1例犬埃立克体病的诊治

犬埃立克体是一种重要的人兽共患传染性病原体,可引起犬科动物的犬单核细胞埃立克体病。为确诊1例临床上以发热、精神沉郁、黏膜苍白为主要特征的宠物犬病例,进行了血常规、血液生化检查、实时荧光定量PCR检测、犬埃立克体抗体检查,最终确诊该病例为犬埃立克体感染,使用盐酸多西环素治疗后患犬恢复良好。     

Molecular detection and characterization of Ehrlichia canis from dogs in Turkey

Seroprevalence of Ehrlichia canis antibodies among dogs in Turkey were previously reported, however, the ehrlichial organism has never been characterized in this region. The current study examined dogs from Ankara with febrile illness for E. canis infection with E. canis-specific PCR. Three of the 12 blood specimens from dogs showing clinical signs compatible with canine ehrlichiosis were found to be positive by PCR using E. canis-specific primers. E. canis detected in one of the blood specimens was designated as Kutahya strain. The representative E. canis strain was characterized by 16S rRNA gene sequencing and Western blot analysis of the plasma sample from the dog infected with E. canis. The 16S rRNA sequence (1,388 bp) of the E. canis Kutahya was identical to that of Ehrlichia ovina from a sheep in Turkey and Venezuelan Dog Ehrlichia (VDE) and was closely related (99.9%) to that of type strain of E. canis, Oklahoma. The plasma of the dog infected with E. canis Kutahya was analyzed by Western blotting using the purified E. canis Oklahoma strain as antigen. The reactive antibody profiles of the dog infected with E. canis Kutahya was found to be similar to those of dogs infected with E. canis Oklahoma and VDE, suggesting the antigenic similarities among these strains. The findings in this study would help for a better understanding of epidemiology of canine ehrlichiosis. This is the first report of molecular detection and characterization of an ehrlichial agent in Turkey.     

Detection of Ehrlichia canis by PCR in different tissues obtained during necropsy from dogs surveyed for naturally occurring canine monocytic ehrlichiosis

A molecular study for the detection of Ehrlichia canis was carried out on tissues obtained at necropsy from randomly selected dogs with the intention of investigating naturally-occurring canine ehrlichiosis. The tissues evaluated for the presence of E. canis included lymph nodes, spleen, liver, bone marrow, and blood. Eight of the 18 dogs included were found to be positive for E. canis by polymerase chain reaction (PCR) and sequencing of the 16S rRNA gene. Two dogs were positive for Anaplasma platys of which one dog was co-infected with E. canis and A. platys. Blood (5/8) and lymph nodes (5/8) were the tissues found to yield the highest number of positive E. canis PCR results with 7/8 dogs positive in the blood or lymph node. E. canis and A. platys DNA could be amplified by PCR when tissue samples were obtained 72h after the time of death.     

First confirmed canine case of Ehrlichia canis infection in Japan

An 11-year-old castrated Pekinese dog that had been moved from Indonesia to Japan eight years previously was diagnosed with an Ehrlichia canis infection by haematological characteristics (normocytic anaemia, mild thrombocytopenia and hypergammaglobulinaemia) and serological findings (antibody titre to E canis 1:3,200 or more). The dog did not respond to treatment with tetracycline and died from renal failure. The diagnosis was confirmed postmortem by pathological evaluation and polymerase chain reaction (PCR) followed by sequencing of the 16S rRNA gene. Typical morulae of Ehrlichia were detected in the cytoplasm of macrophages in spleen tissue by immunohistological staining. Ehrlichia-like organisms were also detected in the spleen by electron microscopy. E canis-specific PCR analysis of DNA extracted from the spleen gave a positive signal, and sequence analysis of the fragment revealed that it was identical to part of the 16s rRNA gene of E canis. The dog was the first confirmed clinical case of E canis infection in Japan.     

广州地区犬场工作人员与一般人群犬埃立克体感染的比较研究

从比格犬埃立克体阳性血清中提取犬埃立克体IgG,用此IgG免疫鸡制备出抗抗体,用已建立的ELISA检测法对采集的人血清样本进行检测。143份随机采集的人血清4份呈阳性,阳性率2.78%;52份犬场工作人员血清6份呈阳性,阳性率11.54%。结果表明,广州地区犬场工作人员较一般人群犬埃立克体感染率高。     

Canine systemic bacterial infections.

