Serological survey of Ehrlichia species in dogs, horses and humans: zoonotic scenery in a rural settlement from southern Brazil

One Health Approach on Ehrlichia canis: Serosurvey of Owners and Dogs, Molecular Detection in Ticks, and Associated Risk Factors in Tick-Infested Households of Southern Brazil

Background: Ehrlichia canis has been the main hemopathogen affecting domestic dogs in Brazil. Even though tick-infested dogs may lead to household infestation and predispose human exposure and public health concern, no comprehensive study has surveyed humans, dogs, and environmental ticks altogether. Materials and Methods: Accordingly, the present study aimed to assess tick-infested households, identify tick species, perform serological (immunofluorescence assay) and molecular (PCR and q-PCR) detection of Ehrlichia in ticks, in the eighth biggest metropolitan area of Brazil. Results: Between 2007 and 2020, 233/5973 (3.9%) out of all complaints were from tick-infested households of 200 different addresses. Overall, 370/552 (67.0%) ticks were collected and identified as adult and 182/552 (33.0%) as immature forms of Rhipicephalus sanguineus s.l. complex; a single tick from one owner, a female tick of Amblyomma sculptum; and 395 ticks from dogs, 319/395 (80.8%) adult and 72/395 (18.2%) immature forms of Rhipicephalus spp., and 4/395 (1.01%) female Amblyomma aureolatum. Overall, 2/135 (1.5%) owners and 13/136 (9.6%) dogs were seropositive for E. canis. The DNA of Anaplasmataceae family was molecularly detected in 16/50 (32.0%) R. sanguineus s.l. As expected, the number of monthly tick infestation complaints were directly associated, and mean (p = 0.01), maximum (p = 0.011), and minimum (p = 0.008) temperature were statistically significant and had a low positive correlation (0.24, 0.23, and 0.24, respectively). In addition, complaints were highly associated to all socioeconomic variables (p < 0.001), with the exception of the presence of vacant lots. Conclusions: Despite low samplings and human negative results, areas with low-income with adequate temperature and urban agglomerations have been shown to be associated risks for tick infestations, predisposing tick-borne diseases. In conclusion, monitoring should always be conducted in such areas, including One Health approach with serosurvey of owners and dogs, along with identification and molecular screening of ticks.

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.

Prevalence of Anaplasma, Ehrlichia and Rickettsia infections in dogs in Iran: A meta-analysis study

The current study aims to assess the prevalence of different genera of Rickettsiales, intracellular bacteria, in dogs across various regions of Iran. Rickettsiales, as zoonotic pathogens, can have various manifestations in different species, including immunosuppression, anaemia and neuropathy. Due to their close interactions with people and livestock, dogs can serve as reservoirs and transmit these pathogens to humans and other animals. The data from this research can be valuable for managing and controlling related diseases and complications in Iran and possibly neighbouring countries. Pertinent data for this study was gathered without time limitations until 1 March 2022, from different databases. Of all the inspected studies, 26 were eligible based on the inclusion criteria. The Egger test result and asymmetry in the funnel plot revealed significant publication bias; therefore, the meta-analysis model was corrected with the trim-and-fill method. After correction, the prevalence of rickettsial infections among dogs varies by genus - 20.1% for Anaplasma spp. and 10% for Ehrlichia spp. - with an overall prevalence estimated at 18.3% by random-effects analysis. The highest and lowest estimated pooled prevalences were associated with the southwestern (38.5%) and southern (0.3%) provinces of Iran, respectively. The pooled prevalence of rickettsial infection was higher in female dogs (OR = 1.198; p < 0.978; 95% CI, 0.842-1.705) and in dogs ≤2 years (OR = 1.014; p < 0.312; 95% CI, 0.598-1.72), but the difference was not statistically significant. Ultimately, the pooled prevalence of rickettsial infections among dogs is relatively low compared to other countries like Qatar, Iraq, Saudi Arabia and Turkey, which are nearby Iran. Given the significant clinical outcomes of this disease, necessary measures for prevention should be taken.

Mathematical model of Ehrlichia chaffeensis transmission dynamics in dogs

Ehrlichia chaffeensis is a tick-borne disease transmitted by ticks to dogs. Few studies have mathematical modelled such tick-borne disease in dogs, and none have developed models that incorporate different ticks' developmental stages (discrete variable) as well as the duration of infection (continuous variable). In this study, we develop and analyze a model that considers these two structural variables using integrated semigroups theory. We address the well-posedness of the model and investigate the existence of steady states. The model exhibits a disease-free equilibrium and an endemic equilibrium. We calculate the reproduction number (T 0 ). We establish a necessary and sufficient condition for the bifurcation of an endemic equilibrium. Specifically, we demonstrate that a bifurcation, either backward or forward, can occur at T 0 = 1 , leading to the existence, or not, of an endemic equilibrium even when T 0 < 1 . Finally, numerical simulations are employed to illustrate these theoretical findings.

