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Objective: We sought to explore the lived experience of people with Debilitating Symptom Complexes Attributed to Ticks (DSCATT) to inform the development of a potential treatment intervention., Methods: We conducted one-to-one in-depth, semi-structured interviews with 13 people living in Australia affected by DSCATT. Interviews were transcribed and analysed using thematic analysis., Results: Although participants attributed the origin of their illness to tick bites, not all were adamant they had Lyme disease. Negative experiences in conventional healthcare were marked and were reported to exacerbate the impact of the illness and affect mental health. Further, these negative experiences propelled participants to seek unapproved treatments (by Australian standards). The desire for the illness to be acknowledged and causative agents identified was pronounced among the participant group., Conclusions: Individuals with DSCATT experience significant challenges amid a contentious healthcare landscape surrounding chronic symptoms attributed to ticks in Australia. Our findings suggest the need for empathetic, supportive and patient-centred treatments for this cohort., Implications for Public Health: DSCATT results in a considerable burden across multiple domains for those affected. Negative experiences with healthcare exacerbate the suffering of people with DSCATT in Australia. New approaches that acknowledge the illness experience of people with DSCATT, alongside evidence-based treatments that encompass biopsychosocial models of care, are needed to tackle this debilitating condition., Competing Interests: Conflicts of interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: GO, VY & AD receive salary payments from the NHMRC grant funding this project. TC reports grants from UK NIHR, UKRI and Guy’s and St Thomas’ Charity on persistent physical symptoms. She has delivered workshops on persistent physical symptoms in the context of long-term conditions for which she has received payment during the course of the study. She is the author of self-help books on fatigue. KBG receives salary support from a Medical Research Futures Fund (MRFF) investigator grant (MRF1193727). VLO, SW & RK report no conflicts of interest., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Ticks are major arthropod vectors of disease, transmitting tick-borne pathogens during blood meal episodes. Rickettsia spp. and Borrelia spp. are two tick-borne pathogens of zoonotic concern previously identified in DNA isolates from the tick genera Amblyomma and Bothriocroton associated with reptilian hosts in Australia. Some reports suggest that these reptile ticks bite and attach to humans via accidental parasitism and transmit disease, with the tick Bothriocroton hydrosauri known to transmit Rickettsia honei or Flinders Island Spotted Fever Rickettsia to humans. This descriptive study aims to identify the ticks collected from wild reptiles submitted to veterinary clinics and captured by snake rescuers from New South Wales (NSW), Australia, and detect the presence of tick-borne bacterial DNA using quantitative polymerase chain reaction (qPCR) to detect Rickettsia spp. and Bartonella spp. and conventional nested-PCR to detect Borrelia spp. Morphological identification revealed ticks removed from one eastern blue-tongued lizard (Tiliqua scincoides scincoides) from North-Eastern NSW (Lismore), one eastern blue-tongued lizard from the Greater Sydney area (Canley Heights), one diamond python (Morelia spilota spilota) from the Greater Sydney area (Woronora Heights) and one red-bellied black snake (Pseudechis porphyriacus) from the Greater Sydney Area (Cronulla) in New South Wales were Amblyomma moreliae. No ticks were positive for Bartonella spp. and Borrelia spp. DNA using real-time PCR targeting ssrA gene and nested PCR targeting Borrelia-specific 16S rRNA gene, respectively. Real-time PCR targeting gltA, ompA, ompB and 17kDa gene of Rickettsia spp. revealed 14 out of 16 ticks were positive. The undescribed Rickettsia sp. DNA was identical to that previously recovered from reptile ticks in Australia and closely related to Rickettsia tamurae and Rickettsia monacensis, both of which are aetiologic pathogens of the Spotted Fever Group Rickettsiosis (SFGR). These results accentuate the ongoing need for increased study efforts to understand zoonotic potential of bacteria from reptile ticks and the tick-reptile-human relationship., (© 2024. The Author(s).)

Ticks are ectoparasites that cause dermatologic reactions directly by their bites and indirectly as vectors of bacterial, protozoal and viral diseases. Consequences vary from minor local reactions to significant systemic sequelae and are therefore of clinical relevance to dermatologists. In this article, Australian ticks of medical importance are reviewed through the lens of dermatology., (© 2023 Australasian College of Dermatologists.)

The present work is an update and a substantial expansion of Barker & Walker (2014). Barker & Walker (2014) dealt with 16 species of particular importance to domestic animals and humans whereas the present work deals with all 125 of the species known from Australasia; that is Australia, New Zealand, the island of New Guinea, Sulawesi, and the islands of the western Pacific. These comprise 102 species of ixodid (hard) ticks and 23 species of argasid (soft) ticks.

Objectives(s): To characterise the clinical profile, aetiology and treatment responsiveness of 'Australian Lyme', or Debilitating Symptom Complexes Attributed to Ticks., Methods: Single-centre retrospective case analysis of patients referred to the Infectious Diseases Unit at Austin Health - a tertiary health service in Heidelberg, Australia - between 2014 and 2020 for investigation and treatment of suspected Debilitating Symptom Complexes Attributed to Ticks. Patients were included if they had debilitating symptoms suggested by either themselves or the referring clinician as being attributed to ticks., Results: Twenty-nine Debilitating Symptom Complexes Attributed to Ticks cases were included in the analysis. Other than Lyme disease (83%), the most common prior medical diagnoses were Epstein-Barr virus (38%), chronic fatigue syndrome (28%) and fibromyalgia (24%). Prior histories of anxiety (48%) and depression (41%) were common. The most frequently reported symptoms included fatigue (83%), headache (72%) and arthralgia (69%). National Association of Testing Authorities/Royal College of Pathologists of Australasia-accredited serology was not diagnostic of acute infective causes, including Lyme disease, in any patient. Of 25 cases with available data, 23 (92%) had previously been prescribed antimicrobials, with 53% reporting benefit from them. The most common diagnoses made by our hospital were chronic fatigue syndrome (31%), migraines (28%) and fibromyalgia (21%). Only one patient's symptoms were not accounted for by other diagnoses., Conclusion: This is the first case series of patients with Debilitating Symptom Complexes Attributed to Ticks. They had high rates of other medically unexplained syndromes, and no evidence of acute Lyme disease, or any common organic disease process. Debilitating Symptom Complexes Attributed to Ticks remains medically unexplained, and may therefore be due to an as yet unidentified cause, or may be considered a medically unexplained syndrome similar to conditions such as chronic fatigue syndrome.

Background: Ticks are ectoparasites that transmit a variety of pathogens that cause many diseases in livestock which can result in skin damage, weight loss, anemia, reduced production of meat and milk, and mortality. Aim: The aim of this study was to identify tick species and the distribution on livestock hosts (sheep, goat, dairy cattle, and buffalo) of Punjab, Khyber Pakhtunkhwa Province and Islamabad from October 2019 to November 2020. Materials and Methods: Surveillance was performed to calculate the prevalence of ticks on livestock. Tick prevalence data (area, host, breed, gender, age, and seasonal infestation rate) was recorded and analyzed. Results: A total of 2080 animals were examined from selected farms, and, of these, 1129 animals were tick-infested. A total of 1010 male tick samples were identified to species using published keys. Haemaphysalis punctata , Haemaphysalis sulcata , Hyalomma anatolicum , Hyalomma detritum , Hyalomma dromedarii , Hyalomma excavatum , Hyalomma marginatum , Hyalomma rufipes , Rhipicephalus decoloratus Rhipicephalus microplus , and Rhipicephalus sanguineus were collected from goats, sheep, buffalo, and cattle. The overall rates of tick infestation on livestock were 34.83% (buffalo), 57.11% (cattle), 51.97% (sheep) and 46.94% (goats). Within each species, different breeds demonstrated different proportions of infestation. For cattle breeds, infestation proportions were as follows: Dhanni (98.73%), Jersey (70.84%) and the Australian breed of cattle (81.81%). The Neeli Ravi breed (40%) of buffalo and the Beetal breed (57.35%) of goats were the most highly infested for these species. Seasonally, the highest prevalence of infestation (76.78%) was observed in summer followed by 70.76% in spring, 45.29% in autumn, and 20% in winter. The prevalence of tick infestation in animals also varied by animal age. In goats, animals aged 4-6 years showed the highest prevalence (90%), but in cattle, the prevalence of ticks was highest (68.75%) in 6 months-1-year-old animals. 1-3 years old buffalo (41.07%) and 6 months-1 year sheep (65.78%) had the highest prevalence rate. Females had significantly higher infestation rates (61.12%, 55.56% and 49.26%, respectively) in cattle, sheep, and goats. In buffalo, males showed a higher prevalence (38.46%) rate. Conclusions : This study showed tick diversity, infestation rate, and numerous factors (season, age, and gender of host) influencing tick infestation rate in different breeds of cattle, sheep, goats, and buffalo in Punjab Province, Khyber Pakhtunkhwa Province, and Islamabad, Pakistan. Higher tick burdens and rates of tick-borne disease reduce production and productivity in animals. Understanding tick species' prevalence and distribution will help to develop informed control measures.

