Tick-borne diseases (TBDs) represent a significant portion of infectious diseases of global public health interest. In Italy, knowledge about the occurrence of tick-borne pathogens (TBPs) in ticks parasitizing cattle is scarce. In this research, we focused on ticks infesting Maremmana cattle grazing in open pasture and silvopasture systems. After being morphologically identified, ticks were molecularly tested for the presence of pathogens of the genus Rickettsia. Of the 794 ticks detected, 117 were collected, being the majority Hyalomma marginatum (72.6%), followed by other Hyalomma species (23%), Rhipicephalus turanicus (1.7%), Rh. bursa (0.9%), Hy. lusitanicum (0.9%) and Dermatocentor marginatus (0.9%). All ticks were adults, 58.1% males and 41.8% females. The highest tick prevalence was noted in April for silvopasture system cattle (90%), and in May for open pasture ones (85%). TBPs were detected only in Hy. marginatum, and all belong to Rickettsia spp. of zoonotic interest. In particular, 21/40 (52.5%) ticks scored positive for Rickettsia spp. by gltA gene and of these 15/21 (71.4%) also to spotted fever group (SFG) rickettsiae by ompA gene. Of the total positive specimens, 19 were successfully sequenced and scored Rickettsia aeschilimannii (17/19, 89.5%), R. slovaca (1/19, 5%), and R. massiliae (1/19, 5%). This research highlights the potential impact of grazing systems on cattle parasitization by hard ticks. The molecular investigation of TBPs in ticks collected from Maremmana cattle shed light on the presence of pathogenic bacteria of SFG Rickettsia spp., pointing out the potential risk of TBPs transmission between livestock and humans.

Forty-five tick species have been recorded in Kazakhstan. However, their genetic diversity and evolutionary relationships, particularly when compared to ticks in neighbouring countries, remain unclear. In the present study, 148 mitochondrial cytochrome c oxidase subunit I (COI) sequence data from our laboratory and NCBI (National Center for Biotechnology Information; https://www.ncbi.nlm.nih.gov/ ) data were used to address this knowledge gap. Phylogenetic analyses showed that i) Hyalomma anatolicum anatolicum (Koch, 1844) ticks from Jambyl Oblast (southeastern Kazakhstan) and Gansu Province (northwestern China) constituted a newly deviated clade; and ii) Dermacentor reticulatus (Fabricius, 1974) ticks from South Kazakhstan Oblast were closer to those in Romania and Turkey. The network diagram of haplotypes showed that i) the H-1 and H-2 haplotypes of Dermacentor marginatus (Sulzer, 1776) ticks from Zhetisu and Almaty were all newly evolved; and ii) the H-3 haplotypes of Haemaphysalis erinacei (Pavesi, 1884) from Almaty Oblast and Xinjiang Uygur Autonomous Region (northwestern China) were evolved from the H-1 haplotype from Italy. In the future, more COI data from different tick species, especially from Kazakhstan and neighbouring countries, should be employed in the field of tick DNA barcoding.

Ticks are specialized ectoparasites that feed on blood, causing physical harm to the host and facilitating pathogen transmission. The genus Haemaphysalis contains vectors for numerous infectious agents. These agents cause various diseases in humans and animals. Mitochondrial genome sequences serve as reliable molecular markers, forming a crucial basis for evolutionary analyses, studying species origins, and exploring molecular phylogeny. We extracted mitochondrial genome from the enriched mitochondria of Haemaphysalis tibetensis and obtained a 14,714-bp sequence. The mitochondrial genome consists of 13 protein-coding genes (PCGs), two ribosomal RNA, 22 transfer RNAs (tRNAs), and two control regions. The nucleotide composition of H. tibetensis mitochondrial genome was 38.38 % for A, 9.61 % for G, 39.32 % for T, and 12.69 % for C. The A + T content of H. tibetensis mitochondrial genome was 77.7 %, significantly higher than the G + C content. The repeat units of H. tibetensis exhibited two identical repeat units of 33 bp in length, positioned downstream of nad1 and rrnL genes. Furthermore, phylogenetic analyses based on the 13 PCGs indicated that Haemaphysalis tibetensis (subgenus Allophysalis) formed a monophyletic clade with Haemaphysalis nepalensis (subgenus Herpetobia) and Haemaphysalis danieli (subgenus Allophysalis). Although the species Haemaphysalis inermis, Haemaphysalis kitaokai, Haemaphysalis kolonini, and Haemaphysalis colasbelcouri belong to the subgenus Alloceraea, which were morphologically primitive hemaphysalines just like H. tibetensis, these four tick species cannot form a single clade with H. tibetensis. In this study, the whole mitochondrial genome sequence of H. tibetensis from Tibet was obtained, which enriched the mitochondrial genome data of ticks and provided genetic markers to study the population heredity and molecular evolution of the genus Haemaphysalis.

