Phage therapy

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Transcript of Phage therapy

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2. Phage Therapy Fatma F. Abu-QadosTo: Dr.Abdelraouf A. El-Manama 30.01.11 3. What is Phage?

  • Virusesthatparasiteonbacteria
  • Distinctfrom the animal and plant viruses
  • Simpleandabundantorganisms on earth.
  • Have either alyticor alysogeniclife cycle.

4. Hello ..Im Phage 5. Types of Phages

  • phage Lysogen
  • T2 phage
  • T4 phage
  • T7 phage
  • M13 phage
  • MS2 phage
  • P1 phage
  • Enterobacteria phage P2

6. What is Phage Therapy ?

  • IS the therapeutic use of bacteriophages to treat pathogenic bacterial infections.
  • But .. " biocontrol :
  • If target host of treatment is not an animal

7. Lytic Vs. Lysogenic

  • Destruction(lysis )
  • Growth suppression effects(lysogeny)
  • lytic phages are the most suitable candidates for phage therapy..
  • Why ?? because theyquickly reproducewithin and lyse the bacteria in their host range,growing exponentiallyin number.
  • In contrast , temperate phages ( lysogenic) , which canbolstertheir bacterial host'svirulence ,resilience , and general capacity toproliferateare generally unsuitable for therapeutic applications.

8. Lytic cycle 9. Attachment 10. More & More 11. Penetration & swelling 12. Lyses 13. Spreading 14. 15.

  • Depending on thespecies and conditions , each parent phage can produce on average approximately200 daughtersper lytic cycle.
  • 40 000 progenyat the end of the 2nd cycle;
  • 8 millionat the end of the 3rd cycle;
  • 1.6 billionat the end of the 4th cycle;
  • and so on.

Amplfication.. 16.

  • Since ancient times,river watershaving the ability to cure infectious diseases, such asleprosy .
  • Phages were discovered in 1915 by British microbiologistFelix Twort , and, independently in 1917, by French-Canadian microbiologistFelix dHrelle.
  • Twort did not pursuehis discovery, whereasdHrelle systematically investigatedthe nature of bacteriophages and explored their ability to function as therapeutic agents

History 17. Is that still being Used now ?

  • Although extensively used and developed mainly in former Soviet Union countries for about 90 years, this method of therapy isstill being testedelsewhere for treatment of a variety ofbacterial and poly-microbial biofilm infections , and has not yet been approved in countries other than Georgia.

18. Advantages

  • Phagesthrivein the presence of bacteria, anddieout in their absence.
  • Extreme specificityand chemically large nature.
  • Do not cause allergies or affect the body's naturalimmune system .
  • Low chemotherapeutic index .
  • Support and enhance vitalmicroflora.

19. Cont. Adv.

  • Morerapidly and effectivelythan standard antibiotics.
  • Have a longshelf life(up to 2 years).
  • Productioncostsof phages arelow .
  • "green-natural-alternative"and its production is environment-friendly.
  • For bothprevention&treatment.
  • Administered in a limited number ofsmall dosesover a shortperiod of time.

20. Disadvantages

  • Must berefrigerateduntil used .
  • Highspecificity .when the exact species of an infectingbacteria is unknownor if there isamultiple infection .
  • Should betestedin the lab prior to application, making phagesless suitable for acute caseswhere time is not available.

21. Cont. Disadv.

  • Resistance
  • However, evolution drives the rapid emergence of new phages that can destroy bacteria that have become resistant. This means that there should be an"inexhaustible" supply.
  • Injectedinto thebloodstreamare recognized by the humanimmune system . For this reason, it appears that a particular phage can only be usedonce for intravenous treatment

22. Where we can find Phage?

  • In humans and animal intestines
  • In running water
  • In the soil
  • Effluent outlets , sewage
  • Fromcorpses .

23. Culture

  • Because Phages are"bacterium-specific", it is necessary to take a swab from the patient and culture it prior to treatment.
  • The samples are taken and applied to the bacteria thatare to be destroyed (To be tested)which have been cultured on growth medium.
  • If the bacteria die, as usually happens, the mixture iscentrifuged ; the phages collect on the top of the mixture and can be drawn off.
  • Occasionally, isolation of therapeutic phages can require afew monthsto complete, but clinics generally keep supplies ofphage cocktailsfor the most common bacterial strains in a geographical area.

24. 25. How can be Administrated ?

  • Orally..
  • Topically on infected wounds
  • Injection is rarely used, avoiding immune system stimulation..

26. Topical use .. 27. Treatment 4 WHAT ?

  • Forbacterial infections..
  • e.g :laryngitis, skin infections, dysentery, conjunctivitis, periodontitis, gingivitis, sinusitis, urinary tract infections and intestinal infections, burns, boils,poly-microbial biofilms on chronic wounds, ulcers and infected surgical sites.

28. Other uses ..

  • Veterinary science
  • Agriculture
  • Food additive .
  • phages againstListeriaoncheese and meatare generally recognized as safe (GRAS status).

29. Phage on Wounds 30. 31. 32. 33. Future hopes

  • Cancer therapy . !
  • Meningitis ,,, cross the BBB !

34. Conclusion

  • Multidrug-resistant bacteriahave opened a secondwindowfor phage therapy.
  • Phage therapy can then serve as astand-alone therapyfor infections that arefully resistant .
  • It will also then be able to serve as aco-therapeuticagent for infections that arestill susceptibleto antibiotics.

35. Questions ? 36.