The order Piroplasmida encompasses tick-borne pathogens of veterinary and medical importance positioned in two main families: Babesiidae and Theileriidae. Even though previous studies carried out in Brazil recorded the occurrence of piroplasmid species circulating in small mammals, 18S RNA gene sequences were only partially sequenced, preventing the assessment of their phylogenetic positioning. The current study aimed to detect and characterize, using morphological, molecular, and bioinformatic approaches, piroplasmids from wild mammals and associated ticks sampled in Central-Western Brazil. Out of 67 Didelphis albiventris sampled, 22 (16.4%) were positive for piroplasmids by PCR. In contrast, none of the 48 small rodents and 14 capybaras (Hydrochoerus hydrochaeris) was PCR-positive. Four Amblyomma dubitatum ticks-one from Rattus rattus, one from H. hydrochaeris, and two from D. albiventris-out of 114 Amblyomma spp. DNA samples were positive for piroplasmids by PCR. The phylogenetic inference performed using the near-complete 18S rRNA gene positioned the putative novel piroplasmid species detected in D. albiventris and associated A. dubitatum ticks near to Babesia sensu lato clade (Western group-cluster III) and distant from the Australian marsupial-associated piroplasms. Phylogenetic inferences based on two additional molecular markers, namely hsp-70 and cox-1, supported the near-complete 18S rRNA gene phylogenetic inference. Finally, the partial 18S rRNA gene sequences detected in ticks from rodents (R. rattus and H. hydrochaeris) showed 97.2-99.4% identity with the Piroplasmida previously detected in a capybara from Brazil, raising evidence that a still uncharacterized piroplasmid species has been identified in the capybara, the largest rodent species from South America., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Perhaps one of the central questions in ecology has been what limits the geographic distribution of species. The geographic distributions of the reptile‐ticks Amblyomma limbatum, Bothriocroton hydrosauri and Amblyomma albolimbatum are a classic example of this problem: where these ticks meet, narrow regions‐of‐overlap often occur. Despite studies of interactions among these ticks, and of these ticks and their environment, we still do not understand what limits their geographic distributions. Many hypotheses have been proposed and tested, but all have seemingly been rejected. Our aim was to account for the abundance and the geographic distributions of A. limbatum and B. hydrosauri at Bundey Bore Station, South Australia, where these species come in contact and have been studied for over 35 years, leading to over 55 000 records of reptiles and their ticks using a capture‐mark‐recapture approach. We constructed models which had combinations of temperature and moisture indices from different months of the year to determine the relationship between climate and tick abundance, and between climate and the shifting local geographic distribution of A. limbatum and B. hydrosauri at Bundey Bore Station. We found that climate together with the abundance of ticks in the previous year and the abundance of the lizard host, accounted for 54%–77% of the variation in the abundance of A. limbatum and B. hydrosauri among years. We also found that the climate in late autumn to winter, together with the abundance of ticks and their host, accounted for 18%–84% of the variation in the geographic distributions of these ticks among years. Climate was central to the abundance and the geographic distributions of A. limbatum and B. hydrosauri at Bundey Bore Station. We speculate that the same mechanisms account for the geographic distributions of A. limbatum, B. hydrosauri and A. albolimbatum elsewhere in Australia; so, climate may explain the three‐tick problem in Austral ecology. [ABSTRACT FROM AUTHOR]

Ticks (Arachnida: Acari) are vectors for pathogens and the biggest threat to animal health. Many Australian ticks are associated with pathogens that impact humans, domestic animals and livestock. However, little is known about the presence or impact of tick-borne pathogens in native Australian wildlife. Wombats are particularly susceptible to the effects of the ectoparasite Sarcoptes scabiei which causes sarcoptic mange, the reason for which is unknown. Factors such as other ectoparasites and their associated pathogens may play a role. A critical understanding of the species of ectoparasites that parasitise wombats and their pathogens, and particularly ticks, is therefore warranted. This review describes the ectoparasites of wombats, pathogens known to be associated with those ectoparasites, and related literature gaps. Pathogens have been isolated in most tick species that typically feed on wombats; however, there are minimal molecular studies to determine the presence of pathogens in any other wombat ectoparasites. The development of next-generation sequencing (NGS) technologies allows us to explore entire microbial communities in ectoparasite samples, allowing fast and accurate identification of potential pathogens in many samples at once. These new techniques have highlighted the diversity and uniqueness of native ticks and their microbiomes, including pathogens of potential medical and veterinary importance. An increased understanding of all ectoparasites that parasitise wombats, and their associated pathogens, requires further investigation.

Tick‐borne zoonoses are emerging globally due to changes in climate and land use. While the zoonotic threats associated with ticks are well studied elsewhere, in Australia, the diversity of potentially zoonotic agents carried by ticks and their significance to human and animal health is not sufficiently understood. To this end, we used untargeted metatranscriptomics to audit the prokaryotic, eukaryotic and viral biomes of questing ticks and wildlife blood samples from two urban and rural sites in New South Wales, Australia. Ixodes holocyclus and Haemaphysalis bancrofti were the main tick species collected, and blood samples from Rattus rattus, Rattus fuscipes, Perameles nasuta and Trichosurus vulpecula were also collected and screened for tick‐borne microorganisms using metatranscriptomics followed by conventional targeted PCR to identify important microbial taxa to the species level. Our analyses identified 32 unique tick‐borne taxa, including 10 novel putative species. Overall, a wide range of tick‐borne microorganisms were found in questing ticks including haemoprotozoa such as Babesia, Theileria, Hepatozoon and Trypanosoma spp., bacteria such as Borrelia, Rickettsia, Ehrlichia, Neoehrlichia and Anaplasma spp., and numerous viral taxa including Reoviridiae (including two coltiviruses) and a novel Flaviviridae‐like jingmenvirus. Of note, a novel hard tick‐borne relapsing fever Borrelia sp. was identified in questing H. bancrofti ticks which is closely related to, but distinct from, cervid‐associated Borrelia spp. found throughout Asia. Notably, all tick‐borne microorganisms were phylogenetically unique compared to their relatives found outside Australia, and no foreign tick‐borne human pathogens such as Borrelia burgdorferi s.l. or Babesia microti were found. This work adds to the growing literature demonstrating that Australian ticks harbour a unique and endemic microbial fauna, including potentially zoonotic agents which should be further studied to determine their relative risk to human and animal health. [ABSTRACT FROM AUTHOR]

Despite its isolation and extreme climate, Antarctica is home to diverse fauna and associated microorganisms. It has been proposed that the most iconic Antarctic animal, the penguin, experiences low pathogen pressure, accounting for their disease susceptibility in foreign environments. There is, however, a limited understanding of virome diversity in Antarctic species, the extent of in situ virus evolution, or how it relates to that in other geographic regions. To assess whether penguins have limited microbial diversity we determined the RNA viromes of three species of penguins and their ticks sampled on the Antarctic peninsula. Using total RNA sequencing we identified 107 viral species, comprising likely penguin associated viruses (n = 13), penguin diet and microbiome associated viruses (n = 82), and tick viruses (n = 8), two of which may have the potential to infect penguins. Notably, the level of virome diversity revealed in penguins is comparable to that seen in Australian waterbirds, including many of the same viral families. These data run counter to the idea that penguins are subject to lower pathogen pressure. The repeated detection of specific viruses in Antarctic penguins also suggests that rather than being simply spill-over hosts, these animals may act as key virus reservoirs.

