Search Results (13)

Multiple blood pathogen infections are increasingly found in many areas, particularly in tropical regions. This study aimed to investigate the effectiveness and safety of using doxycycline monotherapy to treat triple blood pathogen infection in sheltered dogs. A total of 375 sheltered dogs were screened for blood pathogen using polymerase chain reaction technique (PCR). There were 34 dogs with triple infection (Babesia vogeli, Ehrlichia canis, and Anaplasma platys), and most dogs displayed anemia and thrombocytopenia. These dogs were treated with doxycycline (10 mg/kg/day) orally for four weeks, and their blood profiles were monitored. Almost all pathogens were undetectable by PCR by day 14 and pathogens were all cleared by day 28. Most blood profiles significantly improved after 14 days. The improvement continued after 28 days. The red blood cell and platelet count (PLT) were increased in similar trends between mild-to-moderate and severe thrombocytopenia groups. The average PLT in the mild-to-moderate thrombocytopenia group raised to normal level by day 14, whereas in the severe group, it was gradually increased to normal level by day 70. We propose using doxycycline monotherapy for 28 days to eliminate all pathogens, and facilitate recovery and welfare in dogs suffering with triple blood pathogen infections. Full article

More than one-hundred Babesia species that affect animals and humans have been described, eight of which have been associated with emerging and underdiagnosed zoonoses. Most diagnostic studies in humans have used serology or molecular assays based on the 18S rRNA gene. Because the 18S rRNA gene is highly conserved, obtaining an accurate diagnosis at the species level is difficult, particularly when the amplified DNA fragment is small. Also, due to its low copy number, sequencing of the product is often unsuccessful. In contrast, because the Babesia internal transcribed regions (ITS), between 18S rRNA and 5.8S rRNA, and between 5.8S rRNA and 28S rRNA, contain highly variable non-coding regions, the sequences in these regions provide a good option for developing molecular assays that facilitate differentiation at the species level. In this study, the complete ITS1 and ITS2 intergenic regions of different Piroplasmida species were sequenced to add to the existing GenBank database. Subsequently, ITS1 and ITS2 sequences were used to develop species-specific PCR assays and specific single-plex and multiplex conventional (c)PCR, quantitative real-time (q)PCR, and digital (d)PCR assays for four zoonotic Babesia species (Babesia divergens, Babesia odocoilei, Babesia duncani, and Babesia microti). The efficacy of the assay protocols was confirmed by testing DNA samples extracted from human blood or enrichment blood cultures. Primers were first designed based on the 18S rRNA-5.8S rRNA and 5.8S rRNA-28S rRNA regions to obtain the ITS1 and ITS2 sequences derived from different Piroplasmida species (B. odocoilei, Babesia vulpes, Babesia canis, Babesia vogeli, Babesia gibsoni, Babesia lengau, Babesia divergens-like, B. duncani, B. microti, Babesia capreoli, Babesia negevi, Babesia conradae, Theileria bicornis, and Cytauxzoon felis). Subsequently, using these sequences, single-plex or multiplex protocols were optimized targeting the ITS1 region of B. divergens, B. microti, and B. odocoilei. Each protocol proved to be sensitive and specific for the four targeted Babesia sp., detecting 10⁻² (for B. microti and B. odocoilei) and 10⁻¹ (for B. divergens and B. duncani) DNA copies per microliter. There was no cross-amplification among the Babesia species tested. Using 226 DNA extractions from blood or enrichment blood cultures obtained from 82 humans, B. divergens (seven individuals), B. odocoilei (seven individuals), and B. microti (two individuals) were detected and identified as a single infection, whereas co-infection with more than one Babesia sp. was documented by DNA sequencing in six (7.3%) additional individuals (representing a 26.8% overall prevalence). These newly developed protocols proved to be effective in detecting DNA of four Babesia species and facilitated documentation of co-infection with more than one Babesia sp. in the same individual. Full article

