It is common practice to apply antibacterial ointment or cream to an open wound before dressing it. However, some new light has shed new concerns that might alter this practice.
Regeneration of skin tissues might be dependent on many species of bacteria through IL-1B signaling. Yet, topical antibiotics might interfere with this process by exerting bactericidal effects on organisms that are helpful to heal skin. A study examined healing in mice—some completely devoid of skin bacteria through antibiotic exposure and others with normal bacterial skin populations [Wang, G.; Sweren, E.; Liu, H.; Garza, L.; et al. Bacteria induce skin regeneration via IL-1β signaling. Cell Host Microbe 2021 May 12;29(5):777-791.e6. doi: 10.1016/j.chom.2021.03.003.]
The researchers discovered that wounds on the germ-free mice did not heal as quickly as the normal mice. Fewer hair follicles and sebaceous glands were present in the germ-free individuals—these organelles are typically stimulated with wound regeneration. Bacterial presence might relay information to the immune system to trigger the healing process by inflammatory cytokine IL-1B signaling and controlling morphogenesis.
Another test the team performed was to treat human wounds with Vaseline and others with Neosporin. Those treated with Neosporin healed much more slowly than the Vaseline-treated wounds.
This study might also have impacts on wound management in animals and how one considers the use of topical antibiotics on a wound. The premise is that a normal skin microbiome is critically important to skin regeneration and efforts to eliminate bacteria might impede wound healing.