Although systemic bacterial diseases are an uncommon cause of uveitis in dogs, they should be included in the differential diagnoses for uveitis. A work-up for uveitis should include tests for B. canis and B. burgdorferi. If an aqueous centesis is performed, Leptospira titers or PCR can be performed on the aqueous humor and the serum. Better documentation of the role of Leptospira and B. burgdorferi in uveitis in the dog is needed. Any suspected cases should be worked-up thoroughly. If the dog does prove to be positive for the organism, the case should be submitted to a peer-reviewed journal.     

Outbreak of canine monocytic ehrlichiosis in Saudi Arabia

BACKGROUND: Canine monocytic ehrlichiosis (CME) is a widespread tickborne infection of canids caused by Ehrlichia canis, a gram-negative obligatory intracellular bacteria belonging to the family Anaplasmataceae. CME is reported to have worldwide distribution, but its presence in a region requires the presence of the vector, the brown dog tick Rhipicephalus sanguineus. OBJECTIVE: This purpose of this report was to describe an outbreak of CME in a colony of dogs resident in the eastern region of Saudi Arabia. METHODS: History, presenting clinical signs, and the results of a CBC, biochemical panel, and serology (using a commercial test for E canis antibodies) were evaluated in 9 male Labrador Retrievers between October and December 2006. RESULTS: The majority of dogs presented with severe lethargy (7/9) and acute anorexia (5/9), and had fever (7/9) and generalized lymphadenopathy (7/9). The most common laboratory abnormalities were anemia (8/9), leukopenia (7/9), and hypoalbuminemia (6/9). Thrombocytopenia was found in only 2 dogs, 1 of which had increased bleeding tendency. Ehrlichia morulae were identified in blood films from 4/9 dogs and serologic test results were positive in 7/9 dogs. Confirmation of Ehrlichia sp infection was obtained in 1 dog by using a genus-specific real-time PCR assay. Four dogs had tick infestation; the ticks on 1 dog were identified as R sanguineus. All of the dogs had a rapid clinical response to doxycycline hyclate. CONCLUSIONS: This report, to our knowledge, is the first to describe the presence of a pathogenic Ehrlichia organism affecting dogs in Saudi Arabia. Additional molecular studies are necessary to confirm E canis infection, and to identify the strain of the organism.     

First isolation and molecular characterization of Ehrlichia canis in Spain

This paper reports the first isolation and culture of Ehrlichia canis in Spain from a naturally infected dog using the DH82 cell line. After DNA extraction and PCR amplification, a nearly complete (1412bp) sequence of the 16S rRNA gene of the new E. canis strain was obtained. The GenBank accession number for the nucleotide sequence of this strain is AY394465. This sequence was aligned with the 16S rRNA gene sequences of other Ehrlichia strains accessible in GenBank. The 16S rRNA gene sequence of the E. canis strain reported here showed a high percentage of similarity with the 16S rRNA gene sequence of E. canis from different geographic areas including Japan, Venezuela and Israel. These data confirm the presence of E. canis in Spain.     

Molecular and serological detection of Ehrlichia canis and Babesia vogeli in dogs in Colombia

Ehrlichiosis and babesiosis are tick-borne diseases, caused mainly by Ehrlichia canis and Babesia canis, respectively, with a worldwide occurrence in dogs, whose main vector is the brown-dog tick, Rhipicephalus sanguineus. The present work aimed to detect the presence of E. canis and Babesia sp. in 91 dog blood samples in Colombia, by molecular and serological techniques. We also performed sequence alignment to indicate the identity of the parasite species infecting these animals. The present work shows the first molecular detection of E. canis and B. vogeli in dogs from Colombia. Immunoglobulin-G (IgG) antibodies to E. canis and Babesia vogeli were found in 75 (82.4%) and 47 (51.6%) sampled dogs, respectively. Thirty-seven (40.6%) and 5 (5.5%) dogs were positive in PCR for E. canis and Babesia sp., respectively. After sequencing, amplicons showed 99% of identity with isolates of E. canis and B. vogeli. The phylogenetic trees based on 16S rRNA-Anaplasmataceae sequences and 18S rRNA-piroplasmid sequences supported the identity of the found E. canis and B. vogeli DNAs, respectively. The present work shows the first molecular detection of E. canis and B. vogeli in dogs in Colombia.     

