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Experimental infection with Rickettsia rickettsii in an Amblyomma dubitatum tick colony, naturally infected by Rickettsia bellii.

Amblyomma dubitatum engorged females, naturally infected by Rickettsia bellii, were used to establish a laboratory colony. Larvae, nymphs, and adults were exposed to two strains of Rickettsia rickettsii by feeding on needle-inoculated guinea pigs, and thereafter reared on uninfected guinea pigs. After acquisition feeding, engorged larvae and nymphs molted to nymphs and adults, respectively, which were shown to be infected (confirming transstadial perpetuation), and were able to transmit both strains of R. rickettsii to uninfected animals, as demonstrated by clinical, serological, and molecular…

Characterization of the bacterial communities of life stages of free living lone star ticks (Amblyomma americanum).

The lone star tick (Amblyomma americanum) is an abundant and aggressive biter of humans, domestic animals, and wildlife in the southeastern-central USA and an important vector of several known and suspected zoonotic bacterial pathogens. However, the biological drivers of bacterial community variation in this tick are still poorly defined. Knowing the community context in which tick-borne bacterial pathogens exist and evolve is required to fully understand the ecology and immunobiology of the ticks and to design effective public health and veterinary interventions. We performed a metagenomic su…

Development of Theileria mutans (Theiler, 1906) in the gut and the haemolymph of the tick Amblyomma variegatum (Fabricius, 1794).

The development of Theileria mutans in the gut and haemolymph of its tick vector, Amblyomma variegatum, was studied by Giemsa-stained smears after the nymphal tick had completed engorgement on parasitaemic calves. Sexual stages occurred in the gut between five and seven days after repletion. The zygotes were observed in the gut from day 29 and the kinetes from day 30, i.e. three and four days after the nymphs moulted to adults. From day 34 kinetes were observed in the haemolymph. The developmental stages of T. mutans in the tick were compared with those of other Theileria spp. of cattle.

Rickettsia africae infection rates and transovarial transmission in Amblyomma hebraeum ticks in Mnisi, Bushbuckridge, South Africa.

Rickettsia africae is a gram-negative bacterium, which causes African tick bite fever (ATBF) in humans. ATBF is a febrile disease mainly affecting travellers to southern Africa. This bacterium is known to be transmitted by Amblyomma hebraeum and Amblyomma variegatum ticks. In southern Africa, the principal vector is A. hebraeum. Febrile disease is a serious issue in the study area. There is a high prevalence of non-malaria illness caused by Rickettsia, so there is a need to have more knowledge on these species. Infection rates and transovarial transmission efficiency of R. africae in A. hebrae…

Vector competence of human-biting ticks Ixodes scapularis, Amblyomma americanum and Dermacentor variabilis for Powassan virus.

BACKGROUND: Powassan virus (POWV; genus Flavivirus) is the sole North American member of the tick-borne encephalitis sero-complex and an increasing public health threat in the USA. Maintained in nature by Ixodes spp. ticks, POWV has also been isolated from species of other hard tick genera, yet it is unclear if these species can serve as vectors. Dermacentor variabilis and Amblyomma americanum share geographic and ecologic overlap with Ixodes spp. ticks and POWV transmission foci, raising the possibility that POWV could become established in these tick species and leading to range expansion an…

Primary isolation of spotted fever group rickettsiae from Amblyomma cooperi collected from Hydrochaeris hydrochaeris in Brazil.

This paper reports the first isolation of a spotted fever group rickettsia from an Amblyomma cooperi ixodid collected from a capybara (Hydrochaeris hydrochaeris) in an endemic area of spotted fever in the County of Pedreira, State of São Paulo, Brazil. Isolation was performed in Vero cell culture and submitted to immunofluorescence, using antibody from Rickettsia rickettsii-positive human serum.

First record and molecular identification of Amblyomma geoemydae and Haemaphysalis campanulata parasitizing wildlife in Ashanti Region, Ghana.

In sub-Saharan Africa, ticks, which are ectoparasites, pose a serious risk to public health and the economy as important vectors of a variet … dant species, infesting only grasscutters. This study reports the first molecular identification of Amblyomma geoemydae and Haemaphysalis campanulata in Ghana. Furthermore, the sequences from this study were similar to those reported from Asia and other African countries, highlighting the diversity and possibility for tick species to spread across regions. …

Vector competence and transovarial transmission of Rickettsia rickettsii in Rickettsia bellii-infected and -uninfected Amblyomma dubitatum ticks.

