First molecular detection of Ehrlichia canis and Anaplasma platys in ticks from dogs in Cebu, Philippines

Molecular detection of Anaplasma platys in Pshdar Kurdish shepherd dogs of Sulaymaniyah Province, Iraq

Background and Aim

Anaplasma platys is a dog pathogen that causes anaplasmosis in various hosts, including humans. It is a rickettsial pathogen that causes cyclic thrombocytopenia in primary canine recipients and is spread by the brown dog tick Rhipicephalus sanguineus. This study aimed to map the genetic sequences of Anaplasma spp. isolates comparable with those of different global locations and determine the infection status of Pshdar Kurdish shepherd dogs from three regions in Sulaymaniyah province who did not exhibit clinical indications for Anaplasma.

Materials and Methods

A total of 75 dog blood samples were collected from the center of the Sulaymaniyah, Dukan, and Ranya districts in the Sulaymaniyah province and subjected to polymerase chain reaction to determine the 16S ribosomal RNA (16S rRNA) gene of A. platys.

Results

Only two dogs (2.7%) were positive for A. platys. The 16S rRNA gene of A. platys was sequenced and registered in the National Center for Biotechnology Information GenBank with accession number OR467538. With four nucleotide changes, the sequence exhibited 99.72% similarity to strains identified as human infections and those found in recognized tick vectors.

Conclusion

We conclude that the blood of Pshdar Kurdish shepherd dogs in the Sulaymaniyah region of Iraq contains a small number of A. platys. Moreover, the phylogenetic tree of the isolated species, A. platys, was significantly similar to other strains of A. platys found worldwide. In the Kurdistan region of Iraq, this study represents the first molecular detection of the 16S rRNA gene of A. platys.

Molecular Screening and Genetic Identification of Anaplasma platys in Brown Dog Tick (Rhipicephalus sanguineus s. l.) Infested on Stray Dogs in Taiwan

Anaplasma platys is a tick-borne zoonotic pathogen of canines. In this study, the presence of A. platys was screened for in brown dog ticks (Rhipicephalus sanguineus s. l.) infesting stray dogs in Taiwan to determine overall prevalence. This study represents the first instance of genetic identification of A. platys in brown dog ticks in Taiwan. In total, we examined 324 brown dog ticks for A. platys infection by nested polymerase chain reaction assay targeting the 16S ribosomal RNA gene. The general prevalence of A. platys infection was 3.1%, with 3.6%, 4.0%, and 2.1% in nymph, female, and male ticks, respectively. Monthly prevalence of infection was observed from May to September. Genetic relatedness was determined by comparing the sequences of the 16S rRNA gene obtained from six Taiwan strains and seventeen other strains, representing six genospecies of Anaplasma spp. and three outgroups (Ehrlichia canis, Rickettsia rickettsia, and Escherichia coli). All Taiwan specimens were shown to genetically belong to the A. platys group, and could be clearly discriminated from other Anaplasma spp. Genetic similarities revealed a 100% identity match with various A. platys documented in GenBank. This study highlights the epidemiological importance of geographical transmission of A. platys among dogs and the possible risk for human infections in Taiwan.

Molecular detection and phylogeny of Ehrlichia canis and Anaplasma platys in naturally infected dogs in Central and Northeast Thailand

Background and Aim

Ehrlichia canis and Anaplasma platys are tick-borne, Gram-negative bacteria that cause canine monocytic ehrlichiosis and canine cyclic thrombocytopenia, respectively. These diseases are of great importance and are distributed globally. This study aimed to create new primers for the identification of E. canis and A. platys in naturally infected dogs using polymerase chain reaction (PCR), DNA sequencing, and phylogenetic analysis using the 16S rDNA and gltA genes.

Materials and Methods

In total, 120 blood samples were collected from dogs in three different locations (Saraburi, Buriram, and Nakhon Ratchasima provinces) in Central and Northeast Thailand. The molecular prevalence of E. canis and A. platys was assessed using PCR targeting the 16S rDNA and gltA genes. All positive PCR amplicons were sequenced, and phylogenetic trees were constructed based on the maximum likelihood method.

Results

Ehrlichia canis had an overall molecular prevalence of 15.8% based on the 16S rDNA gene, compared to 8.3% based on the gltA gene. In addition, the overall molecular prevalence of A. platys using the 16S rDNA gene was 10.8%, while the prevalence rate was 5.8% using the gltA gene. Coinfection was 0.8% in Saraburi province. The partial sequences of the 16S rDNA and gltA genes of E. canis and A. platys in dogs in Central and Northeast Thailand showed 96.75%-100% identity to reference sequences in GenBank. Phylogenetic analysis of the 16S rDNA and gltA genes revealed that E. canis and A. platys sequences were clearly grouped into their own clades.

Conclusion

This study demonstrated the molecular prevalence of E. canis and A. platys in Central and Northeast Thailand. The 16S rDNA and gltA genes were useful for the diagnosis of E. canis and A. platys. Based on the phylogenetic analysis, the partial sequences of the 16S rDNA and gltA genes in E. canis and A. platys were related to prior Thai strains and those from other countries.

