Klinichescheskaya Laboratornaya Diagnostika最新文献

The development of mycotic colonization of the base surface with further biodegradation of acrylic plastics is currently of undoubted interest. The oral cavity is a favorable ecological niche for colonization by fungi and their subsequent possible invasion into the epithelium of the oral mucosa. The method of modulation interference laser microscopy is of considerable interest to researchers in medicine in the context of obtaining the necessary information about the morphological characteristics of microbial cells and the microbiome community as a whole during the colonization of a certain ecological niche in the human body. Purpose of the study: to analyze the microrelief of the biofilm of yeast-like fungi of the species Candida albicans of base plastics of the hot type of polymerization using the method of laser modulation interference microscopy. An experimental study was carried out in order to study biofilms of yeast-like fungi of the genus Candida on samples of basic plastics, an image of a biofilm of yeast-like fungi of the species Candida albicans was obtained on the surface of a plastic of a hot type of polymerization (polymethyl methacrylate) in the visualization of the phase portrait, a description of its horizontal and vertical bioprofile. As a result of the research, the heterogeneous structure of the biofilm was determined, due to the different density and accumulation of cells along the surface, the characteristics of the surface were established in accordance with the roughness criteria. The microrelief parameters on a separately arbitrarily selected section line allow one to determine the characteristics of the biofilm in the required area and make it possible to judge the nature of its formation in a certain biological niche.

Pelvic venous disorder (PVD) in women is a polyetiological multifactorial disease characterized by a high prevalence (up to 80%), a high risk of infertility, and a progressive recurrent course. Morphological changes of the venous bed occur in PVD, contributing to retrograde blood flow and pelvic phlebohypertension. It is occur due to dynamic hypervolemia and hypertension long-term exposure on the venous wall. However, PVD pathogenesis analysis only from venous hemodynamic disorders position does not explain all mechanisms of the disease development and does not contribute to the treatment measures effectiveness. Currently oxidative stress reactions are considered as the most important markers of the pathological process. The aim of our work was a comparative analysis of lipid peroxidation-antioxidant defense component changes in the peripheral and regional blood flow in women with primary pelvic venous disorder depending on the disease stage. The study involved 137 women of reproductive age (mean age 37.4±9.1 years old) with diagnosed primary PVD divided into 3 groups according to the pathological process stages (stages I, II, III). Data from 30 practically healthy women (mean age 33.5±6.3 years old) were used as controls. Spectrophotometric, fluorometric, immunoassay and statistical methods were used. In patients with PVD stage I in peripheral bloodstream were higher values of SOD and GPO activity; in the regional bloodstream were higher levels of TBARs, SOD, catalase, GPO and lower GSH. In PVD stage II the peripheral bloodstream showed elevated levels of DC, GSH and SOD reduced levels; the regional bloodstream showed higher levels of DC, TBARs, GPO and GSH reduced levels relative to controls. PVD stage III was characterized by: higher levels of DC and TBARs and lower levels of SOD and GSH in the peripheral bloodstream; higher levels of DC, TBARs and lower levels of GSH and catalase in the regional bloodstream compared with control. Thus, the results of our study showed no significant differences in the LPO-AOD system between peripheral and regional bloodstreams in patients with PVD depending on the disease stage. However, negative changes in the redox balance in the regional bloodstream were earlier and were already registered at the first stage of the disease. It is likely that control of antioxidant insufficiency in patients with PVD should be an important component of preventive measures in the early stages and pathogenetic treatment in the pathological process progression, particularly in stage III of the disease.

Postischemic neuroinflammation is a critical pathophysiological process within the entire scheme of cerebral ischemia, covering early damage and the period of tissue repair. It is characterized by microglial and astroglial activation with increased expression of inflammatory mediators and is accompanied by impaired innate and adaptive immune responses. In acute ischemic stroke (IS), neuroinflammation is caused by the response of resident immune cells of microglia and peripheral immunocompetent cells infiltrating the brain tissue, which penetrate the blood-brain barrier (BBB) into the lesion. Recent studies have shown the important role of the NLRP3-mediated inflammation in the death of neurons and glial cells in acute IS. The review presents the main mechanisms of activation of NLRP3-mediated inflammation in acute IS, leading to the caspase-1 formation and the IL-1β and IL-18 release, which are involved in the initiation and progression of inflammation in the brain parenchyma. The literature data on the role of autophagy in the inhibition of postischemic neuroinflammation are summarized. Autophagy can suppress neuroinflammation through a wide range of the autophagy - related proteins. The role of autophagy as a negative regulator of NLRP3-mediated inflammation in acute IS is analyzed. Data on the participation of autophagic proteins Beclin-1, LC3, and p62 in the suppression of NLRP3 inflammation due to the induction of basic mitophagy are presented. Prospects for modulating autophagy aimed at suppressing postischemic neuroinflammation, including the inhibition of NLRP3-inflammasome, have been noted. The review was based on sources from international and national data bases: Scopus, Web of Science, Springer, RINC.

