Vol 12, No 4 (2022)

Globalization and high-speed means of transportation contribute to the spread of infections dangerous to humans. Airborne pathogens have pandemic potential as currently shown in case of the novel coronavirus SARS-CoV-2. Natural focal Lassa fever (LF) common in West African countries, in 35 cases was registered in non-endemic geographical areas because any person infected with Lassa virus (LASV) is a long-term source of infection (up to two months). Cases of person-to-person infection in endemic territories are described. In Germany, the facts of secondary virus transmission from patients to doctors have been recorded during the examination and blood collection from an apparently healthy person as well as during the autopsy of a deceased subjects due to severe LF course. Nonspecific malaise symptoms in LF are also characteristic of numerous other diseases common on the African continent, e.g., malaria and typhoid fever or viral infections such as yellow fever, Chikungunya, dengue and Zika, monkey pox and Ebola virus disease. In this regard, there may be similar dermatological manifestations. Timely detection of cases and differential diagnosis are crucial to ensure safe patient care and use of affordable antiviral therapy for LL provided by the drug Ribavirin. Research methods for studying LASV use polymerase chain reaction (PCR) for detecting viral RNA, electron microscopy, isolation of infectious virus cultured sensitive cells, indirect immunofluorescence reaction, enzyme immunoassay (ELISA) and immunochromatographic assays for the detection of antibodies and/or antigen as well as immunoblotting. Currently, test kits based on molecular and genetic methods are mainly used for LF laboratory diagnostics. Since the 1980s, ribavirin has been used to treat patients with LF. The serum accumulation of the drug in large quantities causes hemolysis, development of anemia and impaired renal function. In this regard, treatment options are being considered with decline in its concentration due to combined use with other antiviral drugs. A search for new therapeutic agents capable of inhibiting viral replication at disease early stage has been in progress due to lack of any approved vaccines.

Pathological conditions of various natures are capable of mutual aggravation, significantly affecting the overall burden of the disease, its manifestations and severity. This analytical review is devoted to the interaction between pathogens of socially significant infections — human immunodeficiency viruses (HIV), hepatitis C, Mycobacterium tuberculosis and SARS-CoV-2. Foreign and own data covering the issues of syndemia and interference of pathogens are presented. The results of epidemiological analysis in the North-Western Federal District (NWFD) are presented, which demonstrated the absence of a significant impact of the pandemic caused by a new coronavirus infection (COVID-19) on the epidemic incidence of HIV, viral hepatitis C or tuberculosis at the population level, which may be due to various mechanisms of transmission of infections and the required infectious dose of the pathogen. The absence of a negative effect of COVID-19 on mortality rates in HIV infection, viral hepatitis C and tuberculosis in the territories of the NWFD was noted. Special attention is paid to the clinical picture of the combined course of HIV infection, tuberculosis and COVID-19. The data are demonstrated, which allow us to conclude that the worst prognosis and risk of death are patients in the progressive stage of the disease, which is characterized by the presence of opportunistic infections, especially AIDS-indicator conditions, with disseminated tuberculosis and in the cirrhotic stage of viral hepatitis. The significance of severe manifestations of infectious pathology in cases of deterioration of the prognosis of COVID-19 is shown. Based on the experience of two years of the pandemic, the problems contributing to the syndrome of new coronavirus infection and other conditions, as well as the causes of high mortality from COVID-19, which include: limited resources for non-infectious areas of medical care; insufficient funding for planned and high-tech care; a decrease in the volume of primary diagnosis and detection of infectious and non-infectious pathology; delayed and limited research in areas; distraction of specialists from preventive and dispensary work outside of infectious pathology; shortage of medicines and consumables; social instability and deterioration of the well-being of the population, characteristic of pandemics. The role of a personalized approach to patients with concomitant somatic and infectious diseases as a preventive measure for the severe course and complications of COVID-19 is determined.

