Corynebacterium diphtheria, Adhesion, Type and Biofilm Cultures

Abstract

Relevance. It is now known that toxigenic strains of Corynebacterium diphtheriae are capable not only of adhesion, but also of invasion into epithelial cells of the upper respiratory tract. In addition, Corynebacteria have the ability to form biofilms, as a part of which they can change to some extent their properties (sizes of bacterial cells, antibiotic sensitivity), which can affect their adhesion and invasive properties. Aims. Identification and comparative analysis of adhesive and invasive activity of typical and biofilm cultures of various toxigenic strains of C. diphtheriae. Materials & Methods. Abstract adhesive and invasive properties of standard and biop^nochnyh (120- and 720-hour) cultures of toxigenic strains of C. diphtheriae gravis tox + № 665, № 6765, C. diphtheriae mitis tox + № 269, derived from NISC L.A. Tarasevich, strain C. diphtheriae gravis tox +, isolated from patients with a diagnosis of "localized form of diphtheria" bacteriological laboratory FSI «1002 CSSE SNCMD» Ministry of defence of the Russian Federation, C. diphtheriae gravis strain with a “silent" tox-gene provided by the MBUZ “GB № 1 them. ON. Semashko Rostov-on-Don " on culture pharyngeal epithelial carcinoma cells Hep-2. Results. The identification and comparative analysis of the adhesive and invasive activity of typical an biofilm cultures of various toxigenic strains of C. diphtheriae was carried out. The adhesive and invasive properties of typical and biofilm (120- and 720-hour) cultures of toxigenic C. diphtheriae strains were studied on the culture of Hep-2 carcinoma cells of the pharyngeal epithelium. The ability to adhere type cultures of all toxigenic strains of corynebacteria increased by the 8th and 18th hours of cultivation, and the dynamics of their invasive properties correlated with adhesion. The most pronounced adhesive-invasive potential was found in the circulating strain of C. diphtheriae gravis tox +. Adhesion processes prevailed over invasion in the C. diphtheriae gravis tox + strains № 6765, C. diphtheriae gravis with the “silent" tox-gene and C. diphtheriae mitis tox + № 269. When biofilm was formed, adhesion of corynebacterium increased, and invasiveness decreased dramatically. Conclusion All studied toxigenic strains of C. diphtheriae had adhesive and invasive activity. These properties were most pronounced in the circulating strain of C. diphtheriae gravis tox +. Conclusions. Adhesion and invasion of the causative agent of diphtheria play a significant role in the early stages of the infectious process, whereas subsequently, during the formation of a biofilm, the adhesion of corynebacteria increases and the invasiveness decreases sharply.