Ehrlichial infection in Cameroonian canines by Ehrlichia canis and Ehrlichia ewingii

Ehrlichia chaffeensis and Ehrlichia ewingii are agents of emerging human ehrlichioses in North America and are transmitted primarily by Amblyomma americanum ticks, while Ehrlichia canis is the globally distributed cause of canine monocytic ehrlichiosis (CME) and is transmitted by the brown dog tick, Rhipicephalus sanguineus. Although E. canis and Ehrlichia ruminantium are endemic in Africa, the presence of ehrlichial agents in dogs and ticks in Cameroon has not been investigated. The objective of this study was to determine the prevalence of ehrlichial infections in Cameronian dogs using a combination of serologic and molecular methods. Peripheral blood was collected, clinical signs and the presence or absence of ticks on dogs (n=104) presenting for various reasons at local veterinary clinics around the Mount Cameroon region were noted. IFA identified 33 dogs (32%) with antibodies reactive with E. canis, and reactivity of these sera with all major E. canis antigens (200, 140, 95, 75, 47, 36, 28, and 19-kDa) was confirmed by immunoblotting. Multicolor real-time PCR detected ehrlichial DNA (E. canis (15) and E. ewingii (2)) in 17 dogs (16.3%), all of which had attached ticks at time of presentation. The dsb amplicons (378 bp) from E. canis and E. ewingii were identical to gene sequences from North American isolates. This study identifies canine ehrlichiosis as a prevalent unrecognized cause of disease in Cameroonian canines.     

Detection of ehrlichial infection by PCR in dogs from Yamaguchi and Okinawa Prefectures, Japan

Species-specific nested polymerase chain reaction (PCR) was used to detect the presence of possible canine ehrlichial agents (Ehrlichia canis, E. chaffeensis, E. ewingii, E. equi and E. platys) and monocytic ehrlichial agents found in Japan (E. muris and a recently discovered Ehrlichia species detected from Ixodes ovatus) in blood samples from dogs in Yamaguchi and Okinawa Prefecture, Japan. Partial sequence of E. platys was detected from 1 of 67 dogs (1.5%) tested from Yamaguchi Prefecture and 24 out of 87 (27.6%) in the subtropical Okinawa Prefecture. Dogs in Okinawa and Miyako Islands had a higher positive rate (69.2 and 45.0%, respectively) than Ishigaki Island (11.1%). Another dog in Yamaguchi Prefecture had a positive PCR reaction to the Ehrlichia sp. detected from I. ovatus. No other Ehrlichia were found in these samples.     

Comparison of results for serologic testing and a polymerase chain reaction assay to determine the prevalence of stray dogs in eastern Tennessee seropositive to Ehrlichia canis

OBJECTIVE: To determine the prevalence of stray dogs in eastern Tennessee seropositive to Ehrlichia canis and examine the correlation between results for an ELISA, indirect immunofluorescent antibody (IFA) test, and polymerase chain reaction (PCR) assay. SAMPLE POPULATION: Blood samples obtained from 90 adult dogs admitted to an animal shelter in eastern Tennessee. PROCEDURE: Serum samples were analyzed for antibodies against E. canis by use of a commercially available ELISA kit, 2 IFA tests, and a PCR assay; testing was performed at the University of Tennessee (TN) and North Carolina State University (NCSU). The PCR amplification was performed by use of DNA extracted from EDTA-anticoagulated blood and primers designed to amplify DNA of Ehrlichia spp. RESULTS: Antibodies against E. canis were detected in only 1 dog by use of the ELISA. By IFA testing at TN, 10 of 90 (11%) dogs were seroreactive against E. canis antigens, all of which had medium to high titers to E. canis. Only 5 of the 10 TN seroreactors were also reactive against E. canis antigens in IFA tests conducted at NCSU, and all 5 had low to medium titers. The DNA of Ehrlichia spp was not amplified in any blood samples by use of PCR assays conducted at the TN or NCSU. CONCLUSIONS AND CLINICAL RELEVANCE: The discordant ELISA, IFA, and PCR results obtained in this study were unexpected and may have been related to exposure of dogs to an Ehrlichia species other than E. canis, such as E. ewingii.     

Ehrlichia canis-related polyarthritis in a dog

Ehrlichia canis-related polyarthritis was diagnosed in a 7-month-old Boxer. The diagnosis was based on intraneutrophilic morulae found in synovial fluid specimens, thrombocytopenia, a positive result for indirect fluorescent antibody testing for E canis, the presence on the dog of the known vector of E canis infection (Rhipicephalus sanguineus), and a favorable response to treatment with tetracycline hydrochloride. The dog has had no recurrence of lameness for 18 months after cessation of treatment.     

