Phenology of five tick species in the central Great Plains.

The states of Kansas and Oklahoma, in the central Great Plains, lie at the western periphery of the geographic distributions of several tick species. As the focus of most research on ticks and tick-borne diseases has been on Lyme disease which commonly occurs in areas to the north and east, the ticks of this region have seen little research attention. Here, we report on the phenology and activity patterns shown by tick species observed at 10 sites across the two states and explore factors associated with abundance of all and life specific individuals of the dominant species. Ticks were collected in 2020-2022 using dragging, flagging and carbon-dioxide trapping techniques, designed to detect questing ticks. The dominant species was A. americanum (24098, 97%) followed by Dermacentor variabilis (370, 2%), D. albipictus (271, 1%), Ixodes scapularis (91, <1%) and A. maculatum (38, <1%). Amblyomma americanum, A. maculatum and D. variabilis were active in Spring and Summer, while D. albipictus and I. scapularis were active in Fall and Winter. Factors associated with numbers of individuals of A. americanum included day of year, habitat, and latitude. Similar associations were observed when abundance was examined by life-stage. Overall, the picture is one of broadly distributed tick species that shows seasonal limitations in the timing of their questing activity.

Unraveling the phylogenetics of genetically closely related species, Haemaphysalis japonica and Haemaphysalis megaspinosa, using entire tick mitogenomes and microbiomes.

Ticks have a profound impact on public health. Haemaphysalis is one of the most widespread genera in Asia, including Japan. The taxonomy and genetic differentiation of Haemaphysalis spp. is challenging. For instance, previous studies struggled to distinguish Haemaphysalis japonica and Haemaphysalis megaspinosa due to the dearth of nucleotide sequence polymorphisms in widely used barcoding genes. The classification of H. japonica japonica and its related sub-species Haemaphysalis japonica douglasi or Haemaphysalis jezoensis is also confused due to their high morphological similarity and a lack of molecular data that support the current classification. We used mitogenomes and microbiomes of H. japonica and H. megaspinosa to gain deeper insights into the phylogenetic relationships and genetic divergence between two species. Phylogenetic analyses of concatenated nucleotide sequences of protein-coding genes and ribosomal DNA genes distinguished H. japonica and H. megaspinosa as monophyletic clades, with further subdivision within the H. japonica clade. The 16S rRNA and NAD5 genes were valuable markers for distinguishing H. japonica and H. megaspinosa. Population genetic structure analyses indicated that genetic variation within populations accounted for a large proportion of the total variation compared to variation between populations. Microbiome analyses revealed differences in alpha and beta diversity between H. japonica and H. megaspinosa: H. japonica had the higher diversity. Coxiella sp., a likely endosymbiont, was found in both Haemaphysalis species. The abundance profiles of likely endosymbionts, pathogens, and commensals differed between H. japonica and H. megaspinosa: H. megaspinosa was more diverse.

Redescription of adults and first description of the larva of Haemaphysalis (Rhipistoma) adleri Feldman-Muhsam, 1951 (Acari: Ixodidae), parasite of carnivorans in Western Asia.

The adults of Haemaphysalis (Rhipistoma) adleri Feldman-Muhsam, 1951 (Acari: Ixodidae) are redescribed and the larva of this species is described for the first time here. The adults of H. adleri that we studied were collected from various canid, felid and hyaenid carnivorans (Carnivora: Canidae, Felidae, Hyaenidae) as well as a hedgehog (Erinaceomorpha: Erinaceidae) in Iraq, Israel and West Bank. The males, females and larvae of H. adleri can be differentiated from Haemaphysalis (Rhipistoma) species occurring in the Palearctic portion of West Asia and Egypt as well those in the H. asiatica subgroup by the length of idiosomal setae, development and size of spurs on palpi, dental formula on the hypostome and size of spur on coxae. A lectotype of H. adleri has been designated and the geographic distribution and hosts of this tick species are discussed.

Molecular characterization and induced changes of histone acetyltransferases in the tick Haemaphysalis longicornis in response to cold stress.