Immuno-serological diagnostic tools particularly identifying pathogen antigens are the most important methods of pseudotuberculosis studies. The main immunodominant and species-specific antigens located in the surface structures of the bacterial cell are of practical interest. Thereby the aim of the work was to isolate and characterize biologically active surface structures of the pseudotuberculosis microbe. Here, the living cells of Y. pseudotuberculosis 3704 (O:1b) were lysed by using 9 M urea solution to extract antigens localized in the microbial surface structures. The subcellular fractions obtained such as outer membranes (OM), urea extract (UE) and isolated protein-lipopolysaccharide complex (PLPSC) are characterized by physical and chemical parameters. The protein content in the preparations ranged from 42% to 53%. The polypeptide band of the OM preparation, UE polypeptide and PLPSC for pseudotuberculosis microbe was presented by 14, 16 and 9 major polypeptides with molecular weight ranging from 13.9 kDa to 131.5 kDa, 13.5 kDa to 101.6 kDa, and 20.7 kDa to 66.6 kDa, respectively. Proteolytically active proteins and polypeptides were detected in isolated subcellular fractions (OM and UE) by using the radial enzyme diffusion test and substrate-gel electrophoresis found to be presented by 4 and 7 polypeptides with molecular weight ranging from 28.0 kDa to 118.0 kDa and 29.2 kDa to 97.7 kDa in the OM and UE preparation, respectively. The subcellular fractions obtained are capable to exhibit immunogenic activity after inoculation to experimental animals and antigenic activity while interacting with specific antibodies in the radial immunodiffusion (RID) assay and antibodies labeled with colloidal silver nanoparticles in dot immunoassay (DIA). OM and PLPSC preparations in DIA with immunoglobulins isolated from experimental antisera and labeled with colloidal silver nanoparticles were detected at a concentration of ≥ 0.12 μg/ml (dry weight), cells of strain Y. pseudotuberculosis 3704 at a concentration of ≥ 3, 9 × 10⁶ m.c./ml, which is similar to the results of DIA with immunoglobulins isolated from commercial pseudotuberculosis antiserum (St. Petersburg) and labeled with nanoparticles of colloidal silver. Thus, the subcellular fractions of pseudotuberculosis microbe isolated by using urea as a lysing and decontaminating agent retain their antigenic and immunogenic properties and enzymatic activity suggesting about their potential benefits for use to improve early diagnostics of pseudotuberculosis.

In the context of the global spread of the new coronavirus infection, studies aimed at investigating formation of anti-infectious and post-vaccination immunity are of special importance, which is necessary to prevent and reduce morbidity and mortality due to SARS-CoV-2 infection. Purpose: to assess anti-infectious immunity against SARS-CoV-2 in various forms of the disease and development of post-vaccination humoral reactions in medical workers of the perinatal center.

Materials and methods. A study of blood serum was carried out to assess SARS-CoV-2-specific IgM and IgG antibodies in 119 medical workers recovered after COVID-19, divided into groups based on the disease severity (mild, moderate and asymptomatic), as well as in 62 vaccinated employees, divided into groups according to age. Semi-quantitative measurement of virus-specific antibodies was carried out by ELISA with test systems “SARS-CoV-2-IgG-ELISA-BEST” and “SARS-CoV-2-IgM-ELISA-BEST”. Statistical processing of the research results was carried out using Microsoft Excel 2010 and Statistica 6. Quantitative characteristics were presented as median (ME), lower and upper quartiles (LQ1-UQ3); qualitative parameters — as absolute value and relative number (%). Difference between groups was analyzed by using the χ² test (qualitative) and the Mann–Whitney U-test (quantitative).

Results. The results of the study showed that the majority of employees with a moderate-severe form of SARS-CoV-2 had a high level of IgG (PR — a positivity rate of more than 9.0 arbitrary units) 9 months after the disease compared to those who suffered from mild or asymptomatic (83.3% versus 25.8% and 13.3%, p < 0.017) infection. The duration of IgG circulation after former illness had no relation to its severity and patient age. The effectiveness of the primary vaccination “Sputnik V” and revaccination with “Sputnik Light” and “KoviVak” was 100% after inoculating the vaccine second component. The lowest level of antibodies after the first vaccination is recorded in persons over 60 years old (1.48 (1.12–3.25 versus PR = 8.48 (5.78–10.11) and 9.27 (5.84–10.31) arbitrary units, p < 0.017)), in comparison with young and middle-age subjects. The speed SARS-CoV-2 elimination of IgG at 6, 9 or more months after vaccination depends on relevant initial peak antibody concentration. Subjects who were initially vaccinated with the KoviVac vaccine, IgG was not detected 2 months after vaccination. The protective effect of “Sputnik V”, “Sputnik Light”, “KoviVac” after re-infection with SARS-CoV-2 averages 71.2%.

