Thèse Pavel Ionut

Ionut Pavel

Le polymorphisme génétique et l'écologie des tiques (Ixodidae)

Conclusion générale :

Ixodes ricinus is the most widespread species in north-eastern Romania, with a great capacity of adapting to the environmental factors in the Moldavia region, being the most abundent species from the outdor leisure zones in Iasi: CA Rosetti, Ciric, Bucium and strength, with a prevalence of 90%.
Haemaphysalis inermis, was re-signalized again in Romania, after half of century, since Feider (1965) last record.
Dermacentor reticulatus has a significant population in Iaşi (4%) compared with other recent studies, where prevalence is 0.1%;
We note the high prevalence of Haemaphysalis punctata at the outdoor leisure zone Cetățuia (35%) with a peak activity in April, due to the influence of ecological factors (slopes exposure, etc.).
Seasonal dynamics of the species Ixodes ricinus, showed a modified seasonal activity in Iaşi, peaking in April-May . We suppose this shift is due climatic change of the last decade, with an increase of annual isotherm over the value 10°C compared with the value registered by Feider (1965)
Multiplex PCR/ReverseLineBlot Hybridization (RLB) technique, adapted by Humair 7 years ago, assume host identification by ticks blood meal analysis. Aplied by us on 96 nymphs, 30% responded positively from the total, but showing a high diversity of hosts, being involved wild animals and domesticated animals due to vicinities households with the pastures where ticks were collected
This study represents the first attempt of describing genetic diversity of the two species of the genus Dermacentor in Europe, namely Dermacentor marginatus and D. reticulatus. We studied 19 specimens of D. marginatus from 9 countries (Tunisia, Italy, Portugal, France, Hungary, Germany, Romania, Turkey and Iran) and 9 specimens of the species Dermacentor reticulatus from 6 countries (Portugal, Turkey, Romania, Slovakia Germany and France). Resulting phylogenetic trees showed a weak phylogeographical structure of both species studied. However turkish D. reticulatus population is slighty divergent from the other. Haplotidic diversity registered for D. marginatus was 0.9322 and for D. reticulatus was 0.41667. The values of nucleotidic diversity were 0.006668 for D. marginatus and 0.00082 for D. reticulatus. For both species studied Tajimas ”D” statistical test had a negative value (-0.590342 and -1.362405 for D. marginatus, and D. reticulatus respectively). The negative values registered along with a high A-T content suggest the existence of a population in expansion.