| Objective:The drug susceptibility test of Mycobacterium tuberculosis(M.tuberculosis)in patients with pulmonary tuberculosis during the period from 2014 to 2016 in Lianyungang and the related test results of rifampicin and isoniazid resistance genes were analyzed retrospectively.To provide reference for the effective prevention and treatment of M.tuberculosis in clinic.Methods:1.Source of data.From January 1,2014 to December 31,2016,Tuberculosis Prevention and Control Agency of Lianyungang County sent 1747 sputum smear specimens of suspected pulmonary tuberculosis patients.The data of age,gender,initial treatment and retreatment,the culture of M.tuberculosis culture and drug susceptibility testing,as well as the test results of drug-resistant gene chip were analyzed.2.M.tuberculosis culture,identification and drug susceptibility test.The sputum specimens were cultured in Roche medium and identified by p-nitrobenzoic acid method.Ratio drug sensitive test was used to detect M.tuberculosis resistance to isoniazid(INH),rifampicin(RFP),kanamycin(KM)and ofloxacin(OFX).3.Gene chip analysis.The rop B gene of RFP-resistant M.tuberculosis and kat G and inh A genes of RFP-resistant were analyzed by gene chip technique.4.Statistical analysis.SPSS20.0 software was used for statistical analysis,continuous measures were compared using the chi-square test.P < 0.05 indicates statistical difference,P < 0.01 indicates significant statistical difference.Results:1.Epidemic situation of M.tuberculosis in Lianyungang.In 1747 samples,1307 M.tuberculosis cultures were positive,with a positive rate of 74.81%.In three years,the number of initial treated patients was 1114(85.23%),and the number of retreatment patients was 193(14.77%).The number of male and female patients was 1017(77.81%)and 290(22.19%),respectively the male to female ratio was 3.51:1(1017/290).The ages of patient were from 1 to 94 years and the average age was 51.1 years.The number of patients with age 21 to 30 years interval was the most,followed by the 61 to 70-years interval.2.Drug resistance of M.tuberculosis in Lianyungang.(1)From 2014 to 2016,the total resistant rate was 16.14%,and the drug resistant rate is decreasing during three years(20.39%,14.04%,13.55%),x~2 = 9.67,P = 0.008 < 0.05,and the difference was statistically significant.(2)From 2014 to 2016,the resistance rates of M.tuberculosis to four drugs were as follows: INH(9.72%),OFX(6.27%),RFP(6.04%),and KM(1.07%).Among them,the resistance rate of OFX statistically decreased(8.58%,5.08%,4.91%),x~2 = 6.52,P = 0.04 < 0.05.The resistant rate of RFP and INH was not statistically different in 3 years,but there was a downward trend.(3)The drug-resistant rate of M.tuberculosis isolated from initial treated patients was 14.00%(17.42%,13.39%,10.80%).The drug-resistant rate of M.tuberculosis isolated from retreated patients was was 28.50%(37.14%,19.15%,26.32%),which was significantly higher than that of initial treated patients,x~2 = 25.53,P = 0.000 < 0.05.(4)In the three years,the average MDR-TB rate was 3.67%(3.86%,3.87%,3.27%)and the XDR-TB rate was 0.31%(0.43%,0.24%,0.23%).The MDR-TB rate in the retreatment group(9.33%)was significantly higher than that in the initial treated group(2.69%),x~2 = 20.46,P = 0.000 < 0.01.3.The mutations of drug resistance genes of M.tuberculosis to RFP and INH.(1)Gene mutation sites for RFP resistance were mainly at rpoB531(46.75%)and rpoB526(19.48%),and the most common mutations were 531(TCG→TTG)and 526(CAC→TAC).(2)Gene mutation sites for INH resistance was predominantly kat G315(78.64%),and the most common mutation was 315(AGC→ACC).4.The comparative study of ratio drug sensitive test and drug-resistance gene chip in detecting M.tuberculosis.(1)There was no significant difference between the two methods in the detection of M.tuberculosis resistance to RFP and INH(x~2 = 0.749,P = 0.387 > 0.05;x~2 = 0.794,P = 0.373 > 0.05).(2)The sensitivity of RFP detected by the chip method was 80.30%,the specificity was 97.93%,and the coincidence was 96.94%.(3)The sensitivity of INH detected by the chip method was 63.81%,the specificity was 97.01%,and the coincidence was 94.56%.Conclusions:1.Male patients with tuberculosis are higher than females.The largest number of patients is between the ages of 21 and 30.2.The total drug resistance rate of M.tuberculosis showed a decreasing trend from 2014 to 2016,especially the resistance rate of OFX was statistically significant.The MDR-TB rate of M.tuberculosis isolated from retreatment patients was significantly higher than that of in initial treated patients.3.The RFP resistance mutation sites of M.tuberculosis were mainly rpoB531 and rpoB526,and the most common mutation types were 531(TCG→TTG)and 526(CAC→TAC);The INH resistance mutation site was mainly kat G315,and the most common mutation type was 315(AGC→ACC).4.There was no significant difference between ratio drug sensitive test and gene chip method in detecting M.tuberculosis resistance to RFP and INH.Gene chip could be a rapid and effective method for early screening of M.tuberculosis drug resistance. |
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