Original scientific paper

RNA polymerase sub-unit β (rpoB) characterization of Ehrlichia canis detected from dogs and Rhipicephalus sanguineus ticks in Cebu, Philippines.

Adrian P. Ybañez ; Biology and Environmental Sciences Program, Sciences Cluster, University of the Philippines Cebu, Lahug, Cebu City, Philippines; Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine,Obihiro City, Japan
Rochelle Haidee D. Ybañez ; Biology and Environmental Sciences Program, Sciences Cluster, University of the Philippines Cebu, Lahug, Cebu City, Philippines; National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro City, Japa
Naoaki Yokoyama ; National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro City, Japan
Hisashi Inokuma ; Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine,Obihiro City, Japan

Abstract

Ehrlichia canis, a canine tick-borne pathogen with wide geographic distribution, has been serologically and molecularly detected in the Philippines. The present study aimed to characterize E. canis detected from Rhipicephalus sanguineus ticks and dogs in Cebu, Philippines, using the RNA polymerase sub-unit Beta (rpoB), a gene that has been used for disease diagnosis and resolution of phylogenetic relationships between closelyrelated species. Using a 16S rRNA gene-based PCR that screens Ehrlichia spp., DNA samples obtained from the blood of 10 dogs, confirmed to be serologically positive for E. canis, were tested and found positive for E. canis after subsequent DNA sequencing. DNA from infected ticks and the 16S rRNA-E. canis-positive canine blood samples from the present study were further analyzed using the rpoB gene. All registered Ehrlichia spp. rpoB gene sequences were aligned to design specific primers that can amplify a partial 1572-bp length sequence of E. canis. The obtained sequences revealed 99.8-100 % identities with each other, and 99.8-100 % and 87.8-89.1 % identities with registered E. canis and E. chaffeensis sequences from the USA, respectively. Phylogenetic analysis revealed that the obtained partial rpOB sequences formed a clade with E. canis strains from the USA. The present study is the first rpoB characterization of E. canis in the Philippines, and apparently in Asia, and provides additional evidence of the presence of the pathogen in the country. It also adds information on the high conservation of the rpoB gene in E. canis.

Keywords

Ehrlichia canis; rpoB; dogs; Rhipicephalus sanguineus; Philippines

Hrčak ID:

149770

URI

https://hrcak.srce.hr/149770

Publication date:

9.12.2015.

Article data in other languages: croatian

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