Microbiome diversity in Diaphorina citri populations from Kenya and Tanzania shows links to China

PLoS One. 2020 Jun 26;15(6):e0235348. doi: 10.1371/journal.pone.0235348. eCollection 2020.

Abstract

The Asian citrus psyllid (Diaphorina citri) is a key pest of Citrus spp. worldwide, as it acts as a vector for "Candidatus Liberibacter asiaticus (Las)", the bacterial pathogen associated with the destructive Huanglongbing (HLB) disease. Recent detection of D. citri in Africa and reports of Las-associated HLB in Ethiopia suggest that the citrus industry on the continent is under imminent threat. Endosymbionts and gut bacteria play key roles in the biology of arthropods, especially with regards to vector-pathogen interactions and resistance to antibiotics. Thus, we aim to profile the bacterial genera and to identify antibiotic resistance genes within the microbiome of different populations worldwide of D. citri. The metagenome of D. citri was sequenced using the Oxford Nanopore full-length 16S metagenomics protocol, and the "What's in my pot" (WIMP) analysis pipeline. Microbial diversity within and between D. citri populations was assessed, and antibiotic resistance genes were identified using the WIMP-ARMA workflow. The most abundant genera were key endosymbionts of D. citri ("Candidatus Carsonella", "Candidatus Profftella", and Wolbachia). The Shannon diversity index showed that D. citri from Tanzania had the highest diversity of bacterial genera (1.92), and D. citri from China had the lowest (1.34). The Bray-Curtis dissimilarity showed that China and Kenya represented the most diverged populations, while the populations from Kenya and Tanzania were the least diverged. The WIMP-ARMA analyses generated 48 CARD genes from 13 bacterial species in each of the populations. Spectinomycin resistance genes were the most frequently found, with an average of 65.98% in all the populations. These findings add to the knowledge on the diversity of the African D. citri populations and the probable introduction source of the psyllid in these African countries.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biodiversity*
  • China
  • Drug Resistance, Microbial / genetics
  • Hemiptera / microbiology*
  • Insect Vectors / microbiology
  • Kenya
  • Microbiota* / drug effects
  • Microbiota* / genetics
  • Phylogeny*
  • Plant Diseases / microbiology
  • Sequence Analysis
  • Symbiosis
  • Tanzania

Grants and funding

This research was supported by the following organizations and agencies: German Academic Exchange (DAAD) to IJA, Department of Genetics, Stellenbosch University, German Ministry for Economic Cooperation and Development (BMZ) through GIZ to the project ‘Strengthening Citrus Production Systems through the Introduction of Integrated Pest Management (IPM) Measures for Pests and Diseases in Kenya and Tanzania (SCIPM), through the International Centre of Insect Physiology and Ecology (icipe) (grant 14.1432.5‐001.00 to IJA, FMK, BVA, GP, BAR, FLO, AWW, KSA, MS, SM, and SE), UK Aid from the UK Government, Swedish International Development Cooperation Agency (Sida), Swiss Agency for Development and Cooperation (SDC), and the Kenyan Government. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.