Molecular survey of Ehrlichia infection in ticks from animals in Yamaguchi Prefecture, Japan

Molecular detection of rickettsial agents in Amblyomma maculatum ticks (Ixodida: Ixodidae) from Ecuador

Rickettsiales are obligate intracellular bacteria that need vertebrates and arthropods to maintain their life cycles. Some species of the genera Anaplasma, Ehrlichia, and Rickettsia are transmitted by ticks to both animals and humans and can cause mild to severe and even fatal cases. In the Americas, there is substantial data on rickettsial agents, encompassing both clinical cases and the detection of these agents in ticks, but in Ecuador, the information about them remains poorly understood. Therefore, the objective of this study was to detect molecularly rickettsial agents in Amblyomma maculatum ticks in both parasitic and free-living phases collected from domestic animals and pasture in five localities across three coastal provinces of Ecuador. Rickettsia parkeri, Candidatus Rickettsia andeanae, and Ehrlichia sp. were recorded in A. maculatum for the first time in Ecuador. These records were made in a region where antibodies to the Spotted Fever Rickettsia Group were detected in humans. Additional studies are needed to characterize Ehrlichia sp. at a specific level. Furthermore, recognizing the specific Rickettsiales species circulating in the ticks and the hosts within a region is crucial for assessing potential contact risks.

Ehrlichia effector TRP120 manipulates bacteremia to facilitate tick acquisition

Ehrlichia species are obligatory intracellular bacteria that cause a potentially fatal disease, human ehrlichiosis. The biomolecular mechanisms of tick acquisition of Ehrlichia and transmission between ticks and mammals are poorly understood. Ehrlichia japonica infection of mice recapitulates the full spectrum of human ehrlichiosis. We compared the pathogenicity and host acquisition of wild-type E. japonica with an isogenic transposon mutant of E. japonica that lacks tandem repeat protein 120 (TRP120) (ΔTRP120). Both wild-type and ΔTRP120 E. japonica proliferated similarly in cultures of mammalian and tick cells. Upon inoculation into mice, both wild-type and ΔTRP120 E. japonica multiplied to high levels in various tissues, with similar clinical chemistry and hematologic changes, proinflammatory cytokine induction, and fatal disease. However, the blood levels of ΔTRP120 E. japonica were almost undetectable within 24 h, whereas the levels of the wild type increased exponentially. Greater than 90% of TRP120 was released from infected cells into the culture medium. Mouse blood monocytes exposed to native TRP120 from culture supernatants showed significantly reduced cell surface expression of the transmigration-related markers Ly6C and CD11b. Larval ticks attached to mice infected with either wild-type or ΔTRP120 E. japonica imbibed similar amounts of blood and subsequently molted to nymphs at similar rates. However, unlike wild-type E. japonica, the ΔTRP120 mutant was minimally acquired by larval ticks and subsequent molted nymphs and, thus, failed to transmit to naïve mice. Thus, TRP120 is required for bacteremia but not disease. These findings suggest a novel mechanism whereby an obligatory intracellular bacterium manipulates infected blood monocytes to sustain the tick-mammal transmission cycle.

IMPORTANCE

Effective prevention of tick-borne diseases such as human ehrlichiosis requires an understanding of how disease-causing organisms are acquired. Ehrlichia species are intracellular bacteria that require infection of both mammals and ticks, involving cycles of transmission between them. Mouse models of ehrlichiosis and tick-mouse transmission can advance our fundamental understanding of the pathogenesis and prevention of ehrlichiosis. Herein, a mutant of Ehrlichia japonica was used to investigate the role of a single Ehrlichia factor, named tandem repeat protein 120 (TRP120), in infection of mammalian and tick cells in culture, infection and disease progression in mice, and tick acquisition of E. japonica from infected mice. Our results suggest that TRP120 is necessary only for Ehrlichia proliferation in circulating mouse blood and ongoing bacteremia to permit Ehrlichia acquisition by ticks. This study provides new insights into the importance of bacterial factors in regulating bacteremia, which may facilitate tick acquisition of pathogens.

Molecular screening of tick-borne microorganisms in ticks from rural areas of Panama, with the first record of Ehrlichia minasensis in Rhipicephalus microplus from Central America

During a molecular screening of rickettsial, borrelial and protozoal agents in ticks from rural areas of Panama, we detected DNA of Rickettsia amblyommatis in four Amblyomma mixtum collected from horses in a locality in Los Santos province. Ehrlichia minasensis and Anaplasma marginale were identified from three and two Rhipicephalus microplus, respectively, collected on cows from Chiriqui province. No DNA from other tick-borne agents was found. These results increase the information of R. amblyommatis and A. marginale in Panama, and also mark the first record of E. minasensis in Central America.

