AUTHOR=Huang Tianpeng , Zhang Jinbao , Sun Changyun , Liu Zhicheng , He Haiyan , Wu Jie , Geriletu  

TITLE=A Novel Arthropod Host of Brucellosis in the Arid Steppe Ecosystem

JOURNAL=Frontiers in Veterinary Science

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2020.566253

DOI=10.3389/fvets.2020.566253

ISSN=2297-1769

ABSTRACT=<p>Brucellosis is a severe public health problem in the Inner Mongolia regions of China. The recent prevalence of brucellosis outbreaks may be attributed to an increase in the activity of ticks and other air-borne vectors. <italic>Dermacentor nuttalli</italic> (<italic>D. nuttalli</italic>) is a native tick species of Inner Mongolia; similar to other tick species, <italic>D. nuttalli</italic> carries a variety of pathogens that can be transmitted to a wide range of animals. In this study, we have investigated the potential of <italic>D. nuttalli</italic> in transmitting brucellosis. From 2015 to 2019, 2,256 ticks were collected from 23 different pastoral areas of Hulun Buir. Brucellosis pathogen was detected using DNA extracted from different developmental stages of ticks. Salivary gland and midgut tissue samples were used as templates to amplify <italic>Brucella Bscp31</italic> gene (<italic>Brucella</italic> genus-specific gene) by using TaqMan Real-Time polymerase chain reaction (PCR). To detect the presence of Bscp31 protein, which is specific to <italic>Brucella</italic> spp., in the midgut and salivary gland tissues of <italic>D. nuttalli</italic>, Western blotting and immunofluorescence were performed. Additionally, <italic>Brucella</italic> spp. were isolated using a culture medium. Tick samples were identified as <italic>D. nuttalli</italic>. Different percentages of <italic>Brucella</italic> genus-specific genes could be found in the tick samples. From 2015 to 2019, the positivity rate for the detection of <italic>Bscp31</italic> gene in <italic>D. nuttalli</italic> ranged from 0.00 to 87.80%, with the highest rate of 89.00%. In addition, <italic>Brucella</italic> genus-specific genes were successfully detected in the samples isolated from all the developmental stages and anatomical regions of ticks. Bscp31 protein was present in the midgut and salivary gland of <italic>D. nuttalli</italic>. Further, <italic>B. melitensis</italic> biotype 3 was isolated from eggs and engorged adults of <italic>D. nuttalli</italic>. These findings demonstrate that <italic>D. nuttalli</italic> is a potent, long-term carrier of <italic>Brucella</italic> spp. that can exhibit transovarial transmission potential, presenting <italic>D. nuttalli</italic> as a novel arthropod host for <italic>Brucella</italic> spp. This study, therefore, indicates the potential risk of transmission of brucellosis via tick bites among animals as well as human beings.</p>