Ticks and tick-borne pathogens pose a significant threat to the health and welfare of humans and animals. Our knowledge about pathogens carried by ticks of Australian wildlife is limited. This study aimed to characterise ticks and tick-borne microorganisms from a range of wildlife species across six sites in Victoria, Australia. Following morphological and molecular characterisation (targeting 16S rRNA and cytochrome c oxidase I), tick DNA extracts (n = 140) were subjected to microfluidic real-time PCR-based screening for the detection of microorganisms and Rickettsia-specific real-time qPCRs. Five species of ixodid ticks were identified, including Aponomma auruginans, Ixodes (I.) antechini, I. kohlsi, I. tasmani and I. trichosuri. Phylogenetic analyses of 16S rRNA sequences of I. tasmani revealed two subclades, indicating a potential cryptic species. The microfluidic real-time PCR detected seven different microorganisms as a single (in 13/45 ticks) or multiple infections (27/45). The most common microorganisms detected were Apicomplexa (84.4%, 38/45) followed by Rickettsia sp. (55.6%, 25/45), Theileria sp. (22.2% 10/45), Bartonella sp. (17.8%, 8/45), Coxiella-like sp. (6.7%, 3/45), Hepatozoon sp. (2.2%, 1/45), and Ehrlichia sp. (2.2%, 1/45). Phylogenetic analyses of four Rickettsia loci showed that the Rickettsia isolates detected herein potentially belonged to a novel species of Rickettsia. This study demonstrated that ticks of Australian wildlife carry a diverse array of microorganisms. Given the direct and indirect human–wildlife–livestock interactions, there is a need to adopt a One Health approach for continuous surveillance of tick-associated pathogens/microorganisms to minimise the associated threats to animal and human health. [ABSTRACT FROM AUTHOR]

We describe a new genus Cryptocroton n. gen. for Amblyomma papuanum Hirst, 1914, a tick of North Queensland, Australia, and Papua New Guinea.

Background: Among hard ticks (Acari: Ixodidae), the genus Ixodes comprises the highest number of species, which in turn are most numerous in the Afrotropical zoogeographic region. In South Africa extensive morphological studies have been performed on Ixodes species but only few reports included molecular analyses., Methods: In this study, 58 Ixodes spp. ticks, collected from ten mammalian and eight avian host species in South Africa, were molecularly and phylogenetically analyzed. In addition, a newly collected sample of the Palearctic Ixodes trianguliceps was included in the analyses., Results: Among the ticks from South Africa, 11 species were identified morphologically. The majority of ticks from mammals represented the Ixodes pilosus group with two species (n = 20), followed by ticks resembling Ixodes rubicundus (n = 18) and Ixodes alluaudi (n = 3). In addition, single specimens of Ixodes rhabdomysae, Ixodes ugandanus, Ixodes nairobiensis and Ixodes simplex were also found. Considering bird-infesting ticks, Ixodes theilerae (n = 7), Ixodes uriae (n = 4) and ticks most similar to Ixodes daveyi (provisionally named I. cf. daveyi, n = 2) were identified. Molecular analyses confirmed two species in the I. pilosus group and a new species (I. cf. rubicundus) closely related to I. rubicundus sensu stricto. Phylogenetic trees based on concatenated mitochondrial or mitochondrial and nuclear gene sequences indicated that the subgenus Afrixodes forms a monophyletic clade with bird-associated exophilic ticks (subgenus Trichotoixodes). Ixodes trianguliceps clustered separately whereas I. alluaudi with their morphologically assigned subgenus, Exopalpiger., Conclusions: Phylogenetic analyses shed new lights on the relationships of Ixodes subgenera when including multiple sequences from subgenus Afrixodes and African as well as Palearctic species of subgenera Trichotoixodes and Exopalpiger. Subgenera Afrixodes and bird-associated Trichotoixodes share common ancestry, suggesting that the latter might have also originated in Africa. Regarding the subgenus Exopalpiger, I. alluaudi is properly assigned as it clusters among different Australian Ixodes, whereas I. trianguliceps should be excluded., (© 2023. The Author(s).)

Background: A subset of Australians who have been bitten by ticks experience a complex of chronic and debilitating symptoms which cannot be attributed to the known pathogenic species of bacteria present in Australia. As a result, there has been a renewed effort to identify and characterise viruses in Australian terrestrial ticks. Recent transcriptome sequencing of Ixodes and Amblyomma ticks has revealed the presence of multiple virus sequences. However, without virus isolates our ability to understand the host range and pathogenesis of newly identified viruses is limited. We have established a successful method for high-throughput virus discovery and isolation in mosquitoes using antibodies to double-stranded RNA. In this study we sought to characterise five archival tick-borne viruses to adapt our virus discovery protocol for Australian ticks. Methods: We performed virus characterisation using a combination of bioinformatic sequence analysis and in vitro techniques including replication kinetics, antigenic profiling, virus purification and mass spectrometry. Results: Our sequence analysis of Nugget virus, Catch-me-Cave virus and Finch Creek virus revealed marked genetic stability in isolates collected from the same location approximately 30 years apart. We demonstrate that the Ixodes scapularis-derived ISE6 cell line supports replication of Australian members of the Flaviviridae, Nairoviridae, Phenuiviridae and Reoviridae families, including Saumarez Reef virus (SREV), a flavivirus isolated from the soft tick Ornithodoros capensis. While antibodies against double-stranded RNA could be used to detect replication of a tick-borne reovirus and mosquito-borne flavivirus, the tick-borne flaviviruses Gadgets Gully virus and SREV could not be detected using this method. Finally, four novel virus-like sequences were identified in transcriptome sequencing of the Australian native tick Ixodes holocyclus. Conclusions: Genetic and antigenic characterisations of archival viruses in this study confirm that three viruses described in 2002 represent contemporary isolates of virus species first identified 30 years prior. Our findings with antibodies to double-stranded RNA highlight an unusual characteristic shared by two Australian tick-borne flaviviruses. Finally, comparative growth kinetics analyses of Australian tick-borne members of the Flaviviridae, Nairoviridae, Phenuiviridae and Reoviridae families in ISE6 and BSR cells will provide a useful resource for isolation of Australian tick-borne viruses using existing cell lines. [ABSTRACT FROM AUTHOR]

Advances in sequencing technologies have revealed the complex and diverse microbial communities present in ticks (Ixodida). As obligate blood-feeding arthropods, ticks are responsible for a number of infectious diseases that can affect humans, livestock, domestic animals and wildlife. While cases of human tick-borne diseases continue to increase in the northern hemisphere, there has been relatively little recognition of zoonotic tick-borne pathogens in Australia. Over the past 5 years, studies using high-throughput sequencing technologies have shown that Australian ticks harbour unique and diverse bacterial communities. In the present study, free-ranging wildlife ( n =203), representing ten mammal species, were sampled from urban and peri-urban areas in New South Wales (NSW), Queensland (QLD) and Western Australia (WA). Bacterial metabarcoding targeting the 16S rRNA locus was used to characterize the microbiomes of three sample types collected from wildlife: blood, ticks and tissue samples. Further sequence information was obtained for selected taxa of interest. Six tick species were identified from wildlife: Amblyomma triguttatum , Ixodes antechini , Ixodes australiensis , Ixodes holocyclus , Ixodes tasmani and Ixodes trichosuri . Bacterial 16S rRNA metabarcoding was performed on 536 samples and 65 controls, generating over 100 million sequences. Alpha diversity was significantly different between the three sample types, with tissue samples displaying the highest alpha diversity ( P <0.001). Proteobacteria was the most abundant taxon identified across all sample types (37.3 %). Beta diversity analysis and ordination revealed little overlap between the three sample types ( P <0.001). Taxa of interest included Anaplasmataceae , Bartonella , Borrelia , Coxiellaceae , Francisella , Midichloria , Mycoplasma and Rickettsia . Anaplasmataceae bacteria were detected in 17.7% (95/536) of samples and included Anaplasma , Ehrlichia and Neoehrlichia species. In samples from NSW, ' Ca . Neoehrlichia australis', ' Ca . Neoehrlichia arcana', Neoehrlichia sp. and Ehrlichia sp. were identified. A putative novel Ehrlichia sp. was identified from WA and Anaplasma platys was identified from QLD. Nine rodent tissue samples were positive for a novel Borrelia sp. that formed a phylogenetically distinct clade separate from the Lyme Borrelia and relapsing fever groups. This novel clade included recently identified rodent-associated Borrelia genotypes, which were described from Spain and North America. Bartonella was identified in 12.9% (69/536) of samples. Over half of these positive samples were obtained from black rats ( Rattus rattus ), and the dominant bacterial species identified were Bartonella coopersplainsensis and Bartonella queenslandensis . The results from the present study show the value of using unbiased high-throughput sequencing applied to samples collected from wildlife. In addition to understanding the sylvatic cycle of known vector-associated pathogens, surveillance work is important to ensure preparedness for potential zoonotic spillover events.

