Multiple infections of variants in Philippine dogs.

Aim: , the causative agent of infectious canine cyclic thrombocytopenia, is a tick-borne pathogen that also has been implicated as potentially zoonotic. To provide molecular evidence on the multiple infections of variants in Philippine dogs.

Materials And Methods: DNA fragments of from infected dogs in the Philippines were molecularly characterized. For screening, 25 dogs suspected to have canine anaplasmosis were tested using a 16S rRNA-based nested polymerase chain reaction (PCR). Infection was confirmed by sequencing of positive amplicons. Second round PCR targeting a longer 16S rRNA fragment was subsequently performed on the first round PCR amplicons of the positive samples. Further characterization using the heat-shock operon () gene was also performed on the -positive samples.

Results: 10 16S rRNA sequences were obtained and found 99.6-100% identical to each other and 99.6-99.7% identical to the closest registered sequences. On the other hand, 36 clone sequences were obtained and found to be 85.1-99.8% identical with each other and 85.0-88.9% identical to the closest previously registered sequences. Four dogs were found coinfected with 2-3 variant sequences. Phylogenetic analyses suggest that the detected in the Philippines may represent unique variants.

Conclusion: variants were detected in Philippine dogs. Coinfection of different variants in dogs was also demonstrated. The present study may indicate the potential genetic diversity of in the country.