Vol 7, No 4 (2017)

Abstract. Ascorbic acid (vitamin C, AA) is an essential nutrient of the human diet due to its participation on numerous regulatory and enzymatic processes. AA takes part in such vital physiological processes as hormone production, collagen synthesis, stimulation of the immune system, etc. In the present review the activities of AA are considered that provide its protective effect at influenza infection. This effect can be result of direct virus-inhibiting activity of AA as well as of anti-inflammatory and antioxidant properties. Oxidative stress during influenza infection leads to nonspecific damage of the pulmonary tissue and subsequent inflammation of the lungs. The antioxidant activity of AA results in alleviation of infection due to suppression of tissue damage as well as in inhibition of reactive oxygen species-mediated signal transduction and regulatory reactions. After oxidation by ROS, AA is converted to dehydroascorbic acid (DAA) and inhibits the key enzymes of NF-κB pathway, such as kinases IKKα and IKKβ. AA itself blocks the activity of another component of the NF-kB pathway, kinase IKKβ(SS/EE), whose activity is directed to the phosphorylation of the factor IκBα. As a result, activation of NF-κB and its transport to the nucleus does not occur. Thus, AA performs a dual function: first, it neutralizes free radicals, preventing them from activating NF-κB, and secondly, the product of its oxidation, DAA, further blocks the activation of this pathway. In addition, in some cases AA results in the decrease in the infectious activity of influenza virus that is not due to the antioxidant activity of AA, but to direct virus-inhibiting activity. Taken together, the presented data suggests that the use of drugs with antiviral and antioxidant activity, as a combination of individual drugs or, as in the case of AA, as a single drug with complex activity, for treatment of influenza has advantages over the etiotropic drug monotherapy scheme.

Studies of the metagenome of the upper respiratory tract in children showed the presence of five major bacterial phyla: Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria and Fusobacteria. Were revealed population differences in the distribution of weights of the above listed phyla, but subject to the dominance of the Firmicutes. Proved the role of environmental factors and time of year for representation in these biotopes of the phyla: Firmicutes, Proteobacteria, Bacteroidetes. Recurrent respiratory infections, hypertrophy of the tonsils of the lymphoid pharyngeal ring, secretory middle ear infections in children is associated with carriage of Haemophilus (H.) parainfluenzae, H. paraphrohaemolyticus, Gemella (G.) haemolysans, G. morbillorum, G. sanguinis, Streptococcus (S.) pneumoniae, S. pseudopneumoniae, S. intermedius, S. agalactiae.

The aim of the study was to identify the epidemiological features of bacterial infections in patients and circulation of epidemiologically significant microorganisms in the bone marrow transplant (BMT) units. Materials and methods. The study was conducted in three BMT departments. To identify the epidemiological features of bacterial infections, a prospective observational study was conducted from 01 April 2014 to 31 August 2014 (91 patients) which included active detection of cases of infection and microbiological examination of patients. In order to detect the circulation of epidemiologically significant microorganisms, point prevalence studies (59 patients, 170 environmental samples) were conducted. To study the role of colonization, microbiological monitoring of patients on admission to the department was carried out, and repeated every week before discharge. Swab samples from skin and mucous membrane of the oral cavity and stool sampleswere included in the monitoring. In total, 639 samples from 50 patients were tested. Results. The study revealed a high incidence of infectious complications in BMT patients (100 cases of bacterial infections in 57 patients: sepsis 30.8 per 100 patients, pneumonia 26.4 per 100 patients, urinary tract infections 32.9 per 100 patients, soft tissue infection 9.9 per 100 patients, catheter-associated bloodstream infection 9.9 per 100 patients). Most infections were caused by Gram-negative bacteria, in particular K. pneumoniae. The onset of disease manifestation was preceded by colonization of the patient with these microorganisms. Fatal outcomes were observed from sepsis and pneumonia caused by K. pneumoniae and/or P. aeruginosa. Sepsis and pneumonia were often associated with cytopenia, RR 2.63 [95% CI 1.52–4.57] p = 0.004 and RR 3.97 [95% CI 2.19–7.19] p < 0.001 respectively. In course of observation, the frequency of colonization of patients with microorganisms susceptible to antibiotics decreased, and colonization with resistant pathogens increased. A series of prevalence studies revealed a constant circulation of VRE in the BMT units with a contacttransmission via household objects. Multidrug-resistant gram-negative microorganisms did not have a constant circulation and appeared sporadically against the background of the constant circulation of susceptible strains of these pathogens. Conclusions. Prospective epidemiological surveillance and microbiological monitoring are required in the BMT units. Widespread contamination of household objects in the environment indicates the need to strengthen the hygienic education of patients and visitors as well as disinfection of these facilities. In addition, we recommend introduction of weekly fecal screening cultures to monitor intestinal colonization of patients with MDRO.

