Identification of Amblyomma javanense and detection of tick-borne Ehrlichia spp. in confiscated Malayan Pangolins

Junqiong Zhai; Yajiang Wu; Jinping Chen; Jiejian Zou; Fen Shan; Wanping Li; Wu Chen; Niu Zhou

doi:10.1016/j.ijppaw.2021.01.008

Identification of Amblyomma javanense and detection of tick-borne Ehrlichia spp. in confiscated Malayan Pangolins

Int J Parasitol Parasites Wildl. 2021 Jan 30:14:107-116. doi: 10.1016/j.ijppaw.2021.01.008. eCollection 2021 Apr.

Authors

Junqiong Zhai^{1

2}, Yajiang Wu^{1

2}, Jinping Chen³, Jiejian Zou⁴, Fen Shan^{1

2}, Wanping Li^{1

2}, Wu Chen^{1

2}, Niu Zhou^{1

2}

Affiliations

¹ Guangzhou Zoo, Guangzhou, 510070, China.
² Wildlife Microbiology Laboratory, Guangzhou Wildlife Research Center, Guangzhou, 510070, China.
³ Guangdong Institute of Applied Biological Resources, Guangzhou, 510260, China.
⁴ Guangdong Provincial Wildlife Rescue Center, Guangzhou, 510520, China.

Abstract

Due to habitat destruction and illegal hunting and trade, the number of pangolins has been sharply reduced. To protect pangolins from extinction, relevant departments are combined and active action have been taken. A total of 21 confiscated Malayan pangolins were rescued in 2019, but died continuously for unknown reasons. This study aimed to investigate the reasons for the death of these pangolin and rescue them. 19 of the 21 confiscated pangolins had ticks on their body integument. A total of 303 ticks were collected and identified as Amblyomma javanense (A. javanense) according to their morphology and the sequences of 16S rRNA and internal transcribed spacer 2 (ITS2). There were multi-organ damages in the dead pangolins, especially congestion and hemorrhage in lung, heart and kidney and inflammation of which were observed using HE staining. Pathogens' nucleic acid detection showed ticks were only positive for Ehrlichia spp, with 56.7% positive rate of collected ticks (127/224), which was further confirmed in tissues from dead pangolins. Our findings confirm that ehrlichiosis caused by Ehrlichia spp. from A. javanense might accelerate the confiscated pangolin's death. More attention should be payed to tick-elimination work and the diagnoses and treatment of tick-borne diseases in the follow-up rescue operation.

Keywords: 16S rRNA, 16 Svedberg ribosomal ribonucleic acid; Amblyomma javanense; BLAST, basic local alignment search tool; Ehrlichia spp.; Ehrlichiosis; Malayan pangolin; PCR, polymerase chain reaction; Tick; Tick-borne pathogen.