Microbiota of Acute and Chronic Wounds with Respect to Clinical Condition and the Stage of Infection Process
Introduction. Traditionally, to assess the etiological significance, qualitative and quantitative characteristics of the isolated microbiota are taken into account. To optimize the interpretation of the results of wound swabs culture and to assess the etiological significance, it is relevant to analyze the wound microbiota at different time points and in terms of the stage of infectious process, established on the basis of clinical criteria. Purpose. To assess qualitative and quantitative characteristics of the microbiota isolated from acute and chronic wounds at various stages of the infectious process. Materials and methods. Clinical and microbiological parameters of acute and chronic wounds of 405 patients were analyzed. WUWHS recommendations and NERDS&STONEES mnemonics were used to assess the clinical condition of the wound and determine the stage of the infectious process. Microbiological assay of the wound swabs was performed by the sector method, according to the recommendations we elaborated; the result was presented as CFU/ml. The structure of microorganisms was assessed depending on the wound duration and clinical condition. Results. At the earliest stages of wounds (up to 4 days), no clinical signs of inflammation were recorded in patients, while only Gram (+) bacteria were isolated from wounds in 76% of cases. Despite the potential pathogenicity of S. aureus and quantitative characteristics, the absence of clinical signs of infection indicates contamination, and, therefore, does not require systemic antibiotic therapy. The high frequency of positive cultures at later stages of wound existence, even in the absence of clinical signs of inflammation, determines the need to use the concept colonized wound, due to the potential pathogenetic role of microorganisms in disrupting the healing process. In order to determine the indications for etiotropic systemic antibiotic therapy, it is necessary to differentiate two conditions: critical colonization and infection. The variability in the quantitative characteristics of the microbiota isolated from colonized, critically colonized and infected wounds necessitates taking into account bacteria not only in the amount of >105 CFU/ml, but also in ≤105 CFU/ml, as well as bacteria obtained from the enrichment broth. Conclusions. The results obtained determined the need to take into account the wound duration and the use of such concepts as contaminated wound, colonized wound, critically colonized wound, and infected wound when interpreting the microbiological culture results. To expand the qualitative characteristics of the microbiota, the microbiological study of the wound swabs should be carried out by the sector method with the presentation of the result in CFU/ml that would be useful for dynamic microbiological monitoring of ongoing therapeutic measures.