ABSTRACT
The paper presents the results of a study of the prevalence of Ixodid ticks - potential carriers of tick-borne rickettsiosis pathogens. Ectoparasites were collected in various natural and climatic zones of the Crimean Peninsula within the year 2016-2018. As a result of screening with the help of real-time PCR analysis (PCR-RT), a genetic marker (a section of the gltA gene) of the rickettsia group of tick-borne spotted fever was detected in ticks. The most common DNA marker of rickettsia was found in ticks in the eastern regions of the steppe zone - 50,6 %, in the north-western part of the steppe zone this value was 12,0 %. The least amount of rickettsia target DNA was detected in ticks collected in the mountain forest and south bank zones - 4,5 %. As a result of sequencing of positive DNA samples from fragments of the gltA, ompA, ompB, and sca4 genes, the species composition of rickettsias was established. The DNA of 8 species of rickettsia was identified: Circulation of three R. conorii, R. massiliae, R. sibirica subsp. mongolotimonae, R. slovaca, R. aeschlimannii, R. monacensis, R. helvetica, R. raoultii. R. massiliae, R. slovaca, and R. helvetica were established in the Crimean Peninsula for the first time. The peculiarities of the geographical distribution of the identified rickettsia species were determined, which was due to the spread of mites-carriers of pathogens. The revealed diversity of rickettsia species and their vectors, due to the isolation of the areas of the main feeding animals and the established routes of migratory birds, suggests the circulation of other rickettsia species on the territory of the Crimean Peninsula. The obtained results suggest that the diseases of tick-borne rickettsiosis in the Crimean Peninsula can be caused not only by R. conorii, as previously thought, but also by other types of rickettsii.
Subject(s)
Rickettsia Infections , Rickettsia , Ticks , Animals , Humans , Prevalence , Real-Time Polymerase Chain Reaction , Rickettsia/genetics , Ticks/genetics , Ticks/microbiologyABSTRACT
AIM: Analysis of epidemic manifestations of natural-foci infections (NFI), clarification of spectrum of their causative agents, determination of epizootic activity of natural foci in the Crimea Federal District (KFD). MATERIALS AND METHODS: Epizootologic examination of 10 administrative districts of KDF was carried out. 291 pools (2705 specimens) of ixodes ticks and 283 samples of organs of small mammals were studied by PCRmethod for the presence of DNA/RNA of causative agents of a number of NFI. RESULTS: Morbidity by NFI in KFD was registered by 6 nosologies: Lyme borreliosis, Marseilles fever, leptospirosis; tularemia, intestine yersiniosis and tick-borne viral encephalitis, wherein, transmissive infections made up 91.6%. Circulation of causative agents of Crimea hemorrhagic fever, Q fever, group of tick-borne spotted fever, Lyme borreliosis, human granulocytic anaplasmosis, human monocytic ehrlichiosis, hemorrhagic fever with renal syndrome, West Nile fever, tularemia and leptospirosis was established. CONCLUSION: Due to activity of natural foci of NFI further monitoring of epidemiologic and epizootologic manifestations of these infections in the Crimea, including using genetic methods of analysis, is necessary for ensuring sanitary-epidemiologic welfare of KFD population.
Subject(s)
Focal Infection/epidemiology , Lyme Disease/epidemiology , Tick-Borne Diseases/epidemiology , Viruses/isolation & purification , West Nile Fever/epidemiology , Animals , DNA, Viral/genetics , DNA, Viral/isolation & purification , Disease Reservoirs , Focal Infection/genetics , Focal Infection/virology , Humans , Ixodes/pathogenicity , Ixodes/virology , Lyme Disease/genetics , Lyme Disease/virology , Mammals/virology , Russia , Tick-Borne Diseases/genetics , Tick-Borne Diseases/virology , Viruses/genetics , Viruses/pathogenicity , West Nile Fever/geneticsABSTRACT
Genetic evidence of the Tula virus (TULV) in Crimea region of Russia is presented. Based on the reverse transcription PCR and subsequent sequence analysis, a total of 4 RNA isolates of the TULV were identified from the tissue samples of the Altai voles Microtus obscurus captured in the Bakhchisaray district of the Republic Crimea. Phylogenetic analysis of the S-, M-, and L-segment sequences of the Crimean TULV strains showed that they formed distinct genetic lineage, Russia IV, in the TULV variant. New sequences were most closely related to the lineage Russia I sequences obtained from common vole (M. arvalis) captured in the Tula region in Central Russia