Izolacija i ispitivanje vibrio spp. I aeromonas spp. prouzrokovača bolesti riba i njihovih specifičnih bakteriofaga iz vodene sredine Gruzije

Infekcije povezane sa Vibrio spp. i Aeromonas spp. koje se javljaju kod riba iz morske i slatkovodne sredine se navode širom sveta. Bolest, kada izbije, može izazvati znatan mortalitet u ribnjacima. Cilj ovih ispitivanja je bila izolacija i identifikacija Vibrio spp. i Aeromonas spp. izazivača bolesti riba iz gruzijske obalske zone Crnog mora i slatkovodnih akumulacija, kao i njihovog diverziteta i kvantitativnog učešća. Sezonski monitoring je izvođen u morskim (2006 - 2009) i slatkovodnim akumulacijama-Lisi jezeru, Tbilisi moru i Kumisi jezeru (2006 - 2010). 223 izolata Aeromonas spp. i 858 izolata Vibrio spp. je ispitano. Ukupno 8 vrsta Aeromonas i 14 vrsta Vibrio pronađeno je u vodenoj sredini Gruzije. V. parahaemolyticus, V. natriegens, V. pelagius preovlađuju u morskoj vodi. Veći deo V. mimicus, V. vulnificus, V. alginolyticus, V. cholerae, V. nigripulchritudo, V. nereis, V. campbellii, A. media, A. veronii, A. eucrenopila, A. sobria, A. schuberti, A. salmonicida su nađene u slatkovodnim akumulacijama. V. orientalis, V. metchnikovii, V. splendidus, V. marinus, A. hydrophila, A. caviae se mogu naći u i morskim i u slatkovodnim akumulacijama. Sojevi su podeljeni u grupe po sličnosti zasnovanoj na njihovim zahtevima za salinitetom. Drugi cilj ovih ispitivanja je bilo izolovanje soja specifičnih bakteriofaga iz uzoraka vode. Dobijeno je 49 primarnih fag izolata, većina iz slatkovodnih rezervoara. Litični spektar bakteriofaga je ispitivan koristeći izabrani set sojeva domaćina. U rezultatima kloniranja 9 primarnih mešavina faga dobijeno je 13 klona bakteriofaga aktivnih za A. sobria, A. caviae, A. salmonicida, A. eucrenophila

Antitumor and adjuvant effects of phagelysates of E.coli in mice with Ehrlich carcinoma

Aim: To augment anti-tumor host response and overcome the tumor-induced immunosuppression is of paramount importance especially when patient is subjected to radio-/chemotherapy and immune system suffers significantly. Various immunological methods have been employed as supplemental antitumor therapies. We were aimed to investigate the antitumor potential of phagelysates of gram-negative bacteria and their adjuvant effects for conventional chemotherapy in experiment. Methods: Bacterial phagelysates of E.coli and purified suspensions of corresponding Un bacteriophage were obtained by standard methods of phage research. Experiments were carried out on BL57C/6J mice bearing transplanted Ehrlich carcinoma. Different regimens of phagelysate administration (0,5 ml E. coli phagelysate, 3/8 times with 5 day intervals) and conventional chemotherapy (combination of Doxorubicin 60 mg/m2, Cyclophosphan 800 mg/m2, Ftoruracil 600 mg/m2, 3 times with 21 day intervals) were tested. Treatment efficacy was evaluated by tumor growth inhibition percent, index of malignant growth, lifespan and survival percent. Results: Experiments have shown that application of optimal doses of E. coli phagelysate can be well tolerated in mice. No stimulation or support of malignant growth was observed. E. coli phagelysate exhibited significant anticancer effect and adjuvant efficacy. Cancer development was delayed in 65% of inoculated animals in the test group. E. coli phagelysate inhibited tumor growth by 80–90% without apparent side effects. The mice survival was prolonged twice and more. On 65th-69th days of tumor growth in 13% animals complete regression of neoplasms was registered. Application of phagelysates in combination with chemotherapy significantly increased antitumor efficacy of conventional chemotherapeutic drugs. Conclusion: Application of bacterial phagelysates can be considered as promising novel strategy in cancer therapeutics