First Molecular Identification of Babesia, Theileria, and Anaplasma in Goats from the Philippines

Goats are key livestock animals and goat raising is an income-generating venture for smallholder farmers, supporting agricultural development in many parts of the world. However, goat production is often limited by various factors, such as tick-borne diseases. Goat piroplasmosis is a disease caused by apicomplexan parasites Babesia spp. and Theileria spp., while anaplasmosis is caused by bacterial Anaplasma spp. In the Philippines, the presence of Babesia, Theileria, and Anaplasma has not been reported in goats. In this study, DNA obtained from goats were molecularly screened for Babesia/Theileria and Anaplasma. Of 396, 77.02% (305/396) and 38.64% (153/396) were positive for piroplasma and Anaplasma using PCR assays targeting the 18S rRNA and 16S rRNA genes, respectively. Similarly, Babesia ovis was detected in six samples (1.52%). Representative Babesia/Theileria sequences shared 89.97–97.74% identity with each other and were most closely related to T. orientalis, T. annulata, and Theileria spp. Meanwhile, Anaplasma 16SrRNA sequences were related to A. odocoilei, A. platys, and A. phagocytophilum. This is the first molecular identification of B. ovis, Theileria spp., and Anaplasma spp. in goats from the Philippines.

Molecular detection and characterization of Anaplasma platys and Ehrlichia canis in dogs from the Caribbean

Anaplasma platys is a tick-transmitted rickettsial pathogen, which is known to be the etiologic agent for cyclic thrombocytopenia in its primary canine host. Infections with this pathogen are also reported in cats, cattle and people. Similarly, Ehrlichia canis is another tick-borne rickettsial pathogen responsible for canine monocytic ehrlichiosis and is also reported to cause infections in people. We describe infections in dogs with these two pathogens on the Caribbean island of Grenada, West Indies by detection using molecular methods. We utilized a 16S rRNA gene-based PCR assay to detect both Ehrlichia and Anaplasma species by screening 155 canine blood samples from asymptomatic dogs. We found 18.7 % of the dogs to be positive for A. platys and 16.8 % for E. canis. Samples that tested positive for A. platys were further assessed by sequence analysis targeting 16S rRNA, 23S rRNA, citrate synthase (gltA) and heat shock protein (groEL) genes. Phylogenetic analysis revealed high correlation of A. platys 16S rRNA and gltA gene sequences with the geographic origins, while 23S rRNA and groEL gene sequences clustered independent of the geographic origins. This study represents an important step in defining the widespread distribution of active rickettsial infections in Caribbean dogs with no apparent clinical signs, thus posing a high risk for canine health and to a lesser extent to humans, as most dogs in the Caribbean are free-roaming.

Tick species identification and molecular detection of tick-borne pathogens in blood and ticks collected from cattle in Egypt

To address the lack of information on ticks infesting cattle in Egypt and the pathogens that they transmit, the current study aimed to (i) provide insight into tick species found on cattle in Egypt, (ii) identify the pathogens in ticks and their cattle hosts and (iii) detect pathogen associations in ticks and cattle. Tick samples and blood from their bovine hosts were collected from three different areas in Egypt (EL-Faiyum Oasis, Assiut Governorate and EL-Kharga Oasis). Tick species were identified by morphology and by sequence analysis of the cytochrome C oxidase subunit 1 (cox1) gene. Tick pools and blood samples from cattle were screened by the Reverse Line Blot hybridization (RLB) assay for the simultaneous detection of tick-borne pathogens, including Babesia, Theileria, Anaplasma, Ehrlichia, and Rickettsia spp., as well as the tick endosymbiont Midichloria mitochondrii. The RLB results were confirmed with specific conventional and semi-nested PCRs followed by sequencing. In total, 570 ticks (males, females and nymphs) were collected from 41 heads of cattle. Altogether 398 ticks belonged to the genus Hyalomma (397 Hyalomma excavatum and one Hyalomma scupense) while 172 ticks were identified as Rhipicephalus annulatus. Pooled H. excavatum ticks tested positive for several protozoa and bacteria with different minimum infection rates (MIRs): Theileria annulata (18.1 %), Babesia occultans (1.8 %), Anaplasma marginale (28.5 %), Anaplasma platys (0.25 %), Midichloria mitochondrii (11.6 %), Ehrlichia chaffeensis-like (1.8 %) and Ehrlichia minasensis (1 %). In R. annulatus, several agents were identified at different MIRs: T. annulata (2.3 %), B. bovis (0.6 %), A. marginale (18.0 %), A. platys (1.2 %), M. mitochondrii (2.9 %), E. minasensis (0.6 %). Pathogens co-detection in tick pools revealed A. marginale and T. annulata in 13.3 % samples followed by the co-detection of A. marginale and M. mitochondrii (8.4 %). In addition, triple co-detection with A. marginale, T. annulata and M. mitochondrii were found in 5.3 % of the tick pools. In cattle, the most common coinfection was with A. marginale and T. annulata (82.9 %) followed by the coinfection between A. marginale, T. annulata and B. bovis (4.9 %), A. marginale and B. bigemina (2.4 %) and finally the coinfection between T. annulata and B. occultans (2.4 %). Anaplasma platys, Babesia occultans, and E. minasensis were detected for the first time in Egypt in both cattle and ticks. These findings should be taken in consideration regarding human and animal wellbeing by the public health and veterinary authorities in Egypt.

