OBJECTIVETo identify Streptococcus mutans (S. mutans) strains from clinical samples.

METHODSPlaque samples from caries-active and caries-free sites on enamel surfaces were obtained and cultivated for S. mutans isolation. Morphology, biochemistry, automatic microorganism analysis system and polymerase chain reaction using primers homologous to surface protein antigen I/II (spaP), glucosyltransferase B (gtfB) and dextranase (dexA) were used to identify S. mutans. Genotype of isolated S. mutans was determined by arbitrarily primed polymerase chain reaction.

RESULTSForty-six strains of S. mutans were obtained from the 32 subjects and were identified as S. mutans by biochemistry, automatic microorganism analysis system and polymerase chain reaction. Five identical genotypes were found by arbitrarily primed polymerase chain reaction.

CONCLUSIONForty-one strains of S. mutans with different genotype were obtained from clinical samples.

Dental Caries ; Dental Plaque ; Genotype ; Glucosyltransferases ; Humans ; Polymerase Chain Reaction ; Streptococcus mutans

Objective: To investigate the expression of lncRNA TUG1 (long non-coding RNA taurine up-regulated gene 1) in gastric cancer and its effect on the proliferation and apoptosis of gastric cancer cells. Methods: Surgically resected gastric cancer tissues and corresponding distal normal tissues (>5 cm away from the margin of tumor) of 40 gastric cancer patients from March 2016 to December 2017 at Ganzhou People's Hospital of Jiangxi Province were collected, and qPCR was used to examine the expression of lncRNA TUG1.AGS gastric cancer cells were transfected with lncRNATUG1 over-expression plasmids and siRNAs, and the effects of lncRNA TUG1 on cell proliferation and apoptosis were assessed by CCK-8, qPCR and Flow cytometry. Results: lncRNATUG1 expression was significantly increased in gastric cancer tissues as compared to normal tissues; and it was not correlated with gender, age, tumor size, infiltration depth of tumor, lymph node-metastasis, tumor differentiation and TNM staging. TUG1 over-expression significantly suppressed the expressions of CDKN1A, BAX and Caspase-3 in AGS gastric cancer cells, and decreased G1 phase proportion and apoptosis rate, but increased S phase proportion and cell viability; in contrast, TUG1 siRNA transfection significantly promoted the expressions of CDKN1A, BAX and Caspase-3, and increased G1 phase proportion and apoptosis rate, but decreased S phase proportion and cell viability. Conclusion: Up-regulated lncRNATUG1 promotes proliferation and inhibits apoptosis of gastric cancer cells.