Prevalence and diversity of piroplasms and ticks in young raccoons and an association of Babesia sensu stricto infections with splenomegaly

Invasive raccoon (Procyon lotor) and raccoon dog (Nyctereutes procyonoides) as potential reservoirs of tick-borne pathogens: data review from native and introduced areas

In recent decades, populations of the raccoon (Procyon lotor) and the raccoon dog (Nyctereutes procyonides) have increased and adapted to peri-urban and urban environments in many parts of the world. Their ability to rapidly colonize new territories, high plasticity and behavioral adaptation has enabled these two species to be considered two of the most successful invasive alien species. One of the major threats arising from continually growing and expanding populations is their relevant role in maintaining and transmitting various vector-borne pathogens among wildlife, domestic animals and humans. According to the WHO, over 17% of infectious diseases are vector-borne diseases, including those transmitted by ticks. Every year tick-borne pathogens (TBPs) create new public health challenges. Some of the emerging diseases, such as Lyme borreliosis, anaplasmosis, ehrlichiosis, babesiosis and rickettsiosis, have been described in recent years as posing important threats to global health. In this review we summarize current molecular and serological data on the occurrence, diversity and prevalence of some of the TBPs, namely Babesia, Theileria, Hepatozoon, Borrelia, Rickettsia, Bartonella, Anaplasma and Ehrlichia, that have been detected in raccoons and raccoon dogs that inhabit their native habitats and introduced areas. We draw attention to the limited data currently available on these invasive carnivores as potential reservoirs of TBPs in different parts of the world. Simultaneously we indicate the need for more research in order to better understand the epidemiology of these TBPs and to assess the future risk originating from wildlife.

Prevalence and genetic characterization of a Babesia microti-like species in the North American river otter (Lontra canadensis)

A 4.5-month-old, male, North American river otter (Lontra canadensis) from Athens-Clarke County, Georgia, USA being temporarily housed at a rehabilitation facility, presented with a three-day history of lethargy, anorexia, and severe anemia. Antemortem blood smears revealed intraerythrocytic piroplasms. Supportive care and antiparasitic treatments were initiated, but the animal died three days following presentation. Gross necropsy revealed yellow discoloration of all adipose tissue throughout the carcass and a mildly enlarged, diffusely yellow to pale orange liver. Microscopically, moderate, centrilobular hepatocellular degeneration and necrosis were observed, consistent with hypoxia secondary to apparent hemolytic anemia. Piroplasms were frequently observed in red blood cells in histologic sections. The nearly full-length 18S rRNA gene sequence (1588 bp) was identical to a previously described piroplasm from North American river otters from North Carolina. Phylogenetically, based on the 18S rRNA gene sequence, the otter Babesia sp. was in a sister group with a clade that included several strains of Babesia microti-like species including Babesia sp. from badgers (Meles meles), Babesia vulpes, and Babesia sp. from raccoons (Procyon lotor). To better understand the distribution and genetic variability of this Babesia species, otters from four states in the eastern U.S. and California were tested. Overall, 30 of 57 (53%) otters were positive for Babesia sp. None of four otters from California were positive, but prevalences in eastern states were generally high, 5/9 (55%) in Georgia, 7/14 (50%) in South Carolina, 10/17 (59%) in North Carolina, and 8/13 (62%) in Pennsylvania). Partial 18S rRNA gene sequences from all populations were identical to the clinical case sequence. No Babesia sensu stricto infections were detected. There were six unique COI sequences (937 bp) detected in 18 positive otters. The most common lineage (A) was detected in 12 of 18 (67%) samples from Georgia, North Carolina, South Carolina, and Pennsylvania. Lineage B was found in two otters and the remaining lineage types were found in single otters. These six lineages were 99-99.8% similar to each other and were < 88% similar to related parasites such as B. vulpes, B. microti-like species of raccoons, B. microti, and B. rodhaini. Phylogenetically, the Babesia sp. of otters grouped together in a well-supported clade separate from a sister group including B. vulpes from fox (Vulpes vulpes) and domestic dogs. In conclusion, this report demonstrates that this piroplasm is a potential pathogen of North American river otters and the parasite is widespread in otter populations in the eastern United States.

Cytochrome c oxydase I phylogenetic analysis of Haemogregarina parasites (Apicomplexa, Coccidia, Eucoccidiorida, Haemogregarinidae) confirms the presence of three distinct species within the freshwater turtles of Tunisia

Species of Haemogregarina are apicomplexan blood parasites that use vertebrates as intermediate hosts. Due to limited interspecific morphological characters within the genus during the last decade, 18S rRNA gene sequences were widely used for species identification. As coinfection patterns were recently reported from nuclear molecular data for two sympatric freshwater turtles Mauremys leprosa and Emys orbicularis from Tunisia, our objectives were to design COI specific primers to confirm the presence of three distinct species in both host species. Blood samples were collected from 22 turtles, from which DNAs were extracted and used as templates for amplification. Following different rounds of PCR and nested PCR, we designed specific Haemogregarina COI primers that allowed the sequencing of nine distinct haplotypes. Phylogenetic Bayesian analysis revealed the occurrence of three well-differentiated sublineages that clustered together into a single clade. Based on pairwise genetic distances (p-distance), we confirmed the occurrence of three distinct but phylogenetically closely related species coinfecting M. leprosa and E. orbicularis in the same aquatic environments. Our results demonstrate that the use of fast evolving genes within Haemogregarina will help to investigate the parasite diversity within both intermediate vertebrate and definitive invertebrate hosts, and to assess the evolution, historical biogeography and specificity of haemogregarines.