Canine and feline vector-borne diseases of zoonotic concern in Southeast Asia

Dogs and cats are important hosts and reservoirs of many viral, bacterial, protozoal, and helminthic pathogens transmitted by arthropods, including some of zoonotic concern. By sharing the same environment, these companion animals play an important role in the transmission of zoonotic pathogens to humans in various regions and socioeconomic contexts. While canine and feline vector-borne diseases (VBD) are of major concern in wealthy regions (e.g. Europe and North America), less attention has been received in developing countries such as those in Southeast Asia (SEA). This review provides summarized and updated information on canine and feline VBD with emphasis on those of zoonotic concern in SEA. Of these, zoonotic bacteria (i.e. Bartonella henselae, Bartonella clarridgeiae, and Rickettsia felis) and filarial nematodes (i.e. Brugia malayi, Dirofilaria repens, and Dirofilaria immitis) stand out as the most important in veterinary and human medicine. Additionally, the recent finding of Leishmania infantum in dogs in SEA raised more concerns about the spreading of this zoonotic agent in this region. Further epidemiological surveys, especially in countries with extremely scant information such as Cambodia, Laos, Myanmar, and Timor-Leste are advocated. Additionally, effective control measures of canine and feline VBD as well as their arthropod vectors should be simultaneously performed for the management of zoonotic infections.

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Many canine and feline vector-borne infections affect animals and humans in Southeast Asia.

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Ticks, fleas and mosquitoes are the most common vectors transmitting pathogens to dogs, cats and humans in Southeast Asia.

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Bartonella henselae, Rickettsia felis and Dirofilaria repens are of concern to human health in this region.

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Collaboration between governments and researchers is encouraged for a better management of vector-borne diseases.

Molecular detection and characterization of tick-borne hemoparasites and Anaplasmataceae in dogs in major cities of Malawi

Tick-borne pathogens (TBPs) in dogs have attracted much attention over the last decade since some are now known to be zoonotic and pose a threat to both animal and human health sectors. Despite the increase in the number of studies on canine TBPs worldwide, only a few studies have been conducted in resource-limited countries where research priority is given to food animals than companion animals. In the present study, the occurrence of TBPs of the genera Babesia, Hepatozoon, Anaplasma, and Ehrlichia was investigated in 209 owned and stray dogs in three major cities in Malawi through molecular techniques. Among the examined dogs, 93 (44.5%) were infected with at least one TBP. The detection rates were 23.1% for Babesia rossi, 2.9% for B. vogeli, 19.1% for Hepatozoon canis, 2.4% for Anaplasma platys, and 3.8% for Ehrlichia canis. This is the first molecular study that has provided evidence that dogs in Malawi are infected with TBPs. Sensitization is required for veterinary practitioners, dog handlers, and pet owners as the detected pathogens affect the animals' wellbeing. Further studies focusing on rural areas with limited or no access to veterinary care are required to ascertain the extent of the TBP infection in dogs.

Epidemiology and genotyping of Anaplasma marginale and co-infection with piroplasms and other Anaplasmataceae in cattle and buffaloes from Egypt

BACKGROUND

Anaplasma marginale is an obligate intracellular bacterium and the main cause of bovine anaplasmosis in tropical and subtropical regions. In Egypt, data regarding the prevalence of A. marginale in ruminant hosts and of the circulating genotypes is lacking. This study therefore aimed to (i) investigate the presence, epidemiology and genotypes of A. marginale in cattle and buffaloes in Egypt, (ii) to evaluate suitable diagnostic tools and (iii) to identify co-infections of A. marginale with other selected tick-borne pathogens.

METHODS

Blood samples were collected from 394 animals (309 cattle and 85 buffaloes) from three different areas in Egypt. For the detection of A. marginale infection, several tests were compared for their sensitivity and specificity: blood smear analysis, enzyme-linked immunosorbent assay (ELISA), PCR, real-time PCR and reverse line blot (RLB) assay. Co-infections with A. marginale, piroplasms and other Anaplasmataceae were surveyed by RLB while A. marginale genotypes were identified by amplifying and sequencing the partial msp1α gene.

RESULTS

Anaplasma marginale DNA was amplified by qPCR in 68.3% of cattle and 29.4% of buffaloes. RLB showed infection with A. marginale in 50.2% of cattle and 42.5% of buffaloes. Blood smear analysis detected this agent in 16.2% of cattle and 2.4% of buffaloes. ELISA showed specific antibodies against A. marginale in 54.9% of cattle. Anaplasma marginale was associated, in cattle and buffaloes, with several tick-borne pathogens (Theileria annulata, Babesia bovis, Babesia bigemina, Babesia occultans and Anaplasma platys). A significant difference of A. marginale infection level was noticed in cattle, where animals between 3-5-years-old had a higher prevalence (79.2%) compared to those older than 5 years (36.4%) and younger than 3 years (59.7%) and one year (64.5%), respectively (P = 0.002281). Microsatellite analysis identified 15 different genotypes.