Molecular Detection of Tick-Borne Pathogens in Dogs from Indigenous Communities, Amazon, Brazil

Background: There are few reports of tick-borne pathogens infecting dogs living in indigenous communities of Brazil. Herein, we aimed to molecularly detect vector-borne pathogens in dogs from two indigenous communities in the Brazilian Amazon. Materials and Methods: We surveyed 327 dogs raised in Amazon region at 2 distinct indigenous ethnicities for the molecular detection of tick-borne pathogens (114 from Tapirapé and 213 from Karajá indigenous ethnicity). Whole blood samples were subjected to PCR and sequencing for Ehrlichia, Babesia, and Hepatozoon. Univariate and multivariate analyses were used to investigate the factors affecting the pathogen infection patterns in dogs. Results: Among the 327 blood samples, 40 were positive for Ehrlichia canis (12.2%), 2 for Anaplasma platys (0.61%), and 204 were positive for Hepatozoon canis (66.5%). Binary Logistic Regression showed association between E. canis infection and ethnicity (p = 0.010) and tick attachment (p = 0.041). Karajá dogs were 3.4 times (95% CI 1.3-8.5) more likely to be positive for E. canis than Tapirapé dogs. Dogs with ticks were 2.5 times more likely (95% CI 1.0-7.6) to be positive for E. canis than dogs without ticks. Conclusions: Our survey expands the knowledge regarding the presence of vector-borne pathogens in dogs from indigenous communities in the Amazon region.

Anaplasma and Ehrlichia Species in Ixodidae Ticks Collected from Two Regions of Bulgaria

The aim of the study was to determine prevalence of Anaplasmataceae-infected ticks in the Black Sea Coast and the Pleven regions of Bulgaria. A total of 350 ticks from different tick species were collected. Two hundred fifty-five ticks were removed from dogs in the Black Sea Coast region, and 95 Ixodes ricinus ticks were collected by flagging vegetation with a white flannel cloth in two areas in the region of Pleven. After the DNA isolation of the ticks, a genus-specific polymerase chain reaction (PCR) was performed to identify Anaplasmataceae. Second PCRs were performed with species-specific primers to identify Ehrlichia canis (E. canis) and Anaplasma phagocytophilum (A. phagocytophilum). The results showed that 26.9% of the Ixodes ricinus ticks were infected with Anaplasmataceae in the Black Sea Coast region and 36.8% in the Pleven region. The infection with E. canis was detected in 35.7% and A. phagocytophilum in 25.0% of positive ticks from the Black Sea Coast region. In the Pleven region, 22.9% of ticks were positive for E. canis, while 42.9% were positive for A. phagocytophilum. The molecular identification of E. canis in ticks collected from Bulgaria was performed for the first time. In conclusion, the present study revealed a higher prevalence of ticks infected with Anaplasmataceae, particularly A. phagocytophilum, in the Pleven region than in the Black Sea Coast region.

Molecular Prevalence of Anaplasma marginale and Ehrlichia in Domestic Large Ruminants and Rhipicephalus (Boophilus) microplus Ticks From Southern Luzon, Philippines

Anaplasmosis and ehrlichiosis are tick-borne rickettsial diseases that cause significant economic losses in the livestock industry worldwide. Although bovine anaplasmosis is known to be endemic in the Philippines, epidemiological data is fragmented. Moreover, little is known about bovine ehrlichiosis in the country. In this study, the prevalence of Anaplasma marginale and Ehrlichia in cattle and water buffalo from provinces in the southern part of Luzon, Philippines, was investigated through PCR. Blood samples from 620 animals comprised of 512 cattle and 108 water buffalo and 195 tick samples were subjected to nested PCR targeting the groESL gene of Anaplasmataceae. Positive samples were further subjected to another nested PCR and conventional PCR to amplify the A. marginale groEL gene and the Ehrlichia dsbA gene, respectively. Selected A. marginale-positive samples were also subjected to nested PCR targeting the msp5 gene. Regardless of the animal host, the overall prevalence in blood samples obtained was 51.9% for Anaplasmataceae, 43% for A. marginale, and 1.1% for Ehrlichia. No water buffalo were positive for Ehrlichia. Meanwhile, 15.9, 6.7, and 2% of the tick samples, all morphologically identified as Rhipicephalus (Boophilus) microplus, were positive for Anaplasmataceae, A. marginale, and Ehrlichia, respectively. Sequence analysis of selected A. marginale msp5 amplicons showed that the isolates from the region share 94–98% identity to reported A. marginale from other countries. The phylogenetic tree showed clustering of isolates in the region and a close relationship with A. marginale isolates from other countries. Sequences of Ehrlichia amplicons from cattle and ticks were 97–100% similar to reported Ehrlichia minasensis isolates. This study showed the high prevalence of A. marginale in Luzon, Philippines, and provided the first molecular evidence of E. minasensis in the country.

Characterization of "Candidatus Ehrlichia Pampeana" in Haemaphysalis juxtakochi Ticks and Gray Brocket Deer (Mazama gouazoubira) from Uruguay

Human ehrlichiosis are scantily documented in Uruguay. The aim of this study was to investigate the presence of Ehrlichia spp. in Haemaphysalis juxtakochi and in a gray brocket deer (Mazama gouazoubira) from Uruguay. The presence of Ehrlichia DNA was investigated in free-living H. juxtakochi in five localities of southeast and northeast Uruguay, as well as blood, spleen, and ticks retrieved from a M. gouazoubira. Ehrlichia spp. DNA was detected in six out of 99 tick pools from vegetation, in the spleen of M. gouazoubira, and in one out of five pools of ticks feeding on this cervid. Bayesian inference analyses for three loci (16S rRNA, dsb, and groEL) revealed the presence of a new rickettsial organism, named herein as "Candidatus Ehrlichia pampeana". This new detected Ehrlichia is phylogenetically related to those found in ticks from Asia, as well as Ehrlichia ewingii from USA and Cameroon. Although the potential pathogenicity of "Ca. E. pampeana" for humans is currently unknown, some eco-epidemiological factors may be relevant to its possible pathogenic role, namely: (i) the phylogenetic closeness with the zoonotic agent E. ewingii, (ii) the evidence of H. juxtakochi parasitizing humans, and (iii) the importance of cervids as reservoirs for zoonotic Ehrlichia spp. The molecular detection of "Ca. E. pampeana" represents the third Ehrlichia genotype described in Uruguay.

