[First autochthonous case of spotted fever associated with the Reserva Ecológica Costanera Sur, Buenos Aires City]. / Primer caso autóctono de fiebre manchada asociado a la Reserva Ecológica Costanera Sur, Ciudad Autónoma de Buenos Aires.

The first autochthonous case of rickettsiosis is reported here. The case occurred in the Costanera Sur Ecological Reserve, a protected area of the City of Buenos Aires, in August 2022, where 4 species of ticks were found, namely Amblyomma aureolatum, Ixodes auritulus sensu lato, Rhipicephalus sanguineus sensu stricto and Amblyomma triste. The epidemiological, ecological, clinical and laboratory aspects that allowed timely diagnosis and appropriate treatment are also described.

Pathogens associated with ticks (Acari: Ixodidae) and mammals in the Orinoquia region of Colombia: An approach to understanding vector-pathogen-host interactions.

The hard tick clade (Ixodidae) currently comprises 762 species worldwide (266 Prostriata and 496 Metastriata). A quarter of hard ticks are found in the Neotropical region, and 42 species have been documented in Colombia. Ixodidae species are important vectors of pathogens such as bacteria, helminths, protozoa, and viruses. In tick-borne diseases, vertebrate hosts perform an important role in the transmission, maintenance, and spread of pathogens. Colombia ranks sixth among countries with the highest mammal biodiversity, with a total of 548 species, where some of these species may be involved in pathogen transmission cycles with ticks as vectors. This research evaluated the presence of two genera of bacteria (Borrelia and Rickettsia) and the protozoan (Babesia) in ticks and mammals in the Orinoquia region of Colombia, establishing interaction networks. The information comes from 734 mammals (655 wild and 79 domestic), belonging to 59 species. Tick infestation (n = 1,805) was found with 14.85 % (n = 109) of the examined mammals and corresponds to nine tick species confirmed morphologically and molecularly. To detect pathogens 272 ticks were collected while feeding on 96 mammals; samples from 93 mammals were analyzed. The presence of borreliae from the relapsing fever group (RFG) and the Lyme disease group (LDG) were detected. Rickettsia spp. was detected in ticks and mammals, while Babesia bigemina was only detected in ticks. This research is the first to address the prevalence of zoonotic pathogens in domestic and wild mammals infested with hard ticks in the Department of Arauca, Colombia. Considering that reporting cases of infections with Babesia, Borrelia, and Rickettsia in Colombia is not mandatory, their impact on public health cannot be estimated. This highlights the importance of continuously detecting, confirming, and identifying these and other important pathogens within the "One Health" framework, as they have a significant economic and medical-veterinary impact globally.

Potential zoonotic role of the tick Amblyomma cf. oblongoguttatum (Ixodida: Ixodidae) in the bacterial transmission of Ehrlichia chaffeensis (Rickettsiales: Anaplasmataceae) in a deciduous tropical forest in Mexico.

Ehrlichia chaffeensis is a bacterium belonging to the Anaplasmataceae family. In Mexico, only 2 species have been recorded in association with tick species and humans. The objective of the present study was to detect the presence of bacteria of the genus Ehrlichia in ticks collected from the Chamela-Cuixmala Biosphere Reserve, Jalisco, Mexico. The collected ticks were identified and analyzed individually by polymerase chain reaction to amplify a fragment of the Anaplasmataceae 16S rRNA gene and the Ehrlichia-specific dsb gene. A total of 204 ticks, corresponding to 5 species of Ixodidae and 1 of Argasidae, were collected from 147 mammals of 6 species and 4 orders; 57 ticks collected from vegetation were also included. Among the total ticks collected, 1.47% (3/204) was positive for Ehrlichia sp. DNA was obtained using the primers EHR 16SD and EHR 16SR for 16S rRNA and DSB-330 and DSB-728 for dsb. The positive samples corresponded to a larva (Amblyomma sp.) associated with Didelphis virginiana and 2 nymphs (Amblyomma cf. oblongoguttatum) infesting Nasua narica. None of the ticks collected from the vegetation tested positive for Ehrlichia sp. DNA on the basis of the 16S rRNA and dsb genes. The sequences from the larvae of Amblyomma sp. and the nymphs of A. cf. oblongoguttatum were similar to those of E. chaffeensis. The phylogenetic analysis inferred with maximum likelihood corroborated the identity as E. chaffeensis. Although the role of these tick species as vectors of E. chaffeensis is still undetermined, the presence of infected ticks in the area indicates a potential zoonotic risk.