In the Kaliningrad region, the incidence of tuberculosis (TB) has declined significantly over the past decade (from 134/100 000 in 2006 to 50.6/100 000 in 2015), but still exceeds the average for the North-West Russia (40.7/100 000). In view of the increase in the proportion of primary multidrug resistance (MDR) of the causative agent from 23.9% in 2010 to 30.5% in 2015, the aim of this study was to analyze the current Mycobacterium tuberculosis population structure in the Kaliningrad region and to evaluate its spatial-temporal trends. The 73 M. tuberculosis isolates from patients with pulmonary TB newly diagnosed in 2015 were studied. Drug resistance (DR) was detected in 46 (63.0%) M. tuberculosis strains; of these, 32 (43.8%) were multidrug-resistant (MDR). The 46 (63.0%) of 73 M. tuberculosis strains were of the Beijing genotype with 19.2% (14 out of 73) share of the B0/W148 cluster. Spoligotyping of 27 non-Beijing M. tuberculosis strains made it possible to identify 15 spoligotypes of 5 genetic families — T, LAM, Ural, S, X. About half (16; 51.6%) of non-Beijing strains were represented by spoligotypes — SIT42, SIT53, SIT262, and SIT444. In a heterogeneous group T, mostly drugsusceptible strains of spoligotype SIT53 were prevailing. More than half (55.6%) of the LAM genotype strains exhibited DR. The Ural family was small (5.5%) and included strains of well-known in Russia M. tuberculosis spoligotypes SIT35 and SIT262, and one new, not found previously. MDR was statistically significantly associated with the Beijing genotype: 56.5% versus 25.9% in strains of other genotypes (in total) (P = 0.0134). Moreover, all 14 strains of epidemiologically and clinically significant B0/W148 cluster were MDR. The proportion of MDR strains of the Beijing genotype did not change significantly: in 2006 it was 61.3%, in 2015 — 56.5% (P = 0.6773). However, the spectrum of drug resistance to first-line anti-TB drugs expanded. If previously the majority (78.9%) of MDR strains additionally exhibited resistance to streptomycin only, in present study 72.0% of MDR strains were resistant to streptomycin, ethambutol, and pyrazinamide. The proportion of MDR strains of non-Beijing genotypes was 25.9%, a significantly higher than the similar indicators in 2006 — 2.2% (P = 0.0124). A relatively smaller proportion of strains of the Beijing genotype (50%) was found in TB patients from the shores of the Baltic Sea, a territory with a relatively more favorable socio-economic situation and a higher standard of living. Thus, the current epidemiological situation of TB in the Kaliningrad region is crucially determined by the growing circulation of MDR Beijing family strains, as well as a significant increase in the proportion of MDR strains of other genotypes.