Molecular screening for tick-borne bacteria and hematozoa in Ixodes cf. boliviensis and Ixodes tapirus (Ixodida: Ixodidae) from western highlands of Panama

The first molecular screening for Rickettsia, Anaplasma, Ehrlichia, Borrelia, Babesia and Hepatozoon was carried out in questing Ixodes cf. boliviensis and Ixodes tapirus from Talamanca Mountains, Panama, using specific primers, sequencing and phylogeny. Phylogenetic analyses for the microorganisms in Ixodes cf. boliviensis confirmed the presence of Rickettsia sp. strain IbR/CRC endosymbiont (26/27 ticks), three genotypes of the Borrelia burgdorferi (sensu lato) complex (4/27 ticks), Babesia odocoilei (1/27 ticks), and Hepatozoon sp. (2/27 ticks), tentatively designated Hepatozoon sp. strain Chiriquensis. Phylogenetic analyses for the microorganisms in I. tapirus revealed an undescribed Rickettsia sp., tentatively designated Rickettsia sp. strain Itapirus LQ (6/6 ticks), and Anaplasma phagocytophilum (2/6 ticks). To the best of our knowledge, this is the first report of B. burgdorferi (s.l.) complex, A. phagocytophilum, B. odocoilei, and Hepatozoon sp. in Ixodes ticks from Central America, and also the first detection of Rickettsia spp. in Ixodes species in Panama. In light of the importance of these findings, further studies are needed focusing on the role of I. tapirus and I. cf. boliviensis as vectors, and the vertebrates acting as reservoirs.

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Free-living adult Ixodes ticks collected in Talamanca Mountains, Panama, were PCR-screened for tick-borne pathogens.

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Ixodes tapirus and Ixodes cf. boliviensis identified morphologically and molecularly.

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Genetic differences between Ixodes boliviensis from South America and I. cf. boliviensis from Panama.

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First molecular data for B. burgdorferi (s.l.), Hepatozoon and Babesia odocoilei in I. cf. boliviensis from Central America.

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First molecular data for Anaplasma phagocytophilum and spotted fever group Rickettsia in I. tapirus from Central America.

Molecular characterization of novel Ehrlichia genotypes in Ixodes auritulus from Uruguay

Ehrlichia are small intracellular Gram-negative bacteria transmitted by ticks. These microorganisms cause ehrlichiosis, a complex of life-threatening emerging zoonoses and diseases of global veterinary relevance. The aim of this study was to investigate the presence of Ehrlichia in free-living Ixodes auritulus collected in Uruguay. Ticks were collected from vegetation in five localities from the southeast and northeast of the country between 2014 and 2017. Detection of Ehrlichia DNA was performed in pools of adults or nymphs grouped according to the collection site and date. A total of 1,548 I. auritulus ticks were collected in four of the five locations sampled. Fragments of three loci (16S rRNA, dsb and groEL) were obtained by PCR, and phylogenies inferred using Bayesian inference analysis for each gene independently. DNA of Ehrlichia spp. was found in 15 out of 42 tick pools. Based on the topology of the phylogenetic trees, our sequences represent two novel genotypes for the genus named as Ehrlichia sp. Serrana and Ehrlichia sp. Laguna Negra. Both genotypes were closely related to Ehrlichia sp. Magellanica, a species detected in Ixodes uriae and Magellanic penguins. Considering that all stages of I. auritulus and I. uriae are parasites of birds, their phylogenetic relationships, and common eco–epidemiological profiles, it is reasonable to state that these genotypes of Ehrlichia spp. may represent a natural group likely associated with birds. Our results constitute the first characterization of Ehrlichia spp. in Uruguay. Future studies on birds reported as hosts for I. auritulus are needed to further understand the epidemiological cycles of both Ehrlichia genotypes in the country. Finally, I. auritulus does not feed on humans, so the two Ehrlichia species reported herein might have no implications in human health.

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First molecular characterization of Ehrlichia in Uruguay.

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Two novel genotypes of Ehrlichia were detected in Ixodes auritulus.

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Evidence of a natural lineage of Ehrlichia associated with birds is reinforced.

Detection of a putative novel genotype of Anaplasma in gray-brocket deer (Mazama gouazoubira) from Uruguay