Cultivation and molecular identification of Ehrlichia canis and Ehrlichia chaffeensis from a naturally co-infected dog in Venezuela

Background: Diagnosis of canine ehrlichiosis in Venezuela is normally performed by examination of buffy coat smears (BCS). Characteristic inclusion bodies are frequently observed in leukocytes and platelets from dogs with clinical signs of the disease. Objective: The purpose of this study was to investigate the co-infection of a dog with Ehrlichia canis and E hrlichia chaffeensis using microbiological and molecular techniques. Methods: Primary cultures of monocytes from a dog showing signs of ehrlichiosis were performed. Ehrlichial inclusions in blood cells were demonstrated by BCS and in cultured cell smears with direct immunofluorescence and Dip Quick staining. Nested PCR analysis was performed with DNA from blood samples and cultures, using primers specific for E. canis and E. chaffeensis. The amplified DNA fragments were sequenced to confirm the specificity of the amplifications. Results: The BCS of the naturally infected dog contained intracellular morulae. Ehrlichial inclusions were observed 9 days after inoculation of the primary cultures. After 3 passages with monocytes from a healthy dog, 65% of infected cells, and cells with >60 morulae were observed. A healthy female German Shepherd dog, seronegative for E. canis and E. chaffeensis antigens and without contact to ticks, was inoculated with an infected culture. The animal developed signs of canine monocytic ehrlichiosis and became seropositive. Nested PCR results and sequencing of amplified DNA fragments demonstrated the simultaneous presence of E. canis and E. chaffeensis in both dogs. Conclusions: This is the first report of E. chaffeensis in dogs in South America. This organism was previously identified in dogs by PCR only in the United States.     

Use of plasmapheresis and chemotherapy for treatment of monoclonal gammopathy associated with Ehrlichia canis infection in a dog

Monoclonal gammopathy associated with Ehrlichia canis infection was diagnosed in a German Shepherd Dog. The dog was treated by use of chemotherapy and tetracycline and by plasmapheresis. The dog tolerated plasmapheresis and long-term drug therapy well, and clinical signs resolved over a 90-day period. The monoclonal gammopathy resolved after treatment, but specific antibody to E canis indicated suppression followed by a rebound to the initial high titer.     

Experimental inoculation of beagle dogs with Ehrlichia species detected from Ixodes ovatus

Three beagle dogs were inoculated with mice spleen/liver homogenate infected with Ehrlichia species detected from Ixodes ovatus (EIO) and one dog was used as a control. All three infected dogs did not show clinical signs of disease except for mild pyrexia throughout the 41-day study period. Splenomegaly was observed from Day 7 post-inoculation (p.i.) in two of the dogs. Hematological and biochemical abnormalities included mild thrombocytopenia, hypoproteinaemia, hypoalbuminaemia and increased C-reactive protein values. One of the dogs' splenic aspirate sample was PCR-positive for Ehrlichia Day 7 p.i. and another dogs' blood and bone marrow aspirate sample was PCR-positive Day 41 p.i. Sequence analysis of the PCR products showed 100% homology with the 16SrRNA partial gene sequence of Ehrlichia sp. HF565. Antibody titers to EIO were observed in all three experimentally infected dogs starting from the first week p.i. and cross-reactivity with Ehrlichia canis was detectable in one of the dogs starting Day 7 p.i. These data suggest that infection of dogs with EIO is possible, though is probably of low pathogenic importance. Cross-reactivity of EIO infected dog serum with E. canis raises the likelihood of false E. canis seropositive dogs.     

Detection of Ehrlichia chaffeensis in Brazilian marsh deer (Blastocerus dichotomus)

Ehrlichia chaffeensis was detected for the first time in blood samples from Brazilian marsh deers (Blastocerus dichotomus) captured in the marshes of Parana River in Southeast Brazil in 1998. Seven EDTA-blood samples from deers were analyzed by PCR and nested PCR for presence of Ehrlichia chaffeensis, Ehrlichia ewingii, Ehrlichia canis, Neoriickettsia risticii, Anaplasma phagocytophilum and Anaplasma marginale. Three samples showed positive reactions for E. chaffeensis and Anaplasma marginale. None contained detectable A. phagocytophilum, E. ewingii, E. canis or Neorickettsia risticii DNA. In Brazil, the wild marsh deer may be a natural reservoir of the agents that cause human monocytotropic ehrlichiosis and ruminant erythrocytic anaplasmosis.     