Eight hunting dogs were visited by a state veterinarian on the island of Tobago, Trinidad and Tobago, West Indies, as owners reported anorexia and paralysis in five of their dogs. The veterinarian observed a combination of clinical signs consistent with tick-borne illness, including fever, anorexia, anaemia, lethargy and paralysis. Blood and ticks were collected from each dog and submitted to a diagnostic laboratory for analysis. Microscopic analysis revealed a mixed infection of intracytoplasmic organisms consistent with Babesia spp. (erythrocyte) and Ehrlichia spp. (monocyte), respectively, from one dog, while a complete blood count indicated a regenerative anaemia (n = 1; 12.5%), non-regenerative anaemia (n = 4; 50%), neutrophilia (n = 3; 37.5%), lymphocytosis (n = 2; 25%), thrombocytopaenia (n = 3; 37.5%) and pancytopaenia (n = 1; 12.5%). DNA isolated from the eight blood samples and 20 ticks (16 Rhipicephalus sanguineus and 4 Amblyomma ovale) were subjected to conventional PCR and next-generation sequencing of the 16S rRNA and 18S rRNA gene for Anaplasma/Ehrlichia and Babesia/Theileria/Hepatozoon, respectively. The DNA of Ehrlichia spp., closely related to Ehrlichia canis, was detected in the blood of three dogs (37.5%), Anaplasma spp., closely related to Anaplasma marginale, in two (25%), Babesia vogeli in one dog (12.5%) and seven ticks (35%) and Hepatozoon canis and Anaplasma spp., in one tick (5%), respectively. These findings highlight the need to test both the vector and host for the presence of tick-borne pathogens when undertaking diagnostic investigations. Further studies are also warranted to elucidate the susceptibility of canids to Anaplasma marginale. Full article

Babesia species infect a very wide range of mammal hosts across the globe, and zoonotic infections are of growing concern. Several species of the Babesia genus infect dogs, and some of these cause significant morbidity and mortality. The Apicomplexan parasite resides within the red cell and infections result in direct damage to the host through intra- and extravascular hemolysis. An exuberant inflammatory response by the host to some species of Babesia parasites also results in significant collateral damage to the host. Canine infections have been the subject of many studies as the well-being of these companion animals is increasingly threatened by the spread of tick vectors and an increasingly mobile dog population. There are currently no widely available and effective vaccines, and effective treatment can be challenging. Understanding disease pathogenesis underlies the development of new treatments. The varying pathogenicity of the various Babesia parasite species that infect dogs offers an opportunity to explore the molecular basis for the wide range of diseases caused by infection with this parasite genus. In this review, we focus on what has been reported about the clinical presentation of Babesia-infected dogs in an attempt to compare the severity of disease caused by different Babesia species. Full article

Canine babesiosis is a disease caused by protozoan pathogens belonging to the genus Babesia. Four species of large Babesia cause canine babesiosis (B. canis, B. rossi, B. vogeli, and the informally named B. coco). Although canine babesiosis has a worldwide distribution, different species occur in specific regions: B. rossi in sub-Saharan Africa, B. canis in Europe and Asia, and B. coco in the Eastern Atlantic United States, while B. vogeli occurs in Africa, southern parts of Europe and Asia, northern Australia, southern regions of North America, and in South America. B. vogeli is the most prevalent large Babesia species globally. This results from its wide range of monotropic vector species, the mild or subclinical nature of infections, and likely the longest evolutionary association with dogs. The most important risk factors for infection by large Babesia spp. include living in rural areas, kennels or animal shelters, or regions endemic for the infection, the season of the year (which is associated with increased tick activity), infestation with ticks, and lack of treatment with acaricides. Full article