BACKGROUND: Epigenetic modifications of histones play important roles in the response of eukaryotic organisms to environmental stress. However, many histone acetyltransferases (HATs), which are responsible for histone acetylation, and their roles in mediating the tick response to cold stress have yet to be identified. In the present study, HATs were molecularly characterized and their associations with the cold response of the tick Haemaphysalis longicornis explored. METHODS: HATs were characterized by using polymerase chain reaction (PCR) based on published genome sequences, followed by multiple bioinformatic analyses. The differential expression of genes in H. longicornis under different cold treatment conditions was evaluated using reverse transcription quantitative PCR (RT-qPCR). RNA interference was used to explore the association of HATs with the cold response of H. longicornis. RESULTS: Two HAT genes were identified in H. longicornis (Hl), a GCN5-related N-acetyltransferase (henceforth HlGNAT) and a type B histone acetyltransferase (henceforth HlHAT-B), which are respectively 960 base pairs (bp) and 1239 bp in length. Bioinformatics analysis revealed that HlGNAT and HlHAT-B are unstable hydrophilic proteins characterized by the presence of the acetyltransferase 16 domain and Hat1_N domain, respectively. RT-qPCR revealed that the expression of HlGNAT and HlHAT-B decreased after 3 days of cold treatment, but gradually increased with a longer period of cold treatment. The mortality rate following knockdown of HlGNAT or HlHAT-B by RNA interference, which was confirmed by RT-qPCR, significantly increased (P < 0.05) when H. longicornis was treated at the lowest lethal temperature (- 14 °C) for 2 h. CONCLUSIONS: The findings demonstrate that HATs may play a crucial role in the cold response of H. longicornis. Thus further research is warranted to explore the mechanisms underlying the epigenetic regulation of the cold response in ticks.

Insights into the involvement of male Hyalomma anatolicum ticks in transmitting Anaplasma marginale, lumpy skin disease virus and Theileria annulata.

Ticks can transmit viruses, bacteria, and parasites to humans, livestock, and pet animals causing tick-borne diseases (TBDs) mechanically or biologically in the world. Lumpy skin disease virus, Anaplasma marginale, and Theileria annulata inflict severe infections in cattle, resulting in significant economic losses worldwide. The study investigated the potential transmissions of LSDV, A. marginale, and T. annulata through male Hyalomma anatolicum ticks in cattle calves. Two 6-month-old Holstein crossbred calves designated as A and B were used. On day 1, 15 uninfected female ticks (IIa) and infected batch of 40 male ticks (I) were attached on calf A for 11 days. Filial transmission of the infections was observed in female ticks (IIb) collected from calf A, where 8 female ticks had been co-fed with infected male ticks. The blood sample of calf B was found positive through PCR for the infections. The larvae and egg pools obtained from the infected ticks were also tested positive in PCR. The study confirmed the presence of these mixed pathogens and potential intra-stadial and transovarial transmissions of A. marginale, T. annulata, and LSDV in male and female ticks of H. anatolicum and experimental calves to establish the feasibility of infections through an in vivo approach.

Biological response to Przewalski's horse reintroduction in native desert grasslands: a case study on the spatial analysis of ticks.

