[Biological characteristics and permissiveness to viruses of diploid kidney cells strain from the bat Nathusius' pipistrelle (Pipistrellus nathusii Keyserling & Blasius, 1839; Chiroptera: Microchiroptera: Vespertilionidae)].

INTRODUCTION: Bats are an epidemiologically important natural reservoir of viruses of various taxonomic groups, including causative agents of especially dangerous infections of humans and animals. Considering the relevance of arbovirus infections, it seems advisable to study the spectrum of the sensitivity of cells derived from bats inhabiting and migrating on the territory of the Russian Federation to causative agents of vector-borne diseases of animals.The study aimed to obtain a diploid strain of cells from renal tissue of bats Pipistrellus nathusii and to investigate its biological characteristics, as well as to assess its permissiveness for bluetongue (BTV); Rift Valley fever (RVFV); lumpy skin disease (LSDV); rabbit myxoma (Myxomatosis cuniculi); rabbit, or Shope fibroma (RFV); African horse sickness (AHSV) and African swine fever (ASFV) viruses. MATERIAL AND METHODS: There were 2 clinically healthy male individuals of P. nathusii who taken as donors of organs. To obtain diploid kidney cell culture strain and to study its properties, the level of the 6th passage was investigated by conventional cytological, virological, and molecular methods. The permissiveness of the obtained cell culture for BTV, RVFV, LSDV, Myxomatosis cuniculi, RFV, AHSV and ASFV was determined. RESULTS: The formation of a confluent monolayer was observed after 72 hours, while the proliferation index was 2.7-3.3. The cell monolayer had been maintained without changing the medium for 45 days (observation period). The stability of the karyotype had been demonstrated in continuous subculturing at the 36th passage. The cell culture named «Diploid cell line Pipistrellus nathusii kidney¼, and its permissiveness to BTV, RVFV, LSDV and Myxomatosis cuniculi had been demonstrated. DISCUSSION: The sensitivity of the strain to BTV and RVFV is consistent with the data on the identification of reovirus and RVFV in Egyptian fruit bats (Rousettus aegyptiacus), and its permissiveness for LSDV and rabbits myxoma virus is consistent with the results of detection of poxviruses in big brown bat (Eptesicus fuscus). CONCLUSION: A diploid kidney cell strain derived from P. nathusii was obtained and certified. Its permissiveness to BTV, RVFV, LSDV and rabbits myxoma viruses makes it possible to use this strain for isolation and studies of these viruses. Reproduction of the viruses in diploid kidney cells strain derived from P. nathusii living and migrating in the European part of the Russian Federation indicates their potential role in the epidemiology of significant infections, especially transmissible ones.

Spatial multi-criteria decision analysis for modelling suitable habitats of Ornithodoros soft ticks in the Western Palearctic region.

Ticks are economically and medically important ectoparasites due to the injuries inflicted through their bite, and their ability to transmit pathogens to humans, livestock, and wildlife. Whereas hard ticks have been intensively studied, little is known about soft ticks, even though they can also transmit pathogens, including African Swine Fever Virus (ASFV) affecting domestic and wild suids or Borrelia bacteria causing tick-borne relapsing fever (TBRF) in humans. We thus developed a regional model to identify suitable spatial areas for a community of nine Ornithodoros tick species (O. erraticus, O. sonrai, O. alactagalis, O. nereensis, O. tholozani, O. papillipes, O. tartakovskyi, O. asperus, O. verrucosus), which may be of medical and veterinary importance in the Western Palearctic region. Multi-Criteria Decision Analysis was used due to the relative scarcity of high-quality occurrence data. After an in-depth literature review on the ecological requirements of the selected tick community, five climate-related factors appeared critical for feeding activity and tick development: (i) a spring temperature exceeding 10°C to induce the end of winter soft tick quiescent period, (ii) a three-months summer temperature above 20°C to allow tick physiological activities, (iii) annual precipitation ranging from 60mm to 750mm and, in very arid areas, (iv) dry seasons interrupted by small rain showers to maintain minimum moisture inside their habitat along the year or (v) residual water provided by perennial rivers near habitats. We deliberately chose not to include biological factors such as host availability or vegetation patterns. A sensitivity analysis was done by performing multiple runs of the model altering the environmental variables, their suitability function, and their attributed weights. To validate the models, we used 355 occurrence data points, complemented by random points within sampled ecoregions. All models indicated suitable areas in the Mediterranean Basin and semi-desert areas in South-West and Central Asia. Most variability between models was observed along northern and southern edges of highly suitable areas. The predictions featured a relatively good accuracy with an average Area Under Curve (AUC) of 0.779. These first models provide a useful tool for estimating the global distribution of Ornithodoros ticks and targeting their surveillance in the Western Palearctic region.