Phylogenetic analysis of Ehrlichia species isolated from horses and dogs in Iran

This study aimed to determine the prevalence and phylogenetic analysis of Ehrlichia spp. in horses and dogs in Iran. Blood samples were collected from 400 animals, including 200 horses and 200 dogs, from five different provinces in Iran. Polymerase chain reaction (PCR) was used to detect Ehrlichia spp. based on amplification of the 16S rRNA gene. The semi-nested PCR method was used to amplify the dsb, TRP36, and gltA genes. The results showed that 4.5 % of the samples (3 % horses and 6 % dogs) were positive for Ehrlichia sp. The highest prevalence was observed in Kerman and Khuzestan, while the lowest was found in West Azerbaijan, Golestan, and Mazandaran. The study suggests that the populations of dogs and horses in the country should be considered important factors in the epidemiology of ehrlichiosis. Phylogenetic analysis based on the dsb and TRP36 genes revealed that the prevalent species were E. canis and E. ruminantium.

First molecular detection of Mycoplasma ovis in horses from Brazil

This study aimed to determine the occurrence of hemoplasmas and tick-borne pathogens (TBP) (Theileria equi, Babesia caballi, and Ehrlichia sp.) in horses and ticks' salivary glands, and determine the factors associated with exposure/infection in a rural settlement in southern Brazil. Blood samples from 22 horses were screened for anti-T. equi and anti-Ehrlichia sp. antibodies by an indirect fluorescent antibody test (IFAT) assays. Samples were also tested by PCR assays for T. equi and B. caballi (18S rRNA and rap-1 genes, respectively), hemoplasmas (16S rRNA gene), and Ehrlichia sp. (dsb gene). Ticks were removed from the animals (inspection) and the environment (flannel trawling and dry ice traps), and morphologically identified. Additionally, salivary glands DNA was extracted from 28 adult ticks infesting the animals and four nymphs from the environment, and further screened for Ehrlichia sp. and hemotropic Mycoplasma sp. Anti-T. equi and anti-Ehrlichia sp. antibodies were detected in 40.91% (nine/22; 95% CI: 23.26-61.27) and 31.81% (seven/22; 95% CI: 16.36-52.68) horses, respectively. Theileria equi, B. caballi, and hemotropic Mycoplasma sp. DNA was detected in 59.09% (13/22), 4.55% (one/22), and 50% (11/22) horses, respectively. All horses tested negative in the PCR for Ehrlichia sp. All sequences showed ≥99% identity with multiple T. equi, B. caballi, and Mycoplasma ovis sequences deposited in GenBank database. Adult ticks were identified as Dermacentor nitens (44/47; 93.62%) and Rhipicephalus microplus (three/47; 6.38%). Ticks' salivary glands were negative for Ehrlichia sp., while 39.29% from adults (11/28) and 50% from nymphs (two/four) from the environment were positive for hemotropic Mycoplasma sp. This is the first report of M. ovis infection in horses from Brazil and the first detection of hemoplasma DNA in salivary glands of D. nitens and R. microplus ticks. Further studies are needed to elucidate the vector competence of ticks to transmit hemoplasmas.

Recent Advances in the Immunologic Method Applied to Tick-Borne Diseases in Brazil

Zoonotic-origin infectious diseases are one of the major concerns of human and veterinary health systems. Ticks, as vectors of several zoonotic diseases, are ranked second only to mosquitoes as vectors. Many ticks’ transmitted infections are still endemic in the Americas, Europe, and Africa and represent approximately 17% of their infectious diseases population. Although our scientific capacity to identify and diagnose diseases is increasing, it remains a challenge in the case of tick-borne conditions. For example, in 2017, 160 cases of the Brazilian Spotted Fever (BSF, a tick-borne illness) were confirmed, alarming the notifiable diseases information system. Conversely, Brazilian borreliosis and ehrlichiosis do not require notification. Still, an increasing number of cases in humans and dogs have been reported in southeast and northeastern Brazil. Immunological methods applied to human and dog tick-borne diseases (TBD) show low sensitivity and specificity, cross-reactions, and false IgM positivity. Thus, the diagnosis and management of TBD are hampered by the personal tools and indirect markers used. Therefore, specific and rapid methods urgently need to be developed to diagnose the various types of tick-borne bacterial diseases. This review presents a brief historical perspective on the evolution of serological assays and recent advances in diagnostic tests for TBD (ehrlichiosis, BSF, and borreliosis) in humans and dogs, mainly applied in Brazil. Additionally, this review covers the emerging technologies available in diagnosing TBD, including biosensors, and discusses their potential for future use as gold standards in diagnosing these diseases.

