Anaplasma Species in Ticks Infesting Mammals of Sardinia, Italy

Simple Summary Bacteria in the Anaplasma genus are intracellular parasites of mammal blood cells transmitted by ticks of genera Amblyomma, Dermacentor, Hyalomma, Ixodes, and Rhipicephalus. In this study, the presence of Anaplasma marginale and A. phagocytophilum in ticks was molecularly confirmed in Rhipicephalus sanguineus s.l. and Rhipicephalus bursa ticks, suggesting that these tick species are of importance in the transmission of potential zoonotic infections. Due to the nature of the Anaplasma species detected here, our results, together with data obtained to date in Sardinia, suggest that from a public health point of view, the potential zoonotic Anaplasma species should be further investigated in the island. Additional studies are needed to clarify whether these tick species can transmit these zoonotic bacteria both to human and animal hosts. Ticks are hematophagous ectoparasites that are recognized for their ability to vector a wide variety of pathogens of viral, bacterial, protozoal, and helminthic nature to vertebrate hosts. Among the different diseases transmitted by ticks, also called Tick-Borne Diseases (TBD), many are zoonotic. Pathogens of the genus Anaplasma refer to obligate intracellular bacteria within the Rickettsiales order transmitted mainly through tick bites and considered as well-established threats to domestic animals, livestock, and humans, worldwide. In this retrospective study, 156 ticks collected from twenty goats, one marten, and one cattle from several Sardinian sites, were examined by molecular analyses to detect the presence of Anaplasma species. A total of 10 (10/156; 6.4%) ticks were shown to be Anaplasma-positive by PCR screening. After sequence analyses, A. phagocytophilum was detected in four Rhipicephalus sanguineus s.l. (3.3%) and four Rh. bursa (11%) ticks from goats, while one Rh. sanguineus s.l. (0.8%) and one Rh. bursa (2.8%) collected from the marten and cattle, respectively, exhibited 100% of identity with A. marginale strains. In this study, we provide the first description and molecular detection of A. marginale and A. phagocytophilum in ticks of the Rhiphicephalus genus in Sardinia. Considering the growing impact of tick-borne Anaplasma pathogens on human health, further studies are necessary to monitor the prevalence of these pathogens in Sardinia.

Automated summary

This study molecularly confirmed the presence of Anaplasma marginale and A. phagocytophilum in ticks of the Rhipicephalus genus, suggesting their importance in transmitting potential zoonotic infections. Further investigations are needed to understand the public health implications and determine if these tick species can transmit these zoonotic bacteria to humans and animals. It is important to monitor the prevalence of these pathogens in Sardinia due to the increasing impact of tick-borne Anaplasma pathogens on human health.