Anaplasmataceae includes the genera Anaplasma, Ehrlichia, Neorickettsia and Wolbachia, comprising a group of obligate intracellular bacteria. The genus Anaplasma has pathogenic species transmitted by ticks of veterinary and human health importance. Wild ungulates such as deer represent important reservoirs and amplifiers of Anaplasmataceae. The interaction between deer and domestic ruminants represents a serious problem due to the transmission of these pathogens through their ectoparasites. In the present study, we investigated the presence of Anaplasmataceae organisms in blood, tissues and tick samples of a gray-brocket deer (Mazama gouazoubira). The specimen was found dead in a farm in northeast Uruguay. PCRs targeting partial regions of 16S rRNA and groESL genes were carried out for Anaplasmataceae DNA detection. Moreover, several ectoparasites were identified: the chewing louse Tricholipeurus albimarginatus, the Neotropical deer louse fly Lipoptena mazamae, and the ticks Haemaphysalis juxtakochi and Rhipicephalus microplus. A consensus sequence of 1274 bp of 16S rRNA was generated for Anaplasma sp. from the M. gouazoubira blood sample. All ticks analysed by PCR assays were negative. No band was detected in any of the samples after PCR targeting groESL gene. Phylogenetic analysis using 16S rRNA partial gene sequences, clustered the putative novel genotype sequence obtained in this study, named Anaplasma sp. genotype Mazama-Uruguay, along with Anaplasma sp. detected in Mazama sp., Mazama americana and Mazama bororo, all deer species from Brazil. Furthermore, this cluster showed to be closely related to Anaplasma bovis sequences obtained from various ruminants and other mammals from several parts of the world. The pathogenicity as well as its infecting potential to other cervids or domestic ruminants is currently unknown. Further studies should be performed in order to characterize this novel species, especially targeting other genes.

Prevalence of Mycobacterium avium subsp. paratuberculosis infection in dairy herds in Northern Antioquia (Colombia) and associated risk factors using environmental sampling

This cross-sectional study aimed to determine Mycobacterium avium subsp. paratuberculosis (MAP) herd-level prevalence using a quantitative real-time PCR method (qPCR), performed on environmental samples. Secondly, the study aimed to explore herd-level risk factors associated with the presence of MAP in dairy herds with in-paddock milking facilities of the Northern region of the Province of Antioquia (Colombia). Study herds (n = 292) located in 61 different districts from six municipalities were randomly selected amongst 7794 dairies registered in the foot-and-mouth disease vaccination records from 2015. The sampling strategy considered a proportional allocation, both at municipality and district level. Participant herds were visited once between June and October 2016 to collect one composite environmental sample and to complete a risk assessment questionnaire. Each composite environmental sample contained material from six different sites of concentration of adult cattle and/or high traffic areas (e.g. areas surrounding waterers and feeders, areas surrounding the current mobile milking-unit places). Identification of MAP was achieved using a duplex qPCR (Bactotype MAP PCR Kit^®, Qiagen). A herd was considered as MAP infected if the environmental sample was positive in the qPCR. Information about the general characteristics of the herd, management practices, and knowledge about the disease was collected using the risk-assessment questionnaire. The information on risk factors was analyzed using a multivariable logistic regression model. The apparent herd-level prevalence was 4.1% (12/292; 95% CI: 1.8-6.4). Herds with a history of mixed farming of cattle with other ruminants had higher odds of being MAP infected than herds without (OR = 3.9; 95% CI: 1.2-13.2). Our study demonstrates the MAP prevalence in dairy herds from Antioquia, Colombia and the possible relationship between MAP environmental positivity with the history of mixed farming of cattle with other susceptible ruminants.

Long-term trends of tick-borne pathogens in regard to small mammal and tick populations from Saxony, Germany

BACKGROUND

Rodents are important in the life-cycle of ticks as hosts for immature developmental stages. Both rodents and ticks are of public health interest as they are reservoirs and vectors for different tick-borne pathogens (TBP). The aim of this study was to reassess the prevalence of TBP in previously studied areas of the city of Leipzig (Saxony, Germany).

METHODS

In the years 2015-2017 rodents and ticks were collected in parks and forest areas in Saxony. DNA was extracted from the rodents, attached and questing ticks. Samples were screened for the presence of Anaplasma phagocytophilum, Babesia spp., Borrelia burgdorferi (s.l.), "Candidatus Neoehrlichia mikurensis" (CNM), Bartonella spp., Hepatozoon spp. and Rickettsia spp. using PCR methods. Rodent, attached nymph and questing tick (nymph and adult) samples were tested individually, while attached larvae were further processed in pools.

RESULTS

A total of 165 rodents (Apodemus agrarius, n = 1; A. flavicollis, n = 59; Arvicola terrestris, n = 1; Myodes glareolus, n = 104), 1256 attached ticks (Ixodes ricinus, n = 1164; Dermacentor reticulatus, n = 92) and 577 questing ticks (I. ricinus, n = 547; D. reticulatus, n = 30) were collected. The prevalence levels in rodents were 78.2% for Bartonella spp., 58.2% for CNM, 49.1% for B. burgdorferi (s.l.) 29.1% for Rickettsia spp. and 24.2% for Hepatozoon spp. The minimal infection rates (MIR) in attached larvae ticks were 39.8% for Rickettsia spp., 32.7% for Bartonella spp., 7.1% for CNM and 8.8% for B. burgdorferi (s.l.) and the prevalence rates in attached nymphs were 33.7% for Bartonella spp., 52.9% for Rickettsia spp., 13.5% for CNM and 11.3% for B. burgdorferi (s.l.) Both rodents and attached ticks were negative for Babesia spp. The prevalence in questing ticks was 18.2% for Rickettsia spp., 7.3% for CNM, 6.4% for B. burgdorferi (s.l.) and 1.4% for Babesia spp. All tested samples were Anaplasma-negative. Sequencing revealed the occurrence of 14 identified species.

CONCLUSIONS

This research is the first evaluation of the prevalence for Hepatozoon spp. in rodents from Germany. In comparison to earlier studies, detected pathogens species remained the same; however, the prevalence for particular pathogens differed.