Report of Amblyomma sculptum in a House in a Rickettsia rickettsii Circulation Area

Amblyomma sculptum is a tick that has medical and veterinary importance as, in Brazil, it is the main vector of Rickettsia rickettsii, a disease affecting humans. The presence of ticks was observed outside a residence in a peri-urban area of the Atlantic Forest region in Brazil, as well as on two dogs that lived there. Eighteen A. sculptum adults were seen walking on a cemented pillar at the porch of the house and sheltering inside the pillar's crevices; meanwhile on the dogs, only Rhipicephalus sanguineus sensu lato ticks were found. It is hypothesized that as the dogs circulated in the forest regions, they might have carried A. sculptum to the residence. This situation highlights the role of dogs as possible carriers of Brazilian spotted fever (BSF) tick vectors into human habitation. Strategies for the prevention and control of BSF should consider the hypothesis that ticks infected with R. rickettsii can be harbored in human dwellings in peri-urban areas.

First Evidence of Ehrlichia minasensis Infection in Horses from Brazil

The genus Ehrlichia includes tick-borne bacterial pathogens affecting humans, domestic and wild mammals. Ehrlichia minasensis has been identified in different animal species and geographical locations, suggesting that this is a widely distributed and generalist Ehrlichia. In the present study, we evaluated Ehrlichial infection in 148 Equidae presented to the Medical Clinic Department of a Veterinary Hospital from a midwestern region of Brazil. Blood samples and ticks collected from the animals were tested by Polymerase Chain Reaction (PCR) for the presence of Ehrlichia spp. A multigenic approach including Anaplasmataceae-specific (i.e., 16S rRNA, groEL, gltA) and Ehrlichia-specific (i.e., dsb and trp36) genes was used for accurate bacteria identification. Sera samples were also collected and evaluated for the detection of anti-Ehrlichia antibodies by indirect fluorescent antibody test (IFA). Possible associations between molecular and serological diagnostics and clinical and hematological manifestations were tested using chi-squared or Fisher’s exact tests. Sequence analysis of the dsb fragment revealed that three horses (2.03%) were exposed to E. minasensis. Sixty-one (41.2%) Equidae (58 equines and three mules), were seropositive for Ehrlichia spp., with antibody titers ranging between 40 and 2560. Seropositivity to ehrlichial antigens was statistically associated with tick infestation, rural origin, hypoalbuminemia and hyperproteinemia (p ≤ 0.05). The present study reports the first evidence of natural infection by E. minasensis in horses from Brazil.

Serological Evidence of Natural Exposure to Tick-Borne Pathogens in Horses, Romania

The purpose of this study was to investigate the seroprevalence of selected tick-borne-pathogens (TBPs) among Romanian horses. For this, a total of 223 animals originating from north, central, and southeast Romania, including horses from stud farms (n = 118) and working horses (n = 105), were tested using a commercial rapid ELISA-based test. Overall, 10.3% (95% confidence interval (CI): 6.7-15.1%) of the tested horses were seropositive for antibodies (Ab) against Anaplasma phagocytophilum. Additionally, 18.8% (95% CI: 13.9-24.6%) and 0.5% (95% CI: 0.01-2.5%) of horses were seropositive for Ab against Borrelia burgdorferi sensu lato and Ehrlichia spp., respectively. Among the tested horses, 3.1% were seroreactive to two or three pathogens. These findings show the natural exposure of Romanian horses to zoonotic tick-borne pathogens and emphasize the need for further studies to better understand the epidemiology of equine tick-borne diseases in Romania.

Detection of Ehrlichia sp. in Amblyomma sculptum parasitizing horses from Brazilian Pantanal wetland