Conclusion. Thus, the results obtained on assessing anti-infectious and post-vaccination immunity against SARS-CoV-2 emphasize the need for further studies on a larger patient cohort, especially in those with asymptomatic infection as well as the elderly subjects.

Objective of the research — to specify respiratory tract bacterial microflora in patients suffering from community-acquired pneumonia (CAP) during initial and repeat examination. To determine local factors affecting microflora in the cohort examined.

Materials and methods. Surveillance subject — 241 patients with CAP differed by their status and age who stayed in two healthcare facilities of the Khabarovsk city. Examination of respiratory smears was performed. Results. Indices of Gram-negative enterobacteria (30.8% [22.6–39.7%]) and Gram-negative nonfermentable bacteria (14.5% [8.6–21.7%]), isolated from patients hospitalized in healthcare institution No. 1 and mostly comprised of the elderly (aged over 61 years — 82.0%; 74.3–88.6%) with more severe disease state including patients at the ICU, were higher compared to data obtained from healthcare institution No. 2 (19.8% (13.4–27.0); 6.1% (2.7–10.8) respectively). Prevalent pathogen was Klebsiella pneumoniae — 13.6% (7.8–20.6) and 10.7% (6.0–16.5). Identification of Acinetobacter baumannii complex — 6.4% (2.6–11.7) and 3.1% (0.8–6.7) — should be also noted. A high percentage of drug-resistant bacterial variants was observed and for Klebsiella pneumoniae totaled 66.7% (41.8–87.4) and 57.1% (32.2–80.2) at the healthcare institutions No. 1 and No. 2, respectively. A. baumannii complex drug resistant variants were found in 85.7% (52.7–99.97) at healthcare institution No. 1. All isolates of A. baumannii complex at the healthcare institution No. 2 were drug resistant. High prevalence of Candida spp. was revealed in both healthcare institutions reaching 54.5% (45.2–63.7) and 58.0% (49.5–66.3), respectively, with minimal detection rate of classic pathogens such as S. pneumoniae — 5.4% (2.0–10.4) and 5.3% (2.1–9.8) and H. influenzae — 3.6% (0.9–7.9) and 3.8% (1.2–7.7), respectively. Repeat examination of 122 patients conducted 7–10 days later showed diverse changes in microflora spectrum regardless of the healthcare institution that was manifested as loss or emergence of drug-resistant variants as well as simultaneous presence of different variants of the same pathogen.

Conclusion. The results obtained evidence about complexity and variety of mechanisms underlying microorganism community formation during the course of infectious process in patients. Local factors influencing microflora characteristics of patients at the two healthcare institutions were revealed.

Molecular genetic studies have revealed the involvement of different genotypes of human papillomavirus (HPV) in the carcinogenesis of cervical cancer and malignant lesions of other localizations. It is reported that patients with HPV-positive cancer have a better prognosis of the disease and survival than patients with unconfirmed HPV infection or with a low viral load. The objective was to identify the detectability, viral load, genotypes of human papillomavirus in HPV-associated precancerous and malignant neoplasia of various localization and to determine risk factors for their occurrence in the metropolis of St. Petersburg at the present time.

Materials and methods. A total of 80 samples taken from morphologically confirmed tissues of oropharyngeal and anal cancer, malignant tumors of vulva, vagina, cervix and cervical intraepithelial neoplasia were studied in St. Petersburg Clinical Oncologic Center. Detection, quantification and genotyping of HPV DNA were carried out by real-time PCR at the St. Petersburg Pasteur Institute.

Results. HPV was detected in 89.7% (61/68) of patients with malignant tumors and 83.3% (10/12) — with severe cervical dysplasia. The vast majority (85.9%) of HPV-positive patients were infected with HPV genotype 16; papillomavirus mixed infection (genotypes 16, 18, 31, 33, 35, 39, 45) was detected in anal cancer, cancer and severe cervical dysplasia. The average viral load in stages III–IV of anal cancer, cervical cancer and severe cervical dysplasia exceeded 5.7 lg HPV DNA/10⁵ cells. Among patients with oropharyngeal cancer, men predominated (85.7%); anal cancer was detected in women (90.0%). No statistically significant risk factors (smoking and alcohol consumption) for the occurrence of HPV-associated malignancies were identified.

Conclusions. The detection of HPV, mainly of genotype 16, varied depending on the location of the neoplasia: anal cancer — 100%, cancer of the female genitalia — 94% (in case of cancer of the vagina and cervix — 100.0%), head and neck cancer — 76.2%. The highest HPV DNA load in the tumor tissue was found in III–IV stages of the cervical and anal cancer.

