Novel variants of the newly emerged Anaplasma capra from Korean water deer (Hydropotes inermis argyropus) in South Korea

Anaplasma spp. are tick-borne Gram-negative obligate intracellular bacteria that infect humans and a wide range of animals. Anaplasma capra has emerged as a human pathogen; however, little is known about the occurrence and genetic identity of this agent in wildlife. The present study aimed to determine the infection rate and genetic profile of this pathogen in wild animals in the Republic of Korea. A total of 253 blood samples [198 from Korean water deer (Hydropotes inermis argyropus), 53 from raccoon dogs (Nyctereutes procyonoides) and one sample each from a leopard cat (Prionailurus bengalensis) and a roe deer (Capreolus pygargus)] were collected at Chungbuk Wildlife Center during the period 2015-2018. Genomic DNA was extracted from the samples and screened for presence of Anaplasma species by PCR/sequence analysis of 429 bp of the 16S rRNA gene marker. Anaplasma capra-positive isolates were genetically profiled by amplification of a longer fragment of 16S rRNA (rrs) as well as partial sequences of citrate synthase (gltA), heat-shock protein (groEL), major surface protein 2 (msp2) and major surface protein 4 (msp4). Generated sequences of each gene marker were aligned with homologous sequences in the database and phylogenetically analyzed. Anaplasma capra was detected in blood samples derived from Korean water deer, whereas samples from other animal species were negative. The overall infection rate in tested samples was 13.8% (35/253) and in the water deer the rate was 17.8% (35/198), distributed along the study period from 2015 to 2018. Genetic profiling and a phylogenetic analysis based on analyzed gene markers revealed the occurrence of two distinct strains, clustered in a single clade with counterpart sequences of A. capra in the database. Anaplasma capra infection were detected in Korean water deer in the Republic of Korea, providing insight into the role of wildlife as a potential reservoir for animal and human anaplasmosis. However, further work is needed in order to evaluate the role of Korean water deer as a host/reservoir host of A. capra.