Bacteria of the genus Ehrlichia are transmitted by ticks and also are an important cause of infection in wild and domestic mammals. Infection with Ehrlichia spp. has been reported in horses, especially in the USA, Nicaragua and Brazil. In this study, we report the parasitism by Amblyomma sculptum, Rhipicephalus microplus and Dermacentor nitens ticks in horses from a ranch located in south Pantanal wetland. Molecular and serological analyzes to determine infection by Ehrlichia spp. in horses and their respective ticks were carried out. A total of 12 horses were submitted to blood collection to investigate antibodies by indirect immunofluorescence assay (IFA) using Ehrlichia canis crude antigens and to be tested by polymerase chain reaction (PCR) in order to amplify fragments of the 16S rRNA, dsb, groEL and sodB gene of Ehrlichia spp. A total of 164 tick specimens were removed from horses, stored in isopropanol and later identified as D. nitens, A. sculptum and R. microplus. DNA from ticks were extracted and subjected to the same PCR assays to detect Ehrlichia spp. Anti-Ehrlichia spp. antibodies were detected in five/12 (41.7 %) horses by IFA, with antibody titers ranging from 40 to 160. All horse DNA samples were negative for the 16S rRNA, dsb, groEL and sodB of Ehrlichia spp. One A. sculptum female was positive to all target genes of Ehrlichia. This tick was parasitizing an Ehrlichia-seropositive horse with antibody titer of 80. Nucleotide sequences of 16S rRNA, dsb, groEL and sodB genes showed close relationship with different strains of Ehrlichia detected in wild mammals, Amblyomma ticks and horses from Brazil and Argentina. Detection of anti-Ehrlichia sp. antibodies suggests that horses have been exposed to an ehrlichial agent in the Pantanal. Future studies on Ehrlichia infection should be carried out to better elucidate and to bring new information about equine ehrlichiosis, since these animals are important hosts of ticks in the Brazilian Pantanal wetlands.

Rickettsial pathogens circulating in urban districts of Rio de Janeiro, without report of human Brazilian Spotted Fever

Spotted fever group rickettsioses are emerging diseases. In some of these diseases, domestic dogs act as sentinels. Canine serological studies have demonstrated that rickettsial dispersion is concentrated in rural areas, seroprevalence being higher where human rickettsioses are endemic. In Rio de Janeiro, the Atlantic forest vegetation has been devastated by urbanization. In this context, we aimed to detect Rickettsia spp. in urban areas of the West Zone of Rio de Janeiro. Sera from 130 dogs were tested by Indirect Immunofluorescence Assay, and ticks collected from these dogs were tested by polymerase chain reaction. We found the rate of serological reactions against R. rickettsii and R. parkeri in our study area to exceed those of rural and non-endemic areas, highlighting the importance of dogs as urban sentinels. The possibility of contact with opossums and capybaras increased the chances of exposure to Rickettsia spp., reinforcing the hypothetical link between the landscape and the rickettsial wild cycle. Rhipicephalus sanguineus sensu lato was the tick most frequently observed. PCR-positive samples showed similarity with R. rickettsii and R. felis, an emerging pathogen rarely reported from ticks. We observed that rickettsiae circulate in urban places and ticks from indoor environments, which may be involved in bacterial epidemiology.

Tick-borne pathogens in dogs, wild small mammals and their ectoparasites in the semi-arid Caatinga biome, northeastern Brazil

Caatinga is a biome exclusive to the semiarid zone of Brazil, where studies on ticks and tick-borne diseases are scarce. Herein, we investigated the occurrence of Rickettsia, Ehrlichia, and Coxiella in wild mammals, domestic dogs and their ectoparasites using molecular and serological techniques. During 2014-2016, blood samples and ectoparasites were collected from 70 small mammals (51 rodents, 18 marsupials, 1 wild canid) and 147 domestic dogs in three areas of the Caatinga. Through serological analyses of domestic dogs of the three areas, 8 to 11 % were seropositive for Rickettsia rickettsii, 9 to 37 % for Rickettsia amblyommatis, 61 to 75 % for Ehrlichia canis, and 0-5% for Coxiella burnetii. All wild mammals were seronegative for Rickettsia spp. and C. burnetii, except for one rodent (Wiedomys pyrrhorhinos) and one marsupial (Didelphis albiventris) that were seroreactive to C. burnetii, one wild canid (Cerdocyon thous) for R. amblyommatis, and two Rattus rattus for Rickettsia spp. Through PCR targeting DNA of Rickettsia, Ehrlichia or Coxiella, all blood samples were negative, except for the presence of Ehrlichia canis DNA in 8.8 % of the domestic dogs, and a recently reported novel agent, Ehrlichia sp. strain Natal, in one marsupial (Gracilinanus agilis). A total of 222 ticks, 84 fleas, and six lice were collected. Ticks were mostly Rhipicephalus sanguineus sensu lato, some Ixodes loricatus, Ornithodoros rietcorreai, Haemaphysalis sp., and Amblyomma spp.; fleas were Ctenocephalides felis felis, Pulex sp. and Polygenis (Polygenis) bohlsi jordani; and lice were Polyplax sp. and Gyropus sp. Through molecular detection of microorganisms, 9% of C. felis felis contained Rickettsia felis, 20 % of A. auricularium contained R. amblyommatis and 13 % of A. parvum contained 'Candidatus Rickettsia andeanae', whereas Ehrlichia canis DNA was detected in at least 6% of the R. sanguineus s.l. from one area. We report a variety of ectoparasites infesting small mammals and domestic dogs in the Caatinga biome, where these ectoparasites probably act as vectors of rickettsiae, ehrlichial agents (E. canis and Ehrlichia sp. strain Natal) and C. burnetii. Our results highlight to the potential risks of human infection by these tick-borne agents in the Caatinga biome.