The prevalence of HBV infection is estimated by the frequency of occurrence of HBsAg and varies depending on the geographic region. Chronic infection is characterized by a stable presence of HBsAg for 6 months, with the exception of the occult form of the disease, characterized by the absence of HBsAg, an extremely low level of HBV DNA in the blood serum. The problem of identifying occult HBV (ocHBV) is especially relevant because of the development of transplantology and transfusiology. However, serological screening of donor blood used in the Russian Federation and Central Asian countries does not reveal HBV seronegative donors. Since HBV infection is possible with the introduction of small doses of the virus, the importance of using complex molecular methods for detecting donor ocHBV is obvious, despite the low viral load, since donor blood is used predominantly in patients with severe course of various diseases characterized by increased susceptibility to HBV because of immunosuppression. The aim of our work was to study the characteristics of the genetic structure of the ocHBV in donors in Astana, Kazakhstan. A total of 500 blood plasma samples from HBsAg-negative donors were obtained in 2012 from residents of Kazakhstan, Astana. Using the method, we proposed to detect HBV DNA with a low viral load, HBV was detected in 9.4% of donors. Serological markers were found in 12.7% of patients with HBV DNA, 8.5% had HBcor IgG antibodies, 4.2% had HBcor IgG and HBe IgG antibodies at the same time. Thus, in 41 (87.3%) of the blood donor, ocHBV was seronegative. Based on the phylogenetic analysis of the 47 isolates showed that the HBV of genotype D (95.75%) prevails in the examined group in comparison with HBV of genotype A (4.25%). HBV subgenotypes are represented in the following ratios: D1 — 46.8%, D2 — 17.05%, D3 — 31.9%, A2 — 4.25%. In a comparative analysis, the distribution of HBV subgenotypes in the group with ocHBV and in the case of the manifest form in donors in the Republic of Kazakhstan significantly differed — χ2 = 14.027 at p = 0.0072, df = 4. The incidence of HBV D3 with ocHBV (31.9%) exceeded that of patients with a manifest form (7.4%). The relative risk of occult form of disease in patients with the subgenotype D3 is significantly higher (RR = 1.572, CI: 1.179–2.096, p = 0.0208). When assessing the picture of HBV diversity on the material of the group including HBsAg-negative and HBsAg-positive blood donors, it is evident that the genetic relationship of the manifestations of the manifest HBV and the ocHBV of genotype D is obvious. Among the isolates are both similar in nucleotide sequences with those previously described in various regions of Europe and Central Asia, and circulating in the territory of the Republic of Kazakhstan, which indicates an independent homologous evolution of HBV in the region. The high incidence of ocHBV among HBsAg-negative blood donors is indicative not only of the widespread prevalence of the occult form of the disease course in the population and the inadequacy for the detection of chronic HBV of conventional HBsAg and HBV DNA in the peripheral blood using commercial kits, but also the need to study the characteristics of the immune response with this form of the disease course.

It is known that the functioning of many proteins and enzymes depends on the degree of hydration of their surfaces. In our studies, neuraminidase (NA) of influenza virus was selected as a model for surface antigenic viral protein. The Brunauer–Emmett–Teller (BET) model of adsorption was used to calculate the values of water monolayer (am) at different values of water vapor pressure. The obtained BET isotherms allow for concluding that hysteresis takes place manifested by the difference between the monolayer a_m values for sorption and desorption of water from the surface of the enzyme, which is probably associated with a high degree of cooperation of the hydration shell formed. The maximum binding of water molecules was observed for the vapor pressure p/ps value of 0.65 and was a_m = 224 water molecules per a molecule of the enzyme. Basing on the calculated surface area of a NA tetramer (S = 256 nm² ) and the maximum projection area of water molecule, it may be concluded that the entire surface of the enzyme is completely covered with a water monolayer. For said a_m value the maximum activity of NA was observed, whereas the minimum enzyme activity corresponded to the am value of 98 water molecules per a molecule of the enzyme, which corresponded to the water vapor pressure p/pS value of 0.38. Thus, for the influenza virus NA protein a dependency of the enzymatic activity on the degree of hydration of the surface of the enzyme is demonstrated. The dependence of immunogenicity of influenza virus from the extent of hydration of NA.