Phenotypic and genotypic variations within a single bacteriophage species

<p>Abstract</p> <p>Background</p> <p>Although horizontal gene transfer plays a pivotal role in bacteriophage evolution, many lytic phage genomes are clearly shaped by vertical evolution. We investigated the influence of minor genomic deletions and insertions on various phage-related phenotypic and serological properties.</p> <p>Findings</p> <p>We collected ten different isolates of <it>Pseudomonas aeruginosa </it>bacteriophage ϕKMV. All sequenced genomes (42-43 kb, long direct terminal repeats) are nearly identical, which intuitively implied strongly similar infections cycles. However, their latent periods vary between 21 and 28 minutes and they are able to lyse between 5 and 58% of a collection of 107 clinical <it>P. aeruginosa </it>strains. We also noted that phages with identical tail structures displayed profound differences in host spectra. Moreover, point mutations in tail and spike proteins were sufficient to evade neutralization by two phage-specific antisera, isolated from rabbits.</p> <p>Conclusion</p> <p>Although all analyzed phages are 83-97% identical at the genome level, they display a surprisingly large variation in various phenotypic properties. The small overlap in host spectrum and their ability to readily escape immune defences against a nearly identical phage are promising elements for the application of these phages in phage therapy.</p

Hypoimmunogenic derivatives of induced pluripotent stem cells evade immune rejection in fully immunocompetent allogeneic recipients

Autologous induced pluripotent stem cells (iPSCs) constitute an unlimited cell source for patient-specific cell-based organ repair strategies. However, their generation and subsequent differentiation into specific cells or tissues entail cell line-specific manufacturing challenges and form a lengthy process that precludes acute treatment modalities. These shortcomings could be overcome by using prefabricated allogeneic cell or tissue products, but the vigorous immune response against histo-incompatible cells has prevented the successful implementation of this approach. Here we show that both mouse and human iPSCs lose their immunogenicity when major histocompatibility complex (MHC) class I and II genes are inactivated and CD47 is over-expressed. These hypoimmunogenic iPSCs retain their pluripotent stem cell potential and differentiation capacity. Endothelial cells, smooth muscle cells, and cardiomyocytes derived from hypoimmunogenic mouse or human iPSCs reliably evade immune rejection in fully MHC-mismatched allogeneic recipients and survive long-term without the use of immunosuppression. These findings suggest that hypoimmunogenic cell grafts can be engineered for universal transplantation

Quality-Controlled Small-Scale Production of a Well-Defined Bacteriophage Cocktail for Use in Human Clinical Trials

We describe the small-scale, laboratory-based, production and quality control of a cocktail, consisting of exclusively lytic bacteriophages, designed for the treatment of Pseudomonas aeruginosa and Staphylococcus aureus infections in burn wound patients. Based on succesive selection rounds three bacteriophages were retained from an initial pool of 82 P. aeruginosa and 8 S. aureus bacteriophages, specific for prevalent P. aeruginosa and S. aureus strains in the Burn Centre of the Queen Astrid Military Hospital in Brussels, Belgium. This cocktail, consisting of P. aeruginosa phages 14/1 (Myoviridae) and PNM (Podoviridae) and S. aureus phage ISP (Myoviridae) was produced and purified of endotoxin. Quality control included Stability (shelf life), determination of pyrogenicity, sterility and cytotoxicity, confirmation of the absence of temperate bacteriophages and transmission electron microscopy-based confirmation of the presence of the expected virion morphologic particles as well as of their specific interaction with the target bacteria. Bacteriophage genome and proteome analysis confirmed the lytic nature of the bacteriophages, the absence of toxin-coding genes and showed that the selected phages 14/1, PNM and ISP are close relatives of respectively F8, φKMV and phage G1. The bacteriophage cocktail is currently being evaluated in a pilot clinical study cleared by a leading Medical Ethical Committee