Canine babesiosis is an emerging tick-borne disease of major veterinary concern in Europe. Its prevalence has increased in the last two decades and is spreading rapidly toward the north. The aim of this study was to investigate the genetic diversity of Babesia spp. strains isolated from naturally infected dogs in a tick-endemic area (Dobrogea) in southeastern Romania. For this purpose, a total of twenty-three samples from dogs diagnosed with various clinical forms of babesiosis, evaluated by means of clinical history, physical examination, and hematological tests, were subjected to a molecular investigation using PCR, sequencing analysis, and genetic characterization. A microscopic examination of thin Diff-quick-stained blood smears revealed large intra-erythrocytic Babesia piroplasms in all dogs. The PCR and sequencing analysis results indicated the presence of Babesia canis in 22 dogs (95.7%) and Babesia vogeli in 1 dog (4.3%). Among the B. canis isolates, two genotypes were distinguished based on two nucleotide substitutions (GA→AG) observed in the 18S rRNA gene sequences (at positions 609 and 610), with the AG genotype predominating (54.5% of samples), while the GA variant was identified in 9.1% of samples. In the remaining isolates (36.4%), both variants were identified. The B. vogeli-positive dog also tested positive for antibodies against Ehrlichia canis and displayed severe disease. This study reports, for the first time, the presence of genetically heterogenic B. canis strains in dogs with clinical babesiosis in Romania. These findings provide a basis for future studies on the relationship between the genetic structure of the causative agents of canine babesiosis in Romania and the course of the disease. Full article

Canine vector-borne diseases are of great relevance not only regarding animal welfare but also in relation to the One Health concept. Knowledge concerning the most relevant vector-borne pathogens in dogs is scarce and limited to stray dogs in most western African regions, and there is virtually no information about the situation in kept dogs presenting (regularly) to vets. Therefore, the blood samples of 150 owned guard dogs in the Ibadan area—in the southwest of Nigeria—were collected and analyzed for the DNA of Piroplasmida (Babesia, Hepatozoon, Theileria), Filarioidea (e.g., Dirofilaria immitis, Dirofilaria repens), Anaplasmataceae (e.g., Anaplasma, Ehrlichia), Trypanosomatidae (e.g., Leishmania, Trypanosoma), Rickettsia, Bartonella, Borrelia and hemotropic Mycoplasma using molecular methods. Overall, samples from 18 dogs (12%) tested positive for at least one pathogen. Hepatozoon canis (6%) was the most prevalent blood parasite, followed by Babesia rossi (4%). There was a single positive sample each for Babesia vogeli (0.6%) and Anaplasma platys (0.6%). Moreover, one mixed infection with Trypanosoma brucei/evansi and Trypanosoma congolense kilifi was confirmed (0.67%). Generally, the prevalence of vector-borne pathogens in this sample group of owned dogs in southwest Nigeria was lower than in prior studies from the country and in other parts of Africa in total. This leads to the assumption that, firstly, the exact geographical location has a major influence on the incidence of vector-borne diseases, and, secondly, it seems to make a difference if the dogs are owned and, therefore, regularly checked at a veterinary clinic. This study should raise awareness of the importance of routine health check-ups, tick and mosquito prophylaxis, and a well-managed infectious disease control program to prevent vector-borne diseases in canines. Full article

Even though the epidemiology of tick-borne agents (TBA) in dogs has been extensively investigated around the world, the occurrence, vectors involved, and molecular identity of these agents in cats remains elusive in many regions. Among TBA, Ehrlichia, Anaplasma, Babesia, Cytauxzoon, and Hepatozoon are responsible for diseases with non-specific clinical signs in cats, making essential the use of molecular techniques for accurate diagnosis and proper treatment. The present work aimed to investigate the occurrence and molecular identity of tick-borne agents (Ehrlichia, Anaplasma, Babesia/Theileria, Cytauxzoon, and Hepatozoon) in cats from southeastern (states of São Paulo (SP) and Minas Gerais (MG)) and northern (state of Rondônia (RO)) Brazil. For this purpose, 390 blood samples were collected from domiciled cats in MG (n = 155), SP (n = 151), and RO(n = 84) states, submitted to DNA extraction and PCR assays for Ehrlichia spp. (dsb gene), Anaplasma spp. (rrs gene), piroplasmids (18S rRNA gene), and Hepatozoon spp. (18S rRNA gene), sequencing, and phylogenetic inferences. The overall positivity for Anaplasma spp., Ehrlichia spp., Babesia/Theileria spp., Cytauxzoon spp., and Hepatozoon spp. were 7.4% (12.3% (MG) and 6.6% (SP)), 2% (4.5% (MG) and 0.6% (SP)), 0.7% (0.6% (MG), 0.6% (SP) and 1.2% (RO)), 27.2% (41.9% (MG), 24.5% (SP) and 4.8% (RO), and 0%, respectively. The phylogenetic analysis grouped the obtained sequences with ‘Candidatus Anaplasma amazonensis’, A. platys, B. vogeli, and Cytauxzoon sp. previously detected in wild felids from Brazil. qPCR specific for E. canis based on the dsb gene confirmed the molecular identity of the detected ehrlichial agent. The present study expanded the list and geographical distribution of hemoparasites in cats. ‘Candidatus Anaplasma amazonensis’, recently detected in sloths from northern Brazil, was described for the first time in cats. This is the first report of piroplasmids infecting cats in northern Brazil. Coinfection by Cytauxzoon and other TBA (Ehrlichia, Anaplasma, and B. vogeli) reported in the present study raises the need for veterinary practitioners’ awareness of cats parasitized by multiple TBA. Full article

