Influence of phage-lactoferrin mixture on metabolic condition of human pulmonary epithelial cells and its efficacy in eradication of Drug Resistant Staphylococcus aures from inoculated cell culture

<p><span style="font-size:12.04px">Staphylococcus aureus is a pathogen that is most often responsible for nosocomial infections, such as skin infections, postoperative or burn wounds, soft tissue infections, and nosocomial pneumonia. Due to the development of resistance of S. aureus to commonly used antibiotics, in particular to methicillin - which results in resistance to all other β-lactam class antibiotics, the treatment of infections caused by this pathogen is becoming more and more challenging. Therefore, for years there has been an intensive search for treatment methods that could be an alternative to traditional antibiotic therapy. Phage therapy - using bacteriophages or viruses that multiply in bacteria - is a leading candidate among the proposed solutions. However, due to the decreased sensitivity to phages observed during in vitro evolutionary studies, concerns have arisen about the possibility of development of permanent resistance, which would result in future therapy failure. On the positive side, it was also observed that combining bacteriophages with other bactericidal compounds increased the effectiveness of therapy and prevented the development of phage resistance in bacteria.  This work</span><span style="font-size:12px"> aimed to assess the safety and efficacy of phage therapy in
MRSA respiratory tract infections. Using already isolated and characterized bacteriophages with proven
antibacterial activity mixed with lactoferrin it intends to test the influence of phages on metabolic state and
membrane integrity of human lung epithelial cells (line A549) in order to assess if phages pose no harm to the
cells. </span><span style="font-size:12px">The first step was to analyse the safety of phage-lactoferrin mixture at different concentrations by
analysing human lung cells viability and integrity of cell membranes using commercially available kits and
reagents (Neutral Red staining, LDH release assay). </span><span style="font-size:12px">Additionally, since bacteriophages have been shown to have the ability to
pass through cell layers and taking into consideration that due to rich vascularization, lungs are relatively easy
for bacteriophages to access and penetrate, the rate of phage transcytosis was assessed as another part of
the project.</span></p>