CONCLUSIONS

The epidemiological findings revealed high prevalence of A. marginale in cattle and buffaloes in all the investigated areas. The circulation of diverse genotypes was observed, most of these A. marginale genotypes being specific for Egypt. The qPCR assay was confirmed to be the most sensitive tool for detection of A. marginale in cattle and buffaloes even in the carrier state, highlighting the importance of using suitable diagnostic tests.

An overview of rickettsiae in Southeast Asia: Vector-animal-human interface

Rickettsioses are emerging, and re-emerging diseases caused by obligate intracellular arthropod-borne bacteria that infect humans and animals worldwide. Various rickettsiae such as Orientia, Rickettsia, Anaplasma and Ehrlichia have been circulated in companion, domesticated and wild animals through bites of infected ticks, fleas, lice or mites. This review summarizes the infections of rickettsiae, including the newly discovered regional species Rickettsia thailandii, Candidatus Rickettsia sepangensis, Candidatus Rickettsia johorensis, Candidatus Rickettsia laoensis, Candidatus Rickettsia mahosotii, Candidatus Rickettsia khammouanensis, Candidatus Anaplasma pangolinii, and other novel genotypes in vectors, humans and animals in Southeast Asia. Issues on some unidentified rickettsiae that elicit immune responses and production of antibodies that are cross-reactive with the antigens used are discussed. Knowledge gaps which required attention are also identified in this review.

Tick-borne zoonoses in the Order Rickettsiales and Legionellales in Iran: A systematic review

BACKGROUND

Tick-borne zoonoses in the Order Rickettsiales and Legionellales cause infections that often manifest as undifferentiated fevers that are not easy to distinguish from other causes of acute febrile illnesses clinically. This is partly attributed to difficulty in laboratory confirmation since convalescent sera, specific diagnostic reagents, and the required expertise may not be readily available. As a result, a number of tick-borne zoonoses are underappreciated resulting in unnecessary morbidity, mortality and huge economic loses. In Iran, a significant proportion of human infectious diseases are tick-borne, with anecdotal evidence suggesting that tick-borne zoonoses are widespread but underreported in the country. Epidemiological review is therefore necessary to aid in the effective control and prevention of tick-borne zonooses in Iran. The aim of this review is to provide an in-depth and comprehensive overview of anaplasmosis, ehrlichiosis, spotted fever group rickettsioses and coxiellosis in Iran.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, all relevant publications on tick-borne zoonoses in the Order Rickettsiales and Legionellales in Iran were searched using a number of search terms. The search was confined to authentic resources from repositories of popular data bases among them PubMed, Web of Science, Google Scholar, Science Direct, SpringerLink and SCOPUS. The search items included peer reviewed journals, books and book chapters published between 1996 and 2017.

RESULTS

A total of 1 205 scientific publications and reports were sourced, of which 63 met the search criteria and were reviewed. Of the 63 articles reviewed, 36 (57.1%) reported on coxiellosis, 15 (23.8%) on anaplasmosis, 11 (17.5%) on ehrlichiosis and 1(1.6%) on spotted fever group rickettsiae in a large scale study involving four countries, among them Iran. The existence of tick-borne pathogens in the Order Rickettsiales and Legionellales was confirmed by molecular, serological and microscopic techniques conducted on samples obtained from sheep, cattle, goats, camels, poultry, animal products (milk and eggs), dogs, ticks and even human subjects in different parts of the country; pointing to a countrywide distribution.

DISCUSSION

Based on the review, coxiellosis, anaplasmosis, ehrlichiosis, and SFG rickettsiae can be categorized as emerging tick-borne zoonotic diseases in Iran given the presence of their causiative agents (C. burnetii, A. phagocytophilum, A. marginale, A. bovis, A. ovis, A. central, E. canis, E. ewingii, E. chaffeensis and R. conorii) collectively reported in a variety of domestic animals, animal products, arthropods and human beings drawn from 22 provinces in Iran.

CONCLUSION

Given the asymptomatic nature of some of these zoonoses, there is a high likelihood of silent transmission to humans in many parts of the country, which should be considered a public health concern. Presently, information on the transmission intensity of tick-borne zoonoses caused by pathogens in the Order Rickettsiales and Legionellales to humans and its public health impact in Iran is scanty.