Although the distribution of Babesia spp. and Hepatozoon canis is well known in Romania, there is still a marked lack of information in many places of the country. This study aimed to investigate the occurrence of these haemoparasites in symptomatic dogs and in their ticks in Iasi, eastern Romania. Ninety owned dogs were subjected to clinical examination at the Faculty of Veterinary Medicine of Iasi and all detectable ticks (58 ticks from 15 dogs) were collected. Additionally, 124 ticks collected from the coat of other dogs (no. = 23) were included. Three Babesia species were found in dogs: Babesia canis (94.4%), Babesia vogeli (3.3%), and Babesia rossi (2.2%). All the dogs resulted negative for H. canis. The ticks were identified as follows: Ixodes ricinus (64%), Dermacentor reticulatus (33%), and Rhipicephalus sanguineus group (3%). B. canis (Minimum Infection Rate; MIR = 81%), B. vogeli (MIR = 3%), and Babesia microti-like piroplasm (MIR = 1%) were found in ticks. Moreover, 15 ticks were positive for H. canis, 6 were co-infected with B. canis, and 1 with B. microti-like piroplasm. This is the first molecular identification of B. rossi in two symptomatic dogs from Romania, although further studies are needed to investigate the vector competence of other ticks from Europe. Full article

In southern Thailand, the increasingly growing population of stray dogs is a concern to public health and environmental safety because of the lack of medical attention and control. More importantly, these animals are considered reservoirs for many zoonotic pathogens. The objective of this study was to molecularly detect canine vector-borne pathogens, and to perform genetic characterization of Babesia gibsoni present in stray dogs from southern Thailand. Blood samples were collected from 174 stray dogs in two provinces (Songkhla and Narathiwat) in southern Thailand. PCR analyses were executed using specific primers based on the Babesia spp. 18S rRNA gene, Babesia gibsoni Internal transcribed spacer 1 (ITS1) region, Ehrlichia canis citrate synthase (gltA) gene, Hepatozoon spp. 18S rRNA gene and Anaplasma platys heat shock protein (groEL) gene. The most common canine vector-borne pathogen found infecting stray dogs in this study was Hepatozoon canis (24.7%) followed by A. platys (14.9%), Babesia vogeli (8.0%), B. gibsoni (6.3%), and E. canis (1.72%). Concurrent infection with more than one pathogen occurred in 72 cases. Phylogenetic analysis based on the ITS1 region and 18S rRNA gene revealed that the B. gibsoni isolates from this study shared a large proportion of their identities with each other and with other reported B. gibsoni genotypes from Asia. This study highlights the molecular detection of B. gibsoni in dogs in Thailand for the first time and presents the genetic characterization by sequencing the ITS1 region and 18S rRNA gene of B. gibsoni from Thailand. Follow-up studies are needed to elucidate the origin, distribution, and vectors of B. gibsoni parasites circulating in dogs in Thailand, as well as to determine to what extent dogs are important reservoir hosts for zoonotic canine vector-borne disease infection in the studied area. Full article

