Clinical and diagnostic manifestations of tickborne mixed infection in combination with COVID-19.

The coexistence of various pathogens inside the patient's body is one of the poorly studied and current issues. The aim of the study is to identify the relationship between the indicators of complex laboratory diagnostics and the clinical manifestations of a mixed disease during subsequent infection with the SARS-CoV-2 virus using the example of a case of chronic encephalitis-borreliosis infection. Seven blood serum samples were collected from the patient over the course of a year. For the etiological verification of the causative agents of TBE, Lyme disease and COVID-19, the methods of ELISA and PCR diagnostics were used. The patient was diagnosed with Lyme disease on the basis of the detection of IgG antibodies to Borrelia 5 months after the onset of the disease, since she denied the tick bite. In the clinical picture, there was an articular syndrome and erythema migrans. Later, IgG antibodies to the TBEV were found in the blood. Throughout the study, IgM antibodies to Borrelia were not detected. The exacerbation of Lyme disease could be judged by the clinical manifestations of this disease and by the growth of specific IgG antibodies. A feature of this case was that during an exacerbation of the Lyme disease, an infection with the SARS-CoV-2 virus occurred. Treatment (umifenovir, hydroxychloroquine, azithromycin, ceftriaxone) was prescribed, which improved the condition of the underlying disease, decreased joint pain, decreased IgG levels to borrelia. However, during this period, serological markers of TBEV appear: antigen, IgM antibodies, and the titer of IgG antibodies increases. Most likely, this was facilitated by the switching of the immune system to the SARS-CoV-2 virus, with the simultaneous suppression of borrelia with antibiotics and the appointment of hydroxychloroquine, which has an immunosuppressive effect. Despite the activation of the virus, clinical manifestations of TBE were not observed in the patient, which is most likely associated with infection with a weakly virulent TBEV strain. The further course of tick-borne infections revealed the dominant influence of B. burgdorferi in relation to TBEV. Laboratory studies have shown that suppression of the activity of the borreliosis process by etiotropic treatment subsequently led to the activation of the persistent TBEV.

Indication Q fever pathogen in the south of Far east.

Q fever (coxiellosis) is a widespread natural focal disease in the world. The causative agent of coxiellosis is the gram-negative bacterium Coxiella burnetii, which is highly contagious and low virulence. The main carriers of C. burnetii are ixodid ticks, which feed on domestic and farm animals in anthropurgic foci. To address the possible circulation of the Q fever pathogen in the territory of the Primorsky Territory, 334 samples of various natural material collected in the spring-summer period of 2019 were studied. In the vicinity of the Vladivostok (on Reineke island), genetic markers of C. burnetii were detected in 19.7% of all tick species. In the Khankaisk region, coxiella DNA was detected more often (in 6.3%) in ticks of D. silvarum, in ticks of I. persulcatus and H. japonica, 1 case was detected. From 56 copies. ixodid ticks sucked to humans, C. burnetii DNA was detected in ticks of I. persulcatus in 38.8%, H. concinna - in 14.3%. In the serum of farm animals, the presence of coxiella in sheep in 3 samples was detected, in horses - in two. Sequencing of the obtained sequences showed the presence of the pathogen C. burnetii in the blood serum of animals. The ticks have stuck to people in 6 samples were identified C. burnetii and 6 samples - Coxiella-like endosymbiont. The presented results indicate the circulation of the causative agent of Q fever in the territory of the Primorsky Territory. To obtain a more complete description of the current epidemiological situation, it is necessary to conduct more extensive studies of natural material and blood of people with suspected Q fever.

Verification of mono- and mixed contaminations transmitting agents tick-borne infections.

