BD-2 and BD-3 increase skin flap survival in a model of ischemia and Pseudomonas aeruginosa infection

• Published in: Scientific reports 2019-05, Vol.9 (1), p.7854, Article 7854
• Main Authors: Casal, Diogo, Iria, Inês, Ramalho, José S., Alves, Sara, Mota-Silva, Eduarda, Mascarenhas-Lemos, Luís, Pontinha, Carlos, Guadalupe-Cabral, Maria, Ferreira-Silva, José, Ferraz-Oliveira, Mário, Vassilenko, Valentina, Goyri-O’Neill, João, Pais, Diogo, Videira, Paula A.
• Format: Article
• Language: English
• Subjects: 13/109; 14/28; 14/63; 38/1; 38/77; 42/109; 692/308/1426; 692/420/254; 692/699/255/1318; 96/44; Animals; Anti-Bacterial Agents - metabolism; Anti-Bacterial Agents - therapeutic use; beta-Defensins - genetics; beta-Defensins - therapeutic use; Biofilms; Catheters; Defensins; Disease Models, Animal; Genetic Therapy; Genetic Vectors - genetics; Genetic Vectors - therapeutic use; Graft Survival; Humanities and Social Sciences; Humans; Immune system; Innate immunity; Ischemia; Ischemia - complications; Male; Medical instruments; multidisciplinary; Pseudomonas aeruginosa; Pseudomonas aeruginosa - drug effects; Pseudomonas Infections - complications; Pseudomonas Infections - therapy; Rats; Rats, Wistar; Scanning electron microscopy; Science; Science (multidisciplinary); Skin; Skin Transplantation - adverse effects; Surgical Flaps - adverse effects; Surgical Flaps - microbiology; Survival; Transduction, Genetic
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-44153-y

The main aim of this work was to study the usefulness of human β-defensins 2 (BD-2) and 3 (BD-3), which are part of the innate immune system, in the treatment of infected ischemic skin flaps. We investigated the effect of transducing rat ischemic skin flaps with lentiviral vectors encoding human BD-2, BD-3, or both BD-2 and BD-3, to increase flap survival in the context of a P . aeruginosa infection associated with a foreign body. The secondary endpoints assessed were: bacterial counts, and biofilm formation on the surface of the foreign body. A local ischemic environment was created by producing arterialized venous flaps in the left epigastric region of rats. Flaps were intentionally infected by placing underneath them two catheters with 10 5 CFU of P . aeruginosa before the surgical wounds were hermetically closed. Flap biopsies were performed 3 and 7 days post-operatively, and the specimens submitted to immunohistochemical analysis for BD-2 and BD-3, as well as to bacterial quantification. Subsequently, the catheter segments were analyzed with scanning electron microscopy (SEM). Flaps transduced with BD-2 and BD-3 showed expression of these defensins and presented increased flap survival. Rats transduced with BD-3 presented a net reduction in the number of P . aeruginosa on the surface of the foreign body and lesser biofilm formation.