The aim of the study was to determine the main Candida species isolated from blood of cancer patients, to compare the taxonomic structure of strains obtained from children and adults with candidemia. In total, during the study period, candidemia was microbiologically proven by blood culture in 81 patients (duplicates were excluded). Patients in the intensive care unit (ICU) accounted for 35,8%. The total number of isolates elaborated was 82 strains of 10 Candida species. In general, in the taxonomic structure of candidemias, C. parapsilosis (61.0%) predominates, C. albicans (20.7%) is in the second place, followed by C. glabrata and C. lusitaniae (3.7% each); C. krusei, C. guilliermondii and C. tropicalis (2.4% each). C. parapsilosis was statistically significantly often isolated from blood compared to C. albicans (61.0% versus 20.7%, respectively, p<0.0001). Candidemia was statistically significantly more often detected in adults than in children (63.0% versus 37.0%, respectively, p<0.002). Moreover, in adults, C. parapsilosis was statistically significantly more often isolated from blood than C. albicans (70.6% versus 15.7%, respectively, p<0.0001). In children, there were no significant differences in the frequency of isolation of C. parapsilosis and C. albicans: the proportion of C. parapsilosis was 45.2%, C. albicans - 29.0%. Rare species were identified in 7.8% of cases in adults, and in 12.9% of cases in children without statistical difference (p>0.05). The proportion of Candida non-albicans during the study period was 79.3%, and C. parapsilosis is the main species in this group (76.9%).

One of the most important requirements for the personnel of microbiological laboratories working with pathogenic and infectious agents is the observance of precautionary measures and the implementation of a set of preventive measures, collectively interpreted as biological safety (biosafety). To a large extent, biosafety problems are also relevant for all clinical laboratories working with biosubstrates, with the potential threat of containing pathogens of bloodborne infections in them. On December 30, 2020, the President of the Russian Federation signed Federal Law № 492 «On the Biological Safety of the Russian Federation» (№ 492-FZ), which regulates the basic legal norms and regulation of biosafety issues, as well as a list of measures to prevent the risks of the spread of infections due to accidents, bioterrorist acts and sabotage. The current pandemic of the coronavirus infection COVID-19 has demonstrated, on the one hand, the epidemiological vulnerability of the single world space, and on the other hand, the decisive influence of biological emergencies on the emergence of negative political and economic processes in the world community. In this regard, the issues of ensuring biosafety in the work of microbiological laboratories in the context of protecting personnel and the environment from accidental or unintentional spread of infections are relevant. Working with pathogenic biological agents in microbiological laboratories is constantly associated with the risk of accidents and possible laboratory infection (laboratory-acquired infections) of employees, environmental pollution if the requirements of regulatory documents on biological safety are not met. In accordance with the requirements of № 492-FZ, in order to prevent biological threats, it is necessary to create a system for monitoring biological risks in microbiological laboratories when working with any infected material.

The evaluation of the clinical significance of the test for the detection of the Y-chromosome marker in the plasma of a pregnant woman at different stages of pregnancy by real-time PCR was carried out. The blood samples of 4616 women at 4 to 32 gestation weeks were studied. Identification of the Y-chromosome marker was carried out based on the amplification of a region of the TSPY gene. The Y-chromosome marker was unambiguously identified in 2131 samples, which accounted for 46.2% of the total number of analyzed samples. In 233 samples (5%), the Y-chromosome marker was detected with reduced reliability, and in 15 samples (0.3%), an unambiguous conclusion about the presence or absence of Y-specific DNA in plasma could not be made during the initial study. The diagnostic accuracy of the Y-chromosome marker determination in the plasma of a pregnant woman at the 4-6th gestation week was 95.5%, and from the 7th week and at later stages of pregnancy it reached 97.3-98.2%. Testing from the 7th gestation week may be recommended for reliable prenatal sex determination of the fetus by real-time PCR analysis of extracellular circulating fetal DNA.