Diversity of Anaplasma and Ehrlichia/Neoehrlichia Agents in Terrestrial Wild Carnivores Worldwide: Implications for Human and Domestic Animal Health and Wildlife Conservation

Recently, the incidence and awareness of tick-borne diseases in humans and animals have increased due to several factors, which in association favor the chances of contact among wild animals and their ectoparasites, domestic animals and humans. Wild and domestic carnivores are considered the primary source of tick-borne zoonotic agents to humans. Among emergent tick-borne pathogens, agents belonging to family Anaplasmataceae (Order Rickettsiales) agents stand out due their worldwide distribution and zoonotic potential. In this review we aimed to review the genetic diversity of the tick-transmitted genera Ehrlichia, Anaplasma and "Candidatus Neoehrlichia sp." in wild carnivores Caniformia (Canidae, Mustelidae and Ursidae) and Feliformia (Felidae, Hyanidae, Procyonidae and Viverridae) worldwide, discussing the implications for human and domestic animal health and wildlife conservation. Red foxes (Vulpes vulpes) have been identified as hosts for Anaplasma spp. (A. phagocytophilum, Anaplasma ovis, A. platys), Ehrlichia canis and "Candidatus Neoehrlichia sp." (FU98 strain) and may contribute to the maintaenance of A. phagocytophilum in Europe. Raccoons (Procyon lotor) have been reported as hosts for E. canis, A. bovis, "Candidatus Neoehrlichia lotoris" and A. phagocytophilum, and play a role in the maintenance of A. phagocytophilum in the USA. Raccoon dogs (Nyctereutes procyonoides) may play a role as hosts for A. bovis and A. phagocytophilum. New Ehrlichia and/or Anaplasma genotypes circulate in wild canids and felids from South America and Africa. While Ehrlichia sp. closely related to E. canis has been reported in wild felids from Brazil and Japan, Anaplasma sp. closely related to A. phagocytophilum has been detected in wild felids from Brazil and Africa. Red foxes and mustelids (otters) are exposed to E. canis in countries located in the Mediaterranean basin, probably as a consequence of spillover from domestic dogs. Similarly, E. canis occurs in procyonids in North (raccoons in USA, Spain) and South (Nasua nasua in Brazil) Hemispheres, in areas where E. canis is frequent in dogs. While "Candidatus Neoehrlichia lotoris" seems to be a common and specific agent of raccoons in the USA, "Candidatus Neoehrlichia sp." (FU98 strain) seems to show a broader range of hosts, since it has been detected in red fox, golden jackal (Canis aureus) and badger (Meles meles) in Europe so far. Brown (Ursus arctos) and black (Ursus americanus) bears seem to play a role as hosts for A. phagocytophilum in the North Hemisphere. Anaplasma bovis has been detected in wild Procyonidae, Canidae and Felidae in Asia and Brazil. In order to assess the real identity of the involved agents, future works should benefit from the application of MLST (Multi Locus Sequence Typing), WGS (Whole Genome Sequencing) and NGS (Next Generation Sequencing) technologies aiming at shedding some light on the role of wild carnivores in the epidemiology of Anaplasmataceae agents.

New records and host associations of the tick Ixodes apronophorus and the first detection of Ehrlichia sp. HF in Romania

Ixodes (Ixodes) apronophorus is a neglected tick species and its geographical distribution, host associations, and role as a disease vector are not well known. We collected I. apronophorus from several locations in Romania. Morphological identification of ticks was confirmed by analysis of 16S rDNA and 12S rDNA gene sequences. We report new host associations of I. apronophorus, which was collected from dogs, foxes, and a hare-all new hosts for this tick species in Romania. Furthermore, we report for the first time occurrence of Ehrlichia sp. HF in I. apronophorus. Ehrlichia sp. HF was identified by sequencing a part of the 16S rDNA gene and was found in 16% (3/19) of the tested ticks. Ehrlichia sp. HF has not been previously reported in Eastern Europe and seems to have a much larger geographic distribution than previously known. Currently, it is unknown whether I. apronophorus is a competent vector for Ehrlichia sp. HF, or if the findings in this study represent infection in the hosts, namely dogs and fox.

Molecular detection of Anaplasma spp. in pangolins (Manis javanica) and wild boars (Sus scrofa) in Peninsular Malaysia

Anaplasma spp. infects a wide variety of wildlife and domestic animals. This study describes the identification of a novel species of Anaplasma (Candidatus Anaplasma pangolinii) from pangolins (Manis javanica) and Anaplasma bovis from wild boars (Sus scrofa) in Malaysia. Based on 16S rRNA gene sequences, Candidatus Anaplasma pangolinii is identified in a distinct branch within the family Anaplasmataceae, exhibiting the closest sequence similarity with the type strains of Anaplasma bovis (97.7%) and Anaplasma phagocytophilum (97.6%). The sequence also aligned closely (99.9%) with that of an Anaplasma spp. (strain AnAj360) detected from Amblyomma javanense ticks. The nearly full length sequence of the 16S rRNA gene derived from two wild boars in this study demonstrated the highest sequence similarity (99.7%) to the A. bovis type strain. Partial 16S rRNA gene fragments of A. bovis were also detected from a small population of Haemaphysalis bispinosa cattle ticks in this study. Our finding suggests a possible spread of two Anaplasma species in the Malaysian wildlife and ticks. The zoonotic potential of the Anaplasma species identified in this study is yet to be determined.