The Asia-Pacific hosts a large diversity of canine vector-borne pathogens (VBPs) with some of the most common and most pathogenic, generating significant mortality as well as a spectrum of health impacts on local dog populations. The VBPs Anaplasma platys, Babesia gibsoni, Babesia vogeli, Ehrlichia canis, Hepatozoon canis and haemotropic Mycoplasma spp. are all endemic throughout the region, with many exhibiting shifting geographical distributions that warrant urgent attention. Moreover, many of these species cause similar clinical signs when parasitising canine hosts, whilst knowledge of the exact pathogen is critical to ensure treatment is effective. This is complicated by frequent coinfection that can exacerbate pathology. Here, we describe the development, optimisation and validation of two novel quadruplex Taq-Man based real-time PCRs (qPCRs) for the specific and sensitive detection of the aforementioned VBPs. To ensure accurate evaluation of diagnostic performance, results of our qPCRs were evaluated on field samples from Thai dogs and compared with both conventional PCR (cPCR) results and next-generation sequencing (NGS) metabarcoding. Our qPCRs were found to be more sensitive at detecting canine VBP than cPCR and generated results similar to those achieved by NGS. These qPCRs will provide a valuable high-throughput diagnostic tool available to epidemiologists, researchers and clinicians for the diagnosis of key canine VBPs in the Asia-Pacific and further afield. Full article

Canine tick-borne pathogens (CTBPs) such as Babesia vogeli, Ehrlichia canis, Anaplasma platys, Hepatozoon canis, and Mycoplasma haemocanis are important pathogens in dogs worldwide. Rhipicephalus sanguineus sensu lato, the main vector of several CTBPs, is the most common tick species found on dogs in Thailand. The present study identified CTBPs in dogs and ticks infested dogs. Samples (360 dog blood samples and 85 individual ticks) were collected from stray dogs residing in 37 temples from 24 districts in Bangkok and screened for CTBPs using molecular techniques. The most common CTBP found infecting dogs in this study was Ehrlichia canis (38.3%) followed by Mycoplasma haemocanis (34.2%), Hepatozoon canis (19.7%), Babesia vogeli (18.1%), and Anaplasma platys (13.9%), respectively. Furthermore, A. platys (22.4%) was the most common CTBP in ticks followed by M. haemocanis (18.8%), B. vogeli (9.4%), H. canis (5.9%), and E. canis (2.4%), respectively. The detection of CTBPs from the present study highlights the potential risk of infections that may occur in stray dogs and their ticks residing in Bangkok temples. These findings underline the importance of performing active surveys to understand the complexity of distributions of CTBPs in dogs and their ticks in Thailand. Full article

Polymerase chain reaction (PCR) is a unique technique in molecular biology and biotechnology for amplifying target DNA strands, and is also considered as a gold standard for the diagnosis of many canine diseases as well as many other infectious diseases. However, PCR still faces many challenges and issues related to its sensitivity, specificity, efficiency, and turnaround time. To address these issues, we described the use of unique ZnO nanoflowers in PCR reaction and an efficient ZnO nanoflower-based PCR (nanoPCR) for the molecular diagnosis of canine vector-borne diseases (CVBDs). A total of 1 mM of an aqueous solution of ZnO nanoflowers incorporated in PCR showed a significant enhancement of the PCR assay with respect to its sensitivity and specificity for the diagnosis of two important CVBDs, Babesia canis vogeli and Hepatozoon canis. Interestingly, it drastically reduced the turnaround time of the PCR assay without compromising the yield of the amplified DNA, which can be of benefit for veterinary practitioners for the improved management of diseases. This can be attributed to the favorable adsorption of ZnO nanoflowers to the DNA and thermal conductivity of ZnO nanoflowers. The unique ZnO nanoflower-assisted nanoPCR greatly improved the yield, purity, and quality of the amplified products, but the mechanism behind these properties and the effects and changes due to the different concentrations of ZnO nanoflowers in the PCR system needs to be further studied. Full article