Ixodes ricinus infesting snakes: Insights on a new tick-host association in a Borrelia burgdorferi sensu lato endemic area

Parasites and microorganisms associated with the snakes collected for the "festa Dei serpari" in Cocullo, Italy

While in much of the Western world snakes are feared, in the small, rural, mountainous town of Cocullo, in the middle of central Italy, snakes are annually collected and celebrated in a sacro-profane ritual. Every 1st of May, Serpari (snake catchers) capture and showcase dozens of non-venomous snakes to celebrate the ritual of San Domenico. In order to detect potential zoonotic pathogens within this unique epidemiological context, parasites and microorganisms of snakes harvested for the "festa dei serpari" ritual were investigated. Snakes (n = 112) were examined and ectoparasites collected, as well as blood and feces sampled. Ectoparasites were identified morpho-molecularly, and coprological examination conducted through direct smear and flotation. Molecular screenings were performed to identify parasites and microorganisms in collected samples (i.e., Mesostigmata mites, Anaplasma/Ehrlichia spp., Rickettsia spp., Borrelia burgdorferi sensu lato, Coxiella burnetii, Babesia/Theileria spp., Cryptosporidium spp., Giardia spp., Leishmania spp. and helminths). Overall, 28.5% (32/112) of snakes were molecularly positive for at least one parasite and/or microorganism. Endosymbiont Wolbachia bacteria were identified from Macronyssidae mites and zoonotic vector-borne pathogens (e.g., Rickettsia, Leishmania), as well as orally transmitted pathogens (i.e., Cryptosporidium, Giardia, Proteus vulgaris, Pseudomonas), were detected from blood and feces. Thus, given the central role of the snakes in the tradition of Cocullo, surveys of their parasitic fauna and associated zoonotic pathogens may aid to generate conservation policies to benefit the human-snake interactions, whilst preserving the cultural patrimony of this event.

Ticks on reptiles and amphibians in Central Amazonia, with notes on rickettsial infections

Reptiles and amphibians are exceptional hosts for different ectoparasites, including mites and ticks. In this study, we investigated tick infestations on reptiles and amphibians trapped in Central Amazonia, and also assessed the presence of rickettsial infections in the collected ticks. From September 2016 to September 2019, 385 reptiles (350 lizards, 20 snakes, 12 tortoises, and three caimans) and 120 amphibians (119 anurans and one caecilian) were captured and examined for ectoparasites. Overall, 35 (10%) lizards, three (25%) tortoises and one (0.8%) toad were parasitized by ticks (124 larvae, 32 nymphs, and 22 adults). In lizards, tick infestation varied significantly according to landscape category and age group. Based on combined morphological and molecular analyses, these ticks were identified as Amblyomma humerale (14 larvae, 12 nymphs, 19 males, and one female), Amblyomma nodosum (three larvae, one nymph, and one female), and Amblyomma rotundatum (four larvae, three nymphs, and one female), and Amblyomma spp. (103 larvae and 16 nymphs). Our study presents the first records of A. nodosum in the Amazonas state and suggests that teiid lizards are important hosts for larvae and nymphs of A. humerale in Central Amazonia. Moreover, a nymph of A. humerale collected from a common tegu (Tupinambis teguixin) was found positive for Rickettsia amblyommatis, which agrees with previous reports, suggesting that the A. humerale-R. amblyommatis relationship may be more common than currently recognized.

Mites and ticks of reptiles and amphibians in Brazil

This study focuses on the parasitic associations of mites and ticks infesting reptiles and amphibians through a multifocal approach. Herein, reptiles (n= 3,596) and amphibians (n= 919) were examined to ensure representativeness of the Brazilian herpetofauna megadiversity. The overall prevalence was calculated to better understand which were the preferred hosts for each order of Acari (Trombidiformes, Mesostigmata and Ixodida), as well as to determine which orders frequently parasitize reptiles and amphibians in Brazil, and their host specificity. Infestation rates were calculated [prevalence, mean intensity (MI) and mean abundance (MA)] for each order and species, determining which mites and ticks are more likely to be found parasitizing the ectothermic tetrapod fauna. Parasitic niches and preferred locations were recorded to help identify specific places exploited by different Acari, and to determine the host-parasite adaptations, specificity, and relationships in terms of co-evolution. In total 4,515 reptiles and amphibians were examined, of which 170 specimens were infested by mites and ticks (overall prevalence of 3.8%). Trombidiformes mites were prevalent in lizards (55.3%), followed by Ixodida on snakes (24.7%). Mesostigmata mites were the less prevalent, being identified only on Squamata reptiles (4.3% on snakes, 2.4% on lizards). In amphibians, Ixodida ticks were the most prevalent (63.2%), followed by Trombidiformes (34.6%), and lastly Oribatida (2%). From the 13 species of Trombidiformes identified, Eutrombicula alfreddugesi (19.9%) was the most abundant in terms of number of host species and infested individuals. Specimens of Ixodida, yet more common, showed low preferred locations and different values of infestation rates. Co-infestations were recorded only on snakes. Lizard mites generally adhered to the ventral celomatic area (Pterygosomatidae), and some species to the pocket-like structures (Trombiculidae). Lizards, at variance from snakes, have adapted to endure high parasitic loads with minimum effects on their health. The high number of mites recorded in the digits of toads (Cycloramphus boraceiensis, Corythomantis greening, Cycloramphus dubius, Leptodactylus latrans, Melanophryniscus admirabilis) could lead to avascular necrosis. Frogs were often infested by Hannemania larvae, while Rhinella toads were likely to be infested by Amblyomma ticks. Of note, Rhinella major toad was found infested by an oribatid mite, implying first a new parasitic relationship. The effect of high parasitic loads on critically endangered species of anurans deserves further investigation. Our results add basic knowledge to host association of mites and ticks to Brazilian reptiles and amphibians, highlighting that routine ectoparasite examination is needed in cases of quarantine as well as when for managing reptiles and amphibians in captivity given the wide diversity of Acari on the Brazilian ectothermic tetrapod fauna.