[Approaches to the estimation of some parameters of humoral and cellular immune response to bacteriophages.]

From crisis to cure: harnessing the potential of mycobacteriophages in the battle against tuberculosis

Tuberculosis (TB) is a serious and fatal disease caused by Mycobacterium tuberculosis (Mtb). The World Health Organization reported an estimated 1.30 million TB-related deaths in 2022. The escalating prevalence of Mtb strains classified as being multi-, extensively, extremely, or totally drug resistant, coupled with the decreasing efficacies of conventional therapies, necessitates the development of novel treatments. As viruses that infect Mycobacterium spp., mycobacteriophages may represent a strategy to combat and eradicate drug-resistant TB. More exploration is needed to provide a comprehensive understanding of mycobacteriophages and their genome structure, which could pave the way toward a definitive treatment for TB. This review focuses on the properties of mycobacteriophages, their potential in diagnosing and treating TB, the benefits and drawbacks of their application, and their use in human health. Specifically, we summarize recent research on mycobacteriophages targeted against Mtb infection and newly developed mycobacteriophage-based tools to diagnose and treat diseases caused by Mycobacterium spp. We underscore the urgent need for innovative approaches and highlight the potential of mycobacteriophages as a promising avenue for developing effective diagnosis and treatment to combat drug-resistant Mycobacterium strains.

Determination of Bactericidal Activity Spectrum of Recombinant Endolysins of ECD7, Am24, Ap22, Si3, and St11 Bacteriophages

The bactericidal activity of recombinant endolysins LysECD7, LysAm24, LysAp22, LysSi3 and LysSt11 was assayed in multidrug resistant strains (n=120) of Salmonella enterica, E. coli, Acinetobacter baumannii, Enterobacter spp., Pseudomonas aeruginosa, Klebsiella pneumoniae, and Campylobacter jejuni. The assay showed that the recombinant endolysins had a wide spectrum of bactericidal activity compared to endolysins of their progenitor phages. Among examined endolysins, we selected the active pharmaceutical substances with broad spectrum of bactericidal activity. Most strains were sensitive to LysECD7 (70.7%), LysAm24 (65%), and LysAp22 (58.6%), which seems to be promising causative agents for the development of finished dosage form.

Phage-specific antibodies

Antibodies specific to phage virions have been observed many times, both in animals and in humans. Phages induce the T-dependent type of immune response, which is fundamental for immunological memory and long retention of abilities to recognize and respond to foreign epitopes. Experimental models have shown that phage-specific antibodies can be devastating for a phage in vivo. Observations from phage treatment in humans demonstrate however that antibodies do not necessarily hinder phage therapy. Controlling effective doses may help in controlling the immune response to phage and to create 'therapeutic windows' for the phage. Phage therapy design may also benefit from understanding phage antigenicity and predicting possible cross-reactions between antibodies specific to different phages.