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

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

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

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

Parasitism on domestic cats by Amblyomma auricularium and serological evidence of exposure to Rickettsia amblyommatis.

The domestic cat is not considered a primary host for any specific tick species; however, it can be affected by some Ixodidae species, such as Rhipicephalus sanguineus sensu lato and Amblyomma spp. The study reports parasitism by Amblyomma auricularium and the detection of anti-Rickettsia spp. antibodies in domestic cats from a rural property in the Afrânio municipality, Pernambuco, Brazil. Amblyomma auricularium (24 nymphs, six females, and four males) and Amblyomma sp. (42 larvae) parasitized three cats, and 73 free-living ticks were captured in armadillo burrows: A. auricularium (36 nymphs, six females, five males) and Amblyomma sp. (26 larvae). Blood samples from cats were collected and the obtained plasma were subjected to indirect immunofluorescence assay (IFA) to detect antibodies against Rickettsia antigens. Thus, anti-Rickettsia spp. antibodies were determined (titers ranging from 128 to 512) and showed a predominant antibody response to Rickettsia amblyommatis or a very closely related genotype. This study reports the first infestation of nymphs and adults of A. auricularium on cats in a new area of occurrence in the semi-arid region of Northeastern Brazil and reports for the first time the presence of anti-Ricketsia antibodies in cats in the region, with R. amblyommatis as the probable infectious agent.

Density and behavior of capybara (Hydrochoerus hydrochaeris) ticks (Acari: Ixodidae) Amblyomma sculptum and Amblyomma dubitatum with notes on Rickettsia bellii infection: Assessing human exposure risk.

In several urban and peri­urban areas of Brazil, populations of Amblyomma sculptum and Amblyomma dubitatum ticks are maintained by capybaras (Hydrochoerus hydrochaeris). In some of these areas, this host and these tick species are associated with Brazilian spotted fever (BSF), a lethal human disease caused by the bacterium Rickettsia rickettsii. In this work, we evaluated the risk of human exposure to these tick species using four collection techniques to discern host-seeking behavior. The study was carried out in 10 urban sites inhabited by capybaras in Uberlândia, a BSF-free municipality in southeastern Brazil. Ticks were collected in areas of 400 m2 at each site and at three seasons. Within the same municipality, the distance and speed of A. sculptum nymphs moving towards the CO2 traps were evaluated. In a sample of ticks Rickettsia DNA was investigated. During the study period, 52,953 ticks were collected. Among these, 83.4 % were A. sculptum (1,523 adults, 10,545 nymphs and 32,104 larvae) and 16.6 % were A. dubitatum (464 adults, 2,153 nymphs and 6,164 larvae). An average annual questing tick density of 4.4/m² was observed, with the highest density recorded at one site in autumn (31.8/m²) and the lowest in summer at another site (0.03/m²). The visual search yielded the highest proportion of A. sculptum larvae, constituting 47 % of the total and 63.6 % of all A. sculptum larvae. In contrast, CO2 traps collected a greater proportion of nymphs and adults of A. sculptum ticks. In the case of A. dubitatum, the CO2 trap was the most efficient technique with 57.7 % of captures of this species, especially of nymphs (94.5 % of captures) and adults (97.8 % of captures). Ticks' ambush height on vegetation (9 to 77 cm), observed by visual search 30 times, yielded a total of 20,771 ticks. Of these, 28 (93 %) were A. sculptum ticks, with only two (7 %) identified as A. dubitatum ticks. Among A. sculptum ticks, the nymph was the most attracted stage to humans and larva in the case of A. dubitatum. Amblyomma sculptum adults and nymphs were significantly more attracted to humans than those of A. dubitatum, but A. dubitatum larvae were significantly more attracted than the same stage of A. sculptum. The maximum distance and speed of horizontal displacement for A. sculptum nymphs were five meters and 2.0 m/h, respectively. The only species of Rickettsia detected in ticks, exclusively in A. dubitatum, was R. bellii. Importantly, it was observed that the higher the proportion of A. sculptum in the community of ticks, the lower the rate of infection of A. dubitatum by R. bellii. In conclusion, host-seeking behavior differed between the two tick species, as well as between stages of the same species. A greater restriction of A. dubitatum ticks to the soil was observed, while larvae and nymphs of A. sculptum dispersed higher in the vegetation. The behavior presented by A. sculptum provides greater opportunities for contact with the hosts, while A. dubitatum depends more on an active search for a host, the hunter behavior. Taken together, these observations show that a human being crossing an area infested with A. sculptum and A. dubitatum ticks will have almost exclusive contact with A. sculptum larvae and/or nymphs. Humans in a stationary position (sitting, lying or immobile) are exposed to both tick species, but they are more attractive to adults and mainly nymphs of A. sculptum compared to the corresponding stages of the tick A. dubitatum. The negative effect of A. sculptum on A. dubitatum infection by R. bellii deserves further studies.

