Molecular Detection and Characterization of Zoonotic and Veterinary Pathogens in Ticks from Northeastern China.

Feng Wei,Zhongyu Li,Shuchao Wang,Zheng Zeng,Quan Liu,Bo Wang,Huanhuan Liu,Hongyu Ma,Zedong Wang,Jun Qian,Mingxin Song

doi:10.3389/fmicb.2016.01913

Abstract

Tick-borne diseases are considered as emerging infectious diseases in humans and animals in China. In this study, Ixodes persulcatus (n = 1699), Haemaphysalis concinna (n = 412), Haemaphysalis longicornis (n = 390), Dermacentor nuttalli (n = 253), and Dermacentor silvarum (n = 204) ticks were collected by flagging from northeastern China, and detected for infection with Anaplasma, Ehrlichia, Babesia, and Hepatozoon spp. by using nested polymerase chain reaction assays and sequencing analysis. Anaplasma phagocytophilum was detected in all tick species, i.e., I. persulcatus (9.4%), H. longicornis (1.9%), H. concinna (6.5%), D. nuttalli (1.7%), and D. silvarum (2.3%); Anaplasma bovis was detected in H. longicornis (0.3%) and H. concinna (0.2%); Ehrlichia muris was detected in I. persulcatus (2.5%) and H. concinna (0.2%); Candidatus Neoehrlichia mikurensis was only detected in I. persulcatus (0.4%). The Ehrlichia variant (GenBank access number KU921424), closely related to Ehrlichia ewingii, was found in H. longicornis (0.8%) and H. concinna (0.2%). I. persulcatus was infected with Babesia venatorum (1.2%), Babesia microti (0.6%), and Babesia divergens (0.6%). Additionally, four Babesia sequence variants (GenBank access numbers 862303–862306) were detected in I. persulcatus, H. longicornis, and H. concinna, which belonged to the clusters formed by the parasites of dogs, sheep, and cattle (B. gibsoni, B. motasi, and B. crassa). Two Hepatozoon spp. (GenBank access numbers KX016028 and KX016029) associated with hepatozoonosis in Japanese martens were found in the collected ticks (0.1–3.1%). These findings showed the genetic variability of Anaplasma, Ehrlichia, Babesia, and Hepatozoon spp. circulating in ticks in northeastern China, highlighting the necessity for further research of these tick-associated pathogens and their role in human and animal diseases.

Highlights

Ticks are second only to mosquitoes as vectors to transmit viral, bacterial, and protozoan agents in humans and animals, some of which pose a threat to human and animal health and are frequently zoonotic
Anaplasma DNA was detected in I. persulcatus, H. concinna, H. longicornis, D. silvarum, and D. nuttalli
A. phagocytophilum is considered as an emerging human pathogen of public health importance, which is naturally maintained in tick-mammal cycles, and has been found in sheep, goats, cattle, rabbits, FIGURE 4 | Phylogenetic analysis of the partial 18S rRNA gene (343 bp) from Hepatozoon spp. in ticks from northeastern China

Summary

Introduction

Ticks are second only to mosquitoes as vectors to transmit viral, bacterial, and protozoan agents in humans and animals, some of which pose a threat to human and animal health and are frequently zoonotic. Among tick-borne bacteria, members of the genera Anaplasma and Ehrlichia of the family Anaplasmataceae cause anaplasmoses and ehrlichioses in humans and animals (Ismail et al, 2010). The two most important species include Ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis (HME), and Anaplasma phagocytophilum, the agent of human granulocytic anaplasmosis (HGA). Other species that infect animals include A. marginale, Anaplasma centrale, A. ovis, E. canis, and Ehrlichia minasensis (Wen et al, 2003; Kocan et al, 2015; Cabezas-Cruz et al, 2016). In Asia, Ixodes persulcatus is considered the primary vector of A. phagocytophilum and E. muris (Jin et al, 2012; Ivanova et al, 2016)

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