Objective To establish a viable bacteria assay for Helicobacter pylori(H.pylori)by assessing the cgt gene expression,and to develop accordingly a rapid and novel testing method for clinical precision treatment.Methods Viable bacteria count was determined in bacterial cultures.The transcriptional expression level of cgt(hp0421),the conserved gene that encodes cholesterol-α-glucosyltransferase(CGT)in H.pylori,was measured by RT-PCR.The correlation between the number of colonies and cgt gene transcription expression was analyzed and the regression model was constructed.The linear range,sensitivity,and specificity of the new method were examined accordingly.The bactericidal action of clarithromycin was assessed using this method to verify the performance of the method in determining clinical bacterial drug resistance.Results The Ct values of cgt for H.pylori colony counts of 102,104,106,and 108 CFU/mL were 29.67±0.14,23.37±0.36,17.65±0.37,and 11.38±0.39,respectively.In the range of 101-108 CFU/mL,the regression equation for cgt gene expression and viable bacterial counts determined by RT-qPCR was y=-0.350 1x+12.49,with the correlation coefficient being R2=0.9992 and the sensitivity being 101 CFU/mL,showing no cross-reaction with 13 other bacteria.The lg values of live H.pylori bacteria treated with clarithromycin at 0,5,10,20,and 40 μg/mL for 12 h were 2.57±0.02,2.45±0.01,2.19±0.02,1.91±0.07,and 1.33±0.05,respectively.The corresponding cgt gene Ct values were 27.76±0.09,28.37±0.24,29.51±0.14,30.11±0.12,and 31.66±0.11.By applying the cgt gene expression in the equation,the estimated counts of viable bacteria were found to be 2.73±0.03,2.52±0.08,2.11±0.05,1.89±0.02,and 1.33±0.04,showing no significant difference in statistical analysis(P＞0.05).Conclusion The method for assessing viable bacteria account by evaluating cgt gene expression in H.pylori was successfully established,significantly reducing the time required to determine viable bacteria count and providing a new method for clinical viable bacteria testing.

Background Behcet's disease is a refractory panuveitis with high blindness rate.Multifocal electroretinography (mfERG) is a useful tool for the evaluation of the function of the posterior retina.ObjectiveThe aim of this study is to assess the characteristics of Behcet's disease using the mfERG.Methods mfERG was recorded in 68 eyes of 39 cases with active stage of Behcet's disease.All of the patients were diagnosed based on the Standard of International Study Group for Behcet's Disease and assigned to the cystoid macular edema (CME) group and the diffuse macular edema (DME) group after assessment by fundus fluorescein angiography (FFA).Seventeen normal subjects were used as controls.Oral informed consent was obtained from all of the subjects prior to this trial.mfERG recording followed the ISCEV Guidelines for Clinical Multifocal Electroretinography (2007 edition).The response density and latency of P1 and N1 waves in 6 rings were analyzed and compared.Results The amplitudes of N_1 waves from rings 1 through 6 and N1 wave from rings 1 through 5 were significantly declined in patients with Behcet's disease compared with normal control (P＜0.01).All of the latencies of P_1 waves from rings 1 through 6 were insignificantly shortened in patients with Behcet's disease compared with normal control (P＞0.05).The amplitudes of P_1 and N_1 waves from rings 1 through 6 in diffuse macular edema group were considerably lower than those in the cystoid macular edema group (P＜0.05,P＜0.01).A test of visual acuity showed a negative correlation to the amplitude and latency of N_1 wave (r=-0.36,-0.37,P＜0.05 ) and a positive correlation with the amplitude of N1 wave (r=0.43,P＜0.05) in the DME group.In the CME group,a test of visual acuity presented a negative correlation to the amplitude and latency of N1 wave and latency of P1 (r=-0.41,-0.35,-0.40,P＜0.05 ) and a positive correlation with the amplitude of P1 wave (r=0.48,P＜0.05).Conclusion mfEGR demonstrates that retinal electro-activity is abnormal in eyes with Behcet's disease.The distinct functional disorder is situated around the fovea.