title: The roles of noncoding RNA Rli60 in regulating the virulence of Listeria monocytogenes.
abstract: BACKGROUND
  Listeria monocytogenes (LM) is an important zoonotic foodborne pathogen. Noncoding RNA (ncRNA) has an important role in regulating its virulence. As a member of ncRNA, however, the function of Rli60 in regulating LM virulence remain unclear. The aim of this study was to investigate the role of Rli60 in regulating LM virulence.
  
  
  METHODS
  Using a homologous recombination method, a LM EGD-e rli60 gene deletion strain (LM-Δrli60) was constructed and compared with a LM EGD-e strain in the following respects: (1) adhesiveness, invasion ability, intracellular survival, proliferation, and transcription of virulence genes in the mouse macrophage cell line RAW264.7; (2) 50% lethal dose (LD50) to the BALB/c mouse; and (3) the amount in the mouse liver and spleen and the effects on pathology of mouse liver, spleen, and kidney after inoculation.
  
  
  RESULTS
  The LM-Δrli60 strain had a significantly higher adhesion rate and lower invasion rate with significantly lower intracellular survival and proliferation rates in the RAW264.7 cell line, compared to the LM EGD-e strain. Inoculation with LM-Δrli60 strain significantly affected the transcription of virulence genes. The LD50 of LM-Δrli60 to BALB/c mouse was increased by 2.12 logarithmic magnitude, which indicated that the virulence in LM-Δrli60 is significantly decreased (p < 0.05). The amount of LM-Δrli60 in the liver and spleen was significantly lower than the amount of LM EGD-e in these organs (p < 0.05). The pathological damage due to LM-Δrli60 infection in the mouse liver, spleen, and kidney was lower than the damage due to LM EGD-e infection.
  
  
  CONCLUSIONS
  This study confirmed that the rli60 deletion could significantly affect LM virulence, adhesion, invasion, survival, and proliferation. This suggests that Rli60 has an important role in regulating LM virulence.
authors.affiliation: College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China.
authors.forename: Ye-Long
authors.initials: YL
authors.lastname: Peng
authors.affiliation: College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China.
authors.forename: Qing-Ling
authors.initials: QL
authors.lastname: Meng
authors.affiliation: College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China. Electronic address: qj710625@163.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Qiao
authors.affiliation: College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Xie
authors.affiliation: College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Chen
authors.affiliation: College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China.
authors.forename: Tian-Li
authors.initials: TL
authors.lastname: Liu
authors.affiliation: College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China.
authors.forename: Zheng-Xiang
authors.initials: ZX
authors.lastname: Hu
authors.affiliation: College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, China.
authors.forename: Xue-Peng
authors.initials: XP
authors.lastname: Cai
authors.affiliation: College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China.
authors.forename: Chuang-Fu
authors.initials: CF
authors.lastname: Chen
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics*; D002460:Cell Line; D017353:Gene Deletion; D007668:Kidney / Q000382:microbiology* / Q000473:pathology; D008089:Listeria monocytogenes / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity*; D008088:Listeriosis / Q000382:microbiology; D008099:Liver / Q000382:microbiology* / Q000473:pathology; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D022661:RNA, Untranslated / Q000235:genetics; D013154:Spleen / Q000382:microbiology* / Q000473:pathology; D014774:Virulence / Q000235:genetics
chemical_list: D022661:RNA, Untranslated
keywords: Listeria monocytogenes; noncoding RNA; rli60 gene; virulence