrophages with both M. avium and Mycobacterium smegmatis (the delivery bacteria for the TM4 lytic phage) leads to fusion of the vacuoles of the two, which in turn results in delivery of the phage to the target pathogenic bacteria. A decrease in M. avium number was seen when treated with the delivery bacteria, but a far greater decrease was seen when it was coinfected with the delivery bacteria plus the TM4 phage (Figure 1). This study provides promising support to the potential for the use of other bacteria as a delivery mechanism for bacteriophages to treat pathogenic diseases.

Section 3


Include some current research, with at least one figure showing data.

Conclusion


Overall text length at least 3,000 words, with at least 3 figures.

References

[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.