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

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

Survey of Rickettsia spp. in ticks (Acari: Ixodidae) infesting opossums (Didelphis albiventris) and capybaras (Hydrochoerus hydrochaeris) from an urban park in southeastern Brazil.

Ticks are hematophagous arthropods and, during feeding, may transmit pathogens to vertebrate hosts, including humans. This study aimed to investigate the presence of Rickettsia spp. in ticks collected between 2010 and 2013 from free-ranging capybaras (Hydrochoerus hydrochaeris) and opossums (Didelphis albiventris) that inhabit Sabiá Park in Uberlândia, Brazil. Overall, 1,860 ticks were collected: 1,272 (68.4%) from capybaras (487 of the species Amblyomma sculptum, 475 adults and 12 nymphs; 778 Amblyomma dubitatum, 727 adults and 51 nymphs; and seven larva clusters of the genus Amblyomma); and 588 (31.6%) from opossums (21 A. sculptum, one adult and 20 nymphs; 79 A. dubitatum, all nymphs; 15 Ixodes loricatus, 12 adults and three nymphs; 457 Amblyomma sp. larva clusters; 15 Ixodes sp. larva clusters; and one Argasidae larva cluster). Out of 201 DNA samples tested for the presence of Rickettsia spp. DNA using polymerase chain reaction (PCR) 12 showed amplification of a gtlA gene segment that was specific to Rickettsia bellii, a bacterium non-pathogenic to humans. As there has been a report showing serological evidence of infections caused by Rickettsia species of the spotted fever group (SFG) in capybaras and opossums in the park, including Rickettsia rickettsii, the etiological agent of Brazilian spotted fever, and considering the presence of A. sculptum ticks, which are aggressive to humans, as well as these vertebrate hosts, which are amplifiers of R. rickettsii, it is important to monitor the presence of SFG rickettsiae in the Sabiá Park, which is visited daily by thousands of people.

Tick-borne microorganisms in Amblyomma tigrinum (Acari: Ixodidae) from the Patagonian region of Argentina.