BACKGROUND: Reintroduction represents an effective strategy for the conservation of endangered wildlife, yet it might inadvertently impact the native ecosystems. This investigation assesses the impact of reintroducing endangered Przewalski's horses into the desert grassland ecosystem of the Kalamaili Nature Reserve (KNR), particularly its effect on the spatial distribution of ticks. In a 25 km2 core area of Przewalski's horse distribution, we set up 441 tick sampling sites across diverse habitats, including water sources, donkey trails, and grasslands, recording horse feces and characteristics to analyze the occurrence rate of ticks. Additionally, we gathered the data of 669 fresh feces of horses. To evaluate the spatial dynamics between these feces and ticks, we used methods such as Fixed Kernel Estimation (FKE), Moran's I spatial autocorrelation index, and Generalized Linear Models (GLM). RESULTS: The dominant species of ticks collected in the core area were adult Hyalomma asiaticum (91.36%). Their occurrence rate was higher near donkey trails (65.99%) and water sources (55.81%), particularly in areas with the fresh feces of Przewalski's horses. The ticks' three risk areas, as defined by FKE, showed significant overlap and positive correlation with the distribution of Przewalski's horses, with respective overlap rates being 90.25% in high risk, 33.79% in medium risk, and 23.09% in low risk areas. Moran's I analysis revealed a clustering trend of the fresh feces of Przewalski's horses in these areas. The GLM confirmed a positive correlation between the distribution of H. asiaticum and the presence of horse fresh feces, alongside a negative correlation with the proximity to water sources and donkey trails. CONCLUSIONS: This study reveals the strong spatial correlation between Przewalski's horses and H. asiaticum in desert grasslands, underlining the need to consider interspecific interactions in wildlife reintroductions. The findings are crucial for shaping effective strategies of wildlife conservation and maintaining ecological balance.

Tick-borne bacterial agents in Hyalomma asiaticum ticks from Xinjiang Uygur Autonomous Region, Northwest China.

BACKGROUND: Hyalomma ticks are widely distributed in semi-arid zones in Northwest China. They have been reported to harbor a large number of zoonotic pathogens. METHODS: In this study, a total of 334 Hyalomma asiaticum ticks infesting domestic animals were collected from four locations in Xinjiang, Northwest China, and the bacterial agents in them were investigated. RESULTS: A putative novel Borrelia species was identified in ticks from all four locations, with an overall positive rate of 6.59%. Rickettsia sibirica subsp. mongolitimonae, a human pathogen frequently reported in Europe, was detected for the second time in China. Two Ehrlichia species (Ehrlichia minasensis and Ehrlichia sp.) were identified. Furthermore, two Anaplasma species were characterized in this study: Candidatus Anaplasma camelii and Anaplasma sp. closely related to Candidatus Anaplasma boleense. It is the first report of Candidatus Anaplasma camelii in China. CONCLUSIONS: Six bacterial agents were reported in this study, many of which are possible or validated pathogens for humans and animals. The presence of these bacterial agents may suggest a potential risk for One Health in this area.

MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF AMBLYOMMA SCUTATUM (ACARI: IXODIDAE) ACCIDENTALLY INTRODUCED IN ITALY.

Eight ticks were found in Comacchio (FE), Italy parasitizing a young black iguana (Ctenosaura similis) that had been accidentally transported in a commercial plant container from Costa Rica. Specimens were identified morphologically as Amblyomma scutatum and then confirmed by the barcoding of the mitochondrial cytochrome c oxidase subunit 1 gene. Amblyomma scutatum is a common tick known to infest reptiles in Central America, Mexico, and Venezuela, but not in Europe. In Italy, the possibility for this tick to become endemic is unlikely because of the absence of its principal hosts. Nevertheless, this finding confirms the high risk of introducing exotic species that is linked with global commerce and therefore the need for veterinary control of shipments.

Prevalence of tick-borne pathogens in ticks collected from the wild mountain ungulates mouflon and chamois in 4 regions of France.

Ticks are major vectors of various pathogens of health importance, such as bacteria, viruses and parasites. The problems associated with ticks and vector-borne pathogens are increasing in mountain areas, particularly in connection with global climate change. We collected ticks (n = 2,081) from chamois and mouflon in 4 mountainous areas of France. We identified 6 tick species: Ixodes ricinus, Rhipicephalus bursa, Rh. sanguineus s.l., Haemaphysalis sulcata, H. punctata and Dermacentor marginatus. We observed a strong variation in tick species composition among the study sites, linked in particular to the climate of the sites. We then analysed 791 ticks for DNA of vector-borne pathogens: Babesia/Theileria spp., Borrelia burgdorferi s.l., Anaplasma phagocytophilum, A. marginale, A. ovis, and Rickettsia of the spotted fever group (SFG). Theileria ovis was detected only in Corsica in Rh. bursa. Babesia venatorum (2 sites), Borrelia burgdorferi s.l. (B. afzelii and B. garinii; 2 sites) and Anaplasma phagocytophilum (3 sites) were detected in I. ricinus. Anaplasma ovis was detected at one site in I. ricinus and Rh. sanguineus s.l. SFG Rickettsia were detected at all the study sites: R. monacensis and R. helvetica in I. ricinus at the 3 sites where this tick is present; R. massiliae in Rh. sanguineus s.l. (1 site); and R. hoogstraalii and Candidatus R. barbariae in Rh. bursa in Corsica. These results show that there is a risk of tick-borne diseases for humans and domestic and wild animals frequenting these mountain areas.

