Journal of microbiology, epidemiology and immunobiology

Introduction. Anthrax is registered annually in the Russian Federation. The constant risk of complication of the epizootological and epidemiological situation on anthrax is due to the widespread distribution of soil foci of infection (anthrax burials (AB), «pestilence fields») and associated stationary hazardous areas (SHA).

The aim is to update data on anthrax SHA and soil foci in order to improve epidemiological surveillance of anthrax in the Russian Federation.

Materials and methods. Archival and reference materials on anthrax SHA and soil foci, accounting and reporting data of territorial bodies of Rospotrebnadzor and veterinary service were used.

The selection of criteria for characterizing anthrax SHA, AB and «pestilence fields» was carried out, using which the structure of databases of anthrax SHA and soil foci was developed.

Results. For the first time, electronic databases of anthrax SHA and soil foci on the territory of Russia were developed, containing updated information of the characteristics of 32566 SHA and 3314 soil foci (3185 AB and 129 «pestilence fields»). Analysis of the data revealed a decrease in the number of SHA and AB in the country compared to the reference data, as well as a lack of correlation between the counted number of SHA and AB in most regions, indicating the presence of a large number of unreported AB and the persistence of potential risks of infection situation complications.

Conclusion. The introduction of up-to-date databases of anthrax SHA and soil foci into the practice of Rospotrebnadzor bodies and institutions and veterinary services will improve the level of information support and efficiency of epidemiological surveillance of anthrax in the Russian Federation.

Introduction. Tomsk region is one of the territories of the Russian Federation with the highest possible incidence of tick-borne infections. However, the spectrum and genetic diversity of tick-borne pathogens remain insufficiently studied.

Materials and methods. The study analyzed 534 ticks: Ixodes persulcatus (n = 107), I. pavlovskyi (n = 234) and Dermacentor reticulatus (n = 193), collected in 13 biotopes of Tomsk and its suburbs during 2023. Detection of genetic material of tick-borne pathogens was carried out by PCR and RT-PCR in individual ticks with subsequent sequencing and phylogenetic analysis of nucleotide sequences.

Results. More than fourfold dominance of I. pavlovskyi and D. reticulatus ticks over the taiga tick was observed. Infection of I. persulcatus ticks with tick-borne encephalitis virus (TBEV) of the Siberian genotype amounted to 1.3%, in ticks of the Ixodes genus, the genetic material of Borrelia burgdorferi s.l. was detected in 8.5%, B. miyamotoi – in 2.1%, Anaplasma phagocytophilum — in 1.5%, and Rickettsia tarasevichiae — in 14.1%. R. raoultii infection of D. reticulatus ticks was identified in 48.7%, and Babesia canis DNA was detected in a single sample. Genotyping and phylogenetic analysis of genomic nucleotide sequences showed the presence of new, unusual for the region genetic variants of B. garinii, B. bavariensis, B. afzelii and the Siberian TBEV genotype (subclade V).

Conclusion. In the territory of Tomsk and its suburbs, genetic material of 9 species of tick-borne pathogens, including their new genetic variants, was detected in ixodes ticks.

Introduction. Modern medicine is faced with the resistance of Candida spp. to antimycotics, due to changes in the expression and structure of the ERG11 gene, the molecular target of triazoles. These mechanisms often operate simultaneously, but the interaction between them remains poorly understood.

The aim of this study is to investigate the interaction between ERG11 gene overexpression and mutation in the development of triazole resistance in C. albicans.

Materials and methods. Eleven C. albicans strains from the G.N. Gabrichevsky Moscow Research Institute of Epidemiology culture collection were analyzed. Each strain was characterized by its ERG11 gene expression level, the presence of ERG11 mutations, and its susceptibility to the triazoles posaconazole, voriconazole, itraconazole and fluconazole.

Results. The C. albicans strains (n – number of tested strains) were categorized into four groups: Group 1 (n = 2, ERG11 overexpression only), Group 2 (n = 3, ERG11 mutations only), Group 3 (n = 4, both ERG11 overexpression and mutation) and Group 4 (n = 2, neither ERG11 overexpression nor mutation). The minimum inhibitory concentration (MIC) of Triazoles in Group 1 was 15.76-fold higher than in Group 2, 4.97-fold higher than in Group 3, and 2.51-fold lower than in Group 4 (p < 0.05 for all comparisons). The MIC of triazoles in Group 2 was 3.17-fold lower than in Group 3 and 40.00-fold lower than in Group 4 (p < 0.001). The MIC of triazoles in Group 3 was 12.5-fold lower than in Group 4 (p < 0.001). Population-level variation in triazoles MIC was more strongly influenced by the isolated effect of ERG11 mutations (45.94%) than by the isolated effect of ERG11 overexpression (5.27-fold less).