Results from research on isolation, identification, and study of biological properties of L. monocytogenes clinical isolates and Listeria spp test strains are presented. Peculiarities of modern research methods for indicating and identifying pathogenic listeria to improve the quality of laboratory studies of clinical material are studied. The culture method provides reliable results of microbiological analyses upon detecting Listeria spp. The presented list and algorithm of the laboratory diagnostic methods can be used as a basis for elaborating regulatory documents for carrying out microbiological research on any biological material for the presence of bacteria of the genus Listeria spp. and L. monocytogenes species in it.

The rapid spread of a new coronavirus infection in the country actualizes the conduct of bacteriological studies of clinical material obtained from the respiratory tract of patients with COVID-19. During the experiments, 230 sputum samples and 260 autopsy lung samples from patients with COVID-19 were analyzed. 946 high-risk strains were isolated and identified by MALDI-ToF mass spectrometry on a Microflex LT instrument (Bruker®). According to the results of bacteriological cultures of sputum, a predominance of gram-positive ones was revealed, amounting to 50.5% (222 strains) of the total number of isolated pathogens. However, falling into this group is manifested by natural representatives of the microflora of the human mucous membranes from the genera Streptococcus, Rothia and Lactobacillus (109 strains in total), which can be manifested by the detection of improper sputum collection, causing contamination by the substance of intense salivation and nasopharyngeal discharge. In turn, the "classic" gram-positive causative agents of pneumonia were detected much less frequently: S. aureus in 5 cases, S. pneumoniae in 6 patients. The causative agents in the order Enterobacterales are represented by 42 strains, among which the most likely species are K.pneumoniae (27 strains). In the group of non-fermenting gram-negative bacteria, A. baumanii (29 strains) prevailed, and P. aeruginosa was also identified in 2 cases. When analyzing the results of a microbiological study of autopsy material (lungs) of patients with COVID-19, significant differences in the qualitative and quantitative composition of the microflora were revealed, compared with sputum. In the group of gram-positive bacteria, 15 strains of the natural microflora of the mucous membranes were identified, while sensitive species dominated among gram-negative pathogens: K. pneumoniae (102 strains), A. baumanii (75 strains), P. aeruginosa (11 strains). Regular microbiological monitoring is essential for antibiotic therapy and prevention of secondary bacterial infection. In the event of a fatal outcome, the results of microbiological analysis of autopsy material can determine the cause of death of the patient.

The content ofММР-9 and ММР-2 in oral fluid of 105 individuals between the ages of 19 and 23 has been researched.Of these, 42 people are individuals with dental caries and normal level of the active form of vitamin Din serum (25(OH)D >30ng/mL) and 42 people - with 25(OH)D <30 ng/mL level.The control group was composed of 21 individuals with low DMFt index (1,5) and a normal level of 25(OH)D in blood. It has been established that the level of ММР-9 in mixed salivaincreases against the background of dental caries,while the content of ММР-9 and ММР-2 increasessignificantlyamidthe lack and deficiency of25(OH)Din the body. Inverse correlations between the 25(OH)D level in serum and the value ofmatrix metalloproteinasesin saliva have been revealed: noticeable - with the amount of MMP-9 and moderate- with the concentration of MMP-2.

The results of evaluating the effectiveness of the use of liquid transport media at the preanalytical stage of bacteriological diagnosis of diphtheria infection are presented. A typical toxigenic strain of C. diphtheriae biovar gravis № 665 was used. The experiments were carried out using a laboratory-prepared medium based on GRM-broth (State research center for applied biotechnology and microbiology, Obolensk), a transport system with a fleecy probe swab (DELTALAB) and a transport system ∑-Transwab ® with a polyurethane Sigma-swab (Medical Wire & Equipment Co. (Bath) Ltd.). The tampons were pooled with a 24-hour bacterial culture of C. diphtheriae, then immediately seeded on Tellurite-containing blood agar. Storage conditions were simulated for 6-24 hours: at room conditions +(20-25)° C, in the refrigerator +(4-8)° C, in a thermostat +(37±1)° C. Storage of C. diphtheriae was most optimal on two liquid transport systems in a refrigerator +(4-8)° C for 6 and 24 hours; in room conditions +(20-25)° C - there was a decrease in seeding after 6 hours and loss of pathological material after 24 hours, more pronounced on a fleecy probe swab; under thermostat conditions +(37±1)° C on both transport systems, a decrease in seeding was noted after 6 hours and a complete loss of pathological material after 24 hours. The results obtained demonstrated the efficiency of using the Amies liquid transport medium and justify the need to develop a domestic analogue of the transport system based on the Amies liquid medium for the bacteriological diagnosis of diphtheria infection.