Title: Prévalence d'agents pathogènes vectorisés chez des tiques collectées chez des ongulés sauvages (mouflons, chamois) dans 4 zones montagneuses en France. Abstract: Les tiques sont des vecteurs majeurs de différents agents pathogènes d'importance sanitaire, tels que des bactéries, des virus et des parasites. Les problématiques liées aux tiques et aux pathogènes vectorisés augmentent en zones de montagne, en lien notamment avec le réchauffement climatique. Nous avons collecté des tiques (n = 2 081) sur des chamois et des mouflons dans 4 zones montagneuses en France. Six espèces ont été identifiées : Ixodes ricinus, Rhipicephalus bursa, Rh. sanguineus s.l., Haemaphysalis sulcata, H. punctata et Dermacentor marginatus. Nous avons observé une forte variation de la composition en espèces de tiques entre les sites d'étude, en lien notamment avec le climat des sites. Nous avons ensuite recherché les ADN d'agents pathogènes vectorisés sur 791 tiques : Babesia/Theileria spp, Borrelia burgdorferi s.l., Anaplasma phagocytophilum, A. marginale, A. ovis, et de Rickettsia du groupe des fièvres boutonneuses (SFG). Theileria ovis a été détecté uniquement en Corse chez Rh. bursa. Babesia venatorum (2 sites), Borrelia burgdorferi s.l. (B. afzelii and B. garinii; 2 sites) et Anaplasma phagocytophilum (3 sites) ont été détectés chez I. ricinus. Anaplasma ovis a été détecté dans un site chez I. ricinus et Rh. sanguineus s.l.. Les Rickettsia SFG ont été détectées dans tous les sites d'étude : Rickettsia monacensis et R. helvetica chez I. ricinus dans les 3 sites où cette tique est présente; R. massiliae chez Rh. sanguineus s.l. (1 site); et R. hoogstraalii et Candidatus R. barbariae chez Rh. bursa en Corse. Ces résultats montrent un risque de transmission de maladies par les tiques pour les personnes et les animaux domestiques et sauvages fréquentant ces zones de montagne.

Biochemical analysis of Hyalomma dromedarii salivary glands and gut tissues using SR-FTIR micro-spectroscopy.

Ticks are obligatory voracious blood feeders infesting diverse vertebrate hosts, that have a crucial role in the transmission of diverse pathogens that threaten human and animal health. The continuous emergence of tick-borne diseases due to combined worldwide climatic changes, human activities, and acaricide-resistant tick strains, necessitates the development of novel ameliorative tick control strategies such as vaccines. The synchrotron-based Fourier transform infrared micro-spectroscopy (SR-FTIR) is a bioanalytical microprobe capable of exploring the molecular chemistry within microstructures at a cellular or subcellular level and is considered as a nondestructive analytical approach for biological specimens. In this study, SR-FTIR analysis was able to explore a qualitative and semi-quantitative biochemical composition of gut and salivary glands of Hyalomma dromedarii (H. dromedarii) tick detecting differences in the biochemical composition of both tissues. A notable observation regarding Amide I secondary structure protein profile was the higher ratio of aggregated strands in salivary gland and beta turns in gut tissues. Regarding the lipid profile, there was a higher intensity of lipid regions in gut tissue when compared to salivary glands. This detailed information on the biochemical compositions of tick tissues could assist in selecting vaccine and/or control candidates. Altogether, these findings confirmed SR-FTIR spectroscopy as a tool for detecting differences in the biochemical composition of H. dromedarii salivary glands and gut tissues. This approach could potentially be extended to the analysis of other ticks that are vectors of important diseases such as babesiosis and theileriosis.

