The Effect Of Pseudomonas Aeruginosa On The Formation Of Hypertrophic Scar In Rabbits Ears

Objective:To study the effect of pseudomonas aeruginosa on the formation of hypertrophic scar in rabbits ears after injury.Methods:Full-thickness excisional wounds and 1cm in diameter were created over the ventral surface of 8 adult New Zealand white rabbits ears which were randomly divided into pseudomonas aeruginosa group(groupA),blank group(group B)and were observed wound healing time of groupA,B and incidence of forms of excessive scar.The change of fibroblasts in forms of excessive scar were investatigated in different time thorough histomorphometric, collagen-Ⅰand Microvessel count in forms of excessive scar were tested in different time through immunohistochemistry.Results:Excessive dermal scars on rabbits ears are similar to human hypertrophic scar in pseudomonas aeruginosa group.The mean values of wound healing time of groupA,B was 15.6±1.4,10.8±1.1 days respectively,which have statistical differecnce.The incidence of excessive dermal scar is 91.6%in pseudomonas aeruginosa group.The incidence of excessive dermal scar in pseudomonas aeruginosa group have statistical differecnce with the blank control group which is 62.50%;The number of proliferative fibroblasts of the pseudomonas aeruginosa group are more than the blank group in the postoperation 28days,49days,60days.The Microvessel count and collagen-Ⅰbetween pseudomonas aeruginosa group and the blank control group have statistical differecnce in the postoperation 28days,49days,60days.The number of fibroblast and the express of collagen-Ⅰin all groups decrease along with the time course.Conclusion:Pseudomonas aeruginosa of surgical infection enlarge healing time and increase forms of excessive scar incidence in rabbits ears:The number of fibroblast and collagen-Ⅰin healed excisional wounds of rabbits ears are higher than normal tissues;further proving the animal model of rabbit ear for hypertrophic scar is stable and repeated experiment method for study of the human hypertrophic scar.To apply the hypertrophic scar animal model which was contaminated by pseudomonas aeruginosa infection in rabbits ears after injury will be helpful to study the formation mechanism of human hypertrophic scar.