Molecular epidemiology, associated risk factors, and phylogenetic analysis of anaplasmosis in camel

Camel Anaplasmosis is caused by members of family Anaplasmatacae, a tick transmitted, obligate intracellular bacteria. The etiological bacteria are transmitted by ixodid tick species. The species have multi host range distribution that is why it is crucial to diagnose it timely. The aim of present study was to investigate the molecular epidemiology i.e. prevalence and risk factors analysis of camel anaplasmosis. Furthermore, variations in hematological standards were also evaluated. The study found an overall 13.33% prevalence in camels. The confirmation of PCR positive samples for Anaplasma spp. was made through sequencing, the study isolatesshowed high homology with Iranian, Chinese, Philippines and South African isolates of Anaplasmatacae (Accession numbers'; KX765882, KP062964, KY242456, LC007100 and U54806) on BLAST queries. The phylogenetic analysis revealedthree study isolates of present study clustered with each other and the cluster was found closer to Chinese isolate of A. phagocytophilum (KY242456), A. marginale (KU586048), and Mongolian isolates of A. ovis (LC194134). Two of the isolates resembled Iranian isolate of Candidatus Anaplasmacamelii (KX765882), while one isolate resembled with Chinese isolates of A. Platys (KX987336) and Croatian isolates of A. Platys (KY114935). The key risk factors odds ratio (OR>1) identified for occurrence of camel anaplasmosis using regression model found sex and age of animal, previous tick history, tick infestation and tick control status, housing type, cracks in walls, rearing system and other species in surrounding as the key risk factors. The hematological parameters like lymphocytes, monocytes, granulocytes and platelets count were significantly decreased (p < 0.05) in diseased camels than healthy. This is the first ever molecular data on camel anaplasmosis in Pakistan. The disease should be monitored unceasingly as the etiologies have multi host distribution. Prompt attention should be offered to animals because neutropenia, lymphopenia and thrombocytopenia can exacerbate the disease by making the animal predisposed to otherdiseases.

Serological and molecular detection of Theileria equi and Babesia caballi in Philippine horses

Theileria equi and Babesia caballi are tick-borne protozoan parasites that can cause anemia in horses. In the Philippines, serological detection of these parasites has only been reported in the Northern area (Luzon). In this study, 105 horses from Cebu and Bohol, Philippines were tested using peripheral blood smear examination (PBSE), immunochromatographic test (ICT) strips, and PCR. Clinical history, presenting clinical signs and complete blood count were obtained. Results revealed that although all horses were negative using PBSE, 23 (21.9%) were positive (12 for T. equi, and 11 for B. caballi) using ICT. PCR revealed 26 and 2 horses positive for T. equi and B. caballi, respectively. All positive horses showed no clinical signs. Partial DNA sequences of representative amplicons were found 100% identical to GenBank registered T. equi and B. caballi sequences. Statistical analyses revealed that location was found associated with T. equi PCR positivity and B. caballi seropositivity. This study documents the first serological detection of T. equi and B. caballi in horses in the southern area of the Philippines, and their first molecular detection and characterization in the country.

Tick-borne haemoparasites and Anaplasmataceae in domestic dogs in Zambia

Tick-borne diseases (TBDs), including emerging and re-emerging infectious diseases, are important threats to human and animal health worldwide. Indeed, the number of reported human and animal infectious cases of novel TBD agents has increased in recent decades. However, TBDs tend to be neglected, especially in resource-limited countries that often have limited diagnostic capacity. The aim of this molecular survey was to detect and characterise tick-borne pathogens (Babesia, Theileria, and Hepatozoon parasites and Anaplasmataceae bacteria) in domestic dogs in Zambia. In total, 247 canine peripheral blood samples were collected in Lusaka, Mazabuka, Monze, and Shangombo. Conventional PCR to detect the selected pathogens was performed using DNA extracted from canine blood. One hundred eleven samples were positive for protozoa and 5 were positive for Anaplasmataceae. Sequencing of thirty-five randomly selected protozoa-positive samples revealed the presence of Babesia rossi, Babesia vogeli, and Hepatozoon canis 18S rDNA. Based on these sequences, a multiplex PCR system was developed to yield PCR products with different amplicons, the size of which depended on the parasite species; thus, each species could be identified without the need for sequence analysis. Approximately 40% of dogs were positive for H. canis. In particular, the positive rate (75.2%) of H. canis infection was significantly higher in Shangombo than in other sampling sites. Multiplex PCR assay detected B. rossi and B. vogeli infections in five and seven dogs, respectively, indicating that this approach is useful for detecting parasites with low prevalence. Sequencing analysis of gltA and groEL genes of Anaplasmataceae revealed that two and one dogs in Lusaka were infected with Anaplasma platys and Ehrlichia canis, respectively. The data indicated that Zambian dogs were infected with multiple tick-borne pathogens such as H. canis, B. rossi, B. vogeli, A. platys, E. canis and uncharacterized Ehrlichia sp. Since some of these parasites are zoonotic, concerted efforts are needed to raise awareness of, and control, these tick-borne pathogens.