Ticks (Acari: Ixodidae) on resident and migratory wild birds in Orinoquia region, Colombia.

Several species of hard ticks, including those of the genera Ixodes, Haemaphysalis, Amblyomma, and Rhipicephalus, are of medical and veterinary importance and have been reported in association with Neotropical wild birds. Colombia, known for its great bird diversity, has 57 confirmed tick species. However, there are few studies on the association between wild birds and ticks in Colombia. The Orinoquia region, a migratory center in Colombia, provides a unique opportunity to study wild bird-tick associations and their implications for tick-borne disease dynamics. Our study, conducted between October and December 2021, aimed to identify hard ticks infesting resident and migratory wild birds in the department of Arauca and to assess the presence of bacteria from the genera Anaplasma, Borrelia, Ehrlichia, Rickettsia, and piroplasms. A total of 383 birds were examined, of which 21 were infested. We collected 147 ticks, including Amblyomma dissimile (larvae), Amblyomma longirostre (nymphs), Amblyomma mixtum (adults), and Amblyomma nodosum (larvae and nymphs). We did not detect bacterial DNA in the tested ticks; however, piroplasm DNA was detected in ticks from three of the infested birds. Of the 21 bird-tick associations, six are new to the Americas, and interesting documentation of piroplasm DNA in A. longirostre, A. nodosum, and A. dissimile ticks from wild birds in the region. This study provides valuable insights into the ticks associated with wild birds and their role in the dispersal of ticks and pathogens in Colombia, enhancing our understanding of tick life cycles and tick-borne disease dynamics.

The effect of feeding on different hosts on the egg proteins in Haemaphysalis qinghaiensis tick.

The majority of ixodid ticks display host-specificity to varying extents. Feeding on different hosts affects their development and reproduction. Consequences can be analyzed at the level of the egg, as it is the initial stage of tick development. Tick egg proteins are abundant and diverse, providing nutrients for embryonic development. However, studies on tick egg profiles are scarce. In this study, we aimed to analyze whether feeding Haemaphysalis qinghaiensis ticks on the yaks (Bos grunniens) and domestic sheep (Ovis aries) has an impact on the variety and variability of the egg proteome. Detached engorged females were used to lay eggs, which were then collected, dewaxed, and subjected to protein extraction. The extracted egg proteins were enzymatically digested using Filter-Aided Sample Preparation (FASP), and the unique peptides were separated and detected by Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS). The MS data were searched against the previously constructed whole tick transcriptome library of H. qinghaiensis, and the UniProt database for the identification of tick-derived egg proteins. The analysis revealed 49 and 53 high-confidence proteins identified in eggs collected from B. grunniens (EggBg) and O. aries (EggOa), respectively. Of these, 46 high-confidence proteins were common to both egg types, while three were unique to EggBg and seven to EggOa. All the identified proteins mainly belonged to enzymes, enzyme inhibitors, transporters, and proteins with unknown functions. The differential abundance analysis showed that nine proteins were significantly more present in EggBg, while six were significantly more present in EggOa. Overall, enzymes were the most diverse group, while vitellogenin (Vg) was the most abundant. Blood meal uptake on different hosts has a certain effect on the egg proteome composition and the abundance of some proteins, but it may also lead to compensation of protein roles.

Genetic background of adaptation of Crimean-Congo haemorrhagic fever virus to the different tick hosts.

