Accelerating effects of nonviable Staphylococcus aureus , its cell wall, and cell wall peptidoglycan

108

HemCon bandage is an engineered chitosan acetate preparation designed as a hemostatic dressing, and is under investigation as a topical antimicrobial dressing. We studied its effects on healing of excisional wounds that were or were not infected with Staphylococcus aureus, in normal mice or mice previously pretreated with cyclophosphamide (CY). CY significantly suppressed wound healing in both the early and later stages, while S. aureus alone significantly stimulated wound healing in the early stages by preventing the initial wound expansion. CY plus S. aureus showed an advantage in early stages by preventing expansion, but a significant slowing of wound healing in later stages. In order to study the conflicting clamping and stimulating effects of chitosan acetate bandage on normal wounds, we removed the bandage from wounds at times after application ranging from 1 hour to 9 days. Three days application gave the earliest wound closure, and all application times gave a faster healing slope after removal compared with control wounds. Chitosan acetate bandage reduced the number of inflammatory cells in the wound at days 2 and 4, and had an overall beneficial effect on wound healing especially during the early period where its antimicrobial effect is most important.

Section: Discussionmentioning

confidence: 99%

Effect of chitosan acetate bandage on wound healing in infected and noninfected wounds in mice

Burkatovskaya

Castaño

Demidova-Rice

et al. 2008

108

“…We have previously reported that the increased neutrophil infiltration in SaPG-inoculated sponges is evident as early as 12 hours after subcutaneous implantation of the sponges in rats 23 and is present at 4 and 7 days postoperative. 4,23 Muramyl dipeptide and glucosamyl muramyl tripeptide, synthetic analogues of peptidoglycan components, are potent immunoadjuvants, 24,25 and peptidoglycan is mitogenic for B lymphocytes. 21 S. aureus peptidoglycan activates neutrophils27 and macrophages 28 and stimulates them to release interleukin-1, both in vitro and in vivo,22 and may induce the release (or increased synthesis) of growth-promoting cytokines (e .g ., synovial cells of streptococcal cell wall induced arthritis in rats secrete in vitro TGF-(329 ).…”

Section: Discussionmentioning

confidence: 99%

Nonviable Staphylococcus aureus and its peptidoglycan stimulate macrophage recruitment, angiogenesis, fibroplasia, and collagen accumulation in wounded rats

Kilcullen¹,

Ly²,

Chang³

et al. 1998

Self Cite

We have previously shown that local application at the time of operation of Staphylococcus aureus, nonviable S. aureus, its cell wall, or S. aureus peptidoglycan accelerates wound healing. We hypothesized that this effect is due to both direct and indirect mechanisms, among which is an increase in the inflammatory response to wounding, resulting in an increase in macrophages, angiogenesis, and fibroblasts. Twenty-seven Sprague-Dawley male rats were anesthetized, and two 7-cm paravertebral skin incisions were made. Four polyvinyl alcohol sponges, two on each side, containing either 100 microliter of isotonic saline or 0.5 mg of nonviable S. aureus or S. aureus peptidoglycan in 100-microliter saline were implanted subcutaneously. Nonviable S. aureus or S. aureus peptidoglycan (860 microgram/cm incision) in 200-microliter saline were inoculated into the incisions at closure. The rats ate a commercial rat chow and drank tap water ad libitum throughout. After days 3 and 7 postwounding, rats were euthanized, and tissues were examined for immunohistochemical features of reparative tissue using ED-1, Factor VIII, and vimentin antibodies, markers for monocyte/macrophages, endothelial cells, and mesenchymal cells (including fibroblasts), respectively. Incisions treated with nonviable S. aureus or S. aureus peptidoglycan showed more macrophages along and deep in the wound tract 7 days postoperatively. Nonviable S. aureus or S. aureus peptidoglycan-treated sponges were surrounded and penetrated by much larger capsules of reparative tissue than saline-treated sponges at both 3 and 7 days. Neutrophil influx was much greater in nonviable S. aureus or S. aureus peptidoglycan-treated sponges, especially in central regions, and there were many more ED-1-stained macrophages in distinct geographic locations, specifically, the more peripheral-cortical areas. Some clustering of macrophages occurred around areas of invasion by reparative tissue into the surrounding subcutaneous fat and within the interstices of the sponges at the interface between reparative tissue and acute inflammatory cells. In contrast, saline-treated sponge reparative tissue had significantly fewer macrophages, much thinner and flimsy reparative tissue, with proportionately fewer macrophages clustering centrally. There were many more mesenchymal cells (notably fibroblasts) and new blood vessels and much more reparative collagen in the nonviable S. aureus or S. aureus peptidoglycan-treated sponges. We conclude that local application of nonviable S. aureus or S. aureus peptidoglycan at wounding induces an increased number and alteration in location of macrophages, increased influx (or proliferation) of mesenchymal cells (notably fibroblasts), and increased angiogenesis and reparative collagen accumulation, as well as increasing the overall acute inflammatory response to wounding.