Background: Ticks are obligate haematophagous ectoparasites of vertebrate hosts and transmit the widest range of pathogenic organisms of any arthropod vector. Seven tick species are known to feed on bare-nosed wombats (Vombatus ursinus), in addition to the highly prevalent Sarcoptes scabiei mite which causes fatal sarcoptic mange in most bare-nosed wombat populations. Little is known about the pathogens carried by most wombat ticks or how they may impact wombats and wombat handlers. Methods: Wombat ticks were sourced from wildlife hospitals and sanctuaries across Australia and identified to species level using taxonomic keys. Genomic DNA was extracted from a subsample, and following the amplification of the bacterial 16S rRNA gene V3–V4 hypervariable region, next-generation sequencing (NGS) on the Illumina MiSeq platform was used to assess the microbial composition. Results: A total of 447 tick specimens were collected from 47 bare-nosed wombats between January 2019 and January 2020. Five species of ticks were identified comprising wombat tick Bothriocroton auruginans (n = 420), wallaby tick Haemaphysalis bancrofti (n = 8), bush tick Haemaphysalis longicornis (n = 3), common marsupial tick Ixodes tasmani (n = 12), and Australian paralysis tick Ixodes holocyclus (n = 4). Tick infestations ranged from one to 73 ticks per wombat. The wombat tick was the most prevalent tick species comprising 94% of the total number of samples and was present on 97.9% (46/47) of wombat hosts. NGS results revealed the 16S rRNA gene diversity profile was predominantly Proteobacteria (55.1%) followed by Firmicutes (21.9%) and Actinobacteria (18.4%). A species of Coxiella sharing closest sequence identity to Coxiella burnetii (99.07%), was detected in 72% of B. auruginans and a Rickettsiella endosymbiont dominated the bacterial profile for I. tasmani. Conclusions: A new host record for H. longicornis is the bare-nosed wombat. One adult male and two engorged adult female specimens were found on an adult male wombat from Coolagolite in New South Wales, and more specimens should be collected to confirm this host record. The most prevalent tick found on bare-nosed wombats was B. auruginans, confirming previous records. Analysis of alpha-diversity showed high variability across both sample locations and instars, similar to previous studies. The detection of various Proteobacteria in this study highlights the high bacterial diversity in native Australian ticks. [ABSTRACT FROM AUTHOR]

Ticks (Acari: Ixodidae) are major disease vectors globally making it increasingly important to understand how altered vertebrate communities in urban areas shape tick population dynamics. In urban landscapes of Australia, little is known about which native and introduced small mammals maintain tick populations preventing host‐targeted tick management and leading to human–wildlife conflict. Here, we determined (1) larval, nymphal, and adult tick burdens on host species and potential drivers, (2) the number of ticks supported by the different host populations, and (3) the proportion of medically significant tick species feeding on the different host species in Northern Sydney. We counted 3551 ticks on 241 mammals at 15 sites and found that long‐nosed bandicoots (Perameles nasuta) hosted more ticks of all life stages than other small mammals but introduced black rats (Rattus rattus) were more abundant at most sites (33%–100%) and therefore important in supporting larval and nymphal ticks in our study areas. Black rats and bandicoots hosted a greater proportion of medically significant tick species including Ixodes holocyclus than other hosts. Our results show that an introduced human commensal contributes to maintaining urban tick populations and suggests ticks could be managed by controlling rat populations on urban fringes. [ABSTRACT FROM AUTHOR]

Aim: To understand how nurses talk about documentation audit in relation to their professional role., Background: Nursing documentation in health services is often audited as an indicator of nursing care and patient outcomes. There are few studies exploring the nurses' perspectives on this common process., Design: Secondary qualitative thematic analysis., Methods: Qualitative focus groups (n = 94 nurses) were conducted in nine diverse clinical areas of an Australian metropolitan health service for a service evaluation focussed on comprehensive care planning in 2020. Secondary qualitative analysis of the large data set using reflexive thematic analysis focussed specifically on the nurse experience of audit, as there was the significant emphasis by participants and was outside the scope of the primary study., Results: Nurses': (1) value quality improvement but need to feel involved in the cycle of change, (2) highlight that 'failed audit' does not equal failed care, (3) describe the tension between audited documentation being just bureaucratic and building constructive nursing workflows, (4) value building rapport (with nurses, patients) but this often contrasted with requirements (organizational, legal and audit) and additionally, (5) describe that the focus on completion of documentation for audit creates unintended and undesirable consequences., Conclusion: Documentation audit, while well-intended and historically useful, has unintended negative consequences on patients, nurses and workflows., Impact: Accreditation systems rely on care being auditable, but when individual legal, organizational and professional standards are implemented via documentation forms and systems, the nursing burden is impacted at the point of care for patients, and risks both incomplete cares for patients and incomplete documentation., No Patient or Public Contribution: Patients participated in the primary study on comprehensive care assessment by nurses but did not make any comments about documentation audit., (© 2023 The Authors. Journal of Advanced Nursing published by John Wiley & Sons Ltd.)

The order Piroplasmida encompasses two main families: Babesiidae and Theileriidae, containing tick-borne pathogens of veterinary and medical importance worldwide. While only three genera (Babesia, Cytauxzoon and Theileria) comprising piroplasm parasites are currently recognised, phylogenetic studies at the 18S rRNA (18S) gene suggest that these organisms represent at least ten lineages, one of which comprises the relatively unique and highly diverse Theileria spp. from Australian marsupials and ticks. As an alternative to analysing 18S sequences alone, sequencing of mitochondrial genes has proven to be useful for the elucidation of evolutionary relationships amongst some groups of piroplasms. This research aimed to characterise piroplasms from Australian native mammals and ticks using multiple genetic markers (18S, cytochrome c, oxidase subunit III (cox3) and cytochrome B (cytB)) and microscopy. For this, nearly complete piroplasm-18S sequences were obtained from 32 animals belonging to six marsupial species: eastern bettong (Bettongia gaimardi), eastern quoll (Dasyurus viverrinus), eastern grey kangaroo (Macropus giganteus), swamp wallaby (Wallabia bicolor), quokka (Setonix brachyurus) and Gilbert's potoroo (Potorous gilbertii). The organisms detected represented eight novel Theileria genotypes, which formed five sub-clades within the main marsupial clade containing previously reported Australian marsupial and tick-derived Theileria spp. A selection of both novel and previously described Australian piroplasms at the 18S were also successfully characterised, for the first time, at the cox3 and cytB loci, and corroborated the position of Australian native theilerias in a separate, well-supported clade. Analyses of the cox3 and cytB genes also aided in the taxonomic resolution within the clade of Australian Piroplasmida. Importantly, microscopy and molecular analysis at multiple loci led to the discovery of a unique piroplasm species that clustered with the Australian marsupial theilerias, for which we propose the name Theileria lupei n. sp., Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: LAA has an affiliation to the commercial funder of this research study. However, this does not alter our adherence to PLOS ONE policies on sharing data and materials.

Zoonotic disease vectors, their wildlife hosts, and the surrounding landscape interact in complex ways that vary spatially, temporally and with anthropogenic change. Ticks (Acari: Ixodidae) are one of the most important vectors of human disease globally but managing the risk of tick bites in urban areas requires a detailed understanding of these complex vector-host-environment relationships at multiple spatial scales. Extensive knowledge gaps of these interactions in Australia limits options for managing ticks and exacerbates human-wildlife conflict. To address this, we used an online survey to determine the potential drivers of human-tick encounters operating at the local, yard scale and at the broader, landscape scale in a peri-urban area of Australia. We explored the relationships between reported tick encounters in yards and yard traits, host sightings (yard-scale) and broader landscape traits (landscape-scale). We found that sightings of potential hosts such as long-nosed bandicoots (Perameles nasuta) and brush-turkeys (Alectura lathami), and broader landscape traits such as distance to wet sclerophyll forest, were important predictors of reported tick encounters. Yard traits such as garden mulching and leaf litter cover showed no relationships with tick encounters. However, garden mulching and the absence of pets were predictors of frequent bandicoot sightings in yards. Mulching over 20m2, moderate to dense leaf litter cover on lawns, and living adjacent to bush were predictors of frequent brush-turkey sightings in yards. Our results suggest that residents may be able to reduce tick encounter risk by making yards less attractive to potential hosts. The observed relationships provide a critical foundation for field studies that can determine underlying mechanisms and inform appropriate tick management in urban environments. [ABSTRACT FROM AUTHOR]

