Epidemiological link between canine monocytic ehrlichiosis caused by Ehrlichia canis and the presence of Rhipicephalus sanguineus sensu stricto in Argentina

ABSTRACT Doxycycline is the treatment of choice for canine monocytic ehrlichiosis (CME), a well-characterized disease and valuable model for tick-borne zoonoses. Conflicting reports of clearance of Ehrlichia canis after treatment with doxycycline suggested that the disease phase during which treatment is initiated influences outcomes of these treatments. The purpose of this study was to evaluate the efficacy of a 28-day doxycycline regimen for clearance of experimental E. canis infections from dogs treated during three phases of the disease. Ten dogs were inoculated with blood from E. canis carriers and treated with doxycycline during acute, subclinical, or chronic phases of CME. Daily rectal temperatures and semiweekly blood samples were monitored from each dog, and Rhipicephalus sanguineus ticks were acquisition fed on each dog for xenodiagnosis. Blood collected from dogs treated during acute or subclinical CME became PCR negative for E. canis as clinical parameters improved, but blood samples collected from dogs treated during chronic CME remained intermittently PCR positive. R. sanguineus ticks fed on dogs after doxycycline treatments became PCR positive for E. canis, regardless of when treatment was initiated. However, fewer ticks became PCR positive after feeding on two persistently infected dogs treated with doxycycline followed by rifampin, suggesting that antibiotic therapy can reduce tick acquisition of E. canis.

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Hematological and histopathological changes in medular aplasia resulting from Ehrlichia canis infection in a Border collie dog

Acta Veterinaria Brasilica ◽

10.21708/avb.2021.15.4.10149 ◽

2021 ◽

Vol 15 (4) ◽

pp. 275-280

Author(s):

Carolina Araújo Neves ◽

Reiner Silveira de Moraes ◽

Kaline Ogliari ◽

Antônio Carlos Severino Neto ◽

Dirceu Guilherme de Souza Ramos ◽

...

Keyword(s):

Bone Marrow ◽

Adipose Tissue ◽

Rhipicephalus Sanguineus ◽

Ehrlichia Canis ◽

Major Constituent ◽

Long Bones ◽

Histopathological Changes ◽

Canine Monocytic Ehrlichiosis ◽

The University ◽

Veterinary Hospital

The Canine Monocytic Ehrlichiosis (CME) is an infectious disease that commonly affects dogs of all breeds and ages. It is caused by the bacterium Ehrlichia canis and is transmitted by the tick Rhipicephalus sanguineus. The disease may pre-sent itself in the acute, subclinical, and chronic forms. The present study reports the case of a 2-year-old male Border Collie with advanced stage CME, attended at the Pet Clinic of the Veterinary Hospital of the University Federal de Jataí, which resul-ted in medullary aplasia. The diagnosis of marrow aplasia was based on the necroscopic and histopathological examinations. At necropsy, the diaphyses of the long bones were filled with diffuse, strongly whitish and pasty tissue, typical of the adipose tissue, also found in the femoral epiphyses. The histopathology showed unilocular adipose tissue as the major constituent of the bone marrow and rare islands of marrow cells. These findings were compatible with severe hypoplasia of the red bone mar-row and hyperplasia of the white bone marrow, affecting hematopoiesis, resulting in the laboratory alterations observed in the hematocrit, WBC, and plateletogram.

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SEROPREVALENCE OF CANINE MONOCYTIC EHRLICHIOSIS IN HUNTING DOGS IN THE AUTONOMOUS PROVINCE OF VOJVODINA, SERBIA

Archives of Veterinary Medicine ◽

10.46784/e-avm.v7i1.120 ◽

2015 ◽

Vol 7 (1) ◽

pp. 11-18

Author(s):

Aleksandar Potkonjak ◽

Sara Savić ◽

Ljubica Spasojević Kosić ◽

Vuk Vračar ◽

Radmila Kudus ◽

...

Keyword(s):

