Genome sequence analysis of Malayan pangolin (Manis javanica) forensic samples reveals the presence of Paraburkholderia fungorum sequences

PeerJ. 2023 Oct 4:11:e16002. doi: 10.7717/peerj.16002. eCollection 2023.

Abstract

Background: The Malayan pangolin (Manis javanica) is a placental mammal and is listed as Critically Endangered on the IUCN Red List of Threatened Species. Most previous attempts to breed pangolins in captivity have met with little success because of dietary issues, infections, and other complications, although a previous study reported breeding pangolins in captivity to the third generation. In our previous pangolin genome sequencing data analysis, we obtained a considerable amount of bacterial DNA from a pregnant female Malayan pangolin (named "UM3"), which was likely infected by Paraburkholderia fungorum-an agent of biodegradation and bioremediation in agriculture.

Methodology: Here, we further confirmed and characterized this bacterial species using PCR, histological staining, whole-genome sequencing, and bioinformatics approaches. PCR assays with in-house designed primer sets and 16S universal primers showed clear positive bands in the cerebrum, cerebellum, lung, and blood of UM3 suggesting that UM3 might have developed septicaemia. Histological staining showed the presence of Gram-negative rod-shaped bacteria in the pangolin brain and lungs, indicating the colonization of the bacteria in these two organs. In addition, PCR screening of UM3's fetal tissues revealed the presence of P. fungorum in the gastrocnemius muscle, but not in other tissues that we examined. We also sequenced and reconstructed the genome of pangolin P. fungorum, which has a genome size of 7.7 Mbps.

Conclusion: Our study is the first to present detailed evidence of the presence of P. fungorum in a pangolin and her fetus (although preliminary results were presented in our previous article). Here, we raise the concern that P. fungorum may potentially infect humans, especially YOPI (young, old, pregnant, and immunocompromised) people. Therefore, caution should be exercised when using this bacterial species as biodegradation or bioremediation agents in agriculture.

Keywords: Bacterial genome analysis; Fetal infection; Microbial infection; Pangolin conservation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Eutheria / genetics
  • Female
  • Humans
  • Mammals* / genetics
  • Pangolins* / genetics
  • Placenta
  • Pregnancy
  • Sequence Analysis

Supplementary concepts

  • Paraburkholderia fungorum

Grants and funding

This work was funded by the High-Level Talent Recruitment Programme for Academic and Research Platform Construction (Reference Number: 5000105) from Wenzhou-Kean University. Furthermore, Ka Yun Tan was supported by the Centre for Research in Biotechnology for Agriculture (CEBAR) grant IRU-MRUN (RU023-2015). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.