Molecular Evidence for Transstadial Transmission of Ehrlichia canis by Rhipicephalus sanguineus sensu lato Under Field Conditions

This study investigated possible transstadial transmission of Ehrlichia canis by Rhipicephalus sanguineus sensu lato collected from shelter dogs and the shelter grounds in Diyarbakır Province of south-eastern Turkey. Totally 225 engorged nymphs were collected from eight infected dogs with E. canis and incubated at 28°C for moulting. Unfed ticks from the shelter grounds comprising 1,800 larvae, 3,100 nymphs, and 85 adults were sorted according to sampling origin, life stage, and sex into 116 pools and screened by 16S rRNA PCR. Nine out of 26 pools of unfed adult ticks were positive for E. canis, with overall infection rate maximum likelihood estimation (MLE) of 4.83 (CI 2.39-8.87). E. canis was detected in three of 12 male pools (MLE 3.22, CI 0.86-8.83) and six of 14 female pools (MLE 6.16, CI 2.59-12.90). No adult pools collected from the shelter grounds were positive. Among 62 unfed nymph pools collected from the shelter, six were infected with E. canis (MLE 0.20, CI 0.08-0.42). No E. canis DNA was detected in any of the larva pools. Our results revealed molecular evidence for transstadial transmission of E. canis by R. sanguineus s.l. both from larva to nymph and from nymph to adult. We found no evidence of transovarial transmission.

Molecular detection of Ehrlichia canis in dogs from three districts in Punjab (Pakistan)

Canine monocytic ehrlichiosis is a tick-borne disease caused by an intracellular alpha-proteobacterium, Ehrlichia canis, which replicates within mononuclear cells in the host. This study was designed to use a polymerase chain reaction (PCR) protocol for the molecular detection of E. canis by the amplification of a portion of its 16S rRNA gene, as well as the effects of this alpha-proteobacterium on the haematological parameters of the sampled dogs and the risk factors associated with E. canis infection. A total of 151 blood samples were collected from dogs of various breeds at three sampling sites (Lahore, Rawalpindi/Islamabad and Multan) in Punjab, Pakistan. Data regarding the epidemiological factors (including age, gender, breed, body temperature, deworming, vaccination, mucous membrane status, hydration status, the presence of haematuria and tick infestation) were collected through a questionnaire at the time of sample collection. A 400 bp DNA fragment of the 16S rRNA gene of E. canis was amplified from 42 dog blood samples (28% of the total), [Lahore (N = 24), Rawalpindi/Islamabad (N = 13) and Multan (N = 05)] through PCR. Data analysis revealed that the character of the animals (age, sex and breed) had no significant association (P > 0.05) with the presence of E. canis. Various haematological parameters were also compared, and the results revealed that all of the parameters remained unaffected, except significantly lower white blood cell counts (P = 0.004) in E. canis-positive blood samples, as compared with the control group. We concluded that this is the first molecular confirmation of canine infection by E. canis using PCR. Moreover, no specific epidemiological parameter was found associated with the prevalence of E. canis in dogs.

Detection of Ehrlichia, Anaplasma, and Babesia spp. in dogs of Cebu, Philippines

Background

Ehrlichia, Anaplasma, and Babesia spp. are canine pathogens transmitted by the Rhipicephalus sanguineus tick which can cause varied clinical signs. These pathogens have been investigated in the Philippines, but coinfection has not been reported yet.

Aim

The aim of this study was to evaluate the presence of Ehrlichia/Anaplasma and Babesia spp. in Philippine dogs.

Materials and Methods

A total of 100 dogs from seven different veterinary establishments in Cebu, Philippines, were examined for Ehrlichia/Anaplasma and Babesia spp. infection using peripheral blood smear examination and polymerase chain reaction (PCR). Inclusion criteria included a history or presence of tick infestation, anemia, and/or thrombocytopenia. Clinical signs were recorded. Statistical analyses were performed between PCR positivity and clinical signs and hematological results.

Results

A total of 10 and 18 dogs were found to be positive for Ehrlichia/Anaplasma and Babesia spp., respectively. One animal was PCR positive for both pathogens, which is the first report of coinfection in the country. The most common clinical signs observed include inappetence (89%), lethargy (80%), thrombocytopenia (85%), and anemia (74%). Analyses revealed that inappetence (p=0.044) and weight loss (p=0.028) were found statistically significant with Ehrlichia/Anaplasma infection. Basophil (p=0.001) and eosinophil counts (p=0.000) were also found significantly different between Ehrlichia/Anaplasma spp.-positive and -negative dogs. On the other hand, differential monocyte count (p=0.009) was found significantly different between Babesia spp.-positive and -negative dogs.

Conclusion

The present study showed low infection rates of canine ehrlichiosis/anaplasmosis and babesiosis and provided additional evidence for the presence of the pathogens in the area.

Molecular epidemiology of Anaplasma platys, Ehrlichia canis and Babesia vogeli in stray dogs in Paraná, Brazil

ABSTRACT: Hemoparasitic infections are tick-borne diseases, which affect animals and humans. Considering the importance of canine hemoparasitic infections in veterinary clinics, this study aimed to determine the occurrence of Anaplasma platys, Ehrlichia canis and Babesia vogeli in blood samples from 182 dogs not domiciled in the city of Pato Branco, southwestern region of Paraná State, Brazil, using polymerase chain reaction (PCR). The prevalence of A. platys and B. vogeli was 32.9% and 10.9% respectively, and A. platys infection prevailed (p<0.001). The number of dogs positive for A. platys was larger in Winter (p<0.05). All blood samples were negative for E. canis. In the dogs, infestation by Amblyomma cajennense predominated over that by Rhipicephalus sanguineus (p<0.001); but there was no significant association between PCR and the variables presence of ticks, sex and age. Dogs infected by A. platys and B. vogeli showed thrombocytopenia, lymphopenia and leukocytosis; but there was no correlation between such hematological changes and infection by hemoparasites. This appears to be the first molecular study that demonstrates the existence of A. platys and B. vogeli in dogs from the southwestern region of Paraná.

