Evaluation of the Effectiveness of Staphylococcus Phages in a Skincare Serum against Staphylococcus spp.

The emergence of multidrug-resistant (MDR) Staphylococcus spp. has resulted in the reduced use of antibiotics in many skincare cosmetic products. Alternative treatments using natural bioactive compounds and chemical agents can be replaced. However, these compounds have induced negative side effects among users and are not environmentally friendly. Phage therapy is an alternative to antibiotics for the treatment of specific pathogenic bacteria including Staphylococcus spp., without harmful effects on human skin cells and microflora. Phages can be potentially used in cosmetic products. The direct application of phage-based cosmetic products on skin can reduce the chance of skin infection caused by pathogenic Staphylococcus spp. In the present work, we isolated 17 Staphylococcus phages from sewage and soil samples. Phage A1 showed the highest lytic ability at 50% (B1 profile), covering 13 tested Staphylococcus isolates including Staphylococcus aureus (SA), methicillin-resistant S. aureus (MRSA), S. capitis (SC), and S. epidermidis (SE). Phage A1 reduced the representative S. aureus ATCC 25923 and S. capitis SC1 by 2.0 ± 0.1 and 4.1 ± 0.3 log units at a multiplicity of infection (MOI) of 104 and by 4.2 ± 0.2 and 4.4 ± 0.5 log units at a MOI of 105 after 6 h of post-phage treatment. The transmission electron microscope revealed that phage A1 was classified in the order Caudovirales of the family Myoviridae based on its appearance. Phage A1 showed optimal survival in the presence of a 0.125% (v/v) solidant DMH suspension after 3 h of post-treatment. Under a phage skincare serum formulation, the titers of phage A1 were reduced by 0.46 and 0.85 log units after storage at 4 and 25 °C, whereas a reduction of 2.96 log units was also observed after storage at 37° for 90 days. This study provides strong evidence for the effectiveness of phage application in cosmetic skincare serum for the treatment of skin diseases caused by MDR and pathogenic Staphylococcus spp. The concept of this study could be advantageous for cosmetic and/or cosmeceutical industries searching for new bioactive ingredients for cosmetic/cosmeceutical products.