Premium
Time course study of delayed wound healing in a biofilm‐challenged diabetic mouse model
Author(s) -
Zhao Ge,
Usui Marcia L.,
Underwood Robert A.,
Singh Pradeep K.,
James Garth A.,
Stewart Philip S.,
Fleckman Philip,
Olerud John E.
Publication year - 2012
Publication title -
wound repair and regeneration
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.847
H-Index - 109
eISSN - 1524-475X
pISSN - 1067-1927
DOI - 10.1111/j.1524-475x.2012.00793.x
Subject(s) - biofilm , wound healing , pseudomonas aeruginosa , medicine , wound care , clearance , chronic wound , dorsum , microbiology and biotechnology , staphylococcus aureus , surgery , biology , bacteria , anatomy , urology , genetics
Bacterial biofilm has been shown to play a role in delaying wound healing of chronic wounds, a major medical problem that results in significant health care burden. A reproducible animal model could be very valuable for studying the mechanism and management of chronic wounds. Our previous work showed that P seudomonas aeruginosa ( PAO 1) biofilm challenge on wounds in diabetic (db/db) mice significantly delayed wound healing. In this wound time course study, we further characterize the bacterial burden, delayed wound healing, and certain aspects of the host inflammatory response in the PAO 1 biofilm‐challenged db/db mouse model. PAO 1 biofilms were transferred onto 2‐day‐old wounds created on the dorsal surface of db/db mice. Control wounds without biofilm challenge healed by 4 weeks, consistent with previous studies; none of the biofilm‐challenged wounds healed by 4 weeks. Of the biofilm‐challenged wounds, 64% healed by 6 weeks, and all of the biofilm‐challenged wounds healed by 8 weeks. During the wound‐healing process, P . aeruginosa was gradually cleared from the wounds while the presence of S taphylococcus aureus (part of the normal mouse skin flora) increased. Scabs from all unhealed wounds contained 10 7 P . aeruginosa , which was 100‐fold higher than the counts isolated from wound beds (i.e., 99% of the P . aeruginosa was in the scab). Histology and genetic analysis showed proliferative epidermis, deficient vascularization, and increased inflammatory cytokines. Hypoxia inducible factor expression increased threefold in 4‐week wounds. In summary, our study shows that biofilm‐challenged wounds typically heal in approximately 6 weeks, at least 2 weeks longer than nonbiofilm‐challenged normal wounds. These data suggest that this delayed wound healing model enables the in vivo study of bacterial biofilm responses to host defenses and the effects of biofilms on host wound healing pathways. It may also be used to test antibiofilm strategies for treating chronic wounds.