The article is devoted to the development of a method for detection of viral RNA of two highly pathogenic zoonotic viruses from the genus Henipavirus - Hendra and Nipah using real-time reverse transcription polymerase chain reaction. In the natural environment, these viruses are carried by flying foxes in the family Pteropodidae. Horses and pigs, respectively, are susceptible to infection. The diseases are also transmitted to humans through contact with sick animals, their biological excreta and from person to person. In infected humans and animals, clinical signs of infection may be asymptomatic, or may present with flu-like symptoms at the onset of the disease and progress to neurologic disease and acute respiratory infection, followed by death. In Australia, the subunit vaccine HeV-sG is used against Hendra virus in horses. There is no treatment or vaccine for Hendra or Nipah viruses for humans. The need to develop new detection methods and search for new viral targets remains an urgent task due to the large area of distribution of the described viruses, high contagiousness and mortality of animals and humans. The study describes the original designed primers and probes for conserved regions of the genomes of two viruses: the gene encoding the nucleocapsid protein of Hendra virus and the gene encoding the glycoprotein of Nipah virus. Synthetic controls for the extraction and reverse transcription PCR stages have been created, confirming the quality of the developed method. Biological samples from healthy people (blood plasma, swabs from oral and nasopharyngeal mucous membranes, cerebrospinal fluid) with the addition of artificial controls passed the stages of sample extraction and real-time reverse transcription PCR, thus confirming the quality of control samples. The detection limit of the described viral RNA identification methods was determined as 100 copies/mL for Hendra virus and 1000 copies/mL for Nipah virus. The amplification transit time is less than 90 minutes. The developed method will help in epidemiologic control of the spread of these infections, can be used in the diagnosis of Hendra and Nipah viruses and for solving research tasks to study the properties of these pathogens.
The Fe0.25TaSe2 polycrystalline samples have been synthesized using two routes of solid-state reactions and various heat treatments and cooling conditions. The obtained samples have been studied by x-ray diffraction, magnetization and electrical resistivity measurements. It has been revealed that various methods of preparation and heat treatment do not have a strong effect on the lattice parameters of the main phase in the samples, but they significantly affect the magnetic critical temperature and magnetic hysteresis of the samples. Depending on the sample preparation procedure magnetic ordering temperature of Fe0.25TaSe2 is observed to vary in the range 33-60 K. The coercive field values from 31.7 kOe to 65.3 kOe at T = 2 K are indicative of a very high magnetocrystalline anisotropy in this material. The observed distinctions in the magnetic characteristics of the Fe0.25TaSe2 samples obtained by various methods and after different heat treatments can be ascribed to the difference in the distribution of Fe atoms over the crystal lattice.
Morality rates in COVID-19 are dependent on timely diagnosis. Therefore, studying the relationship between laboratory markers and the severity of disease is important. The first wave of COVID-19 associated with the spread of the original strain of SARS-CoV-2, showed higher mortality rates caused by cytokine storm. As the viral variant changed, a change in the disease course towards a less pronounced inflammatory reaction was observed. These changes affected major players of inflammation, cytokines. However, cytokines are not the only markers in the inflammatory response. The purpose of this work was to determine the significance of laboratory markers in inflammation: WBC, C-reactive protein, ferritin, fibrinogen, and D-dimer. The study included 227 patients with acute COVID-19 in the first 5–7 days from the onset of the disease from January 2021 to March 2022. When compared with reference, all groups were characterized by reduced absolute values of lymphocytes. Correlation analysis between the absolute value of lymphocytes and plasma cytokine concentrations also revealed statistically significant strong relationships with the level of the chemokine CCL22/MDC. Given that CCL22/MDC is an important component of lymphopoiesis, its low concentrations may indicate dysregulation of this process in COVID-19. In addition, we noted a positive correlation between the level of C-reactive protein and IL-6 in peripheral blood. IL-6 is a proinflammatory cytokine, and its elevated levels have been associated with the development of severe COVID-19. One of its functions is the induction of C-reactive protein, and this trend persists regardless of which variant causes COVID-19. We also noted positive correlations between the concentrations of fibrinogen and IL-18, ferritin and IL-6, IL-18. Both of these proteins are involved in inflammation along with cytokines. The literature provides data on the significance of these markers for determining the severity of COVID-19. There is evidence of a synergistic effect of ferritin and IL-18 against viral pathogens. Of interest was the negative correlation between plasma D-dimer levels and IFNα. At the same time, data on the role of the latter in thrombus formation processes are increasingly appearing in the literature.
The aim of the study was to determine the sensitivity of the bacteria of the biovar Acinetobacter baumannii bv. tryptophandestruens to antibiotics used to treat Acinetobacter-infection. The object of the study was 86 primary clinical isolates of A. baumannii, of which 34 strains of A. baumannii bv. tryptophandestruens isolated in the microbiological laboratory of the Military Medical Academy in 2021–2022. Species identification of bacteria was carried out by MALDI-ToF mass spectrometry. The biovar tryptophandestruens of A. baumannii was determined on a dense chromogenic medium. The sensitivity of A. baumannii isolates to antibiotics was determined by a “Vitek 2 compact” microbiological analyzer (bioMerieux, France). Clinical categories of isolates sensitivity to antibiotics (S) were identified based on the boundary values of minimum suppressive concentrations (MSC, mg/L) established by the European Committee for the Determination of Sensitivity to Antimicrobial Preparates (EUCAST), version 11.0. Isolates of A. baumannii bv. tryptophandestruens and groups of isolates of other A. baumannii very rarely sensitive to meropenem (8.8±4.6%; 3.8±2.6%, respectively, p 0.05), ciprofloxacin (5.8±4.0; 9.6±4.1%, p 0.05). Strains sensitive to gentamicin are rarely represented in both groups (26.7±7.55; 19.3±5.5%, p 0.05) trimethoprim/sulfamethoxazole (38.8±8.3%; 23.6±5.3%, p 0.05). Sensitivity to polymyxin B was preserved in all strains of both groups (100%). Strains of the tryptophandestruens biovar A. baumannii group surpass strains of the other strain of A. baumannii group in the frequency of isolates with MSC50% tigecycline (MSC50% — 0.5 mg/l; MSC50% — 2 mg/l, respectively), and also have significantly more strains with MSC 0.5 mg/l (52.9% and 15.4%, respectively, p 0.01 ). Thus, the clinical isolates of the biovar A. baumannii bv. tryptophandestruens have no significant differences with isolates of other strains of A. baumannii in the frequency of strains sensitive (S) to meropenem, ciprofloxacin, gentamicin, trimethoprim/sulfamethoxazole, polymyxin B, but they differ in terms of sensitivity to tigecycline — a higher frequency of strains with an MSC of 0.5 mg/l (p 0.01) and an MSC of 50%.