Molecular identification of vector-borne organisms in Ehrlichia seropositive Nicaraguan horses and first report of Rickettsia felis infection in the horse

Certain vector-borne organisms serve as etiological agents of equine disease. After previously identifying a new Ehrlichia species in horses from Mérida, we aimed to determine the infection frequency and screen for a wide range of vector-borne organisms from 93 tick-exposed, Ehrlichia seropositive horses in this region. PCR assays were performed to identify infection by organisms within the following genera: Anaplasma, Babesia, Bartonella, Ehrlichia, Leishmania, Mycoplasma, Neorickettsia, Rickettsia and Theileria. Overall, 90/93 horses (96.8%) were infected with one or more vector-borne organisms. Ninety (96.8%) horses were infected with Theileria equi and 21 (26.8%) with Babesia caballi. Nine (9.7%) horses were infected with the novel Ehrlichia species previously designated H7, reported in horses from Nicaragua and Brazil. Two horses (2.2%) were infected with Rickettsia felis. Anaplasma, Bartonella, Leishmania, Mycoplasma, or Neorickettsia species DNA was not amplified from any horse. Ticks collected from horses infected with vector-borne organisms were identified as Amblyomma cajennense sensu lato and Dermacentor nitens. Horses in Mérida are infected by a range of vector-borne organisms, including B. caballi, T. equi, Ehrlichia species H7, and R. felis. To the authors' knowledge, this constitutes the first report of molecular detection of R. felis in horses.

Tick-borne pathogens in carthorses from Foz do Iguaçu City, Paraná State, southern Brazil: A tri-border area of Brazil, Paraguay and Argentina

Tick-borne diseases (TBD) constitute an important group of illness affecting animals and humans worldwide. In Brazil, carthorses are frequently exposed to ticks and tick-borne pathogens, leading to impairment of horse performance and imposing restrictions by the international veterinary authorities for the importation of horses. Accordingly, this study has aimed to i) determine the prevalence of the TBD agents Theileria equi, Babesia caballi, Ehrlichia spp., and hemotropic mycoplasmas in carthorses, ii) identify the tick species parasitizing the animals, and iii) determine factors associated with exposure/infection in Foz do Iguaçu City, Parana state, southern Brazil. A total of 103 carthorses were screened for anti-T. equi and anti-Ehrlichia spp. antibodies by indirect fluorescent antibody assays (IFA). Samples were also tested by PCR assays targeting the 18S rRNA gene of T. equi and B. caballi, and 16S rRNA gene of hemoplasmas. Additionally, PCR assays targeting the 16S rRNA, disulfide bond formation protein (dsb) and tandem repeat proteins 36 (trp36) genes of Ehrlichia spp. were also performed. Antibodies to T. equi and Ehrlichia spp. were detected in 43/103 (41.75%; 95% CI: 32.10-51.88%) and 5/103 (4.85%; 95% CI: 1.59-10.97%) horses by IFA, respectively. DNA of T. equi and B. caballi were found in 25/103 (24.27%; 95% CI: 16.36-33.71%) and 10/103 (9.71%; 95% CI: 4.75-17.13%) carthorses, respectively, and all tested negative for Ehrlichia spp. and hemoplasmas. All sequences showed ≥99% identity with multiple T. equi and B. caballi 18S rRNA gene sequences deposited in GenBank. Overall, 191 Dermacentor nitens ticks were collected from 25/103 (24.27%) animals. Carthorses older than 5 years were more likely to be positive for T. equi (p < 0.05). In conclusion, equine piroplasmosis agents are highly prevalent in carthorses from Foz do Iguaçu City. The low prevalence of Ehrlichia spp. found may be due to the absence of Amblyomma ticks infesting animals, which should be further investigated.

Seroprevalence of Anaplasma phagocytophilum, Ehrlichia spp. and Borrelia burgdorferi infections in horses: first report from Northern Bulgaria - Short communication

Lyme borreliosis, granulocytic anaplasmosis and monocytic ehrlichiosis are well studied in humans and dogs. In horses, these diseases are not widely investigated and limited information is available about their occurrence. The purpose of this study was to present the first ELISA-based report on the seroprevalence of Anaplasma phagocytophilum, Ehrlichia spp. and Borrelia burgdorferi in horses from Northern Bulgaria. A total of 192 horses were investigated from three regions in Northern Bulgaria (Northwestern, North-Central and Northeastern Bulgaria). All equine sera were tested for A. phagocytophilum, Ehrlichia spp. and B. burgdorferi antibodies by a commercial rapid ELISA test. Antibodies against A. phagocytophilum were found in all the three regions at a mean frequency of 12% (23/192), ranging from 9.38 to 15.63% by region. Antibodies against Ehrlichia spp. were found in horses from one region (Northeastern) at a rate of 0.5% (1/192). Anti-B. burgdorferi antibodies were detected in all the three regions with a mean frequency of 15.1% (29/192), ranging from 14.06 to 17.19% by region. A co-exposure to A. phagocytophilum and B. burgdorferi was observed in 6.3% of the cases (12/192). This is the first report on the natural exposure of horses to these bacteria (A. phagocytophilum, Ehrlichia spp. and B. burgdorferi) in Northern Bulgaria.

