Corynebacterium spp.: relationship of pathogenic properties and antimicrobial resistance.

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.

[The immune-enzyme techniques of analysis in diagnostic of cholera.]

The optimal conditions of arrangement of direct alternative of flatbed enzyme-linked immunosorbent assay and dot-immunoanalysis with application of monoclonal peroxidase conjugates for express identification of comma bacillus of serogroups O1 and O139 both in hospital and field conditions without device support. The direct technique enzyme-linked immunosorbent assay in flatbed alternative shortens time of analysis up to 70-80 minutes and in case of dot enzyme-linked immunosorbent assay on membrane - up to 70-90 minutes. It is established that in case of analysis in conditions of room temperature (20-25 oC) sensitivity of techniques remains at initial level.

[Evaluation of toxin producing abilities of non-O1/non-O139 serogroup Vibrio cholerae isolated from humans].

AIM: Determination of non-O1/non-O139 Vibrio cholerae toxin (CT) gene expression by using EIA, and biological effect of non-O1/non-O139 V. cholerae supernatant on cell cultures evaluation. MATERIALS AND METHODS: 39 V. cholerae strains from various serological groups were studied. Hemolytic activity of strains was determined by using Greig test, and cholera toxin production--in GM1-EIA and in continuous cell lines by registering cytotonic, cytotoxic and proteolitic effect. RESULTS: GM1-EIA method does not detect CT production in 29 museum strains of non-O1/non-O139 V. cholerae in vitro. CT was detected only in 1 non-O1/non-O139 V. cholerae strain supernatant with OD = 0.577 that is substantially lower than in O1 V. cholerae strains (OD = 2.176). In cell cultures non-O1/non-O139 V. cholerae supernatants diluted to 1:100 caused elongation only in single cells. CONCLUSION: Cytological model is a more sensitive technique to evaluate toxin producing abilities of non-O1/non-O139 V. cholerae strains and is appropriate for use.

[Identification of Vibrio cholerae serogroups O1 and O139 by monoclonal antibodies in the slide agglutination test].

The agglutinating properties of MCA-O1 of the IgG class and MCA-O139 of the IgM class towards epitopes of O-antigen of Vibrio cholerae O1 and accordingly Vibrio cholerae O139 were studied. The ascitic and cultural fluids by hybridomas F8G12 and D11 deposited in the specialized Collection of Cell Cultures of Vertebrates (Saint Petersburg) under RKKK (II) 386 D and RKKK (II) 674 D were the sources of monoclonal immunoglobulins. The advantage of diagnostic monoclonal immunoglobulins is that they are distinguished for strict specificity and their use in practical health care contributes to the higher specificity of a laboratory test for cholera and to its shorter performance.