Effect of Bacterial Exposure on Acellular Human Dermis in a Rat Ventral Hernia Model

The Addition of Lysostaphin Dramatically Improves Survival, Protects Porcine Biomesh from Infection, and Improves Graft Tensile Shear Strength

“…Host immune cells are not able to adequately target the contaminated areas on the mesh, creating a window of opportunity for microorganisms to grow into a fulminant and sometime lethal infection. Milburn may allow the host to eradicate small amounts of bacteria such as 1 3 10 4 CFU, but the host is unable to clear infection challenges of 1 3 10 6 CFU or greater [17,18]. We encountered similar findings in the control group with none of the rats surviving a 1 3 10 6 CFU S. aureus inoculum and only one out of 15 animals surviving a 1 3 10 8 CFU S. aureus inoculum with biologic mesh.…”

“…The one surviving animal showed evidence of extensive mesh degradation and had a positive culture. In our previous experiments, when animals implanted with biologic mesh survived inoculums of 1 3 10 4 to 1 3 10 6 CFU S. aureus, the grafts had partially or completely disintegrated and lost integrity [17].…”

“…Acellular collagen matrix based biologic meshes have been developed and promoted for use in contaminated fields, but not without their own drawbacks. Overall, biologic meshes may allow the host to eradicate low bacterial loads of up to 10 4 CFU, and the meshes can become rapidly integrated into the tissues, but they lose their tensile strength [17]. However, moderate infection challenges (10 6 CFU) of the biologic mesh lead to infection, evidenced by positive wound cultures, as do synthetic implants [17,18].…”

“…Overall, biologic meshes may allow the host to eradicate low bacterial loads of up to 10 4 CFU, and the meshes can become rapidly integrated into the tissues, but they lose their tensile strength [17]. However, moderate infection challenges (10 6 CFU) of the biologic mesh lead to infection, evidenced by positive wound cultures, as do synthetic implants [17,18]. Antimicrobial silver/ chlorhexidine-impregnated prostheses have been shown to withstand mesh infection in in vitro and in vivo models, but had a prohibitive side-effect profile in human clinical trials [15].…”

Histologic and Biomechanical Evaluation of Biologic Meshes following Colonization with Pseudomonas aeruginosa

“…As such, it is imperative that the response of these biologic meshes to bacterial encounters becomes clearly defined. Interestingly, while several studies exist on the effects of a gram-positive bacteria challenge on the biologic mesh in vivo [12][13][14][15], no studies have investigated the effects of a gram-negative bacterial challenge.…”