Molecular and serological detection of tick-borne pathogens in dogs from an area endemic for Leishmania infantumin Mato Grosso do Sul, Brazil

Tick-borne pathogens affect a wide range of vertebrate hosts. To identify tick-borne pathogens among dogs from Campo Grande, MS, Brazil testing seropositive for Leishmania infantum (syn. L. chagasi), a serological and molecular study was conducted to detectEhrlichia canis, Anaplasma platys and Babesia vogeli in 60 serum and spleen samples. A confirmatory diagnosis ofL. infantum based on serological and molecular assays was also performed, as was sequence alignment and phylogenetic analysis to assess the identity of the parasite species infecting these animals. IgG antibodies toEhrlichia spp., B. vogeli and L. infantum were found, respectively, in 39 (65%), 49 (81.6%) and 60 (100%) of the sampled dogs. Twenty-seven (45%), fifty-four (90%), fifty-three (88.3%), two (3.3%) and one (1.6%) dog were positive, respectively, forE. canis, Leishmania spp., Leishmania donovani complex, Babesia sp. and Anaplasma sp. in PCR assays. After sequencing, the amplicons showed 99% of identity with E. canis, B. vogeli, A. platys andLeishmania chagasi isolates. The findings of this study indicate that L. infantum-seropositive dogs from Campo Grande are exposed to multiple tick-borne pathogens, which should therefore be included in the differential diagnosis of dogs with clinical suspicion of leishmaniasis.

Molecular detection of Ehrlichia canis in dogs in Malaysia

An epidemiological study of Ehrlichia canis infection in dogs in Peninsular Malaysia was carried out using molecular detection techniques. A total of 500 canine blood samples were collected from veterinary clinics and dog shelters. Molecular screening by polymerase chain reaction (PCR) was performed using genus-specific primers followed by PCR using E. canis species-specific primers. Ten out of 500 dogs were positive for E. canis. A phylogenetic analysis of the E. canis Malaysia strain showed that it was grouped tightly with other E. canis strains from different geographic regions. The present study revealed for the first time, the presence of genetically confirmed E. canis with a prevalence rate of 2.0% in naturally infected dogs in Malaysia.

Canine vector-borne diseases are a worldwide concern particularly in the tropics and sub-tropics that provide favourable climatic conditions for the vectors. Malaysia, a tropical paradise, is thus home to a wide range of vectors as well as the pathogens that they harbor. Ehrlichia canis, a ubiquitous tick-borne pathogen of dogs, is the causative agent of canine monocytic ehrlichiosis, the most common clinically significant tick-borne disease of dogs in Malaysia. The pet explosion coupled with the increasing number of stray dogs, has resulted in a surge in vector-borne diseases in companion animals in Southeast Asia. Despite this, there is very little published information regarding this subject in Malaysia. There are only two published studies on E.canis in Peninsular Malaysia based on traditional light microscopic detection and antibody detection techniques. This disease has been notoriously difficult to diagnose based on the traditional methods. This research investigates this important disease of canids using molecular techniques for the first time in Malaysia providing a more accurate picture of its presence and prevalence in the country.

Molecular detection of tick-borne bacterial agents in Brazilian and exotic captive carnivores

The present study aims to detect and characterize by molecular techniques, the presence of tick-borne pathogens in wild captive carnivore blood samples from Brazil. Blood was collected from 76 Brazilian felids, 23 exotic felids, 3 European wolves (Canis lupus), and 97 Brazilian canids maintained in captivity in zoos located in São Paulo and Mato Grosso states, Brazil. DNA of each sample was used in PCR reactions for Ehrlichia, Anaplasma, and Rickettsia identification. The blood from 10/100 (10%) of canids (1 European wolf, 3 bush dogs, and 6 crab-eating foxes) and from 21/99 (21%) felids (4 pumas, 6 little spotted cats, 4 ocelots, 3 jaguarundis, 1 tiger, and 3 lions) contained fragments of 16S rRNA gene of Ehrlichia spp. Fragments of Anaplasma spp. groESL and 16S rRNA genes were detected in the blood of 1/100 (1%) canids (1 bush dog) and in 4/99 (3%) felids (4 little spotted cats), respectively. Rickettsia species infections were not identified. The present work showed that new strains of Ehrlichia and Anaplasma spp. circulate among wild carnivores in Brazil.

Investigação molecular de Ehrlichia spp. e Anaplasma platys em felinos domésticos: alterações clínicas, hematológicas e bioquímicas

Ehrlichia sp. e Anaplasma platys são micro-organismos Gram negativos, parasitos intracelulares obrigatórios, residindo em vacúolos citoplasmáticos de leucócitos e plaquetas, encontrados no sangue periférico ou em tecidos. Poucos relatos têm sido feitos sobre erliquiose e anaplasmose em gatos no Brasil, os quais são baseados na presença de mórulas em leucócitos e plaquetas, ou pela detecção de anticorpos. O objetivo deste trabalho foi investigar a infecção natural por Ehrlichia sp. e A.platys em gatos no Município de Campos dos Goytacazes-RJ, através da hematoscopia e pela detecção do DNA desses agentes. Foram utilizadas amostras de sangue total e de soro de 91 gatos, independente de raça, sexo e idade. Realizaram-se hemograma, bioquímica sérica e PCR, utilizando oligonucleotídes para Ehrlichia sp. e A.platys. Os dados de hematoscopia mostraram que 9,89% dos gatos apresentaram mórulas em macroplaquetas. O DNA de A.platys foi detectado em 13,18% dos 91 animais e em 44,44% das amostras positivas à hematoscopia. O DNA de Ehrlichia sp. não foi detectado em nenhuma amostra. Nenhuma alteração foi observada nos sinais clínicos nem nos resultados laboratoriais nos animais estudados. Os dados sugerem que os felinos domésticos podem atuar como potenciais reservatórios para A. platys, como forma não sintomática das enfermidades relacionadas

