title: [Analysis of causes and whole microbial structure in a case of rampant caries].
abstract: OBJECTIVE
  To analyze the whole microbial structure in a case of rampant caries to provide evidence for its prevention and treatment.
  
  
  METHODS
  Clinical samples including blood, supragingival plaque, plaque in the caries cavity, saliva, and mucosal swabs were collected with the patient's consent. The blood sample was sent for routine immune test, and the others samples were stained using Gram method and cultured for identifying colonies and 16S rRNA sequencing. DNA was extracted from the samples and tested for the main cariogenic bacterium (Streptococcus mutans) with qPCR, and the whole microbial structure was analyzed using DGGE.
  
  
  RESULTS
  The patient had a high levels of IgE and segmented neutrophils in his blood. Streptococci with extremely long chains were found in the saliva samples under microscope. Culture of the samples revealed the highest bacterial concentration in the saliva. The relative content of hemolytic bacterium was detected in the samples, the highest in the caries cavity; C. albicans was the highest in the dental plaque. In addition, 33 bacterial colonies were identified by VITEK system and 16S rDNA sequence phylogenetic analysis, and among them streptococci and Leptotrichia wade were enriched in the dental plaque sample, Streptococcus mutans, Fusobacterium nucleatum, and Streptococcus tigurinus in the caries cavity, and Lactobacillus in the saliva. S. mutans was significantly abundant in the mucosal swabs, saliva and plaque samples of the caries cavity as shown by qPCR. Compared to samples collected from a healthy individual and another two patients with rampant caries, the samples from this case showed a decreased bacterial diversity and increased bacterial abundance shown by PCR-DGGE profiling, and multiple Leptotrichia sp. were detected by gel sequencing.
  
  
  CONCLUSIONS
  The outgrowth of such pathogenic microorganisms as S. mutans and Leptotrichia sp., and dysbiosis of oral microbial community might contribute to the pathogenesis of rampant caries in this case.
authors: State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu 610041, China. E-mail: drhuxiaoyu@163.com.
authors: Xiao-Yu
authors: XY
authors: Hu
authors: Yu-Fei
authors: YF
authors: Yao
authors: Bo-Miao
authors: BM
authors: Cui
authors: Jun
authors: J
authors: Lv
authors: Xin
authors: X
authors: Shen
authors: Biao
authors: B
authors: Ren
authors: Ming-Yun
authors: MY
authors: Li
authors: Qiang
authors: Q
authors: Guo
authors: Rui-Jie
authors: RJ
authors: Huang
authors: Yan
authors: Y
authors: Li
mesh_terms: D000015:Abnormalities, Multiple; D003731:Dental Caries / Q000382:microbiology*; D003773:Dental Plaque / Q000382:microbiology; D005673:Fusobacterium / Q000302:isolation & purification; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007778:Lactobacillus / Q000302:isolation & purification; D045183:Leptotrichia / Q000302:isolation & purification; D017880:Limb Deformities, Congenital; D064307:Microbiota; D009061:Mouth Mucosa / Q000382:microbiology; D009504:Neutrophils / Q000166:cytology; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012463:Saliva / Q000382:microbiology; D013291:Streptococcus / Q000302:isolation & purification; D014071:Tooth Abnormalities
chemical_list: D012336:RNA, Ribosomal, 16S; D007073:Immunoglobulin E