Crimean-Congo haemorrhagic fever orthonairovirus (CCHFV) is a negative-sense, single-stranded RNA virus with a segmented genome and the causative agent of a severe Crimean-Congo haemorrhagic fever (CCHF) disease. The virus is transmitted mainly by tick species in Hyalomma genus but other ticks such as representatives of genera Dermacentor and Rhipicephalus may also be involved in virus life cycle. To improve our understanding of CCHFV adaptation to its tick species, we compared nucleotide composition and codon usage patterns among the all CCHFV strains i) which sequences and other metadata as locality of collection and date of isolation are available in GenBank and ii) which were isolated from in-field collected tick species. These criteria fulfilled 70 sequences (24 coding for S, 23 for M, and 23 for L segment) of virus isolates originating from different representatives of Hyalomma and Rhipicephalus genera. Phylogenetic analyses confirmed that Hyalomma- and Rhipicephalus-originating CCHFV isolates belong to phylogenetically distinct CCHFV clades. Analyses of nucleotide composition among the Hyalomma- and Rhipicephalus-originating CCHFV isolates also showed significant differences, mainly in nucleotides located at the 3rd codon positions indicating changes in codon usage among these lineages. Analyses of codon adaptation index (CAI), effective number of codons (ENC), and other codon usage statistics revealed significant differences between Hyalomma- and Rhipicephalus-isolated CCHFV strains. Despite both sets of strains displayed a higher adaptation to use codons that are preferred by Hyalomma ticks than Rhipicephalus ticks, there were distinct codon usage preferences observed between the two tick species. These findings suggest that over the course of its long co-evolution with tick vectors, CCHFV has optimized its codon usage to efficiently utilize translational resources of Hyalomma species.

Risk factors affecting the feeding site predilection of ticks on cattle in Ghana.

Ticks are important disease vectors affecting animal health and causing substantial economic loss, especially in the tropics and subtropics. To examine the tick burden of cattle and associated risk factors for tick infestation, ticks were collected from 388 cattle within five regions in Ghana. Most of the cattle were males (50.3%) and generally older than 3 years (65%). Of the animals sampled, 2187 ticks were collected with a mean tick burden of 5.6 ticks per cattle, and the average tick burden on the udder/scrotum being significantly higher than in the anal region (Generalized Linear Mix Model [GLMM], p = 0.01197). The tick species identified were predominantly Amblyomma variegatum (42.6%) and Hyalomma rufipes (26.2%). High proportions of cattle examined were found to have A. variegatum infesting the udder/scrotum. Furthermore, H. rufipes infested mostly the anal region compared to other examined body parts (OR 14.8, 95% CI 8.6-25.4, p < 0.001). Using the GLMM, tick abundance was found to be significantly higher in cattle older than 3 years. The tick burden in the udder/scrotum was higher than that from the chest and leg/thigh of the cattle (GLMM, p < 0.05). The tick burden at the anal region was also significantly higher than the leg/thigh and chest. This study indicates that the preferred attachment sites of ticks on cattle are species-dependent and effective treatment with acaricides should take into consideration the udder/scrotum and anal regions as well as prioritizing older cattle.

Accounting for missing ticks: Use (or lack thereof) of hierarchical models in tick ecology studies.

Ixodid (hard) ticks play important ecosystem roles and have significant impacts on animal and human health via tick-borne diseases and physiological stress from parasitism. Tick occurrence, abundance, activity, and key life-history traits are highly influenced by host availability, weather, microclimate, and landscape features. As such, changes in the environment can have profound impacts on ticks, their hosts, and the spread of diseases. Researchers recognize that spatial and temporal factors influence activity and abundance and attempt to account for both by conducting replicate sampling bouts spread over the tick questing period. However, common field methods notoriously underestimate abundance, and it is unclear how (or if) tick studies model the confounding effects of factors influencing activity and abundance. This step is critical as unaccounted variance in detection can lead to biased estimates of occurrence and abundance. We performed a descriptive review to evaluate the extent to which studies account for the detection process while modeling tick data. We also categorized the types of analyses that are commonly used to model tick data. We used hierarchical models (HMs) that account for imperfect detection to analyze simulated and empirical tick data, demonstrating that inference is muddled when detection probability is not accounted for in the modeling process. Our review indicates that only 5 of 412 (1 %) papers explicitly accounted for imperfect detection while modeling ticks. By comparing HMs with the most common approaches used for modeling tick data (e.g., ANOVA), we show that population estimates are biased low for simulated and empirical data when using non-HMs, and that confounding occurs due to not explicitly modeling factors that influenced both detection and abundance. Our review and analysis of simulated and empirical data shows that it is important to account for our ability to detect ticks using field methods with imperfect detection. Not doing so leads to biased estimates of occurrence and abundance which could complicate our understanding of parasite-host relationships and the spread of tick-borne diseases. We highlight the resources available for learning HM approaches and applying them to analyzing tick data.