Brazilian spotted fever (BSF) is endemic in southeastern Brazil, where Amblyomma sculptum is the main vector incriminated in the transmission of R. rickettsii to humans. In many BSF-endemic areas capybaras are the main hosts for A. sculptum and also efficient amplifiers of R. rickettsii for this tick species. Capybaras are also primary hosts for Amblyomma dubitatum, a tick species frequently found infected by Rickettsia bellii but with no records of natural infection by R. rickettsii. The present study aimed to evaluate transovarial transmission and vector competence for R. rickettsii in A. du…

Acaricidal efficacy evaluation of amitraz and diazinon against Amblyomma variegatum tick species in Waghimra zone, northern Ethiopia.

Ticks pose a substantial economic burden associated with production loss and treatment costs globally. Ethiopia has tremendous livestock resources, but its productivity is hindered by various animal health challenges in which ticks are the top priority, with a limited response to acaricidal treatments. Hence, we designed an acaricidal efficacy trial for the top commercially available Chemicals (amitraz and diazinon) to examine their efficacy against the widely distributed tick species (Amblyoma variegatum). Ticks were collected from animals admitted to veterinary clinics with no history of tre

Молекулярное обнаружение эндосимбионт Коксиеллы и отсутствие ожогов Коксиеллы в Amblyomma mixtum из Веракруса, Мексика.

Тики обязывают эктопарацитов, связанных с широким кругом позвоночных, включая домашних животных. Кроме того, клещи способны передавать многие патогены, такие как Коксиэлла. На сегодняшний день единственным действительным видом генры является этиологический агент коксиэллоза или лихорадки Q. Тем не менее в ходе недавних исследований был обнаружен целый ряд агентов, деноминированных в коксиелле, главным образом связанных с клещами. Патогенность этих агентов, подобных Коксиелле, противоречива, поскольку некоторые из них могут заразить как птиц, так и людей. В Мексике знания о лихорадке Q ограниче

Совпадение в аннотации оригинала
Ticks are obligate ectoparasites associated with a wide range of vertebrate hosts, including domestic animals. Moreover, ticks are capable o … es detected. From the 10 regions sampled we collected 888 ticks grouped in 180 pools, and only five Amblyomma mixtum from the locality of Castán, and one from Los Angeles from Tuxpan were found positive, which represents a frequency of 20% for each locality. This study represents the first attempt at molecular detection of Coxiella in ticks associated with …

Rickettsia parkeri strain Atlantic rainforest infecting Amblyomma ovale (Acari: Ixodidae) in the Amazon Biome (Acre state, Brazil).

There is a lack of studies regarding tick-associated Rickettsia in the Amazon biome. Aiming to contribute to this knowledge, our research group collected ticks in the Western Amazon to better understand the tick fauna and their associated Rickettsia. In this study, we detected Rickettsia parkeri strain Atlantic rainforest DNA in the tick Amblyomma ovale Koch, 1844 in Rio Branco municipality, Acre state, northern Brazil. This is the first time that the R. parkeri strain Atlantic rainforest has been reported in the Amazon biome and is the first evidence of the circulation of a pathogenic spotted…

Establishment of Amblyomma americanum populations and new records of Borrelia burgdorferi-infected Ixodes scapularis in South Dakota.

Tick-borne diseases are an emerging public health threat in the United States, but surveillance is lacking in some regions. To advance curre … the most commonly identified tick, present in all counties surveyed. However, we also identified 15 Amblyomma americanum from three different locations, providing the first evidence of established populations in the state and expanding the range of this species. In addition, we identified 22 Ixodes scapularis from five different locations, confirming a prev …

Lethal Effects of a Commercial Diatomaceous Earth Dust Product on Amblyomma americanum (Ixodida: Ixodidae) Larvae and Nymphs.

With increasing development of resistance to conventional synthetic acaricides in economically and medically important ixodid species, interest in finding alternative control tactics has intensified. Laboratory bioassays were conducted, using the lone star tick, Amblyomma americanum (L.), as a model species, to assess the efficacy of a diatomaceous earth-based product, Deadzone, in comparison with a silica gel-based product, CimeXa. CimeXa is already known to be highly lethal against A. americanum larvae and nymphs. The two dust treatments were 100% effective against larvae and nymphs within 2…

Reproductive incompatibility between Amblyomma maculatum (Acari: Ixodidae) group ticks from two disjunct geographical regions within the USA.