Molecular detection and characterization of Anaplasma platys and Ehrlichia canis in dogs from northern Colombia

Ehrlichia canis and Anaplasma platys are intracellular tick-transmitted bacteria that infect dogs; there is evidence for limited zoonotic potential as well. The prevalence of E. canis in Colombia has been evaluated in different regions; however little is known about the prevalence or distribution of A. platys. Neither pathogen has been studied in the Magdalena region, thus the purpose of our study was to assess the prevalence of these pathogens in dogs attending veterinary clinics from the cities of Santa Marta and Ciénaga, and to assess possible associated risk factors for infection. A. platys and E. canis infections in blood were evaluated by Taqman PCR assays. E. canis was detected in 26/170 (15.3%, 95% CI 10.4%-21.8%) and A. platys in 34/168 (20.2%, 95% CI 14.6%-27.3%) of all dogs tested. Eleven dogs (6.5%, 95% CI 3.4-11.7%) were coinfected with both pathogens. Sequencing results showed low diversity within E. canis and within A. platys strains, however a strain of E. canis detected in our study area is genetically distinct from strains reported in another city of Colombia. Our results suggest that for A. platys, Santa Marta dogs were at greater risk than Ciénaga dogs, and that purebred dogs were at slightly lower risk in both areas. The confirmation of these pathogens in northern Colombia should cause concern for the possible co-transmission of these agents to humans or animals in the region.

Serological evidence of exposure to some zoonotic microorganisms in cattle and humans with occupational exposure to livestock in Antioquia, Colombia

Bacteria belonging to Anaplasma, Ehrlichia, Rickettsia and Coxiella genera are considered emerging pathogens and livestock is one of the contexts where the transmission of these microorganisms can occur. The goal of this study was to determine serological evidence for the exposure to these bacteria in cattle and humans with occupational exposure to livestock in the subregions North and Magdalena Medio, Antioquia, Colombia, and to explore related factors. A cross-sectional study was conducted in 48 livestock farms distributed in six municipalities from both subregions: Belmira, Entrerríos and San Pedro de los Milagros (North), and Puerto Berrío, Puerto Nare and Puerto Triunfo (Magdalena Medio). Blood samples from 332 people and 384 bovines were evaluated by serology (IgM and IgG) screening for bacteria from the Anaplasma, Ehrlichia, Rickettsia, and Coxiella genera. Seropositivity in humans from both regions was 42.4% (95%CI: 31.2-55.1) for Anaplasma, 74.2% (95%CI: 66.0-84.4) for Ehrlichia, 72.5% (95%CI: 62.1-82.0) for Rickettsia, and 60.7% (95%CI: 59.7-69.1) for Coxiella burnetii. In cattle, seropositivity was 31.6% (95%CI: 19.9-44.2), 66.8% (95%CI: 55.2-78.1), 64.6% (95%CI: 53.8-74.5), and 61.6% (95%CI: 51.9-69.2), respectively. History of biting by ticks, milking, vaccination, having dogs and hens in the residence, as well as the consumption of raw milk derivatives were some factors associated with the infection by the bacteria studied. The results suggest a previous and recent exposure to these zoonotic bacteria genera in people with occupational exposure to livestock, as well as in cattle in the two studied subregions.

Serological Evidence of Borrelia burgdorferi, Anaplasma phagocytophilum and Ehrlichia Spp. Infections in Horses from Southeastern Bulgaria