Infections with spotted fever group rickettsiae represent a worldwide health problem, characterized by persistent high fever, headache, and rash in humans, domestic animals, and wildlife. To date, the occurrence of Rickettsia species in hard ticks has not been thoroughly studied, especially in eastern and southern Kazakhstan. A total of 1,245 adult ticks, comprising 734 Dermacentor marginatus, 219 Hyalomma scupense, 144 Hyalomma asiaticum, 84 Hyalomma marginatum, 48 Rhipicephalus turanicus, and 16 Haemaphysalis erinacei, collected from East Kazakhstan, Abay, Jetsu, Almaty, Jambyl, South Kazakhstan and Qyzylorda oblasts of Kazakhstan, were used to screen rickettsial agents using molecular methods. Rickettsia raoultii, Rickettsia slovaca, Rickettsia aeschlimannii and Rickettsia heilongjiangensis were identified using sequencing, and 31.5% (392/1245) of ticks carried rickettsial agents. The difference in the natural landscapes explains the variety of the collected ticks and expands our knowledge of Rickettsia species and their geographical distribution in Kazakhstan. To the best of our knowledge, this study reports the first finding of R. heilongjiangensis in Kazakhstan.

Ticks are blood-sucking ectoparasites with significant medical and veterinary importance, capable of transmitting bacteria, protozoa, fungi, and viruses that cause a variety of human and animal diseases worldwide. In the present study, we sequenced the complete mitochondrial (mt) genomes of five hard tick species and analyzed features of their gene contents and genome organizations. The complete mt genomes of Haemaphysalis verticalis, H. flava, H. longicornis, Rhipicephalus sanguineus and Hyalomma asiaticum were 14855 bp, 14689 bp, 14693 bp, 14715 bp and 14722 bp in size, respectively. Their gene contents and arrangements are the same as those of most species of metastriate Ixodida, but distinct from species of genus Ixodes. Phylogenetic analyses using concatenated amino acid sequences of 13 protein-coding genes with two different computational algorithms (Bayesian inference and maximum likelihood) revealed the monophylies of the genera Rhipicephalus, Ixodes and Amblyomma, however, rejected the monophyly of the genus Haemaphysalis. To our knowledge, this is the first report of the complete mt genome of H. verticalis. These datasets provide useful mtDNA markers for further studies of the identification and classification of hard ticks.

The tick Haemaphysalis flava (Acari, Ixodidae) is an obligatory blood-feeding ectoparasite of the giant panda and is also a vector for transmission of pathogenic microorganisms. In this study, the complete mitochondrial genome of this tick was sequenced through Illumina sequencing technology. The genome was 14,699 bp in length and encoded 37 genes including 13 protein-coding genes, 22 transfer RNAs and two ribosomal RNAs. Phylogeny revealed that three isolates of H. flava, regardless of host origins and locations, clustered together and formed a monophyletic relationship with Haemaphysalis japonica, supporting their species validity among the genus Haemaphysalis. These cumulative mitochondrial DNA data provides insights into phylogenetic studies among Haemaphysalis ticks.

Spotted fever group (SFG) rickettsiae are important causative agents of (re)emerging tick-borne infectious diseases in humans, and ticks play a key role in their maintenance and transmission. In this study, hard ticks were collected from five sampling sites in North China in 2017 and 2018. Of them, Haemaphysalis longicornis, Rhipicephalus microplus and Dermacentor nuttalli were collected from livestock (sheep and goats) and the vegetation, Hyalomma asiaticum from sheep, goats and camels, and Hyalomma marginatum from sheep and goats. The SFG rickettsiae were identified in these ticks by amplifying the partial rrs and complete 17-kDa genes, with an overall infection rate of 52.9%. In addition, the nearly full-length rrs and gltA and partial ompA genes were recovered to classify the species of SFG rickettsiae further. Phylogenetic analysis revealed the presence of three human pathogenic species in Hy. asiaticum, Hy. marginatum, Ha. longicornis and De. nuttalli, including two cultured ones (Rickettsia raoultii and Rickettsia aeschlimannii) and one uncultured (Candidatus R. jingxinensis). Furthermore, partial groEL gene was also obtained, and phylogenetic trees were also reconstructed to better understand the genetic relationship with known sequences in each SFG rickettsiae species detected in the current study. Notably, the R. aeschlimannii sequences described in this study were closely related to those from abroad rather than from another part of China, indicating their different origin. However, the R. raoultii and Ca. R. jingxinensis sequences presented close relationship with variants from other parts of China. In sum, our data revealed SFG rickettsiae species in northern China, highlighting the need for surveillance of their infection in local humans.