Vol 102, No 6 (2025)

Introduction. Nematode Caenorhabditis elegans is a key model for studying host–pathogen interactions. In our study, we explored the impact of extended-spectrum beta-lactamase (ESBL) and metallo-beta-lactamase (MBL) producing strains of Pseudomonas aeruginosa on C. elegans, examining survival, reproductive fitness, chemotaxis behaviour, and gene expression. Both ESBL and MBL-producing P. aeruginosa showed a slow killing phenotype in C. elegans, with prolonged gut colonization and reduced lifespan compared to worms fed Escherichia coli OP50.

Materials and methods. C. elegans N2 strain was exposed to ESBL/MBL-producing P. aeruginosa strains, non-resistant P. aeruginosa, and E. coli OP50. Survival, reproductive fitness, chemotaxis, and gene expression of daf-16 and age-1 were analyzed via assays and qRT-PCR.

Results. Resistant strains caused accelerated mortality, starting on day 2, while non-resistant strains had delayed mortality from day 5. This indicates that ESBL and MBL enzymes may boost P. aeruginosa's virulence. Worms exposed to these resistant strains had reduced fecundity, showing impaired reproductive fitness. Changes in chemotaxis behaviour suggested that virulence factors and quorum sensing might affect how worms seek food. Gene expression analysis revealed significant changes in daf-16, a gene involved in stress resistance and immunity, in response to ESBL and MBL strains. However, there were no significant differences in the expression of age-1, indicating other mechanisms at play besides insulin/insulin-like growth factor signalling.

Conclusion. This study highlights the complex interactions between bacterial virulence, host survival, and reproductive behaviour. By exploring the effects of antibiotic resistance on C. elegans, we offer insights into the broader implications of antibiotic-resistant infections and potential strategies for managing them.

Introduction. Kyrgyzstan, among other Central Asian countries, is one of the highly endemic regions for hepatitis A. An important tool for assessing the true burden of these infections on the population and the success of ongoing prevention programs is to study the prevalence of markers of past and current hepatitis A in all age groups of the population, as well as the intensity of population immunity to this virus in regions with different morbidity.

Aim. To study the hepatitis A virus (HAV) seroprevalence among residents of the Kyrgyzstan regions.

Materials and methods. Blood serum samples from conditionally healthy individuals (n = 2297) who sought medical attention at medical institutions in Bishkek, Batken, Chüy, Jalal-Abad, Issyk-Kul, Osh, Talas and Naryn regions. IgM and IgG antibodies to hepatitis A virus (anti-HAV IgM, anti-HAV IgG) were determined using the «Vectohep A-IgM» and «Vectohep A-IgG» (Vector-Best) enzyme immunoassay kits. Statistical processing of the results was carried out using Excel and Medcalc programs.

Results. 80.3% of the studied samples contained HAV serologic markers, of which 80.3% contained anti-HAV IgG antibodies and 4.7% contained anti-HAV IgM antibodies. All IgM-positive samples contained specific IgG antibodies. Such samples were identified with the same frequency among women and men. The highest seropositivity rates were observed in the age groups 30–39, 40–49, and 50–59 years. The number of individuals with anti-HAV IgG antibodies in their blood serum increased with their age. An analysis of the immunostructure of the examined individuals by the level of anti-HAV IgG in serum showed relatively stable ratios of low, medium and high levels of antibodies in groups older than 30 years. The most frequently anti-HAV IgM and IgG antibodies were detected in samples from residents of Bishkek. Anti-HAV IgG antibodies were detected in samples from all surveyed regions of Kyrgyzstan, while anti-HAV IgM antibodies were identified in samples from Chüy, Issyk-Kul and Osh regions, as well as Bishkek.

Conclusion. Hepatitis A remains widespread in Kyrgyzstan. The determination of HAV seromarkers in the algorithms of complex hepatitis diagnostics and seroepidemiological studies remains relevant. A decrease in the level of population immunity to HAV in younger age group indicates the country's transition from high to medium endemicity, which suggests an increase in the number of clinically pronounced cases in the future in the absence of a hepatitis A vaccination program for children.

Introduction. Currently, HIV infection remains a global public health issue. Border areas may be significant in the context of the HIV epidemic due to the instability of the population composition and constant migration flows, which, in turn, may affect the epidemic situation of several border states. This study aimed to analyse current trends of HIV infection in the border region of Russia on the example of the Belgorod region.

Materials and methods. The main HIV infection indicators: incidence, prevalence, mortality and lethality, testing and therapy coverage and its success were analysed. Also, we analysed sociodemographic and clinical-epidemiological characteristics among newly diagnosed HIV-infected patients; social status in relation to labour employment among all people living with HIV (PLWH) and the rates of testing and detection of HIV infection among foreign citizens. The data were obtained between 2016–2024. Quantitative data were assessed for normal distribution using the Kolmogorov–Smirnov test. The χ² test and the Spearman correlation coefficient (r) were employed to statistically evaluate the differences between the proportions. Subsequently, the statistical differences were assessed using the relevant criteria

Results. The data obtained show a significant downward trend in HIV incidence and upward trend in prevalence. The identified moderate upward trend in mortality, together with an analysis of the causes of death among people living with HIV (PLWH), highlight the necessity for multidisciplinary clinical monitoring of the aging cohort of PLWH. The coverage of HIV testing and therapy increased over time. For the first time, 95% therapy coverage was noted. Analysis of CD4-cell indicators revealed significant differences between subgroups by age and route of infection. A decrease in the proportion of unemployed in the PLWH population was noted. Moreover, the identified increase in the detection of HIV infection among the working population substantiates the importance of the existing workplace testing programs, as well as their continuation and expansion. The proportion of foreign citizens tested for HIV correlated with the number of tests performed (r = 0.883, p = 0.002): an increase in the coverage of foreign citizens with HIV-1 testing was accompanied by an increase in the proportion of detected HIV cases. It is important to take into account that a significant correlation does not exclude the influence of parameters not studied; it can be assumed that foreign citizens currently remain under-tested and the number of HIV-positive individuals may be somewhat underestimated.

