title: Gut symbiont enhances insecticide resistance in a significant pest, the oriental fruit fly Bactrocera dorsalis (Hendel).
abstract: Symbiotic bacteria affect insect physiology and ecology. They may also mediate insecticide resistance within their hosts and thereby impact pest and vector control practices. Here, we document a novel mechanism of insecticide resistance in which a gut symbiont of the tephritid pest fruit fly Bactrocera dorsalis enhances resistance to the organophosphate insecticide trichlorphon.
  
  
  
  We demonstrated that the gut symbiont Citrobacter sp. (CF-BD) plays a key role in the degradation of trichlorphon. Based on a comparative genomics analysis with other Citrobacter species, phosphatase hydrolase genes were identified in CF-BD. These CF-BD genes had higher expression when trichlorphon was present. Bactrocera dorsalis inoculated with isolated CF-BD obtained higher trichlorphon resistance, while antibiotic-treated flies were less resistant confirming the key role of CF-BD in insecticide resistance.
  
  
  
  Our findings suggest that symbiont-mediated insecticide resistance can readily develop in B. dorsalis and may represent a more widely relevant insecticide resistance mechanism than previously recognized.
authors.affiliation: Department of Entomology, South China Agricultural University, Guangzhou, 510640, China.
authors.forename: Daifeng
authors.initials: D
authors.lastname: Cheng
authors.affiliation: Department of Entomology, South China Agricultural University, Guangzhou, 510640, China.
authors.forename: Zijun
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2751, Australia.
authors.forename: Markus
authors.initials: M
authors.lastname: Riegler
authors.affiliation: Sun Yat-sen University-Michigan State University Joint Center of Vector Control for Tropical Diseases, Guangzhou, Guangdong, 510080, China.|Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Xi
authors.affiliation: Department of Entomology, South China Agricultural University, Guangzhou, 510640, China.
authors.forename: Guangwen
authors.initials: G
authors.lastname: Liang
authors.affiliation: Department of Entomology, South China Agricultural University, Guangzhou, 510640, China. xuyijuan@yahoo.com.
authors.forename: Yijuan
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016971:Citrobacter freundii / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D004351:Drug Resistance / Q000502:physiology*; D000069196:Gastrointestinal Microbiome / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D006867:Hydrolases / Q000235:genetics / Q000378:metabolism; D007305:Insecticide Resistance / Q000502:physiology*; D007306:Insecticides / Q000494:pharmacology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013559:Symbiosis; D033621:Tephritidae / Q000187:drug effects* / Q000382:microbiology*; D014236:Trichlorfon / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D007306:Insecticides; D012336:RNA, Ribosomal, 16S; D014236:Trichlorfon; D006867:Hydrolases
keywords: Bactrocera dorsalis; Insecticide resistance; Oriental fruit fly; Symbiotic bacteria; Trichlorphon