Spectrum of bacterial microflora of trophic ulcers against the background of varicose and post-thrombotic decompensated venous insufficiency

Abstract

Annotation. The main cause of long-term wound healing is chronic inflammation, microcirculation disorders, and bacterial contamination of wound surfaces with the formation of biofilms. The frequency of trophic ulcers of the lower extremities, microbial resistance, and a significant recurrence rate (20-70%) is a topical issue today. The purpose of this work is to establish their bacterial component and possible relationships with microcirculation depending on the etiology of decompensated chronic venous insufficiency in order to improve the healing of trophic ulcers. From 2018 to 2022, 174 patients with chronic venous insufficiency (CVI) C6 according to CEAP, aged from 38 to 69 years (on average, 55±5.3 years), were treated in the surgical clinic of the regional hospital. To monitor microflora and susceptibility to prescribed antimicrobials, a bacteriological study was conducted comparing the widely used paper disc method with the quantitative method of measuring the minimum concentration of growth inhibition. The study of the microcirculation of the skin of the lower extremities was carried out taking into account the angiosomal approach on the TCM 400 Radiometer device (Denmark). The study used the ratio of the value obtained in the first metacarpal area of the lower limbs to the same value in the chest. Statistical processing and analysis of the obtained results was performed using the Jamovi program. Analysis of the selected samples showed the diversity of the polymicrobial community, Gram-positive bacteria (Staphylococcus spp., Enterococcus spp.) were detected in the upper layers of the biofilm, Gram-negative and microscopic fungi Malassezia and Candida – in the deep layers. Anaerobic microorganisms (Prevotella spp., Porphorymonas spp.) were also isolated from samples of such wounds in 2%. When studying the microbial landscape of ulcers, it was found that the share of Staphylococcus spp. is: 65%; Enterococcus spp. – 60%; Pseudomonas spp. – 39%; Proteus spp., Enterobacter spp. and Citrobacter spp. – about 25%; Streptococcus spp. – 26%; Escherichia spp. – 15%; Morganella spp. – 9%; Klebsiella spp., Acinetobacter spp. – 4%; Xanthomonas spp., Prevotella spp., Porphorymonas spp. – 2%, respectively. Fungi culture Candida spp. and Malassezia spp were detected in all patients with CVI in the decompensation stage. The change in tcpCO2 indicators (46.4±1.4) is observed more in patients with gram-negative infectious agents and more acidic pH. In the group of patients where Gr+ infectious agents were detected, the average tcpCO2 level was 44.6±1.5.