Conclusions. A comprehensive study of HIV infection trends in a border region of Russia was conducted, using the Belgorod Region as an example. The results are of direct value to health authorities in the Belgorod region and can be used for planning and adjusting regional programs to combat HIV infection.

Objective. To assess the contribution of HPV and to examine the state of vaginal microecology in women with HPV-induced cervical intraepithelial neoplasia (using the Gomel region as an example).

Materials and methods. The study was carried out in the period from 2018 to 2023 and included 11,382 women from the Gomel region. A study of cervical canal scrapings was performed using the cytological method. The molecular genetic testing of these samples for the presence of DNA of the human papillomavirus (HPV) of high carcinogenic risk (hr) was carried out using the Abbott Real Time hrHPV reagent kit (USA). The genotyping of positive samples was performed using the AmpliSens hrHPV genotype-FL kit (RF). A microbiological study of vaginal discharge from HPV-negative women (n = 78) was conducted with an assessment of the state of the vaginal microbiocenosis and an assessment of the functions of lactobacilli. An immunological study of cervicovaginal secretion included the determination of interleukins: IL-1β, IL-2, IL-6, IL-8, IL-10, tumor necrosis factor-alpha and secretory immunoglobulin A.

Results. The prevalence of hrHPV in women in the Gomel region was 9.0%. hrHPV was detected with the highest frequency in the 18–24 age group — 19% (95% CI 17–21.1). It was found that during the study period, 16, 18, 51, 56 and 31 were found with the highest frequency. Genotype 16 (73.8%) was detected significantly more often in high-grade squamous intraepithelial lesions, genotypes 45 (14.9%) and 58 (11.9%) in low-grade squamous intraepithelial lesions, and genotype 33 (14.8%) in atypical squamous cells of undetermined significance. Dysbiosis was detected significantly more often with HPV-negative cervical dysplasia (87.2%), and severe dysbiosis in this group was noted with a high frequency — 66.7%. The antagonistic activity of lactobacilli in the group with cervical dysplasia was 2 times lower in relation to all test strains compared to the group with normocytogram. In the group with dysplasia, the ability of lactobacilli to produce hydrogen peroxide was absent in 92.3% of cases and the ability to form biofilm was significantly reduced. According to the results of the analysis, the following may be considered unfavorable factors in HPV-negative dysplasia: vaginal dysbiosis, increased pH of vaginal discharge, increased IL-6, decreased levels of secretory immunoglobulin A.

Conclusion. Thus, both HPV and factors characterizing the vaginal microecology contribute to the development of cervical dysplasia. The presented results are not only of practical but also of fundamental importance, as they expand our understanding of the mechanisms of cervical cancer development by studying the role of the vaginal microecology. The identified biomarkers related to the microbiota and local immunity at various HPV infection statuses may help develop new approaches to the diagnosis and prevention of cervical dysplasia and cervical cancer.

Introduction. In most cases, microorganisms are presented on abiotic surfaces in a state of static biofilm, which determines their resistance to environmental influences, as well as disinfectants. Disinfection regimes for facilities developed by traditional conventional methods using planktonic forms of microorganisms do not provide the required level of disinfection under these conditions. Therefore, it is important to create and validate methods for the formation of static biofilms on surfaces and to study the possibility of their use to assess the effectiveness of disinfectants in the development of disinfection regimes for surfaces in rooms, furniture, appliances, sanitary equipment, etc.

Materials and methods. Microbiological methods, cultural and microscopic were used in the work. The developed new method for evaluating the effectiveness of disinfectants differs in that the microorganisms on the surface of the test objects were in a state of static biofilm. To form it, a suspension of the test microorganism was applied to the test surface, prepared in a GRM broth and incubated in a thermostat at 37°C for 24 hours. The presence of biofilm on the test surface is confirmed by microscopic method. After that, the effectiveness of disinfectants was evaluated.

Results. Using the new method, insufficient activity of disinfectants was shown in concentrations recommended for use by the instructions: tablets based on sodium salt of SDIC at a concentration of 0.03–0.06% for active chlorine, HP at a concentration of 3.0–6.0% and ADBAС at a concentration of 0.25–0.5%. When treating test objects with disinfectant solutions at these concentrations, disinfection was below the 99.99% criterion. To achieve the desired effect, the concentration of working solutions of disinfectants had to be increased for the sodium salt of SDIC to 0.1% for active chlorine, HP to 8.0%, and ADBAС to 1.0%.

Conclusion. The proposed method of forming a static biofilm on abiotic surfaces is a tool for evaluating the effectiveness and developing adequate disinfection regimes for various types of surfaces for practical use.