Study of the intensity of microbial contamination and nonspecific immunity under the experimental diabetes after using different ways of fixing the wound edges

Abstract

Diabetes mellitus and its complications are one of the most important causes of death. As a consequence of hyperglycemia in patients with diabetes there is an increased risk of concomitant diseases, and one of the important consequences of diabetes is impaired ability to repair. Healing disorders in diabetes are the result of complex pathophysiology involving vascular, neuropathic, immune and biochemical componentsAim of research: was to analyze changes in inflammation markers, microbial contamination and nonspecific immunity in skin homogenate of rats with diabetes after using sutures and skin glue.Material and research methods. Experimental studies were performed on 130 white outbred adult male rats, weight from 240 to 320 g. Diabetes mellitus was induced by using streptozotocin (Sigma, USA) (intraperitoneally - 65 mg / kg) with previous (15 minutes) injection of nicotinamide (intraperitoneally - 230 mg / kg). On the background of obesity, which was caused by 4 weeks of keeping animals on a high-fat diet. The development of diabetes mellitus 2 was confirmed by determining the concentration of glucose in the blood using a glucometer BAYER Contour Next (Germany). Animals of all groups (I-IV) under thiopental anesthesia (40 mg / kg body weight of rats) were made full-layer rectilinear incisions, 2 cm long, in the anterior-lateral region of the abdomen. All animals were divided into 4 experimental groups: І group (30 rats) – healthy rats, wound edges were sutured with Vicryl 5/0 thread (ETHICON, Inc. and Johnson & Johnson company (USA); ІI group (30 rats) – healthy rats, fixing of the wound edges was performed by applying skin glue Dermabond (ETHICON, Inc. and Johnson & Johnson company (USA)); ІII group (30 rats) – rats with diabetes mellitus, wound edges were sutured with Vicryl 5/0 thread; IV group (30 rats) – Rats with diabetes mellitus, fixing of the wound edges was performed by applying skin glue Dermabond. For control, all the results were compared with those of intact animals (10 rats). Animals were removed from the experiment on 3, 7, 28 days after surgery under thiopental anesthesia (90 mg / kg body weight of rats).The degree of contamination of the wound with opportunistic and pathogenic microflora determined by the level of urease activity using Nessler's reagent. Lysozyme activity was determined by bacteriolytic method, using as a substrate a suspension of bacteria Micrococcus lysodeicticus.Results. The obtained results prove that the wound process under conditions of streptozotocin diabetes mellitus in rats leads to a significantly greater contamination of the wound with pathogenic and opportunistic microflora and a decrease in nonspecific immunity, compared with healthy animals. Also, different effects of suture materials on the indicators of microbial contamination and immune protection were found: significantly larger deviations from the norm were found in groups of rats, where we used surgical sutures to fix the wound edges. When comparing the intensity of microbial contamination and nonspecific immunity in the long term (28 days) in the homogenate of the skin of rats with diabetes mellitus and the use of skin glue, the level of urease was 27.3% lower and the level of lysozyme 7.0% lower than in III group where we used surgical sutures.Changes in the activity of the antimicrobial enzyme lysozyme allow to assess the state of nonspecific immunity in the studied tissues. Many authors note a decrease in lysozyme activity in various bioliquids and tissues in diabetes mellitus. The results of our studies prove a significant decrease in the activity of lysozyme in the homogenate of postoperative skin wounds of rats with diabetes.Conclusion. Wound process in rats with experimental diabetes mellitus leads to reliable contamination of the wound with pathogenic and opportunistic microflora, as evidenced by increased urease activity, and reduced nonspecific immunity, characterized by reduced lysozyme activity in the homogenate of postoperative wound/scar tissue in relation to intact animals during all the terms of observation.In the remote period (28 days) in the skin homogenate of rats with diabetes where skin glue was used for wound closure, the level of urease was 27.3% lower and the level of lysozyme was 7.0% lower than that of rats with diabetes, where surgical sutures were used.

Keywords

• streptozotocin diabetes
• wound healing
• scars
• lysozyme and urease activity