Detection of Anaplasma phagocytophilum and Ehrlichia sp. HF strains in Ixodes ricinus ticks in Brittany, France

DNA extracts from 156 tick pools, 18 blood specimens and 17 spleens from European woodmice (Apodemus sylvaticus) collected in Brittany, France were tested by PCR for the 16S rRNA gene of Anaplasmataceae. Positive amplicons were sequenced and confirmed, either by amplification and sequencing of a second gene, or by a second PCR specific for the P44 and gltA genes of Anaplasma phagocytophilum and the gltA gene of Ehrlichia sp. HF. In addition to A. phagocytophilum, the study detected Ehrlichia sp. HF for the first time in Ixodes ricinus ticks. This organism has only been detected previously in Ixodes ovatus ticks from Japan.

Prevalence of Tick-Borne Rickettsia and Ehrlichia in Ixodes persulcatus and Ixodes ovatus in Tokachi District, Eastern Hokkaido, Japan

DNA from 111 ticks collected by flagging in Tokachi district, Eastern Hokkaido, Japan were examined for infection with Rickettsia and Ehrlichia, by PCR and sequencing methodology. For Rickettsia, analysis of the partial sequence of the citrate synthase gene was successfully performed on 11 DNA samples from I. persulcatus, and 7 of them showed 99.8% identical with Rickettsia helvetica while the other 4 showed 99.8% identical with ;Candidatus Rickettsia tarasevichiae'. For Ehrlichia, a partial sequence of the 16S rRNA gene detected from I. persulcatus was 100% identical with that from Ehrlichia muris, and another DNA sample from I. ovatus showed 99.8% identical with Ehrlichia species detected from I. ovatus. The results suggest that the pathogens detected here might be distributed in this area.

Detection of DNA of 'Candidatus Mycoplasma haemominutum' and Spiroplasma sp. in unfed ticks collected from vegetation in Japan

DNA fragments of 'Candidatus Mycoplasma haemominutum', a feline heamobartonella pathogen, were detected from unfed Ixodes ovatus collected from vegetation in Hokkaido, Fukushima and Yamaguchi Prefectures, and unfed Haemaphysalis flava in Yamaguchi Prefecture. This finding suggests that ixodid tick is a possible vector of 'C. Mycoplasma haemominutum'. Spiroplasma DNA was also detected from unfed I. ovatus in Hokkaido, Fukushima and Yamaguchi Prefectures. The analysis of nucleotides sequence suggested that this Spiroplasma was distinct from registered species.

Molecular identification of Ehrlichia species and 'Candidatus Neoehrlichia mikurensis' from ticks and wild rodents in Shizuoka and Nagano Prefectures, Japan

A total of 293 ticks and 111 wild rodents that were collected in Shizuoka and Nagano Prefectures, Japan, were examined for infection of Ehrlichia species and 'Candidatus Neoehrlichia mikurensis.' The 16S rDNA or the omp-1 gene of these bacterial DNAs were detected from the spleens of tick-inoculated mice (5 positive/total 29 mice) or from the spleens of wild rodents (25 positive/total 111 rodents) by PCR amplifi-cation. Sequencing of the 16S rDNA revealed Ehrlichia spp. from the 5 tick-inoculated mice and 8 wild rodents, and 'Candidatus N. mikurensis' from 17 wild rodents. The data suggest the presence of additional genetic variants, and potential vectors and/or reservoirs for these bacteria in central Japan.

Characterization of Ehrlichia species from Ixodes ovatus ticks at the foot of Mt. Fuji, Japan

A total of 390 adult ticks (288 Ixodes ovatus and 102 I. persulcatus ) collected at the foot of Mt. Fuji and two near cities in Shizuoka prefecture, Japan, were examined for Ehrlichia infection by isolation with laboratory mice from whole tick tissues. Ehrlichial DNAs were detected from the spleens of mice inoculated with tissues from I. ovatus, but not I. persulcatus. The prevalence of ehrlichiae in the ticks was estimated to be ca. 3%. The 16S rDNA analysis revealed that the sequences of 8 ehrlichial isolates (termed "Shizuoka" isolates) obtained were identical, and they were very similar, but not identical, to those of two Ehrlichia species strain variants recently isolated in Japan, followed by Ehrlichia chaffeensis in the US. Analysis of parts of the omp-1 multigene family specific for monocytic ehrlichiosis agents showed that the Shizuoka isolates were distinct from other ehrlichial organisms. The Shizuoka isolates caused death in immunocompetent laboratory mice, suggesting that they are highly pathogenic in mice. The data show that the Shizuoka isolates are likely to be a new strain variant of Ehrlichia species in Japan. Further characterization and surveillance will be required in Japan due to the presence of these human ehrlichiosis agent-like organisms.

Detection of ehrlichial DNA in Haemaphysalis ticks recovered from dogs in Japan that is closely related to a novel Ehrlichia sp. found in cattle ticks from Tibet, Thailand, and Africa

Tick DNA samples from dogs in Japan were examined for Ehrlichia infection by 16S rRNA gene-based PCR and sequencing. Three positive samples were detected from Haemaphysalis ticks, and higher levels of similarity (98.46 to 99.06%) were found to recently detected Ehrlichia spp. from cattle ticks in Tibet, Thailand, and Africa.