“…Each wound was immediately inoculated along its entire length with 157 p1 saline solution or 157 pl saline solution containing 4.7 mg SaPG (860 mg SaPG/cm incision). The amount of SaPG used for inoculation of the sponges and incisions was based on our previously conducted dose-response experiments 12 and our earlier publications. [12][13][14][15] Oddnumbered rats received saline solution in the sponges and wounds on the left side and SaPG in the wounds and sponges on the right side, whereas even-numbered rats received the opposite regimen.…”

Section: Statistical Evaluationmentioning

confidence: 99%

“…Each incision was cut perpendicular to the axis of the wound and into seven strips of equal width (0 .67 cm) using a multiblade cutting device . The first, third, fifth, and sixth strip from each wound (starting at the cephalic end of the wound) were immediately tested for breaking strength using a tensiometer by a standard method in our laboratory ; [11][12][13][14][15]17,18 strip #4 was fixed in 10% buffered formalin for histologic and immunohistochemical evaluation . The upper and middle sponges from each side were removed with the immediately surrounding and penetrating reparative tissue capsule and placed in 6N HCl and hydrolyzed at 130°C for 3 hours prior to measurement of hydroxyproline (Hyp) by the Woessner method .…”

Section: Statistical Evaluationmentioning

confidence: 99%

“…Impaired wound healing is common in diabetic patients and is characteristic of experimental diabetes, both chemically induced (most frequently by streptozotocin [Sz] or alloxan) and genetic (e .g ., BB Wistar viable or nonviable Staphylococcus aureus, its cell wall, or its peptidoglycan (SaPG) increases all of these parameters in normal rats, thereby accelerating wound healing. [11][12][13] Furthermore, local application at wounding of nonviable S. aureus and SaPG each prevent or ameliorate glucocorticoid-induced 14 and cyclophosphamide-induced impairment of wound healing in rats . 15 Accordingly, we hypothesized that inoculation at operation of wounds with SaPG would ameliorate diabetes-induced wound healing impairment, despite persistent, untreated hyperglycemia, polydipsia, glycosuria, and polyuria .…”

mentioning

confidence: 99%

See 1 more Smart Citation

Single local instillation of Staphylococcus aureus peptidoglycan prevents diabetes‐induced impaired wound healing

Qiu¹,

Chang²,

Steinberg

et al. 1998

Self Cite

Diabetes-induced impaired wound healing is characterized by inhibition of the inflammatory response to wounding, macrophage infiltration, angiogenesis, fibroplasia, reparative collagen accumulation, and wound breaking strength. Because all of these processes are accelerated in normal rats by a single local application at operation of Staphylococcus aureus peptidoglycan, we hypothesized that S. aureus peptidoglycan would prevent diabetes-induced impaired wound healing, despite persistent, untreated hyperglycemia, polydipsia, glycosuria, and polyuria. Sprague- Dawley male rats were divided into two groups. One group received an intraperitoneal injection of streptozotocin (65 mg/kg) in citrate solution; the other group received an intraperitoneal injection of an equivalent volume of citrate solution. Seventeen days after the injections, the diabetic and control rats received aseptically two 5.5-cm paravertebral incisions and subcutaneous implantation of six polyvinyl alcohol sponges, three on each side. On one side, each sponge contained 0.5 mg S. aureus peptidoglycan in 50 microliter saline solution, and the incision was inoculated along its length with 4.7 mg S. aureus peptidoglycan in 157 microliter saline solution (860 microgram/S. aureus peptidoglycan/cm incision); on the other side, the same respective volumes of saline were used. During the preoperative and postoperative periods, diabetic rats lost a small amount of weight (2%), were hyperglycemic (363 +/- 10 mg/100 ml blood), polydipsic, glycosuric, and polyuric, whereas the controls gained weight (25%) and were normoglycemic (104 +/- 5 mg/100 ml blood); these differences were significantly different (p <.001 in each case). In controls, S. aureus peptidoglycan inoculation increased wound breaking strength (by a factor of 2.0) and hydroxyproline content (by a factor of 1.4; p <.001 in each case); in diabetics, there were significant decreases in wound breaking strength (by a factor of 1.7) and hydroxyproline content (by a factor of 1.3) of saline solution-inoculated incisions and sponges compared with the wound breaking strength and hydroxyproline content of saline solution-inoculated incisions and sponges in controls (p <.02 and p <.001, respectively). These decreases were completely prevented when the incisions and polyvinyl alcohol sponges had been inoculated at operation with S. aureus peptidoglycan; S. aureus peptidoglycan inoculation in the diabetic rats increased wound breaking strength by a factor of 2.2 and sponge reparative tissue hydroxyproline by a factor of 1.6 (p <.001 in each case). Thus, diabetes-induced impaired wound healing was prevented completely by a single local instillation at operation of S. aureus peptidoglycan, despite persistent, untreated hyperglycemia, polydipsia, polyuria, and glycosuria.