Cloning and catalytic profile of Hyalomma dromedarii leucine aminopeptidase.

Ticks have harmful impacts on both human and animal health and cause considerable economic losses. Leucine aminopeptidase enzymes (LAP) play important roles during tick infestation to liberate vital amino acids necessary for growth. The aim of the current study is to identify, express and characterize the LAP from the hard tick Hyalomma dromedarii and elucidate its biochemical characteristics. We cloned an open reading frame of 1560 bp encoding a protein of 519 amino acids. The LAP full-length was expressed in Escherichia coli BL21 (DE3) and purified. The recombinant enzyme (H.d rLAP- 6×His) had a predicted molecular mass of approximately 55 kDa. Purification and the enzymatic characteristics of H.d rLAP- 6×His were studied. The purified enzyme showed maximum activity at 37 °C and pH 8.0-8.5 using Leu-p-nitroanilide as a substrate. The activity of H.d rLAP- 6×His was sensitive to ß-mercaptoethanol, dl-dithiothreitol, 1,10- phenanthroline, bestatin HCl, and EDTA and completely abolished by 0.05 % SDS. In parallel, the enzymatic activity was enhanced by Ni2+, Mn2+ and Mg2+, partially inhibited by Na+, Cu2+, Ca2+ and completely inhibited by Zn2+.

Ticks (Acari: Ixodidae) and rickettsiae associated with wild boars in a rural area of Minas Gerais, Brazil.

Wild boars or feral pigs are classified by the Brazilian Institute for the Environment and Renewable Resources (IBAMA) in "Category I of invasive exotic species". They cause economic losses, harm the environment, serve as hosts and reservoirs for several zoonotic disease agents, and provide a blood meal for tick species that act as vectors for zoonotic diseases. The objective of this study was to identify tick species on wild boars, assess host-seeking ticks in the related environment, and identify other potential tick hosts coexisting with wild boars on a farm located in the state of Minas Gerais, southeastern Brazil. Additionally, the study aimed to determine the presence of rickettsiae in these arthropods and assess the exposure of wild boars to rickettsiae species from the Spotted Fever Group and Rickettsia bellii through serology. A total of 3585 host-seeking ticks from three species (Amblyomma sculptum - 41.58%; Amblyomma dubitatum - 0.39% and Rhipicephalus microplus - 0.05%) were collected in the environment and A. sculptum was the most abundant species. Thirty-one wild boars were evaluated, resulting in the collection of 415 ticks, all of which were A. sculptum. Rickettsia DNA was not detected in samples of A. sculptum and R. microplus from the environment or in A. sculptum ticks from wild boars. However, all A. dubitatum ticks (n = 14) had Rickettsia bellii DNA confirmed by the species-specific PCR protocol. Out of the 31 serum samples from wild boars, 24 reacted with at least one Rickettsia antigen. Among these, seven individuals exhibited a reaction to a probable homologous antigen (PHA) of three rickettsiae species: R. rickettsii (n = 3), R. amblyommatis (n = 3) and R. rhipicephali (n = 1). Despite the high prevalence of seroreactivity, titers were low, indicating limited exposure to Rickettsia spp. Camera traps generated 874 animal records, capturing a total of 1688 individuals. At least 11 species of birds and 14 species of mammals (12 wild and two domestic) shared the environment with wild boars and potentially shared ticks with them. These findings provide baseline information for understanding the sharing of ticks and tick-borne pathogens between wild boars and other animals within the Cerrado biome. Further studies are necessary to monitor the potential and actual risk of wild boars to harbor infected ticks and their role in the transmission and maintenance cycle of Rickettsia spp.