Ocular signs of canine monocytic ehrlichiosis: a retrospective study in dogs from Barcelona, Spain

Canine monocytic ehrlichiosis (CME) is a tick-borne disease caused by the rickettsia Ehrlichia canis. Ocular lesions are a common feature of the disease and can be present in all stages. The purpose of this retrospective study was to determine the prevalence, type and response to treatment of ocular lesions associated with monocytic ehrlichiosis in 46 affected dogs presented to the Autonomous University of Barcelona-Veterinary Teaching Hospital (UAB-VTH) from January 2000 to December 2002. Dogs were included in the study only if they had a positive serologic test for E. canis and information about the clinical outcome was available. Eighteen breeds were represented, with the German Shepherd dog (n = 6) being the most common. There were 25 intact and three castrated males, and 16 intact and two neutered females. Twenty dogs (43.4%) were between 5 and 10 years old. Seventeen dogs (37% of all cases of monocytic ehrlichiosis diagnosed during the study period) had ocular signs, and 11 dogs (64.7% of the ocular cases) had only ocular lesions without apparent systemic signs. Exudative retinal detachment was the most common ocular manifestation; other prevalent findings included anterior exudative uveitis and optic neuritis. Five of the 17 cases with ocular lesions (29.4%) had ocular bleeding disorders (hyphema or retinal hemorrhages). All the dogs with ocular disease presented with bilateral signs. Dogs with posterior segment disease had titers against E. canis that were > or = 1 : 320, while lower titers were noted in dogs with anterior exudative uveitis. Two dogs presented with chronic autoimmune panuveitis after ehrlichiosis treatment. Canine ehrlichiosis should be considered in the differential diagnosis of exudative retinal detachment and anterior uveal inflammatory lesions.     

Efficacy of a modified polymerase chain reaction assay for detection of Ehrlichia canis infection.

Detection of Ehrlichia canis in acutely infected and convalescent dogs is important for effective treatment and control. However, accurate detection has been difficult to achieve, in part because dogs that have been treated therapeutically often remain seropositive for extended periods. A new method, polymerase chain reaction (PCR) assay using biotinylated E. canis-specific primers (PCR-BP), was developed for detection of E. canis. Four dogs experimentally infected with E. canis by intravenous inoculation of whole blood from carrier dogs and 2 naturally infected convalescent carriers were used to compare the specificity and sensitivity of the new method with that of microscopy/blood smear evaluation, serologic test, and conventional PCR assay using E. canis-specific primers. In experimentally infected animals, infection was detected as early as 7 days post-exposure using PCR-BP. Although the 2 naturally infected dogs were positive by serologic test and PCR-BP, both were negative by conventional PCR. Results suggest that the new method is a sensitive assay for detection of E. canis infection. In addition, results were obtained more rapidly than with other PCR-based assays.     

Brucella canis endophthalmitis in 3 dogs: clinical features, diagnosis, and treatment

Objective  To describe historical, clinical and diagnostic features of dogs with Brucella canis endophthalmitis and the response to medical therapy.
Animals studied  Three dogs with naturally acquired B. canis endophthalmitis.
Procedure  Dogs were treated symptomatically with topical ophthalmic anti-inflammatories and a novel antimicrobial protocol that included doxycycline, enrofloxacin, rifampin and streptomycin.
Results  All dogs presented with chronic or recurrent uveitis in the absence of overt systemic disease. Clinical ophthalmologic abnormalities were unilateral in each dog and included mild-to-moderate anterior uveitis, iris hyperpigmentation, marked vitreal infiltrates, and multifocal chorioretinitis. Dogs were diagnosed with canine brucellosis serologically and by blood culture ( n  = 2 dogs) or polymerase chain reaction of aqueous humor and blood ( n  = 1 dog). Active ocular inflammation resolved in all dogs during treatment, with preservation of vision in 2 dogs. Following treatment, B. canis could not be cultured from blood samples and serological values declined with seronegativity achieved in all dogs after a median of 96 weeks (range: 36–112 weeks) of therapy.
Conclusions  Brucella canis infection should be included in the differential diagnosis for dogs with intraocular inflammation, regardless of previous history or neuter status. This is the first report of apparently successful medical therapy of canine brucellosis with ocular involvement.