OBJECTIVETo detect the presence and distribution of luxS gene in quorum sensing signal system in the periodontal pathogens.

METHODSThe total DNA of Porphyromonas gingivalis (Pg), Fusobacterium nucleatum (Fn), Actinobacillus acitinomycetimcomtans (Aa) were extracted. The presence of luxS was detected by polymerase chain reaction (PCR). The products of PCR were detected by electrophoresis, sequenced and identified by a Blast search of the GenBank database.

RESULTSElectrophoresis, sequencing and Blast searching indicated that the PCR products of Pg were highly consistent with the luxS gene in GenBank. The sequencing result of Fn was also identified with the target gene. The PCR product of Aa was the same as reference through electrophoresis.

CONCLUSIONSPg, Fn, Aa contain luxS gene. Further studies may be required to investigate the functions of luxS in the periodontal pathogens.

Aggregatibacter actinomycetemcomitans ; genetics ; metabolism ; Bacterial Proteins ; genetics ; isolation & purification ; metabolism ; Carbon-Sulfur Lyases ; genetics ; isolation & purification ; metabolism ; Fusobacterium nucleatum ; genetics ; metabolism ; Gene Expression Regulation, Bacterial ; Porphyromonas gingivalis ; genetics ; metabolism ; Quorum Sensing ; genetics ; Signal Transduction

No abstract available.
Adult ; Aged ; Biopsy ; Colon/*microbiology/pathology ; Fusobacterium/genetics/*isolation & purification ; Humans ; Inflammatory Bowel Diseases/microbiology/*pathology ; Male ; Middle Aged ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/chemistry/genetics/metabolism ; Republic of Korea ; Sequence Analysis, DNA ; Young Adult

OBJECTIVETo analyze the whole microbial structure in a case of rampant caries to provide evidence for its prevention and treatment.

METHODSClinical 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.

RESULTSThe 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.

CONCLUSIONThe 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.

Abnormalities, Multiple ; Dental Caries ; microbiology ; Dental Plaque ; microbiology ; Fusobacterium ; isolation & purification ; Humans ; Immunoglobulin E ; blood ; Lactobacillus ; isolation & purification ; Leptotrichia ; isolation & purification ; Limb Deformities, Congenital ; Microbiota ; Mouth Mucosa ; microbiology ; Neutrophils ; cytology ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S ; genetics ; Saliva ; microbiology ; Streptococcus ; isolation & purification ; Tooth Abnormalities