Human Spotted Fever Group <i>Rickettsia</i> Infecting Yaks (<i>Bos grunniens</i>) in the Qinghai-Tibetan Plateau Area

• Main Authors: Yingna Jian, Jixu Li, Paul Franck Adjou Moumouni, Xueyong Zhang, Maria Agnes Tumwebaze, Geping Wang, Qigang Cai, Xiuping Li, Guanghua Wang, Mingming Liu, Yongchang Li, Liqing Ma, Xuenan Xuan
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: Pathogens
• Subjects: fever rickettsioses; human SFG <i>Rickettsia</i>; Qinghai-Tibetan Plateau; yak
• Online Access: https://www.mdpi.com/2076-0817/9/4/249

The Qinghai-Tibetan Plateau Area (QTPA) is a plateau with the highest average altitude, located in Northwestern China. There is a risk for interspecies disease transmission, such as spotted fever rickettsioses. However, information on the molecular characteristics of the spotted fever group (SFG) <i>Rickettsia</i> spp. in the area is limited. This study performed screenings, and detected the DNA of human pathogen, SFG <i>Rickettsia</i> spp., with 11.3% (25/222) infection rates in yaks (<i>Bos</i> <i>grunniens</i>). BLASTn analysis revealed that the <i>Rickettsia</i> sequences obtained shared 94.3–100% identity with isolates of <i>Rickettsia</i> spp. from ticks in China. One <i>Rickettsia</i> sequence (MN536161) had 100% nucleotide identity to two <i>R. raoultii</i> isolates from Chinese <i>Homo sapiens</i>, and one isolate from Qinghai <i>Dermacentor</i> <i>silvarum</i>. Meanwhile, another <i>Rickettsia</i> sequence (MN536157) shared 99.1–99.5% identity to one isolate from <i>Dermacentor</i> spp. in China. Furthermore, the phylogenetic analysis of SFG <i>Rickettsia</i> spp. <i>ompA</i> gene revealed that these two sequences obtained from yaks in the present study grouped with the <i>R. slovaca</i> and <i>R. raoultii</i> clades with isolates identified from <i>Dermacentor</i> spp. and <i>Homo sapiens</i>. Our findings showed the first evidence of human pathogen DNA, SFG <i>Rickettsia</i> spp., from animals, in the QTPA.