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