Lyme Borreliosis and granulocytic anaplasmosis are less extensively studied in horses than in dogs and humans. Equine ehrlichiosis is not known in Europe and is in the initial stage of investigation in South, Central, and North America. The aim of this study was to determine the seroprevalence of these infections in Bulgaria. A total of 155 horses were investigated from five regions in Southeastern Bulgaria. Horses were tested for Borrelia burgdorferi, Anaplasma phagocytophilum, and Ehrlichia spp. antibodies by a commercial rapid ELISA test. B. burgdorferi and A. phagocytophilum antibodies were found in all five regions (Burgas, Sliven, Stara Zagora, Haskovo, and Kardzhali) at frequencies of 36/155 (23.2%; 95% CI: 16.8-30.7%; ranging by region from 6.4% to 50%) and 31/155 (20%; 95% CI: 14-27.2%; ranging by region from 10% to 30.8%), respectively. Antibodies against Ehrlichia spp. were found in horses from three regions (Burgas, Stara Zagora, and Haskovo) at a rate of 6/155 (3.9%; 95% CI: 1.4-8.2%; ranging by region from 5.7% to 6.4%). The combination of B. burgdorferi/A. phagocytophilum (11/155; 7.1%; 95% CI: 3.6-12.3%) was the most common coexposure observed, followed by B. burgdorferi/Ehrlichia spp. (2/155; 1.3%; 95% CI: 0.2-4.6%) and A. phagocytophilum/Ehrlichia spp. (1/155; 0.6%; 95% CI: 0-3.5%). The study shows that horses in Bulgaria are exposed or coexposed to three tick-transmitted zoonotic bacterial species. Furthermore, it reports Ehrlichia spp. seroreactivity in equines in Europe.

Assessment of a quantitative 5' nuclease real-time polymerase chain reaction using groEL gene for Ehrlichia and Anaplasma species in rodents in Brazil

New genotypes of Anaplasmataceae agents have been detected in wild carnivores, birds and deer in Brazil. The present work aimed to investigate the presence of Ehrlichia and Anaplasma species in rodents sampled in Brazil. Additionally, a newly designed quantitative 5' nuclease real-time multiplex PCR for Ehrlichia and Anaplasma spp. detection based on groEL gene amplification was designed, showing high specificity and sensitivity (10 groEL fragment copy/μL). Between 2000 and 2011, different rodent species [n=60] were trapped in 5 Brazilian biomes. Among 458 rodent spleen samples, 0.4% (2/458) and 2.4% (11/458) were positive for Ehrlichia and Anaplasma spp., respectively. Of 458 samples, 2.0% (9/458) and 1.1% (5/458) were positive for Anaplasma sp. and Ehrlichia sp., respectively, using conventional 16S rRNA PCR assays. Maximum Likelihood phylogenetic analyse based on a small region of 16S rRNA genes positioned the Anaplasma genotypes in rodents near Anaplasma phagocytophilum or Anaplasma marginale and Anaplasma odocoilei isolates. Ehrlichia genotypes were closely related to E. canis. There was a low occurrence of Anaplasma and Ehrlichia in wild and synanthropic rodents in Brazil, suggesting the circulation of new genotypes of these agents in rodents in the studied areas.

Survey of spatial distribution of vector-borne disease in neighborhood dogs in southern Brazil

Neighborhood dogs may act as reservoirs and disseminators of vector-borne diseases in urban areas. Accordingly, the aim of this study was to ascertain the health status and the vector-borne pathogens infecting dogs living in public areas with high levels of human movement in the city of Curitiba, southern Brazil. Blood samples from 21 neighborhood dogs that were found in nine of 22 bus stations and two public parks were subjected to a complete blood cell (CBC) count, serum biochemical profiling, a commercial rapid ELISA test and a commercial real-time PCR panel of vector-borne diseases. The CBC count and serum biochemical profiling were within the normal range for dogs and only 1/21 (4.7%) of the dogs was seroreactive for Borrelia burgdorferi sensu stricto. The commercial real-time PCR panel showed that 7/21 (33.3%) of the dogs had Mycoplasma haemocanis infection, 9/21 (42.8%) had ‘Candidatus Mycoplasma haematoparvum’ and 4/21 (19.0%) had both. No statistical association between infected by the agents found here and abnormalities in physical examinations, laboratory tests or ectoparasite presence was found (p > 0.05). In conclusion, neighborhood dogs showed low prevalence of vector-borne diseases and satisfactory wellbeing, and dogs can be used as sentinels for disease exposure.

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.

Serosurvey of Borrelia in dogs, horses, and humans exposed to ticks in a rural settlement of southern Brazil

The aims of the present study were to serosurvey dogs, horses, and humans highly exposed to tick bites for anti-Borrelia burgdorferi s.l. antibodies, identify tick species present, and determine risk factors associated with seropositivity in a rural settlement of Paraná State, southern Brazil. Eighty-seven residents were sampled, along with their 83 dogs and 18 horses, and individual questionnaires were administered. Immunofluorescence antibody test (IFAT) was performed on serum samples and positive samples were subjected to western blot (WB) analysis. Anti-B. burgdorferi antibodies were found in 4/87 (4.6%) humans, 26/83 (31.3%) dogs, and 7/18 (38.9%) horses by IFAT, with 4/4 humans also positive by WB. Ticks identified were mostly from dogs and included 45/67 Rhipicephalus sanguineus, 21/67 Amblyomma ovale, and 1/67 A. cajennense sensu lato. All (34/34) horse ticks were identified as A. cajennense s.l.. No significant association was found when age, gender, or presence of ticks was correlated to seropositivity to Borrelia sp. In conclusion, although anti-Borrelia antibodies have been found in dogs, horses and their owners from the rural settlement, the lack of isolation, molecular characterization, absence of competent vectors and the low specificity of the commercial WB kit used herein may have impaired risk factor analysis.

