Improved molecular detection of Ehrlichia and Anaplasma species applied to Amblyomma ticks collected from cattle and sheep in Ethiopia
| Autor: | Dirk Berkvens, Y. Asfaw, Gobena Ameni, Sori Teshale, Dirk Geysen |
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| Rok vydání: | 2015 |
| Předmět: |
DNA
Bacterial Anaplasmosis Anaplasma Ehrlichiosis Ixodidae Ehrlichia Cattle Diseases Sheep Diseases Ehrlichia ruminantium DNA Ribosomal Polymerase Chain Reaction Microbiology medicine Animals Tick-borne disease Sheep biology Arthropod Vectors Amblyomma Sequence Analysis DNA biology.organism_classification medicine.disease Virology Infectious Diseases Insect Science Cattle Parasitology Ethiopia Amblyomma variegatum |
| Zdroj: | Ticks and Tick-borne Diseases. 6:1-7 |
| ISSN: | 1877-959X |
| Popis: | Detection of Ehrlichia and Anaplasma species in animals and tick vectors is crucial for an understanding of the epidemiology of diseases caused by these pathogens. In this study, a pair of primers designated EBR2 and EBR3 was designed from the Anaplasma 16S rDNA sequence and was used along with a previously described primer EHR 16SD for the simultaneous detection of Ehrlichia and Anaplasma species by nested PCR. The primers were used to amplify 925 bp of DNA from known species of Ehrlichia and Anaplasma . Restriction with Mbo II and Msp I enzymes allowed Ehrlichia and Anaplasma speciation. Restriction with Mbo II differentiated between An. marginale , Anaplasma (formerly Ehrlichia ) sp. Omatjenne, and An. centrale with An. marginale and Anaplasma (formerly Ehrlichia ) sp. Omatjenne yielding 2 distinct fragments each while An. centrale produced 3 distinct bands. Ehrlichia ruminantium and An. phagocytophylum remained undigested. Subsequent restriction with Msp I differentiated E. ruminantium from An. phagocytophylum with 2 and 4 fragments, respectively. When used on tick samples from the field, 63 ticks (16.4%) out of 384 collected from cattle and sheep were positive for one or more species of Ehrlichia and Anaplasma . The positivity ranged from 6.3% at Andasa to 36.7% at Habernosa. Higher overall infection rates were found in Amblyomma lepidum than in Amblyomma variegatum ticks ( p = 0.009). Amblyomma lepidum from Habernosa were more often infected with all detected species of Anaplasma and Ehrlichia than Am. variegatum . At Bako, however, Anaplasma (formerly Ehrlichia ) sp. Omatjenne was detected only in Am. variegatum . A significantly higher proportion of ticks collected from cattle (20.6%) was found positive than in those collected from sheep (3.3%) ( p = 0.003). Simultaneous detection of Ehrlichia and Anaplasma species and correct identification of mixed infections was possible. Since the ticks were collected from animals, the occurrence of the major species of Ehrlichia and Anaplasma in ruminants in the area is confirmed. |
| Databáze: | OpenAIRE |
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