The aim of our study was to evaluate the clinical performance of a monotherapy by Enterococcus faecium-based probiotics and indigenous autoprobiotics against H. pylori associated dyspepsia.

Materials and methods. There were examined 95 patients with dyspepsia. The entire patient cohort underwent clinical evaluation including filling out the questionnaire to assess dyspepsia symptoms before and after treatment, gastric endoscopy as well as gastric multi-focal biopsy (gastric body and gastric antrum) and verification of H. pylori infection with the three clinical laboratory methods (biochemical, bacteriological and molecular detection). An antagonistic in vitro activity of probiotics against H. pylori was detected by drop plate method for probiotic strains Enterococcus faecium SF68 and Bifidobacterium bifidum (Bifiform), Enterococcus faecium L3 (Laminolact), and autoprobiotic strains combined with indigenous Enterococcus faecium. To examine an antagonistic activity of probiotics and autoprobiotics in clinical trials, we used a starter culture based on the Enterococcus faecium L3 strain and an autoprobiotic based on indigenous Enterococcus faecium. The probiotic or autoprobiotic were administered orally to patients with gastritis twice a day at dose of 50 ml (8.0 lgCFU/ml) for 20 days. H. pylori eradication was assessed by stool antigen test 1.5–2 months after the end of treatment.

Results. Initially the H. pylori infection was confirmed with 49.4% of patients. The sensitivity of H. pylori to the probiotics was detected in 81% of individuals for indigenous Enterococci (the autoprobiotic), 76% — for Laminolact, and in 62% — for Bifiform. 22 patients with previous history of allergic reactions to antibiotics used in routine H. pylori eradication regimens were divided in two cohorts. One cohort (10 patients) received the autoprobiotic only, another cohort (12 patients) received only probiotic. Monotherapy with autoprobiotic resulted in 100% H. pylori eradication, single-agent therapy with probiotic led to 60% eradication of H. pylori. Dyspepsia symptoms were completely resolved in both groups of patients.

Conclusion. Our research demonstrated the sensitivity of examined H. pylori strains to be similar for traditional eradication treatment agents (antibiotics) and the proposed intervention agents (probiotics and autoprobiotics). An autoprobiotic monotherapy with indigenous enterococci led to higher levels of H. pylori eradication than with E. faecium L3-based probiotic agent. Our work demonstrated advantage for application of probiotics in patients with antibiotic allergies or other obstacles for the standard eradication therapy. Nonetheless, further investigation to better understand underlying mechanisms of action, as well as larger observational and randomized studies, are necessary to determine the scope of therapeutic application for probiotics and autoprobitics to eradicate H. pylori infection.

The Tunggu Pampang Reservoir is one of the reservoirs located in the city of Makassar. The functions of the reservoir area was tourist attractions and fish farming locations so that the local community uses them for swimming, fishing, selling, and gardening. The existence of various types of freshwater snails in the reservoir has the potential to act as intermediate hosts for trematodes in animals and humans. This study aimed to analyze the type of cercariae in freshwater snails. This research is a descriptive survey to determine the distribution of trematode larvae. The stages of this research began with the snails were collected from Tunggu Pampang Reservoir, Makassar City. Freshwater snails were collected at several points in the reservoir. Freswater snail collection using hand collecting method. The snails were put into a plastic bag with different types of snails and site of collection. The collected samples and cercariae were examined in the Tropical Disease Laboratory of the Study Program of DIII Medical Laboratory Technology, Megarezky University, South Sulawesi, Indonesia. Freshwater snails are placed on a petri dish and their shells were gently crushed with a stamper. Dropped with aquadest on the crushed snail shell. The next step was observed using a microscope to determine the presence of cercariae. Cercariae found then identified according to morphological classification as previously study. A total number of 500 freshwater snail were collected in Tunggu Pampang Reservoir. The results showed that overall snails infected with cercariae was 33,4%. The highest prevalence of cercariae in Indoplanorbis exustus was 94.3%. Total of Echinostoma cercariae found (n = 224) compared to furcocercous cercariae (n = 5). Cercariae of Echinostoma sp., Fasciola gigantica, Fasciolopsis buski living in Tungu Pampang Reservoir can cause diseases in humans and animals. Larval trematodes can be controlled in snails using reducing parasite contamination, monitoring surveillance, information dissemination, and preventive education.