This study presents the results of the molecular detection of tick-borne microorganisms in Amblyomma tigrinum Koch collected near the city of Viedma, Río Negro, Argentina. Ticks were collected in their non-parasitic stage, on pet dogs and on Lycalopex gymnocercus (Pampa fox). Also, six tick samples from humans were analyzed. All ticks were morphologically identified to species level and genomic DNA was extracted. The DNA samples were examined by end point PCR assays to amplified DNA of Anaplasma sp., Babesia sp., Ehrlichia sp., Rickettsia sp. and Theileria sp. Although all tested DNA samples from the collected ticks resulted negative to the detection of Piroplasmida and Rickettsia spp., 16 samples (16.5%, including all hosts) were positive in the 16S rDNA gene PCR that detects bacteria from the Anaplasmataceae family. Phylogenetic analysis of seven obtained partial sequences resulted in the identification of three bacteria: two Ehrlichia spp. (related to Ehrlichia sp. strain Iberá and strain Viedma) and Candidatus Anaplasma boleense. The latter finding represents the first detection of this novel Candidatus species in A. tigrinum. Based on the results of this study, it must be assumed that the diversity of bacteria of the Anaplasmataceae family in Argentina is greater than previously thought, and that these bacteria can infect a wide range of domestic and wild animals.

Molecular detection of Candidatus Ehrlichia pampeana (Rickettsiales: Anaplasmataceae) in Haemaphysalis juxtakochi (Acari: Ixodidae) from central Argentina.

The aim of this study was to report the first detection of Candidatus Ehrlichia pampeana in Haemaphysalis juxtakochi from Argentina. Free-living ticks were collected from vegetation by drag-flag method on five sample sites in Entre Ríos Province, central Argentina, belonging to the Espinal Phytogeographic Province. Molecular detection of order Rickettsiales agents was performed using gltA (Rickettsia spp.), 16 S rRNA and groEL (Anaplasmataceae) genes as targets. A total of 67 ticks of Amblyomma aureolatum (20 nymphs and 4 adults), Amblyomma dubitatum (15 nymphs) and Haemaphysalis juxtakochi (24 nymphs and 4 adults) were collected. While all tested ticks were negative for Rickettsia spp., and Anaplasmataceae agents could neither be detected in A. aureolatum nor in A. dubitatum, Candidatus Ehrlichia pampeana was detected in one male of H. juxtakochi. DNA sequences of this microorganism (16 S rDNA and groEL) are related to sequences of Ehrlichia ewingii. The findings of the current study represent the first report of this Ehrlichia strain for Argentina.

New tick records with notes on rickettsial infection from the wildlife of the state of Espírito Santo, southeastern Brazil.

This work aimed to report ticks infesting the wildlife among 15 municipalities of the state of Espírito Santo between 2016 and 2021, within the Atlantic Forest biome of southeastern Brazil. A total of 576 tick specimens (187 males, 56 females, 149 nymphs, and 184 larvae) was collected from 41 species of wild vertebrates (two reptiles, nine mammals, and 30 birds). Ticks were identified by morphological or molecular methods into 18 species, being 12, four, one and one of the genera Amblyomma, Ixodes, Rhipicephalus and Ornithodoros, respectively. Amblyomma rotundatum was the only species collected from reptiles. Ticks collected from mammals were identified as Amblyomma brasiliense, Amblyomma calcaratum, Amblyomma dubitatum, Amblyomma longirostre, Amblyomma nodosum, Amblyomma pacae, Amblyomma sculptum, Amblyomma varium and Rhipicephalus microplus. Amblyomma sculptum was the species found on the widest variety of hosts, collected from four mammal orders and five bird orders. Passeriformes birds were infested by Amblyomma fuscum, A. longirostre (also found on non- passerine birds), A. nodosum, Amblyomma parkeri, Amblyomma romarioi, A. varium and Ixodes loricatus. An adult female of Ixodes rio was collected from a Piciformes bird. Seabirds of the order Procellariiformes were infested by Ixodes percavatus sensu lato and Ixodes uriae. The argasid Ornithodoros capensis was collected from an offshore metallic platform that was used by Suliformes seabirds. Rickettsial agents of the spotted fever group, Rickettsia amblyommatis and Rickettsia sp. strain Pampulha, were detected in the ticks A. longirostre [from the Paraguayan hairy dwarf porcupine (Coendou spinosus)] and A. dubitatum [from the capybara (Hydrochoerus hydrochaeris)], respectively. The following nine tick species are reported for the first time in Espírito Santo state: A. calcaratum, A. fuscum, A. pacae, A. parkeri, A. romarioi, I. loricatus, I. rio, I. uriae, and O. capensis. Although it is also the first report of I. uriae in Brazil, we do not consider it established in the country. Multiple new tick-host associations are reported in the present study.