Identification of Ehrlichia chaffeensis, Anaplasma phagocytophilum, and A. bovis in Haemaphysalis longicornis and Ixodes persulcatus ticks from Korea

A total of 1,467 tick (1,463 of Haemaphysalis longicornis, three of Ixodes persulcatus and one of I. turdus) collected from nine provinces of Korea were examined by TaqMan real-time PCR for the presence of Ehrlichia and Anaplasma species. One set of primers and a probe were designed for detection of all of the Ehrlichia and Anaplasma species. Template DNAs (total 803) were prepared either from pools of larvae, nymphs, adult males and females, or from the salivary gland and midgut of adult ticks. Only DNAs positive in TaqMan PCR were examined for A. phagocytophilum with nested PCR and for E. chaffeensis with PCR. Four A. phagocytophilum 16S rRNA gene PCR products were sequenced for comparison with sequences previously reported. Amplification of a 16S rRNA gene fragment of Ehrlichia and Anaplasma species was observed in 364 tick DNAs (45.3% of the total). Of these 364 positive ticks, species-specific PCRs confirmed that 35 H. longicornis and one I. persulcatus were positive for A. phagocytophilum and one I. persulcatus was positive in E. chaffeensis. Except for one (AB-GGHL, GenBank accession number [GAN] AF470698), three of the four 16S rRNA gene fragment sequences of the A. phagocytophilum-positive samples were similar or identical to the sequences of variants of A. phagocytophilum deposited in GenBank. The 16S rRNA gene fragment sequence of AB-GGHL was similar to that of Anaplasma (Ehrlichia) bovis 16S rRNA (GAN U03775). The identities of the Anaplasmataceae genus and species DNA in the 327 ticks that could not be confirmed infected with either E. chaffeensis, A. phagocytophilum, or A. bovis are not known. This study is the first to demonstrate the presence of E. chaffeensis, A. phagocytophilum and A. bovis in Korean ticks.

Epidemiological survey of Anaplasma platys and Ehrlichia canis using ticks collected from dogs in Japan

Detection of Anaplasma platys and Ehrlichia canis in ticks recovered from dogs in Japan was attempted using a species-specific nested PCR based on the 16S rRNA gene. A total of 1211 ticks recovered from 1211 dogs from all over Japan were examined for A. platys and E. canis. Four tick samples from Fukushima, Miyazaki and Kagoshima Prefectures recovered from four different dogs showed a positive reaction for A. platys. Although the four dogs did not show any clinical signs and no blood examination data were available, it is possible that A. platys has already been spread widely in Japan. No positive reactions were observed in any ticks examined for E. canis.

Candidatus Ehrlichia walkerii: a new Ehrlichia detected in Ixodes ricinus tick collected from asymptomatic humans in Northern Italy

Ixodes ricinus harbors many infectious agents pathogenic for humans. A cause of fever is found in less than 50% of patients exposed to ticks. Investigations on 359 Ixodes ticks removed from asymptomatic patients in Northern Italy revealed the presence of a new ehrlichial agent in 10 ticks. Comparison of the 16S rRNA and the gltA gene sequences showed the organism is most closely related to Ehrlichia ruminantium. We propose this new Ehrlichia be named "candidatus Ehrlichia walkerii."

Detection of Ehrlichia spp., Anaplasma spp., Rickettsia spp., and other eubacteria in ticks from the Thai-Myanmar border and Vietnam

A total of 650 ticks, including 13 species from five genera, were collected from animals, from people, or by flagging of the vegetation at sites on the Thai-Myanmar border and in Vietnam. They were tested by PCR to detect DNA of bacteria of the order RICKETTSIALES: Three Anaplasma spp. were detected in ticks collected in Thailand, including (i) Anaplasma sp. strain AnDa465, which was considered a genotype of Anaplasma platys (formerly Ehrlichia platys) and which was obtained from Dermacentor auratus ticks collected from dogs; (ii) Anaplasma sp. strain AnAj360, which was obtained from Amblyomma javanense ticks collected on a pangolin; and (iii) Anaplasma sp. strain AnHl446, which was closely related to Anaplasma bovis and which was detected in Haemaphysalis lagrangei ticks collected from a bear. Three Ehrlichia spp. were identified, including (i) Ehrlichia sp. strain EBm52, which was obtained from Boophilus microplus ticks collected from cattle from Thailand; (ii) Ehrlichia sp. strain EHh324, which was closely related to Ehrlichia chaffeensis and which was detected in Haemaphysalis hystricis ticks collected from wild pigs in Vietnam; and (iii) Ehrlichia sp. strain EHh317, which was closely related to Ehrlichia sp. strain EBm52 and which was also detected in H. hystricis ticks collected from wild pigs in Vietnam. Two Rickettsia spp. were detected in Thailand, including (i) Rickettsia sp. strain RDla420, which was detected in Dermacentor auratus ticks collected from a bear, and (ii) Rickettsia sp. strain RDla440, which was identified from two pools of Dermacentor larvae collected from a wild pig nest. Finally, two bacteria named Eubacterium sp. strain Hw124 and Eubacterium sp. strain Hw191 were identified in Haemaphysalis wellingtoni ticks collected from chicken in Thailand; these strains could belong to a new group of bacteria.