Corynebacterium spp. - representatives of the normal microflora of the human body, but their role in the development of diseases in both immunocompromised and immunocompetent patients is known. Corynebacterim spp. (C. pseudodiphtheriticum, C. striatum, C. amycolatum, C. accolens, C. argentoratense, etc.) is associated with diseases of the respiratory tract: tracheitis, pharyngitis, rhinosinusitis, bronchitis, etc. They can be transmitted by airborne droplets, household contact, and possibly by hematogenic pathways. Corynebacterim spp. toxins do not produce, but are capable of adhesion and invasion, biofilm formation, production of neuraminidase, hyaluronidase, and hemolysin. It is necessary to take into account not so much the species, but the strain affiliation of isolates of Corynebacterium spp., since among the representatives of one species of non-diphtheria corynebacteria (for example, C. pseudodiphtheriticum), colonizing the respiratory tract, there may be strains that can exhibit not only pathogenic properties, but also probiotic activity. Microbiological diagnostics is based on their quantitative determination in biological material, phenotypic (culture study, test systems for biochemical identification, Vitek 2 automated systems) and genotypic (16SpRNA gene sequencing and rpoB) methods. It is possible to use mass spectrometric analysis (MALDI-ToF-MS). The greatest activity against Corynebacterium spp. in vitro studies preserve vancomycin, teicoplanin, and linezolid. Successful therapy with at least two of the following antimicrobial agents (AMP) has been reported: vancomycin, rifampicin, linezolid, and daptomycin. The sensitivity of isolates of Corynebacterium spp. to AMP is not related to the species, but is due to strain differences, and therefore it is necessary to test each isolated strain. Continuous monitoring of the sensitivity of Corynebacterium spp. strains to AMP is necessary due to the observed variability of these traits. Of particular importance is the identification of multidrug-resistant isolates that are currently considered highly pathogenic. When compiling the review, the databases Scopus, Web of Science, The Cochrane Library, CyberLeninka, RSCI were used.

Corynebacterium spp. It is associated with inflammatory diseases of the respiratory tract (tracheitis, pharyngitis, rhinosinusitis, bronchitis, pneumonia, etc.). C. pseudodiphtheriticum can be the causative agent of bacterial coinfection in patients with a new coronavirus infection (COVID-19). The aim is to determine the pathogenic properties and resistance to antimicrobial drugs of Corynebacterium spp. strains to establish their etiological significance in the development of inflammatory diseases of the respiratory tract. Strains of Corynebacterium spp. isolated from patients with inflammatory diseases of the respiratory tract (43 pcs.) and practically healthy individuals (29 pcs.). Isolates were identified by mass spectrometric method (MALDI-TOF MS), their cytopathic effect in CHO-K1 cell culture, hemolytic, urease activity, antimicrobial drug resistance were determined. Strains of Corynebacterium spp. isolated from patients in the amount of 105 CFU/ml or more, practically healthy - 104 CFU/ml or less. Isolates of Corynebacterium spp. patients had a more pronounced cytopathic effect (83.7±11.1%) and were more often resistant to antimicrobial drugs than those isolated from practically healthy. To establish the etiological significance of Corynebacterium spp. isolates. in the development of inflammatory diseases of the respiratory tract, it is advisable to determine their amount in biological material (105 CFU/ml or more), the cytopathic effect on CHO-K1 cell culture, as well as the presence of multiple resistance to antimicrobial drugs. Differences in the characteristics of Corynebacterium spp. isolates. from patients with respiratory tract pathology and practically healthy individuals are associated with the strain, not the species, of corynebacteria.

Corynebacterium spp. are part of the human microbiome, but can cause the development of inflammatory diseases of various localization. Purpose - to evaluate the relationship between pathogenic properties and resistance to antimicrobial drugs (AMD) of Corynebacterium spp. from patients with inflammatory diseases of the respiratory tract. Strains of Corynebacterium spp. isolated from patients with inflammatory diseases of the respiratory tract (99 pcs.) and practically healthy individuals (33 pcs.). Isolates were identified by mass spectrometric method (MALDI-ToFMS), their adhesive and invasive activity on Hep-2 cells, cytopathic effect (CPE) in CHO-K1 cell culture, and resistance to antimicrobial drugs (AMD) were determined. Indicators of adhesion (3.65±0.679(CFU±m)x102/ml), invasion (1.72±0.230 (CFU±m)x102/ml), cytotoxicity (69.1±3.8% of dead CHO-K1 cells ) Corynebasterium spp. strains isolated from patients are higher (p≤0.05) than similar indicators in practically healthy people. 90.9% of isolates from patients had resistance to AMD, in most cases (57.6±4.9%) resistance to only one AMP was noted, less often to two (25.2±4.3%), three or more (8.08±2.7%). According to the results of correlation-regression analysis, pathogenic properties (adhesiveness, invasiveness, cytotoxicity) of Corynebacterium spp. strains isolated from patients are in close direct relationship with resistance to AMD. This indicates the importance of identifying strains of non-diphtheria corynebacteria resistant to AMDs, which, under the influence of developing resistance to AMDs, can increase their pathogenic potential, moving from commensalism to parasitism.