Conclusion. Triazole resistance in C. albicans is influenced by the combined actions of ERG11 overexpression and mutation. ERG11 overexpression appears to contribute more to the absolute level of resistance, while ERG11 mutations have a greater impact on the diversity of resistance levels within the C. albicans population.

Introduction. More than 40% of Mycobacterium tuberculosis strains are resistant to rifampicin (RIF) and isoniazid, the first-line drugs. The tuberculosis pathogen becomes resistant to RIF mainly due to mutations in the rpoB gene. The aim of the study was to search for the most probable compensatory mutations in the rpoA, rpoB and rpoC genes encoding α-, β- and β′-subunits of M. tuberculosis RNA polymerase.

Materials and methods. A cross-sectional analysis of phenotypic and genetic resistance to RIF among 2298 clinical strains of M. tuberculosis revealed 8 cases in which resistance as determined by the Xpert Ultra MTB/RIF test was not confirmed bacteriologically. In all cases, these were chronic multidrug-resistant or extensively drug-resistant M. tuberculosis patients in whom RIF was discontinued due to the detection of resistance to this drug in the isolated strains. Two strains were obtained for genotype testing, Sanger sequencing and whole-genome sequencing.

Results. Repeat Xpert Ultra MTB/RIF test, Sanger sequencing and whole genome sequencing revealed the presence of a single S450L mutation in the rpoB gene with phenotypic sensitivity in both strains. Phylogenetic analysis revealed that both genomes belonged to the Beijing B0/W148 genotype. The strains were characterized by a higher growth rate than the other isolates. Two potential compensatory mutations V483G and H748P in the groC gene were identified in the absence of other significant changes in the rpoA and rpoB genes.

Conclusion. It is suggested that the phenomenon of discrepancy between results of bacteriological and molecular genetic tests is associated with the acquisition of compensatory mutations in the groC gene during RIF treatment of Beijing B0/W148 strains, and the identified mutations affect the conformation of the β'-subunit, restoring the transcription efficiency of affected by the major S450L mutation.

Introduction. Currently, listeriosis is regarded as one of the dangerous infections that cannot be prevented by vaccination and is characterized by the severity of the clinical process and high mortality. Improving laboratory diagnostic methods especially in listeriosis meningitis to identify the pathogen in the shortest possible time remains an urgent problem.

The aim of the study was to investigate the behavior of collection and clinical strains of various listeria species on GBM-agar — a nutrient medium for isolating pathogens of purulent bacterial meningitis — in order to improve the bacteriological method for isolating and identifying Listeria monocytogenes.

Materials and methods. In the current study, 1125 samples of clinical material and food produces were used. Of these, 95 were isolated and 5 were reference strains of Listeria spp. The following culture media to isolate listeria were used: Agar Listeria by Ottaviani and Agosti (ALOA); Listeria enrichment broth (LEB), Listeria isolation agar (LIA), GBM-agar.

Results. Of the 1125 samples involved the following strains were isolated using LEB, LIA and ALOA media: L. monocytogenes — 89, L. welshimeri — 2, L. innocua — 3, L. seeligeri — 1. All isolates and reference strains were subcultured by using conventional selective media (LIA, ALOA) and additionally GBM-agar modified by adding a selective additive to isolate L. monocytogenes, and yolk emulsion. Colonies grown on the modified GBM-agar and belonging to the Listeria genus were larger and had distinctive morphological traits making them differ from colonies obtained by means of conventional listeriosis media. This allowed for the primary differentiation of L. monocytogenes from non-pathogenic listeria species and some other pathogens of purulent bacterial meningitis.

Conclusion. It is shown that the algorithm of the culture method can use a new nutrient medium (modified GBM agar) possessing improved growth properties for L. monocytogenes, the introduction of which will serve as an additional effective means for differentiating listeria during research in sanitary and clinical microbiology.

The aim of this review is to characterize the possibilities of using organoid (3D-cell) cultures to assess the ability of viruses for cross-species transmission.

Sources from Web of Science, PubMed, Scopus, Elsevier, Google Scholar, and eLIBRARY.RU databases as of February 2025 were used.

In addition to classical methods of epidemiologic diagnostics and surveillance of viral infections, molecular genetic technologies (polymerase chain reaction and sequencing) are widely used in the epidemiologic surveillance system. As the best world experience shows, the use of organoid (3D-cell) cultures is promising in addressing these issues. This review analyzes data on the use of organoid (3D-cell) cultures of human and animal origin to study immunopathogenesis, as well as to assess the ability of a number of viruses (SARS-CoV-2, influenza, Zika, measles, etc.) for cross-species transmission, which determines their pandemic potential