POSSIBLE MECHANISMS OF THE STERNAL WOUND INFECTION IN PURULENT-INFLAMMATORY COMPLICATIONS DEVELOPED AFTER CARDIAC SURGERY
Objective. To determine the possibility of the sternal wound infection with S. aureus coprocultures in patients after cardiac surgery. Methods. The main biological properties, antibiotic sensitivity and genomic variants of 26 S. aureus isolated from the discharge of the sternal wound and colon of 13 patients with sterno-mediastinitis, sternum and ribs osteomyelitis after cardiac surgery were studied. The virulence factors, persistence and antibiotic sensitivity were determined by standard methods, genotyping was performed by RAPD-PCR. Results. The comparative analysis of phenotypic characteristics revealed in six pairs of S. aureus isolated from the sternal wounds and colon from the specific patients of 13 examined, a definite biological profile: the presence or absence of the same virulence enzymes: hemolysins, DNAasa, lecithinase; persistence factors: anti-lysozyme, anti-complement and anti-lactoferrin activity, as well as ability of biofilm formation. The same pairs of strains were identical in sensitivity to antimicrobial drugs. The analysis of antibiogram of all 12 S. aureus isolates (6 pairs) allowed them to be classified as strains community-acquired origin. Genotyping confirmed the relationship of pairs of S. aureus, isolated from discharge of sternal wounds and feces, in six patients. Conclusions. Intestinal dysbiosis with the pronounced biotope colonization by S. aureus along with the negative factors of long hours of operations with the artificial blood circulation, cause a decrease in colonization resistance, impaired barrier function of the intestinal mucosa. Against this background, hematogenous translocation of S. aureus from the intestinal mucosa and endogenous infection of the surgical area are possible. In the process of the preoperative preparation of patients, it is advisable to perform bacteriological examination of feces for intestinal dysbiosis and, if necessary, to carry out a correction of biotope microbiome. The phenotypic and genotypic characteristics of 13 pairs of S. aureus isolated from a detachable sternal wound and colon of the same patients with infectious and inflammatory complications after cardiac surgery with transsternal access have been studied in a comparative aspect. The kinship of pairs of S. aureus cultures was shown in six patients. The possibility of endogenous infection of the surgical area due to hematogenous translocation of S. aureus from the intestinal mucosa in patients with severe staphylococcal dysbiosis has been established.