Background: Poor owner compliance with monthly control measures means that dogs in Australia can remain susceptible to infestations with fleas, present throughout the whole year, and brown dog ticks, which thrive in tropical and subtropical areas. A 150 mg/ml injectable fluralaner suspension (Bravecto Quantum™) was developed to help ensure year-round protection against these parasites. A study investigated the persistent efficacy of this formulation against repeated challenges with Rhipicephalus sanguineus (sensu lato) and Ctenocephalides felis throughout 12 months following a single subcutaneous treatment. Methods: Twenty dogs were blocked by pre-treatment R. sanguineus s.l. counts and randomized to an untreated control group or to a group treated once, on day 0, with the fluralaner injection (15 mg/kg). Infestations of 50 mixed-sex, unfed adult R. sanguineus s.l. and up to 100 C. felis were done on days 7, 14, 35, 63, 91, 126, 154, 182, 210, 245, 273, 301, 336 and 365. Live flea and tick counts were completed 48 h post-infestation. Flea infestations were also done on day −1, with counts on day 2. Infestations were considered adequate if at each evaluation, at least six dogs in the control group retained at least 20% of tick challenges and 25% of flea challenges. Results: The fluralaner injectable suspension was well tolerated. Efficacy against existing flea infestations was > 99% (arithmetic and geometric means) at 48 h post-treatment. At all subsequent assessments throughout the year following treatment, efficacy against fleas remained at 100%. Arithmetic mean tick count reductions relative to the control group ranged from 97.6% to 100% from day 7 through 11 months and was 92.6% at 12 months (geometric means 95.2% to 100% through 12 months). Conclusion: The injectable fluralaner suspension was effective against fleas and brown dog ticks for 12 months following a single treatment. Compared with more frequently administered products where compliance may be suboptimal, the year-round efficacy of this veterinarian-administered fluralaner formulation has the potential to improve owner compliance for control of fleas and ticks. In turn, by reducing the detrimental effects of flea and tick infestations and risk of transmission of flea- and tick-borne pathogens, canine health can be enhanced. [ABSTRACT FROM AUTHOR]

Trypanosomes are global blood parasites that infect a wide range of vertebrate hosts. Several species of Trypanosoma cause disease in humans and domesticated animals, and the majority are transmitted between hosts by haematophagous invertebrate vectors. Ticks have long been speculated as vectors for Australian trypanosomes. Recent studies using advanced molecular techniques have refocused attention on these arthropods, and whilst they have renewed discussions about Trypanosoma species and their vectors, these reports have simultaneously led to premature conclusions concerning the role of ticks as vectors. Here the controversy surrounding ticks as trypanosome vectors is discussed. We highlight the unanswered questions concerning the role played by ticks in trypanosome transmission and suggest future approaches to resolving these key knowledge gaps. Trypanosomes (genus Trypanosoma) are blood-borne protozoan parasites of vertebrates that typically require a haematophagous invertebrate as a vector. Triatomine bugs and several biting flies are recognized as their main vectors. Ticks, as blood feeders, are predisposed to the ingestion of various parasites during feeding and have therefore long been proposed as vectors for Trypanosoma species. Trypanosomes are reported in Australian wildlife, and early indications suggest that some species may adversely affect the health of native hosts. The vectors responsible for transmitting Australian Trypanosoma species between vertebrate hosts are unknown. Ticks are suggested as vectors for several Australian trypanosomes based on microscopic and molecular detection of trypanosomes in ticks removed from wildlife. However, there are no experimental transmission studies to support this hypothesis to date. [ABSTRACT FROM AUTHOR]

Seventy species of ticks are known from Australia: 14 soft ticks (family Argasidae) and 56 hard ticks (family Ixodidae). Sixteen of the 70 ticks in Australia may feed on humans and domestic animals (Barker and Walker 2014). The other 54 species of ticks in Australia feed only on wild mammals, reptiles and birds. At least 12 of the species of ticks in Australian also occur in Papua New Guinea. We use an image-matching system much like the image-matching systems of field guides to birds and flowers to identify Ixodes holocyclus (paralysis tick), Ixodes cornuatus (southern paralysis tick) and Rhipicephalus (Boophilus) australis (Australian cattle tick). Our species accounts have reviews of the literature on I. holocyclus (paralysis tick) from the first paper on the biology of an Australian tick by Bancroft (1884), on paralysis of dogs by I. holocyclus, to papers published recently, and of I. cornuatus (southern paralysis tick) and Rhipicephalus (Boophilus) australis (Australian cattle tick). We comment on four controversial questions in the evolutionary biology of ticks: (i) were labyrinthodont amphibians in Australia in the Devonian the first hosts of soft, hard and nuttalliellid ticks?; (ii) are the nuttalliellid ticks the sister-group to the hard ticks or the soft ticks?; (iii) is Nuttalliella namaqua the missing link between the soft and hard ticks?; and (iv) the evidence for a lineage of large bodied parasitiform mites (ticks plus the holothyrid mites plus the opiliocarid mites)., (Copyright © 2014. Published by Elsevier Ltd.)

We studied over 222,000 cases of emergency veterinary consultations in four regions along the eastern coast of Australia. We found that cases of tick paralysis (TP) caused by the eastern paralysis tick, Ixodes holocyclus, accounted for 7.5% of these cases: >16,000 cases. The season of TP and the number (prevalence) of TP cases varied among regions and over the years. Our study of the association between weather and (i) the start of the season of TP, and (ii) the number of TP cases revealed much about the intricate relationship between the weather and I. holocyclus. We studied the effect of the hypothetical availability of isoxazoline‐containing tick‐preventative medicines and found that an increase in the availability of these medicines had significantly contributed to the decrease in TP cases. We found that the weather in winter accounted for the time of the year the season of TP starts whereas the weather in summer accounted for the number of TP cases in the TP season. Last, through a study of the effects of shifts in the climate under four hypothetical scenarios (warmer/cooler and drier/wetter than average), we propose that the start of the season of TP depends on how soon the weather in winter becomes suitable for the activity (e.g. host‐seeking) and the development of I. holocyclus nymphs, and that the number of TP cases during the TP season depends on how many engorged female ticks and their eggs survive during summer. [ABSTRACT FROM AUTHOR]

Simple Summary: Tick paralysis (TP) in dogs caused by Ixodes holocyclus can be perplexing for clinicians, with some dogs recovering rapidly after the administration of tick antiserum and others deteriorating before improving or dying despite clinical interventions. The prediction of individual case disease progression, recovery time, and mortality is difficult. This study collected a large body of clinical data from natural cases of TP across the eastern seaboard of Australia, with the veterinarians involved receiving training prior to the tick season to use two new tools to assess disease severity (visual analogue scales (VAS) and facial expressions of distress) as well as established methods of assessment. VAS scores for respiratory dysfunction and muscular weakness were highly predictive of mortality, but established methods for respiratory evaluation were not. Specific respiratory clinical signs present at admission and during hospitalisation were identified as highly predictive of mortality, and other specific clinical signs were shown to be highly predictive of prolonged hospitalisation times. These findings will assist in the management of TP cases: veterinarians can utilise the risk factors for mortality reported here to improve their communication with owners about prognosis and to make timely decisions to prioritise intensive care therapy. Survey data from 42 Australian eastern seaboard veterinary practices involving 506 cases are reported with regard to clinical signs, disease severity, mortality, use of pharmaceuticals, and recovery times. New measures of disease severity (visual analogue scales (VAS) and facial expressions) were tested alongside "gold standard" measures (neuromuscular junction (NMJ) scores). Univariable and multivariable logistic regression analyses were conducted to evaluate associations between variables. The VAS scores were progressive, prognostic (especially the respiratory scores) and correlated with the NMJ scores. The presence of inspiratory dyspnoea and crackles on the day of hospitalisation, progressing to expiratory dyspnoea and an expiratory wheeze 24 h later, were highly predictive of mortality. Altered facial features on hospital admission were also highly predictive of mortality. The previously used respiratory score (using various clinical signs) was not predictive of mortality. Older animals had a higher mortality rate, and no gender or breed susceptibility was found. The only pharmaceuticals that were positively associated with mortality were tick antiserum and, in severe cases, antibiotics. The use of many pharmaceutical products (acepromazine, atropine, steroids, antihistamines, antiemetics, diuretics, and S8 anti-anxiety and sedation drugs) had no effect on mortality. More drug classes were used with increasing clinical severity and specific factors (e.g., vomiting/retching, hydration) affected the period of hospitalisation. Geographic variation in respiratory signs and toxicity scores was evident, whereas mortality and disease severity were not different across regions. [ABSTRACT FROM AUTHOR]