Viral infections are the first ranked conditions among infectious diseases causing 5–15% of all community-acquired pneumonia. The aim of the study was to describe a case of COVID-19 infection, proceeding with acquired bacterial infection and developing abscess pneumonia in a young patient.

Material and methods. The accompanying medical documentation was examined, clinical and morphological analysis was carried out for assessing macro- and micropreparations.

Results. Patient A.E., 31 years old, within 5 hours 10 minutes was at in-hospital treatment with a diagnosis of Coronavirus infection, severe course. Community-acquired bilateral polysegmental pneumonia. The patient admitted with complaints of respiratory difficulty, shortness of breath, weakness, fever up to febrile level, severe pain in the right groin area, both lower extremities, swelling in hands and feet. However, despite initiated treatment, the patient’s condition worsened and biological death was verified. The postmortem examination revealed signs of total bilateral hemorrhagic pneumonia. Histological examination showed areas of necrosis in the alveolar epithelium and signs of marked edema with a hemorrhagic component; hemolyzed erythrocytes were found in alveolar lumen. Focal hemorrhages were visualized in the pulmonary parenchyma, sometimes merging along with lung tissue with forming microabscesses. a well-defined shaft consisting of granular leukocytes and congested vessels with erythrocyte sludge was noted on the periphery of necrosis area. In the alveoli located closer to the abscesses, fibrinous and serous exudate was detected. Signs of edema were observed in the brain; histological examination revealed perivascular, pericellular optical voids with vascular congestion, erythrocyte sludge and minor hemorrhages. SARS-CoV-2-caused pneumonia and acquired bacterial infection, in this case due to staphylococcus, led to abscess pneumonia and severe respiratory failure with developing acute distress syndrome. Obviously, the high frequency of destructive processes in staphylococcal pneumonia is due to the pathogenic staphylococci characterized by production of high-level proteolytic enzymes destroying body tissues. Thus, the current case of COVID-19 infection in a young patient is of particular importance and relevance, because it demonstrates an unfavorable disease outcome despite patient young age and lack of concomitant pathology.

According to current data, SARS-CoV-2 virus has the ability to cause multi-organ pathology, leading to acute damage of various organs and systems and long-term consequences characterized by polymorphic symptoms. Recently, a high incidence of invasive mycoses, particularly mucormycosis — COVID-M, has been noted among the COVID-19 complications. The predisposing factor for the development of this pathology is diabetes mellitus, immunodeficiency states, and prolonged use of high doses of glucocorticosteroids. Mucormycosis is characterized by severe clinical manifestations and high lethality, and timely diagnostics of this pathology often represents a difficult problem. The aim of this study was to analyze a clinical case of rhino-orbital mucormycosis in convalescent COVID-19 patient. In the study, there was used mucopurulent nasal discharge from the patient previously hospitalized with a severe novel coronavirus infection. Here, we describe the methodology allowing to isolate and identify a pure mold fungus culture from the biomaterial using methods of routine bacteriology and MALDI-ToF mass spectrometry. Direct microscopy examination of nasal cavity discharge revealed branched non-septic hyphae with a characteristic branching angle, allowing to preliminarily diagnose invasive mucormycosis. Growth of mycelial fungus colony was observed by using Sabouraud’s medium with potassium tellurite. Microscopy of the pure culture revealed branching mycelium without septa, broad, with irregular thickness, unsegregated hyphae, and sporangia with a typical column specific to mucormycetes. Analysis of the obtained mass spectra allowed to establish the microbial species identity as Lichtheimia corymbifera. The latter along with other members of the order Mucorales, are known to cause mucormycosis. As a result of antifungal treatment (Amphotericin B) and timely surgical intervention, the patient was discharged from the hospital with prominent clinical improvement and no complaints during further outpatient follow-up period. The analysis of this clinical case showed the lack of alertness in some clinical diagnostic laboratories to detect pathogens of invasive mycoses. To avoid errors, while making a diagnosis, attention should be paid not only to detection of fungal spores in clinical material, but also take into account the structure of mycelium underlying major difference between yeast-like fungi, higher and lower molds. The isolation and identification of a pure pathogen culture allows to confidently verify the diagnosis, timely correct the treatment tactics and monitor circulation of mycotic agents to prevent occurrence of mycoses in most vulnerable patients cohorts.