Diversity of rickettsiae in ticks (Acari: Ixodidae) collected from wild vertebrates in part of the Amazon, Cerrado, and Pantanal biomes in Brazil.

Ticks parasitizing 102 wild animals in the states of Mato Grosso and Goiás, Brazil were collected between 2015 and 2018. A total of 2338 ticks (865 males, 541 females, 823 nymphs, and 109 larvae) belonging to four genera (Amblyomma, Dermacentor, Haemaphysalis, and Rhipicephalus) and at least 21 species were identified. DNA extraction and a molecular survey for rickettsial agents were performed on 650 ticks. The results revealed parasitism by the following species: Rickettsia amblyommatis in Amblyomma cajennense s.s., A. cajennense s.l., Amblyomma coelebs, Amblyomma humerale, Amblyomma longirostre, Amblyomma nodosum, Amblyomma scalpturatum, Amblyomma sculptum, and Amblyomma romitii; Rickettsia parkeri in Amblyomma nodosum, Amblyomma ovale, Amblyomma scalpturatum, and Amblyomma triste; Rickettsia rhipicephali in Haemaphysalis juxtakochi; Rickettsia sp. in A. cajennense s.s., A. nodosum, and A. sculptum, and lastly, 'Candidatus Rickettsia andeanae' in Amblyomma parvum and Rhipicephalus microplus. This study expands the body of knowledge about tick parasitism among wild animals, including new data concerning tick-host associations, and provides information about the epidemiology of tick-borne pathogens in the Center-West region of Brazil.

The anal pore route is efficient to infect Amblyomma spp. ticks with Rickettsia rickettsii and allows the assessment of the role played by infection control targets.

Adult Amblyomma sculptum and Amblyomma aureolatum ticks are partially refractory to Rickettsia rickettsii when fed on infected hosts, hindering the functional characterization of potentially protective targets in the bacterial acquisition. In the current study, we used the anal pore route to infect adult A. sculptum and A. aureolatum ticks with R. rickettsii and to assess the effects of the knockdown of microplusin in infection control. The anal pore route was efficient to infect both species, resulting in a prevalence of around 100% of infected ticks. Higher loads of R. rickettsii were detected in microplusin-silenced A. aureolatum in relation to the control, as previously obtained when microplusin-silenced ticks were fed on R. rickettsii-infected rabbits. This is the first report showing R. rickettsii infection through the anal pore in Amblyomma ticks, highlighting this route as a powerful tool to assess the role played by additional targets in the control of pathogens.

Detection of Rickettsia amblyommatis and Rickettsia bellii in ticks collected from pet dogs in peri-urban and rural areas in Yucatan, Mexico.

Rickettsia species are bacteria that may cause multiple diseases in animals and humans, via transmission through multiple arthropod vectors. Routine surveillance of Rickettsia spp. within vectors is critical to determine their presence and risk to mammalian hosts within human populations. Therefore, to better characterize the circulating Rickettsia species in an understudied region we targeted pet dogs to survey. Ticks were collected from pet dogs in three populations of the Yucatan where we tested for the presence of Rickettsia spp. by PCR in metagenomic DNA. In these ticks removed from pet dogs we detected Rickettsia amblyommatis and Rickettsia bellii in Amblyomma auriculatum, Amblyomma ovale and Amblyomma mixtum ticks obtained in a rural community in the Mexican state of Yucatan. This is the first report detecting both species for this state in Mexico, underpinning the importance of more routine surveillance.