MOLECULAR INVESTIGATION OF HEMOTROPIC MYCOPLASMAS IN HUMAN BEINGS, DOGS AND HORSES IN A RURAL SETTLEMENT IN SOUTHERN BRAZIL

The aims of this study were to determine the prevalence of hemoplasmas in a rural Brazilian settlement's population of human beings, their dogs and horses, highly exposed to tick bites; to identify the tick species parasitizing dogs and horses, and analyze factors associated with their infection. Blood samples from 132 dogs, 16 horses and 100 humans were screened using a pan-hemoplasma SYBR green real-time PCR assay followed by a species-specific TaqMan real-time PCR. A total of 59/132 (44.7%) dog samples were positive for hemoplasmas (21 Mycoplasma haemocanisalone, 12 ' Candidatus Mycoplasma haematoparvum' alone and 21 both). Only 1/100 (1.0%) human sample was positive by qPCR SYBR green, with no successful amplification of 16S rRNA or 23 rRNA genes despite multiple attempts. All horse samples were negative. Dogs >1 year of age were more likely to be positive for hemoplasmas ( p= 0.0014). In conclusion, although canine hemoplasma infection was highly prevalent, cross-species hemoplasma transmission was not observed, and therefore may not frequently occur despite overexposure of agents and vectors.

Iron metabolism and oxidative profile of dogs naturally infected by Ehrlichia canis: Acute and subclinical disease

The aim of this study was to evaluate the oxidant profile and iron metabolism in serum of dogs infected by Ehrlichia canis. Banked sera samples of dogs were divided into two groups: negative control (n = 17) and infected by E. canis on acute (n = 24), and subclinical (n = 18) phases of the disease. The eritrogram, leucogram, and platelet counts were evaluate as well as iron, ferritin, and transferrin levels, latent iron binding capacity (LIBC), and transferrin saturation index (TSI) concentration. In addition, the advanced oxidation protein products (AOPP) and ferric reducing ability of plasma (FRAP) in sera were also analyzed. Blood samples were examined for the presence of E. canis by PCR techniques. History and clinical signals were recorded for each dog. During the acute phase of the disease, infected animals showed thrombocytopenia and anemia when compared to healthy animals (P < 0.05) as a consequence of lower iron levels. Ferritin and transferrin levels were higher in both phases (acute and subclinical) of the disease. The AOPP and FRAP levels increased in infected animals on the acute phase; however, the opposite occurred in the subclinical phase. We concluded that dogs naturally infected by E. canis showed changes in the iron metabolism and developed an oxidant status in consequence of disease pathophysiology.

Potentially novel Ehrlichia species in horses, Nicaragua

Ehrlichia sp. DNA was amplified from 4 Ehrlichia-seroreactive horses from Mérida, Nicaragua. Sequencing of 16S rDNA, sodB, and groEL genes indicated that the bacterium is most likely a novel Ehrlichia species. The tick vector and the potential for canine and human infection remain unknown.

Dogs, cats, parasites, and humans in Brazil: opening the black box

Dogs and cats in Brazil serve as primary hosts for a considerable number of parasites, which may affect their health and wellbeing. These may include endoparasites (e.g., protozoa, cestodes, trematodes, and nematodes) and ectoparasites (i.e., fleas, lice, mites, and ticks). While some dog and cat parasites are highly host-specific (e.g., Aelurostrongylus abstrusus and Felicola subrostratus for cats, and Angiostrongylus vasorum and Trichodectes canis for dogs), others may easily switch to other hosts, including humans. In fact, several dog and cat parasites (e.g., Toxoplasma gondii, Dipylidium caninum, Ancylostoma caninum, Strongyloides stercoralis, and Toxocara canis) are important not only from a veterinary perspective but also from a medical standpoint. In addition, some of them (e.g., Lynxacarus radovskyi on cats and Rangelia vitalii in dogs) are little known to most veterinary practitioners working in Brazil. This article is a compendium on dog and cat parasites in Brazil and a call for a One Health approach towards a better management of some of these parasites, which may potentially affect humans. Practical aspects related to the diagnosis, treatment, and control of parasitic diseases of dogs and cats in Brazil are discussed.