Evaluation of Healing and Microbial Responses to Surgical Wounds in Alloxan-induced Diabetic Rabbits

Abstract

The wounds of diabetic patients are associated with delayed healing and microbial invasion. This study evaluated the healing and microbial responses to surgical wounds in diabetic rabbits. Sixteen (16) New Zealand White rabbits were used in this study. They were divided into 4 groups of 4 rabbits each, namely; A, B, C and D. A is the control (non-diabetic and non-wounded), B (diabetic and non-wounded), C (wounded and non-diabetic) and D (wounded and diabetic). Three (3) cm2 skin wounds were created in a standard aseptic condition while diabetes was induced by intravenous administration of 200 mg/kg of alloxan monohydrate. Blood samples were collected from ear vein of each rabbit on days 0, 3, 7, 14, 21 and 28 post-surgery for analysis of blood glucose level.  Wound samples were collected on days 3, 7, 14 and 21 to evaluate microbial contaminants. The wounds were examined for exudation and recorded as none (0), scant (1), moderate (2) and large (3) and diameter of wound epithelialization and contraction were determined. The blood glucose concentration of groups B and D  from days 3 to 28 ranged between 288.00 ± 40.22 mg/dl to 358.65 ± 25.89 mg/dl), and were significantly higher (P < 0.05) than the corresponding values of groups A and C which ranged from  120.60 mg/dl ± 14.29 to 129.60 ± 8.18 mg/dl. The rate of wound contraction in the C group on day 7 (11.02 ± 2.17%) was significantly higher (P < 0.05) than the D group (2.23 ± 4.60%). Staphylococcus and Pseudomonas subspecies were identified in the wounds of rabbits in groups C and D. It was concluded that alloxan-induced diabetes caused delayed wound healing. At the same time Staphyloccocus and Pseudomonas species were the predominant microorganism detected in the acute wounds of diabetic and non-diabetic rabbits.