Initial study and phylogenetic analysis of hard ticks (Acari: Ixodidae) in Nantong, China along the route of avian migration.

The growing concern about migratory birds potentially spreading ticks due to global warming has become a significant issue. The city of Nantong in this study is situated along the East Asia-Australasian Flyway (EAAF), with numerous wetlands serving as roosting sites for migratory birds. We conducted an investigation of hard ticks and determined the phylogenetic characteristics of tick species in this city. We utilized three different genes for our study: the mitochondrial cytochrome oxidase subunit 1 (COX1) gene, the second internal transcribed spacer (ITS2), and the mitochondrial small subunit rRNA (12 S rRNA) gene. The predominant tick species were Haemaphysalis flava (H. flava) and Haemaphysalis longicornis (H. longicornis). Additionally, specimens of Haemaphysalis campanulata (H. campanulata) and Rhipicephalus sanguineus (R. sanguineus) were collected. The H. flava specimens in this study showed a close genetic relationship with those from inland provinces of China, as well as South Korea and Japan. Furthermore, samples of H. longicornis exhibited a close genetic relationship with those from South Korea, Japan, Australia, and the USA, as well as specific provinces in China. Furthermore, R. sanguineus specimens captured in Nantong showed genetic similarities with specimens from Egypt, Nigeria, and Argentina.

Alpha- and beta-pinene isomers act differently to control Rhipicephalus microplus (Acari: Ixodidae).

The cattle tick Rhipicephalus microplus is an ectoparasite of high importance in veterinary medicine and public health. Since synthetic chemicals used to control these ticks can select resistant strains and cause toxic effects in their hosts, there is a need to identify effective substances with fewer adverse effects. For this reason, we investigated the effects of alpha- and beta-pinene, known for their various biological effects, on the mortality and reproductive performance of R. microplus engorged female ticks. The products were diluted in a 2% Tween 80 aqueous solution. The ticks were first weighed and then immersed in the test solutions for five minutes. Then, they were dried with paper towels and fixed dorsoventrally in Petri dishes, totalling five treatment groups for each pinene and a control group treated with the solvent alone. The ticks were monitored daily for mortality, and their eggs were collected and weighed. The larval hatching rate was estimated, and the pre-oviposition and incubation periods were determined. From these data, the following parameters were calculated: egg production index, fertility rate, estimated reproduction rate, percentages of reduction in oviposition and hatching, and product efficacy. Alpha-pinene showed better results at higher concentrations, unlike beta-pinene, which was more effective at lower concentrations. The effectiveness of alpha-pinene was 74% at a concentration of 14.0 µL/mL, while beta-pinene showed 78% efficacy at 2.0 µL/mL. The results indicated for the first time different effects of two isomers in ticks, suggesting that these compounds act on R. microplus females in different ways.

New hard tick (Acari: Ixodidae) reports and detection of Rickettsia in ticks from Sierra Nevada de Santa Marta, Colombia.

The Sierra Nevada de Santa Marta (SNSM), located in northern Colombia, is considered a geographical island with high levels of biodiversity and endemism. However, little is known about tick species and their associated microorganisms at the SNSM. In this study we sampled host-seeking ticks in areas of the town of Minca within the SNSM. We collected 47 ticks identified as Amblyomma pacae, Amblyomma longirostre, Amblyomma ovale, Amblyomma mixtum, Haemaphysalis juxtakochi, Ixodes sp. cf. Ixodes affinis and Ixodes sp. Of these ticks, we tested for Rickettsia spp. by amplifying the gltA, SCA1, and 16S rRNA genes via PCR. Rickettsia amblyommatis was detected in one pool of 3 larvae and in a female of A. pacae. Additonally, we isolated Rickettsia sp. belonging to the group of spotted fevers in larvae of A. longirostre. This study reports new findings of six species of ticks and two species of Rickettsia within the SNSM.