The book Australian Ticks by F.H.S. Roberts (1970) is a land-mark in Australian tick biology. But it is time for a new and improved book on the ticks of Australia. The present book has identification guides and accounts of the biology and diseases associated with the 16 species of ticks that may feed on domestic animals and humans in Australia. These comprise five argasid (soft) ticks: Argas persicus (poultry tick), Argas robertsi (Robert's bird tick), Ornithodoros capensis (seabird soft tick), O. gurneyi (kangaroo soft tick), Otobius megnini (spinose ear tick); and 11 ixodid (hard) ticks, Amblyomma triguttatum (ornate kangaroo tick), Bothriocroton auruginans (wombat tick), B. hydrosauri (southern reptile tick), Haemaphysalis bancrofti (wallaby tick), H. longicornis (bush tick), Ixodes cornuatus (southern paralysis tick), I. hirsti (Hirst's marsupial tick), I. holocyclus (paralysis tick), I. tasmani (common marsupial tick), Rhipicephalus (Boophilus) australis (Australian cattle tick) and R. sanguineus (brown dog tick).  We use an image-matching system to identify ticks, much like the image-matching systems used in field-guides for birds and flowers. Ticks may be identified by drawings that emphasise unique matrices of uniformly defined morphological characters that, together, allow these 16 ticks to be identified by morphology unequivocally. The species accounts have seven sections: (i) General; (ii)  Differential diagnosis; (iii) Hosts; (iv) Life-cycle and seasonality; (v) Disease; (vi) Habitat and geographic distribution; (vii) Genes and genomes; and (viii) Other information. There are 71 figures and tables, including a glossary character matrices, drawings of life-cycles, drawings of genera, species, and colour photographs of tick biology.

The association of ticks (Acarina) and seabirds provides an intriguing system for assessing the influence of long-distance dispersal on the evolution of parasitic species. Recent research has focused on host-parasite evolutionary relationships and dispersal capacity of ticks parasitising flighted seabirds. Evolutionary research on the ticks of non-flighted seabirds is, in contrast, scarce. We conducted the first phylogeographic investigation of a hard tick species (Ixodes eudyptidis) that parasitises the Little Blue Penguin (Eudyptula minor). Using one nuclear (28S) and two mitochondrial (COI and 16S) markers, we assessed genetic diversity among several populations in Australia and a single population on the South Island of New Zealand. Our results reveal two deeply divergent lineages, possibly representing different species: one comprising all New Zealand samples and some from Australia, and the other representing all other samples from Australian sites. No significant population differentiation was observed among any Australian sites from within each major clade, even those separated by hundreds of kilometres of coastline. In contrast, the New Zealand population was significantly different to all samples from Australia. Our phylogenetic results suggest that the New Zealand and Australian populations are effectively isolated from each other; although rare long-distance dispersal events must occur, these are insufficient to maintain trans-Tasman gene flow. Despite the evidence for limited dispersal of penguin ticks between Australia and New Zealand, we found no evidence to suggest that ticks are unable to disperse shorter distances at sea with their hosts, with no pattern of population differentiation found among Australian sites. Our results suggest that terrestrial seabird parasites may be quite capable of short-distance movements, but only sporadic longer-distance (trans-oceanic) dispersal.

Recent concerns have arisen in Australia regarding detections of the exotic bacterium Ehrlichia canis which has resulted in ehrlichiosis outbreaks. In Australia, it is spread by the tropical brown dog tick Rhipicephalus linnaei, formerly Rhipicephalus sanguineus sensu lato tropical lineage. Previously, the tick has been recorded in South Australia in the Coober Pedy and the Oodnadatta areas. This study, which includes historical specimens data held in historical Australian arthropod collections, along with 10 sampled remote communities, confirms the wide distribution range of this species within the State. E. canis was detected by PCR in the ticks. The percentage of dogs hosting PCR‐positive ticks increased from 2.8% (95% confidence interval [CI]: 0.3 to 9.7) in November–December 2020 to 62.9% (95% CI: 44.9 to 78.5) end of February 2021, initially in two then in seven Anangu Pitjantjatjara Yankunytjatjara lands communities in the far northern regions of South Australia. Our results suggest a rapid spread of the pathogen. No evidence of E. canis was found in nine regional communities. The extended tropical brown dog tick distribution indicates a greater area where E. canis may occur and may require management to minimise the impacts of ehrlichiosis outbreaks. Without the implementation of effective detection and control programs, this extended distribution of R. linnaei is likely to result in the spread of the bacterium to other regions. [ABSTRACT FROM AUTHOR]

Background: Ticks are among the most important vectors of pathogens affecting companion animals, and also cause health problems such as tick paralysis, anaemia, dermatitis, and secondary infections. Twenty ixodid species have previously been recorded on dogs, cats, and horses in Australia, including Rhipicephalus sanguineus, Ixodes holocyclus and Haemaphysalis longicornis, which transmit tick-borne diseases. A survey of hard ticks (Acari: Ixodidae) was conducted during 2012-2015 to investigate tick species that infest dogs, cats, and horses in Australia. Methods: Individual tick specimens were collected from dogs, cats and horses across Australia and sample collection locations were mapped using QGIS software. Ticks were morphologically examined to determine species, instar and sex. The companion animal owners responded to questionnaires and data collected were summarised with SPSS software. Results: A total of 4765 individual ticks were identified in this study from 7/8 states and territories in Australia. Overall, 220 larvae, 805 nymphs, 1404 males, and 2336 females of 11 tick species were identified from 837 companion animal hosts. One novel host record was obtained during this study for Ixodes myrmecobii, which was found on Felis catus (domestic cat) in the town of Esperance, Western Australia. The most common tick species identified included R. sanguineus on dogs (73 %), I. holocyclus on cats (81 %) and H. longicornis on horses (60 %). Conclusions: This study is the first of its kind to be conducted in Australia and our results contribute to the understanding of the species and distribution of ticks that parasitise dogs, cats, and horses in Australia. Records of R. sanguineus outside of the recorded distribution range emphasise the need for a systematic study of the habitat range of this species. Several incomplete descriptions of ixodid species encountered in this study hindered morphological identification. [ABSTRACT FROM AUTHOR]

We examined the phylogeny of ticks (Acari:Parasitiformes:Ixodida) and their closest known mite relatives (Acari:Parasitiformes:Mesostigmata and Holothyrida) using 18S rRNA sequences. In our analyses, we included sequences from 36 taxa. Sequences for 13 hard ticks (Family Ixodidae), 5 soft ticks (Family Argasidae), and 2 mesostigmatid mites were obtained from the GenBank database and we generated sequences for 15 hard ticks and 1 holothyrid mite. Ten of these tick species were endemic to Australia. Our analyses indicated that the suborder Holothyrida is more closely related to Ixodida than to Mesostigmata, the group used as outgroup in earlier molecular studies. This finding is consistent with Lehtinen's (1991) hypothesis that the Holothyrida rather than the Mesostigmata is the sister-group to the Ixodida. Within the hard ticks the genus Aponomma and thus the family Amblyomminae were paraphyletic. Taxonomic revision of these taxa is needed. The genus Amblyomma was paraphyletic without the inclusion of "typical" Aponomma species (Ap. latum and Ap. fimbriatum). There was a basal divergence between endemic Australian and other species in both the Metastriata and the Prostriata divisions of the hard ticks., (Copyright 1999 Academic Press.)