Examining the gut microbiota from several human-biting tick species in Northwestern Spain.

Tick-borne diseases have increased significantly in Europe and Spain in recent years. One strategy explored for tick surveillance and control is the study of the microbiota. The focus is on understanding the relationships between pathogens and endosymbionts within the microbiota and how these relationships can alter these arthropods' vectorial capacity. Thus, it is pivotal to depict the bacterial communities composing the microbiota of ticks present in specific territories. This work aimed to describe the microbiota present in 29 adult individuals of 5 tick species collected from 4 provinces of Castilla y Leon in northwestern Spain from 2015 to 2022. DNA extraction and sequencing of the V4 hypervariable region of 16S-rRNA was performed on the tick samples, with subsequent analysis of diversity, taxonomic composition, and correlations between genera of microorganisms. There were no differences in the alpha diversity of microbiota by tick species, nor were compositional changes evident at the phylum level for microorganisms. However, interindividual differences at the microbial genus level allowed spatial differentiation of the 5 tick species included in the study. Correlation analyses showed complex interactions between different genera of microbiota members. These findings provide an initial insight into the composition of the gut microbiota of various tick species in northwestern Spain, which can contribute to establishing surveillance and control measures to reduce diseases such as rickettsiosis, Lyme disease, and Crimean-Congo hemorrhagic fever.

Rickettsial antibodies and Rickettsia bellii detection in lagomorphs and their ectoparasites in Northern Baja California, Mexico.

Lagomorphs-principally rabbits and hares-have been implicated as hosts for vectors and reservoirs for pathogens associated with multiple rickettsial diseases. Western North America is home to diverse rickettsial pathogens which circulate among multiple wild and domestic hosts and tick and flea vectors. The purpose of this study was to assess lagomorphs and their ectoparasites in 2 locations in northern Baja California, Mexico, for exposure to and infection with rickettsial organisms. In total, 55 desert cottontail rabbits (Sylvilagus audubonii) (Baird) and 2 black-tailed jackrabbits (Lepus californicus) (Gray) were captured. In Mexicali, ticks were collected from 44% (14/32) of individuals, and were exclusively Haemaphysalis leporispalustrisNeumann (Acari: Ixodidae); in Ensenada, ticks were collected from 70% (16/23) individuals, and 95% were Dermacentor parumapertus. Euhoplopsyllus glacialis affinisBaker (Siphonaptera: Pulicidae) fleas were collected from 72% of rabbits and 1 jackrabbit from Mexicali, while the few fleas found on hosts in Ensenada were Echidnophaga gallinaceaWestwood (Siphonaptera: Pulicidae) and Cediopsylla inaequalis(Siphonaptera: Pulicidae). Rickettsia bellii was the only rickettsial organism detected and was identified in 88% of D. parumapertus and 67% of H. leporispalustris ticks from Ensenada. A single tissue sample from a jackrabbit was positive for R. belli (Rickettsiales: Rickettsiaceae). Hosts in Ensenada had a significantly higher prevalence of rickettsial antibodies than hosts in Mexicali (52.3% vs. 21.4%). Although R. bellii is not regarded as pathogenic in humans or other mammals, it may contribute to immunity to other rickettsiae. The marked difference in distribution of ticks, fleas, and rickettsial exposure between the 2 locations suggests that disease transmission risk may vary markedly between communities within the same region.

A story of a lone star tick: an imported case of Amblyomma americanum (Linnaeus, 1758) infected with Rickettsia amblyommatis that parasitized a US traveler returning to Mexico.

