Background: Increasing numbers of antibiotics have lost efficiency because of bacterial resistance. The consequences can be severe when surgical wounds become infected during postoperative care. Natural peptide antibiotics, the so-called host defence peptides (HDPs), have been investigated since the 1990s in a search for alternative treatment strategies. HDPs build up a protection shield against pathological microorganisms, especially in human epithelium. The use of HDPs is currently being discussed as a new antimicrobial therapeutic strategy. Accordingly, a profound knowledge of the quantitative relationships of the effectors is essential.
Objectives: To evaluate differences in HDP expression between postoperatively inflamed and healthy epithelium.
Methods: Expression profiles of the genes encoding HDP human beta-defensin (hBD)-1 (DEFB1, previously known as HBD-1), hBD-2 (DEFB4A, previously known as HBD-2), hBD-3 (DEFB103A, previously known as HBD-3) and psoriasin (S100A7) were assessed in samples of surgical wound healing disorders (n = 27) and healthy epithelium (n = 16) by using real-time polymerase chain reaction. Immunohistochemical staining was performed in the same samples.
Results: A significant overexpression of DEFB4A (P < 0.001), DEFB103A (P = 0.001) and S100A7 (P < 0.001) was found in cutaneous surgical site infections. Immunohistochemistry revealed intensely elevated protein levels of psoriasin in infected wounds, and differences in distribution with respect to the epithelial layers.
Conclusions: The study demonstrates upregulated mRNA expression and protein levels of HDPs in postoperatively inflamed epithelium. The results may be a starting point for novel pharmacological treatments.