The majority of reports, concerning resistance in multi-host ticks, continue to be confined to the cyclodiene group and lindane, with sparse references to resistance affecting the organophosphorus acaricides. In contrast, the resistance picture in Boophilus spp., particularly in relation to B. microplus in Australia, continues to degenerate. Recent reports, documenting the emergence of a complex of pyrethroid resistant strains in the latter species, are the cause of considerable current concern, due to the lack of a suitable, commercially available, replacement group. These developments reinforce the need for a close examination of the strategies recommended for the management of acaricide resistance, particularly for Boophilus spp. The choice of options to select, in circumstances following the detection of resistance to an acaricide, is limited to those aimed at preserving the use of the affected chemical, or selection of an effective alternative, either from within the same class, or from a new acaricide group. Success of the former options, including tactics such as increased concentration or eradication of resistant alleles, and the rational choice of alternative acaricides for use in localized areas where necessary, are critically dependent on early detection of a newly emerged resistance mechanism, its localization, and an understanding of its spectrum of effect. Avermectins and acarine growth regulators show promise as potential future tick control agents. However, the dearth of new chemistry in this area stresses the importance of developing optimal strategies to extend the effective life of these and currently available compounds, in areas where they remain effective.(ABSTRACT TRUNCATED AT 250 WORDS)

The ending of the nineteenth-century was characterized by an escalation of ticks and tick-borne diseases that resulted in the death of many cattle. This necessitated the search for an effective means of tick control. Arsenicals were introduced in Australia in 1895, and arsenic-based dipping vats went on to be used for about 40 years until resistance was found in ticks and more effective alternatives - chemical acaricides - were developed after World War II. However, the development of resistance by ticks, environmental persistence, and mammalian toxicity militated against the sustained use of subsequent chemical acaricides. Furthermore, the development of resistance is a phenomenon that would always evolve, and the multiple mechanisms underlying the synthetic acaricides resistance are of great importance for future integrated control of ticks and tick-borne diseases. Hence, this study retrospectively reviewed the development of synthetic acaricides and the underlying mechanisms of tick resistance against synthetic acaricides in the hope of providing the implications and perspectives for resistance prevention and mitigation for future tick control., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Ticks Acari:Ixodida transmit a greater variety of pathogens than any other blood-feeding group of arthropods. While numerous microbes have been identified inhabiting Australian Ixodidae, some of which are related to globally important tick-borne pathogens, little is known about the bacterial communities within ticks collected from Australian wildlife. In this study, 1,019 ticks were identified on 221 hosts spanning 27 wildlife species. Next-generation sequencing was used to amplify the V1-2 hypervariable region of the bacterial 16S rRNA gene from 238 ticks; Amblyomma triguttatum (n = 6), Bothriocroton auruginans (n = 11), Bothriocroton concolor (n = 20), Haemaphysalis bancrofti (n = 10), Haemaphysalis bremneri (n = 4), Haemaphysalis humerosa (n = 13), Haemaphysalis longicornis (n = 4), Ixodes antechini (n = 29), Ixodes australiensis (n = 26), Ixodes fecialis (n = 13), Ixodes holocyclus (n = 37), Ixodes myrmecobii (n = 1), Ixodes ornithorhynchi (n = 10), Ixodes tasmani (n = 51) and Ixodes trichosuri (n = 3). After bioinformatic analyses, over 14 million assigned bacterial sequences revealed the presence of recently described bacteria 'Candidatus Borrelia tachyglossi', 'Candidatus Neoehrlichia australis', 'Candidatus Neoehrlichia arcana' and 'Candidatus Ehrlichia ornithorhynchi'. Furthermore, three novel Anaplasmataceae species were identified in the present study including; a Neoehrlichia sp. in I. australiensis and I. fecialis collected from quenda (Isoodon fusciventer) (Western Australia), an Anaplasma sp. from one B. concolor from echidna (Tachyglossus aculeatus) (New South Wales), and an Ehrlichia sp. from a single I. fecialis parasitising a quenda (WA). This study highlights the diversity of bacterial genera harboured within wildlife ticks, which may prove to be of medical and/or veterinary importance in the future., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Permethrin is a pyrethroid insecticide that has been widely used for the impregnation of fabrics to prevent the bites from arthropods such as mosquitoes and ticks. There are two types of permethrin impregnation: Do‐It‐Yourself (DIY) packs and pre‐impregnated fabrics. Both forms have been on sale for many years in Australia, however to date, no data are available regarding their efficacy against Ixodes holocyclus. The aims of this study were to test and compare the contact toxicity of a DIY product versus two pre‐impregnated fabrics (shirt and trousers) against I. holocyclus, and to test the efficacy of the fabrics after repeated laundering. All treated and untreated fabrics were tested before laundering (0 washes) and after 10, 30 and 50 washes. Five ticks were placed onto each test fabric for 2 min, with four replicates for a total of 20 ticks per test. Both knockdown and mortality of I. holocyclus ticks were recorded at 60 min and 24 h, respectively. Logistic regression analysis was used to assess the relationship between knockdown and mortality in ticks exposed to each fabric product, before and after laundering. All of the unwashed treated fabrics were effective in causing 100% knockdown. With 10 washes, the percentage of knockdown with the pre‐impregnated shirt and trousers was 95% and 90%, respectively. The DIY product was less effective with only 15% knockdown. The levels of knockdown with the pre‐impregnated shirt and trousers further decreased with 30 washes to 70% and 20%, respectively, and then further declined to 45% and 20% with 50 washes. For the DIY product, knockdown was only 10% and 5% with 30 and 50 washes, respectively. There was minimal mortality recorded at 24 h even with the unwashed fabrics. This study indicated that the pre‐impregnated product was more effective in repelling I. holocyclus ticks than the DIY impregnation pack and the efficacy of this product degrades notably after 10 washes. [ABSTRACT FROM AUTHOR]

Background: Ixodes barkeri, a tick with a distinctive ventrolateral horn-like projection on palpal segment 1, was described in 2019 from two male ticks from the Wet Tropics of Far North Queensland, Australia. However, females lie at the core of the taxonomy and subgenus classification of Ixodes; hence, we sought specimens of female ticks, successfully recovering females, plus nymphs and larvae. Mitochondrial genomes are also desirable additions to the descriptions of species of ticks particularly regarding subgenus systematics. So, we sequenced the mt genomes of I. barkeri Barker, 2019, and the possible relatives of I. barkeri that were available to us (I. australiensis Neumann, 1904, I. fecialis Warburton & Nuttall, 1909, and I. woyliei Ash et al. 2017) with a view to discovering which if any of the subgenera of Ixodes would be most suitable for I. barkeri Barker, 2019. Results: The female, nymph, larva and mitochondrial genome of Ixodes barkeri Barker, 2019, are described for the first time and the male of I. barkeri is redescribed in greater detail than previously. So far, I. barkeri is known only from a monotreme, the short-beaked echidna, Tachyglossus aculeatus (Shaw, 1792), from the highland rainforests of the Wet Tropics of Far North Queensland, Australia. Conclusions: Our phylogeny from entire mitochondrial genomes indicated that I. barkeri and indeed I. woyliei Ash et al., 2017, another tick that was described recently, are best placed in the subgenus Endopalpiger Schulze, 1935. [ABSTRACT FROM AUTHOR]

This review outlines the history of parasiticide resistance in the principal ectoparasites of sheep and cattle in New Zealand and Australia, blowflies, buffalo fly (Haematobia irritans exigua), sheep biting louse (Bovicola ovis) and cattle ticks, and discusses recent changes in their response to insecticides and acaricides. Mechanisms of resistance and evaluation methods are described, with ways in which insecticide resistance can be avoided or ameliorated also discussed. Resistance in sheep blowflies (Lucilia cuprina; L. sericata) to organophosphates and benzoylphenyl urea compounds is widespread in Australia and New Zealand, but there are lesser concerns about a pyrimidine carbonitrile product as well as cyromazine and macrocyclic lactone actives which still offer the promise of long-term protection. In Australia the effectiveness of synthetic pyrethroid and benzoylphenyl urea products against the biting louse of sheep have been reduced by widespread resistance but effective temephos, macrocyclic lactone, imidacloprid and spinosyn-based products are now available. Pyrethroid-resistant sheep lice are also present in New Zealand. Buffalo fly remains a significant problem in Australia and control relies heavily on insecticide use. Resistance to synthetic pyrethroids is widespread and organophosphate resistance common, but less evenly distributed. There is no evidence of resistance to acaricides used against the New Zealand cattle tick, Haemaphysalis longicornis and experience in Japan with the most commonly available active, flumethrin (a synthetic pyrethroid), suggests that this three-host tick is, in the short term, likely to remain susceptible. The same cannot be said for Rhipicephalus australis (formerly Boophilus microplus) which, in some strains, is highly resistant to many of the active ingredients in the acaricides used against it. A formamidine, a benzoylphenyl urea and macrocyclic lactones still show efficacy although some resistance is being detected to macrocyclic lactones in a few strains and the occurrence of resistance to the benzoylphenyl urea active in Brazil is ominous for Australian producers. Insecticide resistance is a price paid for improved livestock health, welfare and cost-effective animal production, but it can be managed through judicious and targeted use of insecticides, consideration of refugia, and observance of the principles of integrated pest management. The use of traps, biological control agents and judicious husbandry all have a role to play, but strict adherence to the correct application of insecticides and recognition of their capabilities and limitations is also required. Alternative methods of ectoparasite control and recommendations for their integration into preventative programmes are discussed briefly in this review.

