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Description
The aim of the project is to isolate, characterize and prepare of a phage cocktail specific to extremely resistant Acinetobacter baumannii which is an opportunistic pathogen, capable of
producing biofilm and widely spread in the hospital environment, and causes numerous infections among long-hospitalized patients, including those in Intensive Care Units. It is classified by the
World Health Organization as a critical priority group. This pathogen is one of possible causes of difficult to treat urinary tract infections. This type of infections pose huge social problem among
women and decrease significantly their quality of life. Therefore, there is an extremely need for an effective therapeutic agent in situations where available antibiotic therapy is not effective.
For search and isolate new phages active against A. baumannii both multidrug resistant hospital strains and water samples will be collected. Newly isolated phages will be amplified to examine
its morphology and taxonomy. In order to obtain the confirmation the lytic character of the phages, their genetic material will be sequenced. The phage lytic spectrum and their stability under
different storage conditions will be examined. Moreover, we will also use the phages from the collection of Bacteriophage Laboratory to the testing the composition of designed phage
preparation e.g. possible phage synergy in the potential target formulation. Both different cocktail variants and single phages will be used for testing phage effectivity in vitro. Next phages
which able to fight with bacterial biofilm with the highest efficiency will be used for in vivo studies that will involve experimentally induced urinary tract infection in mice.
The study on the composition of the active preparation against multidrug resistant A. baumannii to treat urinary tract infections will contribute both to the development of phage therapy and to
the overcoming of huge health problem of a significant social scope.
Summary of project results
The project was a response to the public health threat posed by Acinetobacter baumannii. The bacterium is particularly dangerous for patients treated in hospital settings. Its ability to form biofilms and resistance to antibiotics, including those used as a last resort, complicates treatment options, particularly for immunocompromised patients undergoing prolonged invasive medical procedures. Diseases caused by A. baumannii are a significant social problem, particularly affecting women and reducing their quality of life.
This project developed Acinetobacter baumannii -specific phage preparation composition specific to multi-drug resistant clinical strains. Total 461 water samples from various sources were tested on 297 Acinetobacter spp. strains. This effort led to the isolation of 2 phages (apecific to Acinetobacter strains other than A.abumannii) and characterization 12 phages from Bacteriophage Laboratory collection. Mostly of them are temperate and one lytic. Transmission Electron Microscopy (TEM) identified these phages primarily as siphoviruses, except for one podovirus. They displayed diverse lytic capabilities, from 11% to 75%. The phages were most stable when stored at -70°C and within a pH range of 7.0-9.0. Ethanol-based disinfectants and solutions with copper and silver nanoparticles decreased phage titers, essential oils like cinnamon and eucalyptus proved more favorable for maintaining phage stability. We evaluated the phages'' ability to combat A. baumannii biofilms in vitro and observed that single phages were more effective in biofilm degradation. The great effect in biofilm degradatin was indicated when phages combined with silver nanoparticles. The most effective phage preparations were then tested in vivo using a mouse model of UTI.
However, these in vivo tests did not show significant antibacterial effects and the studies requre repetition. The project provided essential insights into Acinetobacter – specific phage potential and limitations. The project highlighted the potential for phage therapy to serve as an alternative or complement to traditional antibiotics, helping to address significant public health challenges and improve treatment outcomes for patients with drug-resistant infections.