In the territory of the Primorsky region, the nosoareas of causative agents of tick-borne infections often coincide and lead to mixed infection of ticks, which causes the mixed pathology in humans . We investigated ixodid ticks taken from people during the epidemic season of 2019 for the spectrum of pathogens of transmissible infections to determine the degree of their mono- and mixed infection. 651 specimens of ixodid ticks investigated. RNA/DNA pathogens was determined by the method of polymerase chain reaction (PCR), TBEV antigen by ELISA. The presence in ticks of pathogens of the following diseases was detected: Lyme borreliosis (35.3%), tick-borne replasing fever (11.3%), human granulocytic anaplasmosis (2.6%), human monocytic ehrlichiosis (2.4%), tick-borne encephalitis (1.8%), tick-borne ricketsiosis (1.0%). As agents of mono-infections, the virus of TBE, ehrlichia, anaplasma and rickettsia in ticks occurred less frequently than in combination with other pathogens. A high frequency of occurrence B. burgdorferi s.l. in mono-infection detected (58.7%). B. miyamotoi has met evenly at ticks with mono- and mixed infections. Total mixed infection of ticks was 23.1%. Borrelia have been identified in all mixed cases. Variants of double combinations (95.5 % of cases from all mixed infections) were as follows: B. burgdorferi s. l. + A. phagocytophilum, B. burgdorferi s.l. + E. chaffeensis / E. muris, B. burgdorferi s.l. + TBEV, B. burgdorferi s.l. + R. heilongjiangensis, B. burgdorferi s.l. + B. miyamotoi. The most frequent combination was B. burgdorferi s.l. + B. miyamotoi (37.8% of all mixed infections). In triple infection of B. burgdorferi s.l. + A. phagocytophilum + TBEV and B. burgdorferi s.l. + A. phagocytophilum + B. miyamotoi, the frequency of occurrence for each combination was 2.2%. Given the above, a complex laboratory diagnosis of tick-borne infections in individuals who have been bitten by a tick is necessary, including the detection of all pathogens common in focal areas.

Inhibitory Activity of Scutellaria baicalensis Flavonoids against Tick-Borne Encephalitis Virus.

We studied virus-inhibiting activity of Baikal skullcap (Scutellaria baicalensis) flavonoids against tick-borne encephalitis virus using various model schemes. The half-maximum cytotoxic concentration (CC50) for the plant extract was found (363.9±58.6 µg/ml). Based on the CC50 and IC50, selective index (SI) was calculated for viricidal (53.4), preventive (50.5), and direct antiviral actions (39.1) and for-intracellular replication of the virus (40.4). Suppression of virus reproduction ≥2.0 lg TCID50 was observed at extract concentration ≥5 µg/ml (viricidal effect), ≥11.2 µg/ml (preventive and direct antiviral effects), and ≥9 µg/ml (intracellular replication). Flavonoids of Baikal skullcap extract produced an in vitro inhibitory effect on tick-borne encephalitis virus due to their direct viricidal activity and direct inhibition of adsorption and intracellular replication of tick-borne encephalitis virus, which determines their value as highly effective antiviral drugs.

[Molecular-genetic monitoring as the basis of modern epidemiological surveillance of tick-borne infections.]

Molecular genetic monitoring of natural focal of tick-borne infections in the epidemic season of 2018 revealed infectiousness of ixodid ticks causative agents of tick-borne encephalitis (0.58% of cases), Lyme disease (31% of cases), human monocytic ehrlichiosis (1.6% of cases) and granulocytic anaplasmosis (3.9% of cases) is registered and also co-infections of ticks by these infections (2.9% of cases) is revealed in natural and anthropourgic foci (B. burgdorferi s.l.+A. phagocytophilum, B. burgdorferi s.l.+E. chaffeensis/E. muris and B. burgdorferi s.l.+tick-borne encephalitis virus). The major epidemiological importance of ticks of the species I. persulcatus is found, their share being 87,6%. The majority of patients being bitten by a tick were from the southern and southeast areas of Primorye. Contamination of ticks with Borrelia was revealed not only in I. persulcatus, but also in ticks of the Haemaphysalis and Dermacentor. The infectiousness of ticks of B. burgdorferi s.l. (42,3%), tick-borne encephalitis virus (7,7%) and A. phagocytophilum (15,4%) was highest on Russky Island.

[Evaluation of adjuvant effects of fucoidane from brown seaweed Fucus evanescens and its structural analogues for the strengthening vaccines effectiveness]. / Otsenka ad"iuvantnykh éffektov fukoidana iz buroi vodorosli Fucus evanescens i ego strukturnykh analogov dlia usileniia éffektivnosti vaktsin.

The use of sulfated polysaccharides from brown seaweed Fucus evanescens as adjuvants (native fucoidan in combination with polyphenols, fucoidan without polyphenols, a product of enzymatic hydrolysis of fucoidan) stimulated the formation of specific antibodies to the surface antigen of the hepatitis B virus (HBs-AG). Immunization of mice with vaccine compositions containing HBs-AG and fucoidan samples resulted in increasing the serum level of the pro-inflammatory (TNF-a, IFN-g, IL-2) cytokines. Increased production of these cytokines was detected in the culture of splenocytes additionally stimulated in vitro by fucoidans or phytohemagglutinin. The adjuvant effect of fucoidan and its structural modifications was comparable to that of the traditional licensed adjuvant aluminum hydroxide. The obtained results indicate a promising use of sulfated polysaccharides from F. evanescens as vaccine adjuvants.