First molecular evidence for the presence of Anaplasma DNA in milk from sheep and goats in China.

Anaplasmosis, a disease caused by bacteria in the genus of Anaplasma, imposes economic constraints on animal breeders and also threatens human health. In the present study, we investigated the presence of Anaplasma spp. DNA in milk collected from sheep and goats in China. A total of 120 milk samples and 414 field-sampled blood specimens from sheep and goats were analyzed by PCR and DNA sequencing. Anaplasma ovis was detected in 12 milk samples (three from sheep and nine from goats). The blood specimens corresponding to the A. ovis DNA-positive milk were analyzed for Anaplasma DNA presence, and A. ovis DNA was identified in 10 out of the 12 blood specimens. One goat's milk sample was Anaplasma bovis DNA-positive, as was the corresponding blood sample. Anaplasma phagocytophilum was found in a milk sample and blood sample from one goat. One milk sample from Xinmi in Henan province was simultaneously positive for A. bovis and A. phagocytophilum; however, the corresponding blood was negative for both species. DNA sequencing of the PCR products and phylogenetic analysis confirmed that the sequences from the milk samples matched those of the corresponding blood samples. This is the first report to detect the Anaplasma DNA in milk samples under natural condition, and represents the first evidence of the presence of A. ovis, A. bovis and A. phagocytophilum DNA in milk from sheep and goats.