The Amblyomma maculatum Koch group of ixodid ticks consists of three species: A. maculatum, A. triste, and A. tigrinum. However, since Koch described this group in 1844, the systematics of its members has been the subject of ongoing debate. This is especially true of A. maculatum and A. triste; recent molecular analyses reveal insufficient genetic divergence to separate these as distinct species. Further confounding this issue is the discovery in 2014 of A. maculatum group ticks in southern Arizona (AZ), USA, that share morphological characteristics with both A. triste and A. maculatum. To bio…

First molecular detection of Rickettsia africae in a tropical bont tick, Amblyomma variegatum, collected in Corsica, France.

Here we report the first detection of Amblyomma variegatum, a tick species of medical and veterinary importance, and the first molecular evidence of a pathogen, Rickettsia africae, both new to Corsica (France). In August 2018, an ixodid tick with an unusual morphology was removed from the ventral part of a cow's whole skin in a slaughterhouse located in the village of Ponte-Leccia (Haute-Corse). The tick was morphologically identified as an adult male of A. variegatum. This result was confirmed by 16S rDNA sequence analysis with a close relative being a sequence from Senegal showing 99% nucleo…

Laboratory evaluation of the efficacy of lotilaner (Credelio™) against Amblyomma cajennense (sensu lato) infestations of dogs.

BACKGROUND: The ixodid tick Amblyomma cajennense (sensu lato) complex, widespread throughout South and Central America, is also present in Mexico, Texas and Florida. As a vector of Rickettsia rickettsii, and potentially of other pathogens, infestations with A. cajennense present a substantial health risk to humans, dogs and other mammals. Oral administration of lotilaner flavored chewable tablets (CredelioTM, Elanco) to dogs was previously shown to rapidly provide killing activity of infesting ticks. This study investigated lotilaner's efficacy against A. cajennense (s.l.). METHODS: Twenty pu…

Rickettsia gravesii sp. nov.: a novel spotted fever group rickettsia in Western Australian Amblyomma triguttatum triguttatum ticks.

A rickettsial organism harboured by Amblyomma triguttatum ticks on Barrow Island, Western Australia, was discovered after reports of possible rickettsiosis among local workers. Subsequent isolation of this rickettsia (strain BWI-1) in cell culture and analysis of its phylogenetic, genotypic and phenotypic relationships with type strains of Rickettsia species with standing in nomenclature suggested that it was sufficiently divergent to warrant its classification as a new species. Multiple gene comparison of strain BWI-1 revealed degrees of sequence similarity with Rickettsia raoultii, its close…

A novel relapsing fever Borrelia sp. infects the salivary glands of the molted hard tick, Amblyomma geoemydae.

A novel relapsing fever Borrelia sp. was found in Amblyomma geoemydae in Japan. The novel Borrelia sp. was phylogenetically related to the hard (ixodid) tick-borne relapsing fever Borrelia spp. Borrelia miyamotoi and B. lonestari. The novel relapsing fever Borrelia sp. was detected in 39 A. geoemydae (39/274: 14.2%), of which 14 (14/274: 5.1%) were co-infected with the novel relapsing fever Borrelia sp. and Borrelia sp. tAG, one of the reptile-associated borreliae. Transstadial transmission of the novel relapsing fever Borrelia sp. occurred in the tick midgut and the salivary glands, although …

Characterization of bacterial microbiome and molecular detection of rickettsiosis in free-living ticks (Amblyomma sculptum Berlese, 1888).

Amblyomma sculptum is a major tick species in southeastern Brazil and an important vector in the epidemiology of Brazilian Spotted Fever (BSF). This study characterized the bacterial microbiome of free-living A. sculptum ticks in a BSF-endemic area, focusing on differences among developmental stages and sexes, and investigated rickettsial agents using 16S rRNA gene (V3-V4) sequencing. A total of 154 ticks were collected and analysed as 13 pooled samples grouped by stage and sex. Sequencing identified a diverse bacterial community of 180 genera, dominated by Sphingomonas, Nocardioides, Actinomy…

Importation of the exotic tick Amblyomma geoemydae into Sweden via illegally introduced turtles (Geoemyda spengleri) from Thailand.

Illegal importation of animals as pets might be followed by the introduction of exotic tick species, potential vectors of pathogens that can … ed by the SVA itself. The three collected ticks were identified based on morphology and genetics as Amblyomma geoemydae nymphs. This discovery demonstrates that SVA's surveillance tool can function as an early warning system for newly introduced tick species and to promptly identify exotic tick species which can carry viruses, bacteria, and/or parasites tha …