Multiple infections of Anaplasma platys variants in Philippine dogs

Aim:

Anaplasma platys, the causative agent of infectious canine cyclic thrombocytopenia, is a tick-borne pathogen that also has been implicated as potentially zoonotic. To provide molecular evidence on the multiple infections of A. platys variants in Philippine dogs.

Materials and Methods:

DNA fragments of A. platys from infected dogs in the Philippines were molecularly characterized. For screening, 25 dogs suspected to have canine anaplasmosis were tested using a 16S rRNA-based nested polymerase chain reaction (PCR). Infection was confirmed by sequencing of positive amplicons. Second round PCR targeting a longer 16S rRNA fragment was subsequently performed on the first round PCR amplicons of the positive samples. Further characterization using the heat-shock operon (groEL) gene was also performed on the A. platys-positive samples.

Results:

10 16S rRNA sequences were obtained and found 99.6-100% identical to each other and 99.6-99.7% identical to the closest registered A. platys sequences. On the other hand, 36 groEL clone sequences were obtained and found to be 85.1-99.8% identical with each other and 85.0-88.9% identical to the closest previously registered A. platys sequences. Four dogs were found coinfected with 2-3 groEL variant sequences. Phylogenetic analyses suggest that the detected A. platys in the Philippines may represent unique variants.

Conclusion:

A. platys variants were detected in Philippine dogs. Coinfection of different A. platys variants in dogs was also demonstrated. The present study may indicate the potential genetic diversity of A. platys in the country.

Anaplasma species of veterinary importance in Japan

Anaplasma species of the family Anaplasmataceae, order Rickettsiales are tick-borne organisms that can cause disease in animals and humans. In Japan, all recognized species of Anaplasma (except for Anaplasma ovis) and a potentially novel Anaplasma sp. closely related to Anaplasma phagocytophilum have been reported. Most of these detected tick-borne pathogens are believed to be lowly pathogenic in animals in Japan although the zoonotic A. phagocytophilum has recently been reported to cause clinical signs in a dog and in humans. This review documents the studies and reports about Anaplasma spp. in Japan.

WITHDRAWN:First report on Babesia canis vogeli infection in dogs in the Philippines

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.parint.2016.10.001.The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Molecular detection of Anaplasma platys infection in free-roaming dogs and ticks from Kenya and Ivory Coast

Background

Anaplasma platys is a bacterium parasitic in the canine platelets, representing the causative agent of canine cyclic thrombocytopenia, with a worldwide distribution, mainly in tropical countries. The agent has zoonotic potential, being reported in several human clinical cases. The suspected vector is the tick Rhipicephalus sanguineus (sensu lato), widely distributed in animals and humans in the tropical regions of South America, Africa, Asia and Australia, but also in southern Europe. Only few scattered data concerning the epidemiology of A. platys in sub-Saharan Africa are available. The aim of our study was to evaluate the epidemiological status of A. platys in dogs and cats from rural communities in eastern and western Africa, where dogs and their ticks live in close contact with humans.

Methods

A total of 216 canine and 22 feline blood samples and ticks feeding on them were collected in 2013 and 2014 from eight localities in Ivory Coast and four localities in Kenya. PCR was performed using specific primers targeting a portion of the 16S rRNA gene, followed by sequencing.

Results

The main results highlight the high prevalence of A. platys infection in dogs in both Eastern and Western Africa and report it for the first time in Eastern Africa and in Rhipicephalus camicasi.

Conclusions

The presence of A. platys DNA in R. camicasi feeding on negative hosts together with the relatively high prevalence of A. platys, correlated with the absence of the probable vector Rhipicephalus sanguineus (s.l.) in Kenyan Island suggest the involvement of other tick species in the transmission of A. platys.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1443-3) contains supplementary material, which is available to authorized users.

Molecular detection of Rickettsia, Anaplasma, Coxiella and Francisella bacteria in ticks collected from Artiodactyla in Thailand

