Phage therapy. Institute of Molecular Biomedicine Comenius University, Faculty of Medicine

Transcription

1 Phage therapy Institute of Molecular Biomedicine Comenius University, Faculty of Medicine

2 Outline Introduction Taxonomy Cycles of phages Bacterial resistance Phage therapy Conditions for phage therapy Enzybiotics Phages in other industries Phage typing Phage display Bacterial sensing Future outlook

3 Microbiome Total microorganisms, their genomes and ecosystem in/on the human body Together supraorganism New genes with advantages Mouth, skin, gut... Unique ecosystems

4 We are bacteria Human cells Bacterial cells

5 core microbiome variable microbiome Personalized medicine Host s physiology Health status HUMAN MICROBIOME PROJECT 2007

6 Mammalian virome Viruses of eukaryotic cells (e.virome) Bacteriophages infecting bacterial cells (b.virome) Viruses of archea (a.virome) Virus-derived genetic elements in host chromosomes

7 10 31 members of virome 1% explored

8 Bacteriophages Most abundant entities in biosphere Viruses specific for bacterial cells Distribution according to their hosts

9 Where can we find phages? Everyday life Soil Sewage Food Water... Everywhere where bacteria are present

10 Taxonomy ICTV (not CVTI ) International Committee for Taxonomy of Viruses Up-to-date taxanomic guidelines Tailed bacteriophages order CAUDOVIRALES Three families Myoviridae Siphoviridae Podoviridae Different genera 13 families and 31 genera

11 Diverse genome size ss DNA, ds DNA or ss RNA, ds RNA Phage particles (VIRIONS) lipoprotein or protein coat Tails ~ 200 nm

12 Life cycles of phages Lytic Lysogenic Pseudolysogenic

13 Phage therapy Therapeutical usage of bacteriophages for treating bacterial infections Long history (1915/1917) Some approvals Georgia, Russia and Poland Frederick Twort Félix d Herelle Medicine, dentistry, veterinary science and agriculture

14 Mechanisms of antibiotics Cell wall synthesis Protein synthesis Nucleic acid synthesis Cell membrane functions Metabolism Others

15 Resistance of bacteria Antibiotics vs. multidrug resistant bacterial strains Biofilm

16 Resistance of bacteria Absence of a susceptible target Multidrug resistance efflux pumps Mutations Transformation Modification of target site Direct antibiotic inactivation

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18 Lack of new antibiotics or effective treatment!!!

19 Phage therapy renaissance

20 Pros and cons of bacteriophage therapy Bacteriophages infect only bacterial cells Bacteriophages are capable of self-replication and self-elimination Bacteriophages with narrow host range Phage therapy trials without serious side effects or allergic reactions Single dose would be sufficient to cure the patient Bacteriophages in combination with antibiotic therapy may lower the occurrence of bacterial resistance Bacteriophages are highly speciesspecific, it is necessary to precisely characterize the infectious bacterial agent prior to their application Phage defined in vitro environment as strictly lytic, could change this cycle under the physiological conditions of the human body Possibility of toxic shock after the bacterial lysis and subsequent amplification of neutralizing antibodies during the re-treatment of the patient

21 Prerequisites for phage therapy Host range Purity of phage preparations Clearance of phage therapeuthics Lysogeny in vivo Complete phage characterization (genes, receptors... host-phage interactions..., ) Safety testing!!!

22 Commercial products Phagobioderm Biophage-PA Routes of administration Oral Topical Intravenous

23 Phages in agriculture Intralytix, Inc. ( EBI Food Safety ( Omnilytics, Inc. ( Sevapharma, a.s.(

24 Enzybiotics Hybrid name lytic enzymes + antimicrobial potential Enzymes able to cause microbial cell death Endolysins (from phages) Bacteriocins (from bacteria) Autolysins (from bacteria) Lysozymes (various organisms)

25 How endolysins work? Enzymatic cleavage of bacterial cell wall peptidoglycans (cell lysis) ds DNA phages end of the lytic cycle (1) N-acetylmuramoyl-L-alanine amidases; (2) endopeptidases; (3) N-acetyl-β-D-glucosaminidase; (4) N-acetyl-β-D-muramidases (lysozymes) (5) lytic transglycosylases

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28 Methods: Vectors in MB

29 Methods: Phage typing Used for identification and differentiating of bacterial pathogens Lysis due to viral infection is specific Bacteriopage-based diagnostics

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31 Methods : Bacteria sensing

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33 Biosensors advantages Sensitive, rapid and selective detection Cost-effective and portable Lower limit of detection Minimum sample preparation

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35 Methods : Phage display More information by J.B.

36 Future outlook Large range appplication of phages in molecular biology, biotechnology and medicine!!!!! Safety and efficacy issues Unexplored entities

37 Thanks for Your attention!