Rhipicephalus Sanguineus ◽

Ehrlichia Canis ◽

Transmitted Infection ◽

Hunting Dogs ◽

Mediterranean Countries ◽

Bacterial Vector ◽

Canine Monocytic Ehrlichiosis ◽

Autonomous Province ◽

Epidemiological Characteristics ◽

Continental Climate

Canine monocytic ehrlichiosis is a bacterial, vector-transmitted infection caused by Ehrlichia canis. Th e pathogen is mainly transmitted by ticks Rhipicephalus sanguineus. The disease highest distributionis most widely distributed in tropical and subtropical countries but it is also reported in Mediterranean countries of Europe (Spain, France, Italy, Turkey). Temperate continental climate and presence of these tick species are responsible for the maintenance and spreading of canine monocytic ehrlichiosis within the dog population in our region as well. Since hunting dogs are more exposed to tick bites then pet dogs, ed thisour study was conducted with the aims of determining the seroprevalence and basic epidemiological characteristics of monocytic ehrlichiosis infection in the population of hunting dogs, and comparing the obtained results with the results of other authors. This research involved 58 hunting dogs from the region of Autonomous Province of Vojvodina. All dogs were clinically examined and their basic epidemiological characteristics were recorded. Then, blood samples were collected in order to determine the presence of specifi c G class antibodies against Ehrlichia canis antigens. An indirect immunofl uorescence test manufactured by VMRD, U.S.A., was used. In this study, the seroprevalence of monocytic ehrlichiosis in a population of examined hunting dogs from the region of Vojvodina was 13.79%. Th is rate is similar to the seroprevalence of monocytic ehrlichiosis in the general population of dogs in Vojvodina.

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Primer reporte de un caso de ehrlichiosis monocítica canina en la provincia de Santa Fe, Argentina

FAVE Sección Ciencias Veterinarias ◽

10.14409/favecv.v18i2.8438 ◽

2019 ◽

Vol 18 (2) ◽

pp. 49-54 ◽

Cited By ~ 3

Author(s):

Evelina L. TARRAGONA ◽

Fernando S. FLORES ◽

Candelaria L. HERRERA ◽

Miriam DALINGER ◽

Nerina AGUIRRE ◽

...

Keyword(s):

Buenos Aires ◽

Rhipicephalus Sanguineus ◽

Sensu Stricto ◽

Ehrlichia Canis ◽

Santa Fe ◽

Rhipicephalus Sanguineus Sensu Lato

La ehrlichiosis monocítica canina (EMC) es una enfermedad causada por la bacteria intracelular obligada Ehrlichia canis (Rickettsiales, Anaplasmataceae). La EMC es de importancia en salud animal por ser considerada de alta mortalidad en caninos domésticos, con distribución mundial; con síntomas inespecíficos como fiebre alta, depresión, letargia, anorexia y signos clínicos como linfoadenomegalia, esplenomegalia y trombocitopenia con tendencia hemorrágica, por lo que su diagnostico es un desafío en el entorno clínico. Ehrlichia canis es transmitida a un hospedador susceptible por ninfas y adultos de la garrapata Rhipicephalus sanguineus sensu lato. El taxón R. sanguineus s.l. representa un complejo de especies asociadas a caninos domésticos con distribución cosmopolita y particularmente en la región Neotropical se reconocen dos linajes: tropical y templado. El linaje templado, que representa a R. sanguineus sensu stricto, siendo el límite geográfico que separa ambos linajes una zona ecotonal situada entre 24 ° y 25 ° de latitud sur. En condiciones experimentales, R. sanguineus s.s. (linaje presente en la región centro de Argentina) demostró no tener competencia vectorial para transmitir E. canis (cepa Jaboticabal, Brasil) pero si R. sanguineus s.l. del linaje tropical. Sin embargo, estudios recientes han determinado molecularmente la infección con E. canis en muestras de sangre de perros con diagnóstico presuntivo de EMC en la provincia de Buenos Aires, dónde prevalece R. sanguineus s.s. Además, poblaciones de R. sanguineus s.l. (LT) y R. sanguineus s.s. de las provincias de Formosa y Buenos Aires, respectivamente, se detectaron naturalmente infectadas con E. canis. El presente informe de caso es el primer reporte de caso confirmado de EMC por E. canis en un canino de la ciudad de Rafaela, Santa Fe, área endémica de R. sanguineus s.s.

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Molecular Detection of Ehrlichia canis in the Pet-Dog Population in R. N. Macedonia

Acta veterinaria ◽

10.2478/acve-2021-0020 ◽

2021 ◽

Vol 71 (2) ◽

pp. 230-238

Author(s):

Elena Atanaskova Petrov ◽

Irena Celeska ◽

Zagorka Popova ◽

Kiril Krstevski ◽

Igor Djadjovski

Keyword(s):

Molecular Detection ◽

Clinical Symptoms ◽

Rhipicephalus Sanguineus ◽

Ehrlichia Canis ◽

Diagnostic Methods ◽

Molecular Diagnostic ◽

Positive Serology ◽

Western Asia ◽

Canine Monocytic Ehrlichiosis ◽

The City

Abstract Canine monocytic ehrlichiosis (CME) is a widespread, tick-borne, canine disease, caused by an obligate intracellular bacterium, Ehrlichia canis. The main vector, a brown-dog tick, Rhipicephalus sanguineus, is widely distributed, especially in areas with tropic, subtropic, or Mediterranean climates (Central and South America, Eastern and Western Asia, Africa, Australia and Southern Europe). The study performed in 2012, by Stefanovska et al., determined a seroprevalence of 18.7% of E. canis among the Macedonian dog population. Up to date, the presence of E. canis, using molecular diagnostic methods, has not been investigated in Macedonia. Therefore, this study aimed to confirm the presence of E. canis, in the pet-dog population on the territory of the city of Skopje, North Macedonia, using a highly sensitive multiplex Real-Time PCR method (qPCR). Whole blood samples from 80 dogs of different breeds and ages, with clinical symptoms of CME and positive serology result for the presence of antibodies against E.canis, were collected for analyses. Out of 80 dogs, 36 (45%) were found as positive. The present work reports the first molecular detection of E. canis in pet dogs on the territory of the city of Skopje, Macedonia.