A total of 79 ticks collected from Sambar deer (Cervus unicolor), Barking deer (Muntiacus muntjak) and Wild boar (Sus scrofa) were examined by PCR for the presence of Rickettsia, Anaplasma, Coxiella, and Francisella bacteria. Of the 79 ticks, 13% tested positive for Rickettsia, 15% tested positive for Anaplasma, 4% tested positive for Coxiella, and 3% tested positive for Francisella. Interestingly, triple infection with Anaplasma, Rickettsia and Francisella was determined in a Dermacentor auratus tick. Moreover, another triple infection with Rickettsia, Anaplasma, and Coxiella was found in a Haemaphysalis lagrangei tick. Double infection of Rickettsia with Coxiella was also detected in another H. lagrangei tick. From the phylogenetic analyses, we found a Rickettsia sp. with a close evolutionary relationship to Rickettsia bellii in the H. lagrangei tick. We also found the first evidence of a Rickettsia sp. that is closely related to Rickettsia tamurae in Rhipicephalus (Boophilus) microplus ticks from Thailand. H. lagrangei and Haemaphysalis obesa ticks collected from Sambar deer tested positive for Anaplasma species form the same clade with Anaplasma bovis. In contrast, other H. lagrangei ticks collected from Sambar deer and D. auratus ticks collected from Wild boar were also reported for the first time to be infected with an Anaplasma species that is closely related to Anaplasma platys. The phylogenetic analysis of the 16S rRNA gene of Coxiella bacteria revealed that Coxiella symbionts from H. lagrangei formed a distinctly different lineage from Coxiella burnetii (a human pathogen). Additionally, Francisella bacteria identified in D. auratus ticks were found to be distantly related to a group of pathogenic Francisella species. The identification of these bacteria in several feeding ticks suggests the risk of various emerging tick-borne diseases and endosymbionts in humans, wildlife, and domestic animals in Thailand.

Retrospective analyses of dogs found serologically positive for Ehrlichia canis in Cebu, Philippines from 2003 to 2014

AIM

The study aimed to document the clinical and hematological observations of dogs found serologically positive for Ehrlichia canis and to identify parameters or factors that are associated with the disease with focus on the anemic and thrombocytopenic state of the infected dogs.

MATERIALS AND METHODS

From 7 participating veterinary establishments, a total of 913 cases from 2003 to 2014 were initially assessed using inclusion criteria, including E. canis diagnosis by the attending veterinarian and the presence of ticks or history of infestation, thrombocytopenia, and/or anemia. From these, 438 cases that were found serologically positive for E. canis using commercial test kits were selected. Profile, clinical observations and hematological test results were obtained from the selected cases. Computations for statistical associations between the anemic and thrombocytopenic state of the infected dogs and their profile, observed clinical signs and other hematological values were performed.

RESULTS

Most of the dogs were purebred (60.0%) and female (51.1%) and were within the age range of 1-5 years (38.4%). The mean packed cell volume (PCV), red blood cell (RBC) count, and platelet count were lower than the normal values while the absolute count of basophils were higher than normal values. Creatinine and blood urea nitrogen (BUN) appear to be elevated. The most common clinical signs observed were inappetence (41.3%), lethargy/depression (35.6%), vomiting (32.4%), fever (18.5%), paleness (8.2%), and epistaxis (6.6%). Analyses showed that there were no significant differences on the hematological values and clinical signs between thrombocytopenic and non-thrombocytopenic seropositive dogs. Moreover, very weak correlations between platelet count and RBC count, absolute lymphocyte count, and neutrophil count were found. On the other hand, only paleness (p=0.008) and epistaxis (p=0.004) were found to be significantly different between anemic and non-anemic patients. This coincided with the linear regression results where PCV (p=0.000, R=0.787, R(2)=0.619) was moderately correlated with the RBC count. In addition, eosinophil count was found weakly correlated.

CONCLUSION

E. canis infection in dogs may produce varied clinical signs that may be influenced by the thrombocytopenic and anemic states of affected animals. Complete blood counts remain important in the diagnosis of the disease, especially the platelet and RBC counts. Creatinine, BUN and alanine aminotransferase can be of value in the diagnosis of the infection. Several cases were lost to follow-up and appeared to be a challenge for handling veterinarians to monitor compliance of owners and progress of infected patients.

Vector-Borne Diseases in Stray Dogs in Peninsular Malaysia and Molecular Detection of Anaplasma and Ehrlichia spp. from Rhipicephalus sanguineus (Acari: Ixodidae) Ticks

Little data are available on the prevalence and transmission of vector-borne diseases in stray dogs in Peninsular Malaysia. This study was designed to determine the occurrence of vector-borne pathogens in Malaysian stray dogs using serological and molecular approaches. In total, 48 dog blood samples were subjected to serological analysis using SNAP 4Dx kit (IDEXX Laboratories, Westbrook, ME). The presence of Ehrlichia and Anaplasma DNA in the dog blood samples and Rhipicephalus sanguineus (Latreille) ticks was detected using nested polymerase chain reaction assays. Positive serological findings against Ehrlichia canis and Anaplasma phagocytophilum were obtained in 17 (39.5%) and four (9.3%) of 43 dog samples, respectively. None of the dog blood samples were positive for Borrelia burgdorferi and Dirofilaria immitis. DNA of E. canis and A. phagocytophilum was detected in 12 (25.5%) and two (4.3%) of 47 dog blood samples, and 17 (51.5%) and one (3.0%) of 33 R. sanguineus ticks, respectively. Additionally, DNA of Ehrlichia spp. closely related to Ehrlichia chaffeensis was detected in two (6.1%) R. sanguineus ticks. This study highlights the prevalence of anaplasmosis and ehrlichiosis in dogs in Malaysia. Due to the zoonotic potential of Ehrlichia and Anaplasma spp., appropriate measures should be instituted for prevention and control of vector-borne diseases in dogs.