An Experimental Study on Surgical Wound Contamination from Distant Infective Source
Department of Clinical Sciences, College of Veterinary Medicine, Urmia University
Wound contamination and infection that could be caused by distant endogenous infective source is one of the complications in surgical wound healing. The objective of this study was to evaluate the effect of a remote inoculated infective source on the contamination of surgical wounds.
Materials & Methods
Thirty White New-Zealand rabbits of both sexes weighing about 1.8 kg divided randomly into three control and three treatment equal groups. In treatment groups 24 hours before surgical intervention Staphylococcus aureus (8 * 108 CFU/ml dilution) was injected subcutaneously in right thigh at the dose rate of 5m1/kg/bw. In both treatment and control groups after routine surgical preparation, skin and left longissimus dorsi muscle were incised (3cm/kg/bw) and sutured, immediately. Biopsy samples for bacteriological culture were obtained at 24, 48 and 72 hours post-operation from incised tissues. Vital signs were assessed before and after operation.
Clinical assessment showed that in treated groups there were a statistically significant increase in rectal temperature 24 hours after inoculation of Staphylococcus aureus (p<0.05). The relative frequency of staphylococcal contamination of tissue samples at 24 and 48 hours after surgery in treatment groups were 20% and 60%, respectively. Statistical analysis did not show any significant differences in rate of contamination between control and treatment groups at aforementioned times (p>0.05). However, comparison at 72 hour after surgery, showed that the rate of contamination in treatment group is significantly more than control ones, i.e., 0 vs. 100%, respectively (p= 0.004).
In this study the presence of Staphylococcus aureus in wounds of treatment animals in comparison with control groups at 72 hours after surgery, suggested that microorganisms lodged in any part of body other than wound region could contaminate it, which could be important on wound healing.