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Comparative Evaluation of the Vector Competence of Four South American Populations of the Rhipicephalus sanguineus Group for the Bacterium Ehrlichia canis, the Agent of Canine Monocytic Ehrlichiosis

PLoS ONE ◽

10.1371/journal.pone.0139386 ◽

2015 ◽

Vol 10 (9) ◽

pp. e0139386 ◽

Cited By ~ 63

Author(s):

Jonas Moraes-Filho ◽

Felipe S. Krawczak ◽

Francisco B. Costa ◽

João Fábio Soares ◽

Marcelo B. Labruna

Keyword(s):

Comparative Evaluation ◽

Vector Competence ◽

Rhipicephalus Sanguineus ◽

Ehrlichia Canis ◽

South American ◽

Canine Monocytic Ehrlichiosis ◽

Rhipicephalus Sanguineus Group

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A Retrospective Study of Dogs Infected with Ehrlichia canis from 2017-2019 in the Thonburi Area of Bangkok Province, Thailand

International Journal of Veterinary Science ◽

10.37422/ijvs/20.062 ◽

2020 ◽

Keyword(s):

Body Weight ◽

Retrospective Study ◽

Liver Enzymes ◽

Serum Biochemistry ◽

Ehrlichia Canis ◽

Housing System ◽

Housing Systems ◽

Mixed Breed ◽

Canine Monocytic Ehrlichiosis ◽

Open Housing

Ehrlichia canis is a tick-borne rickettsia. It can cause canine monocytic ehrlichiosis (CME). Infected dogs are often reported to have changes in their blood values, such as anemia, thrombocytopenia, increased liver enzymes, and increased kidney function values. This study aimed to collect data that may be related to infected dogs, including age, gender, breed, weight, close-open housing system, the use of ectoparasiticides products. The sample comprised 57 infected dogs. Collecting hematology and serum biochemistry changes in comparison with the reference values of dogs detected with Ehrlichia canis from 2017-2019, Thonburi District, Bangkok, Thailand was also carried out. In summary, dogs infected with Ehrlichia canis mostly included mixed-breed dogs aged between 1 and 10 years. There were no differences in body weight or housing systems. Dogs that had never used ectoparasiticide products or used them intermittently were infected more often (by 7.14 times) than protected. Clinical hematology and serum biochemistry found anemia, thrombocytopenia, and increased liver enzymes.

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Characterization of the Major Antigenic Protein 2 of Ehrlichia canis and Ehrlichia chaffeensis and Its Application for Serodiagnosis of Ehrlichiosis

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.10.4.520-524.2003 ◽

2003 ◽

Vol 10 (4) ◽

pp. 520-524 ◽

Cited By ~ 7

Author(s):

Tamece T. Knowles ◽

A. Rick Alleman ◽

Heather L. Sorenson ◽

David C. Marciano ◽

Edward B. Breitschwerdt ◽

...

Keyword(s):

Blot Analysis ◽

Single Copy ◽

Ehrlichia Canis ◽

Specific Method ◽

Ehrlichia Chaffeensis ◽

Antigenic Protein ◽

Canine Monocytic Ehrlichiosis ◽

Copy Gene ◽

Species Specific

ABSTRACT Canine monocytic ehrlichiosis, caused by Ehrlichia canis or Ehrlichia chaffeensis, can result in clinical disease in naturally infected animals. Coinfections with these agents may be common in certain areas of endemicity. Currently, a species-specific method for serological diagnosis of monocytic ehrlichiosis is not available. Previously, we developed two indirect enzyme-linked immunosorbent assays (ELISAs) using the major antigenic protein 2 (MAP2) of E. chaffeensis and E. canis. In this study, we further characterized the conservation of MAP2 among various geographic isolates of each organism and determined if the recombinant MAP2 (rMAP2) of E. chaffeensis would cross-react with E. canis-infected dog sera. Genomic Southern blot analysis using digoxigenin-labeled species-specific probes suggested that map2 is a single-copy gene in both Ehrlichia species. Sequences of the single map2 genes of seven geographically different isolates of E. chaffeensis and five isolates of E. canis are highly conserved among the various isolates of each respective ehrlichial species. ELISA and Western blot analysis confirmed that the E. chaffeensis rMAP2 failed to serologically differentiate between E. canis and E. chaffeensis infections.

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