Tarek Dishisha , *; Adel Abouhamed ; Gashaw Mamo ; Magdy Aly Amin ; Rajni Hatti-Kaul
Association of Egyptian-American Scholars
Multi-drug resistant microorganisms are creating a serious problem for infection control in Egyptian hospitals. Several innovation alternatives to the conventional antibiotics have been proposed including the use of antimicrobial peptides, bacteriocins, cell lytic enzymes, and bacteriophages. Phage-derived lysins (endolysins) are a new class of antimicrobials acting by hydrolysing the peptidoglycan layer of bacterial cell wall.
Development of innovative formulations for facile application of phage-derived lysins in prophylaxis and treatment of microbial infections.
Bacteriophage T4 lysozyme (T4Lyz); a product of gene e; was fused with Cellulose Binding Module (CBM) from Cellulomonas fimi. Genes encoding T4Lyz and T4Lyz-CBM were cloned and expressed in Escherichia coli. The resulting enzymes were purified and evaluated with regards to optimum pH, stability, lytic activity and bactericidal activity. The recombinant enzymes were immobilised on cellulosic wound dressing gauze as well as chitosan nanoparticles.
The CBM tag did not alter the optimum pH and stability of T4Lyz, while the lytic activity was reduced. The bactericidal activity of T4Lyz-CBM was 97.5% against Micrococcus lysodeikticus (using 10 µg/mI protein solution), and 99.96%and 95% against E.coli and Pseudomonas mendocina, respectively, (using 200 µg/mI protein solution). In contrast to unmodified T4Lyz, T4Lyz-CBM was successfully and irreversibly immobilised to cellulosic dressing gauze. The immobilised fusion protein retained its bactericidal activity against both Gram- positive and –negative bacteria. Immobilisation also enhanced the enzyme compared to that of the free one. The recombinant proteins were also immobilised over chitosan and cellulose nanomaterials however the activity was significantly reduced.
Phage-derived lysins is a potential alternative to the conventional antibiotics. Proper engineering of these lysins would facilitate their formulations for medical applications. Tagging T4Lyz with CBM provides a facile, irreversible binding to cellulosic wound dressing while retaining its activity. Currently, the development of lysins against several notorious multi-drug resistant microorganisms that are widely spread in the Egyptian community is being conducted.
This article was published in 3alamaltanmya
sponsored by Future Builders International Academy
Led by Dr.Maha Fouad