During the investigations on ticks and tick-borne pathogens (TBP) range expansion in the Northern Appenines, Italy, in May-August 2011-2013, we captured 107 lizards (Podarcis muralis). Captures were carried out in nine sites ranging from 800 to1600m of altitude, specifically chosen to be an optimal habitat for lizards (good sun exposure and abundant refuges). Sixty-eight animals were found infested by Ixodes ricinus (145 larvae, 25 nymphs; infesting 45 lizards), Haemaphysalis sulcata (119 larvae, 107 nymphs; infesting 37 lizards) and Haemaphysalis punctata (2 larvae; infesting two lizards). Coinfestation by I.ricinus and Haemaphysalis spp. was observed in 14 animals. Borrelia burgdorferi s.l. was detected in 3.5% I. ricinus larvae (number of positives=5, 95%CI: 1.2-8.0) and in two nymphs (8.0%, 95%CI: 1.0-26). Together with the specie-specific Borrelia lusitaniae, we identified Borrelia garinii, Borrelia afzelii and Borrelia valaisiana. I.ricinus were also infected by Rickettsia spp. (17.6% of larvae, 95%CI: 11.7-24.9; 12.0% of nymphs, 95%CI: 2.5-31.2), namely Rickettsia monacensis (41.9%), Rickettsia helvetica (16.1%) and Rickettsia hoogstraalii, a Rickettsia felis-like organism that we detected in a sample of H.sulcata nymphs as well. The two H.punctata larvae did not harbour any bacteria. Coinfection by B.afzelii and R.monacensis was observed in one I.ricinus larva. Our results confirm the involvement of lizards in the transmission cycle of TBP. The heterogeneity of B.burgdorferi genospecies mirrors previous findings in small rodents' and questing ticks in the area, and suggests that lizards may be involved in the maintenance of genospecies other than B.lusitaniae. Moreover, we detected three rickettsial species other than R.slovaca, that has a natural focus of transmission in our study area and is associated to Dermacentor marginatus. We had already detected R.monacensis in I.ricinus attached on small rodents, but not R.helvetica, which other authors report as associated to lizards. R.hoogstraalii is probably an endosymbiont of Haemaphysalis ticks in Europe; our finding of this organism in I.ricinus may have implications in public health, since it could preclude secondary infection with other -pathogenic- rickettsiae.
Infection by Borrelia burgdorferi s.l. and Rickettsia spp. in ticks from lizards in the Tuscan Appennine, Italy.
TOMASSONE, Laura;MARTELLO, ELISA;STELLA, Maria Cristina;GUILLEMI, ELIANA CAROLINA;MANNELLI, Alessandro
2016-01-01
Abstract
During the investigations on ticks and tick-borne pathogens (TBP) range expansion in the Northern Appenines, Italy, in May-August 2011-2013, we captured 107 lizards (Podarcis muralis). Captures were carried out in nine sites ranging from 800 to1600m of altitude, specifically chosen to be an optimal habitat for lizards (good sun exposure and abundant refuges). Sixty-eight animals were found infested by Ixodes ricinus (145 larvae, 25 nymphs; infesting 45 lizards), Haemaphysalis sulcata (119 larvae, 107 nymphs; infesting 37 lizards) and Haemaphysalis punctata (2 larvae; infesting two lizards). Coinfestation by I.ricinus and Haemaphysalis spp. was observed in 14 animals. Borrelia burgdorferi s.l. was detected in 3.5% I. ricinus larvae (number of positives=5, 95%CI: 1.2-8.0) and in two nymphs (8.0%, 95%CI: 1.0-26). Together with the specie-specific Borrelia lusitaniae, we identified Borrelia garinii, Borrelia afzelii and Borrelia valaisiana. I.ricinus were also infected by Rickettsia spp. (17.6% of larvae, 95%CI: 11.7-24.9; 12.0% of nymphs, 95%CI: 2.5-31.2), namely Rickettsia monacensis (41.9%), Rickettsia helvetica (16.1%) and Rickettsia hoogstraalii, a Rickettsia felis-like organism that we detected in a sample of H.sulcata nymphs as well. The two H.punctata larvae did not harbour any bacteria. Coinfection by B.afzelii and R.monacensis was observed in one I.ricinus larva. Our results confirm the involvement of lizards in the transmission cycle of TBP. The heterogeneity of B.burgdorferi genospecies mirrors previous findings in small rodents' and questing ticks in the area, and suggests that lizards may be involved in the maintenance of genospecies other than B.lusitaniae. Moreover, we detected three rickettsial species other than R.slovaca, that has a natural focus of transmission in our study area and is associated to Dermacentor marginatus. We had already detected R.monacensis in I.ricinus attached on small rodents, but not R.helvetica, which other authors report as associated to lizards. R.hoogstraalii is probably an endosymbiont of Haemaphysalis ticks in Europe; our finding of this organism in I.ricinus may have implications in public health, since it could preclude secondary infection with other -pathogenic- rickettsiae.
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