In this study, we report the presence of a female Amblyomma americanum tick attached to a former resident of the East Coast of the United States who moved to Mexico city. The amplification and sequencing of gene fragments of the 16S-rDNA and cytochrome c oxidase subunit 1 corroborated the identification of the species of the tick. Additionally, the presence of DNA of Rickettsia amblyommatis was confirmed. This work is the first report of an exotic tick of the genus Amblyomma in a traveler from the US to Mexico and represents the second record of an imported tick attached to humans in Mexico.

Ticks and tick-borne rickettsiae from dogs in El Salvador, with report of the human pathogen Rickettsia parkeri.

Twelve tick species have been reported in El Salvador; however, information regarding ticks infesting domestic dogs is lacking, and pathogenic tick-borne Rickettsia species have never been reported in El Salvador. This work evaluated ticks infesting 230 dogs from ten municipalities in El Salvador from July 2019 to August 2020. A total of 1,264 ticks were collected and identified into five species: Rhipicephalus sanguineus sensu lato (s.l.), Rhipicephalus microplus, Amblyomma mixtum, Amblyomma ovale, and Amblyoma cf. parvum. The tick R. sanguineus s.l. was the most frequent species in all localities (81.3% of sampled dogs), followed by Amblyomma mixtum (13.0%), Amblyomma ovale (10.9%) and Amblyomma cf. parvum (10.4%). The overall mean intensity of tick infestation was 5.5 ticks/dog. The highest specific mean intensity value was for R. sanguineus s.l. (4.8 ticks/dog), varying from 1.6 to 2.7 ticks/dog for the three Amblyomma species. From a random sample of 288 tick specimens tested molecularly for the presence of rickettsial agents, three spotted fever group Rickettsia were detected: Rickettsia amblyommatis in 90% (36/40) A. mixtum, 46% (11/24) A. cf. parvum, 4% (7/186) R. sanguineus s.l., and 17% Amblyomma spp.; Rickettsia parkeri strain Atlantic rainforest in 4% (1/25) A. ovale; and an unnamed rickettsia agent, designated as 'Rickettsia sp. ES-A.cf.parvum', in 4% (1/24) A. cf. parvum. Our finding of R. parkeri strain Atlantic rainforest in A. ovale is highly relevant because this agent has been associated to spotted fever illness in other Latin American countries, where A. ovale is implicated as its main vector. These findings suggest that spotted fever cases caused by R. parkeri strain Atlantic rainforest could be occurring in El Salvador.

Detection of Rickettsia tamurae-like and other spotted fever group rickettsiae in ticks (Acari: Ixodidae) associated with wild birds in the Western Amazon, Brazil.

Ticks are vectors for several pathogens, including bacteria belonging to the Rickettsia genus, such as Rickettsia rickettsii and Rickettsia parkeri, the causative agents of spotted fever. The aim of the present study was to investigate the tick species richness and rickettsial agents associated with wild birds captured in the Humaita Forest Reserve, Acre, in the Western Amazon region. Wild birds were captured with ornithological nets for visual inspection with the purpose of collecting ticks, which were identified through morphological analyses and molecular tests for several genes (12S rDNA, 16S rDNA, gltA, ompA, and sca4). A total of 607 wild birds were captured, 12% of which were parasitized by 268 ticks of the Amblyomma genus, with new host-parasite associations reported for Amblyomma calcaratum, Amblyomma geayi, Amblyomma longirostre, Amblyomma naponense, Amblyomma nodosum, and Amblyomma varium. Of the total ticks collected, 113 were tested for the presence of rickettsial DNA fragments, with 19 testing positive for R. parkeri in A. geayi, Rickettsia tamurae-like in Amblyomma sp., and Rickettsia amblyommatis in A. geayi, A. longirostre, and Amblyomma sp. We detected R. tamurae-like in Amblyomma larvae for the first time in the Western Brazilian Amazon biome, and registered spotted fever group rickettsiae, although the relevance of the detected species in a public health context should be further explored in South America, as well as new host-parasite interactions in this underexplored region.