Abstract: The mode of action of amitraz is thought to be its toxic effects on a receptor for a neuromodulator, octopamine. Resistance could arise from modifications of this receptor so that it would not be affected by amitraz. A putative octopamine receptor cDNA was cloned and sequenced from a cattle tick in Australia. However, when the sequence was compared between Australian strains of amitraz-susceptible and resistant ticks, no differences were detected. We have sequenced this putative octopamine receptor gene in tick strains from America. The American ticks have a sequence almost identical to that of the Australian ticks with no deletions or additions in the open reading frame. In a Brazilian strain and a Mexican strain that are very resistant to amitraz, there are two nucleotide substitutions that result in amino acids different from all the susceptible strains. Discovery of these mutations only in amitraz-resistant ticks provides the first evidence for the possibility of an altered pesticide target site as a mechanism of amitraz resistance in ticks. [Copyright &y& Elsevier]

We describe here a molecular genetic study designed to elucidate the ability of an ixodid tick to move within their range as well as between species or hosts. A direct match from the contiguous regions of the small rRNA subunit, control region #1, tRNA-Ile, tRNA-Gln and tRNA-Met of the population studied here with previously published sequence suggests that the species is likely Ixodes hirsti. Phylogenetic analysis of tick haplotypes showed no evidence for bird-host specialisation, and a nested clade analysis indicated a high degree of migration between our three collection sites (two sites on Kangaroo Island, and one site on mainland South Australia). [ABSTRACT FROM AUTHOR]

The widespread geographical distribution of Rhipicephalus decoloratus in southern Africa and its ability to transmit the pathogens causing redwater, gallsickness and spirochaetosis in cattle makes this hematophagous ectoparasite of economic importance. In South Africa, the most commonly used chemical acaricides to control tick populations are pyrethroids and amitraz. The current amitraz resistance mechanism described in R. microplus, from South Africa and Australia, involves mutations in the octopamine receptor, but it is unlikely that this will be the only contributing factor to mediate resistance. Therefore, in this study we aimed to gain insight into the more complex mechanism(s) underlying amitraz resistance in R. decoloratus using RNA-sequencing. Differentially expressed genes (DEGs) were identified when comparing amitraz susceptible and resistant ticks in the presence of amitraz while fed on bovine hosts. The most significant DEGs were further analysed using several annotation tools. The predicted annotations from these genes, as well as KEGG pathways potentially point towards a relationship between the α-adrenergic-like octopamine receptor and ionotropic glutamate receptors in establishing amitraz resistance. All genes with KEGG pathway annotations were further validated using RT-qPCR across all life stages of the tick. In susceptible ticks, the proposed model is that in the presence of amitraz, there is inhibition of Ca 2+ entry into cells and subsequent membrane hyperpolarization which prevents the release of neurotransmitters. In resistant ticks, we hypothesize that this is overcome by ionotropic glutamate receptors (NMDA and AMPA) to enhance synaptic transmission and plasticity in the presence of neurosteroids. Activation of NMDA receptors initiates long term potentiation (LTP) which may allow the ticks to respond more rapidly and with less stimulus when exposed to amitraz in future. Overactivation of the NMDA receptor and excitotoxicity is attenuated by the estrone, NAD + and ATP hydrolysing enzymes. This proposed pathway paves the way to future studies on understanding amitraz resistance and should be validated using in vivo activity assays (through the use of inhibitors or antagonists) in combination with metabolome analyses., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Ticks are blood-sucking parasites of vertebrates that may embed in human skin and are therefore of clinical relevance to dermatologists and their medical colleagues. Depending on the species involved, consequences of tick attachment vary from minor local reactions to significant systemic sequelae. It is possible to minimize morbidity by removing the tick in its entirely as soon as it is detected. Some techniques to achieve this are described. The review will aid clinicians in the recognition and practical management of tick bites in Australia. [ABSTRACT FROM AUTHOR]

A growing number of indigenous trypanosomes have been reported to naturally infect a variety of Australian wildlife with some species of Trypanosoma implicated in the population decline of critically endangered marsupials. However, the mode of transmission of Australian trypanosomes is unknown since their vectors remain unidentified. Here we aimed to fill this current knowledge gap about the occurrence and identity of indigenous trypanosomes in Australian invertebrates by conducting molecular screening for the presence of Trypanosoma spp. in native ticks collected from south-west Australia. A total of 231 ticks (148 collected from vegetation and 83 retrieved directly from 76 marsupial hosts) were screened for Trypanosoma using a High-Resolution Melt (HRM) qPCR assay. An overall Trypanosoma qPCR positivity of 37% (46/125) and 34% (26/76) was detected in questing ticks and host-collected (i.e., feeding) ticks, respectively. Of these, sequencing revealed 28% (35/125) of questing and 28% (21/76) of feeding ticks were infected with one or more of the five species of trypanosome previously reported in this region (T. copemani, T. noyesi, T. vegrandis, T. gilletti, Trypanosoma sp. ANU2). This work has confirmed that Australian ticks are capable of harbouring several species of indigenous trypanosome and likely serve as their vectors. [ABSTRACT FROM AUTHOR]

The black rat Rattus rattus has a distribution that includes much of Earth's terrestrial surface, and has adapted to exploit both habitats extensively modified by humans and rural habitats. Despite the fact that R. rattus are nearly ubiquitous, few studies have investigated urban or peri-urban R. rattus as potential hosts for ticks. In this study, we identified the species of ticks that parasitize R. rattus in a remnant bush area within Sydney, Australia. We then examined the relationship between ticks and R. rattus by testing several rat body characteristics as predictors of tick abundance. We show that larva and nymphs of five species of native Australian tick parasitize R. rattus in urban Australia. The most abundance species was Ixodes holocyclus, a tick of veterinary and human health concern. We found that ticks were more abundant on R. rattus in better condition, for larva and nymphs of I. holocyclus and I. tasmani. Rattus rattus supports a rich assembly of ticks in a remnant forest in urban Australia, and as the R. rattus in best condition have the most ticks, tick parasitism at the levels observed does not appear to negatively impact R. rattus. Our findings illustrate that R. rattus, and other human commensal species, may be important hosts for ticks in human modified environments., (Copyright © 2019 Elsevier GmbH. All rights reserved.)

Ticks cause substantial production losses for beef and dairy cattle. Cattle resistance to ticks is one of the most important factors affecting tick control, but largely neglected due to the challenge of phenotyping. In this study, we evaluate the pooling of tick resistance phenotyped reference populations from multi-country beef cattle breeds to assess the possibility of improving host resistance through multi-trait genomic selection. Data consisted of tick counts or scores assessing the number of female ticks at least 4.5 mm length and derived from seven populations, with breed, country, number of records and genotyped/phenotyped animals being respectively: Angus (AN), Brazil, 2,263, 921/1,156, Hereford (HH), Brazil, 6,615, 1,910/2,802, Brangus (BN), Brazil, 2,441, 851/851, Braford (BO), Brazil, 9,523, 3,062/4,095, Tropical Composite (TC), Australia, 229, 229/229, Brahman (BR), Australia, 675, 675/675, and Nguni (NG), South Africa, 490, 490/490. All populations were genotyped using medium density Illumina SNP BeadChips and imputed to a common high-density panel of 332,468 markers. The mean linkage disequilibrium (LD) between adjacent SNPs varied from 0.24 to 0.37 across populations and so was sufficient to allow genomic breeding values (GEBV) prediction. Correlations of LD phase between breeds were higher between composites and their founder breeds (0.81 to 0.95) and lower between NG and the other breeds (0.27 and 0.35). There was wide range of estimated heritability (0.05 and 0.42) and genetic correlation (-0.01 and 0.87) for tick resistance across the studied populations, with the largest genetic correlation observed between BN and BO. Predictive ability was improved under the old-young validation for three of the seven populations using a multi-trait approach compared to a single trait within-population prediction, while whole and partial data GEBV correlations increased in all cases, with relative improvements ranging from 3% for BO to 64% for TC. Moreover, the multi-trait analysis was useful to correct typical over-dispersion of the GEBV. Results from this study indicate that a joint genomic evaluation of AN, HH, BN, BO and BR can be readily implemented to improve tick resistance of these populations using selection on GEBV. For NG and TC additional phenotyping will be required to obtain accurate GEBV. [ABSTRACT FROM AUTHOR]