The problem of prophylaxis and treatment of the hospital-acquired infections caused remains actual and urgent and stubborn in modern medicine. Appearance of antimicrobial agents resistant and high virulent strains adapting also to desinfectants. Development of innovative hi-tech diagnostic methods and treatment at wide circulation of microorganisms with multiple antimicrobial agents resistance defines need of continuous improvement of epidemiological surveillance and microbiological monitoring of this group of infections. Aim of project: to carry out the epidemiological analysis of a case rate of hospital-acquired infections in Primorsky Krai and to determine the specific role of hospital-acquired infections which arose in surgical hospitals and units. Material and methods: In work there were used statistical forms, e.g. No. 2 «The information on infectious and parasitic diseases» in Primorsky Krai. A research method — the retrospective epidemiological analysis. Results of a research: In 2015 in Primorsky Krai there were registered 159 cases of hospitalacquired infections, the indicator of a case rate made 0.05 per 1000 treated patients. In comparison with 2014 the case rate decreased, rate of depression made — 28%. According to the statistical reporting the greatest number of cases of hospital-acquired infections was registered in obstetrical institutions — 60 cases (38% of all hospital-acquired infections), in children’s hospitals — 46 (29%) and in surgical hospitals and units — 33 (21%). Other hospital-acquired infections are registered in out-patient and polyclinic institutions and in institutions of a therapeutic profile. In structure of hospitalacquired infections in the territory of Primorsky Krai in 2015, as well as in previous years, acute intestinal infections dominated (35 cases — 22%) and it is purulent — septic infections at newborns (34 cases — 21%). Conclusions: In the territory of Primorsky Krai the hospital-acquired infections are often registered in obstetrical institutions, in children’s and surgical hospitals and units. The tendency to hospital-acquired infections morbidity growthin surgical hospitals and units, most likely, not owing to augmentation of cases of postoperative complications, and at the expense of other nosologies.

It is known that any surfaces in environment of healthcare organizations are a reservoir for microorganisms and contribute to transmission of pathogens, increasing the risk of cross-contamination through indirect contact with the patient. Wide and not always rational use of chemical disinfectants carries risks for the safety of the environment, the patient and medical staff. In this regard, there remains the search for alternative methods of purification and decontamination of abiotic surfaces in health care facilities. Tested the tool for cleaning areas that contain 3 strains of the genus Bacillus: B. subtillis, B. licheniformis, B. pumilus. Were treated areas of the medical centre in St. Petersburg Pasteur Institute: the treatment room (experience) and the office of the gynecologist (control with conventional cleaning and disinfection). Within 30 days of the sowing of samples of swabs from surfaces were made of 3 Petri dishes with the “blood” agar-based environment “agar of Givental–Witch” debilitating touch (gold method). Isolated cultures of bacteria identified by microscopy, biochemical typing and MALDI-TOF MS (Bruker). In control and the experience in the 1st day of observation prior to the cleaning sown Enterococcus faecium 10⁴ –10⁵ CFU/ml. The 2nd day of observation in the control was dominated by E. faecium, then his growth stopped. For the 2nd–4th day watched the growth of Enterobacteriaceae to 10⁶ CFU/ml, in the future, the number was 10 CFU/ml until the end of the observation period (30 days). The 5th day in the control revealed the growth of bacteria of the genus Staphylococcus spp. mainly S. epidermidis. The experience from the 2nd day of observation revealed a significant increase in Bacillus spp. at 10⁵ CFU/ml, then before the end of the experiment, the number was 10² –10³ CFU/ml. In the 1st–2nd day revealed growth of E. faecium, and then it stopped. For the 2nd–4th day watched the growth of Enterobacteriaceae to the level of 10⁶ CFU/ml, on the 8th day — to 10² CFU/ml, the growth of conditionally pathogenic microflora was absent. Cleaning of the premises on the basis of probiotic bacteria of the genus Bacillus inhibits the growth of sanitary-indicative microorganisms compared to control. Thus, the means of probiotic treatment did not have a biocidal effect, but inhabiting the surface, they inhibit the growth and proliferation of opportunistic bacteria.