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把总共266株结核分支杆菌分离株做DNA RFLP分析。分离株是从短程化疗并随访2年的病人的每月痰培养中获得的,分别来自42名短程化疗后复发的病人和42名化疗后仅一次培养阳性的病人,包括治疗前分离的1株和治疗期间最后一次分离的1株分离株,以及复发期间相距至少2个月培养的2株式化疗后分离的1株分离株。在DNA RFLP分析前先编码,然后用肉眼观察相同的或几乎相同的带型进行分组。译码后,每位病人显然是被1个具有不同带型(即指纹图谱)的菌株感染的。100对治疗前分离株与化疗期间最后一次的培养菌株或复发期间第一次分离株与第二次分离株的配对比较中,15对带型不同;其中4对复查后发现是由于阅读错误所致(错误率1.5％),其余11对(11％)带型明显不同。42对复发病人中,5对(12％)复发分离株的指纹图谱与治疗前分离株有显著差别。相反,40对化疗后的孤立的阳性培养菌株与最初的分离株的配对比较中,36对(90％)的指纹图谱有显著差别。无法确定这其余的10—12％的指纹差别多少是由于临床混合感染,多少是实验室交叉污染所致。84名病人的连续分离株中,7名(8％)显示一步1或2条带的增多或减少,提示指纹图型的演变。RELP指纹方法作为鉴别菌株的手段显然优于噬菌体分型。
A total of 266 strains of Mycobacterium tuberculosis isolates were subjected to DNA RFLP analysis. The isolates were obtained from monthly sputum cultures of patients who had undergone short-term chemotherapy and were followed up for 2 years, respectively, from 42 patients who relapsed after short-course chemotherapy and 42 patients who had positive culture after chemotherapy alone, including 1 before treatment And one isolate that was last isolated during treatment, and two isolates that had been isolated after chemotherapy for at least two months during relapse. The DNA RFLP analysis was preceded by coding and then the same or nearly identical bands were grouped with the naked eye. After decoding, each patient is apparently infected with a strain with a different banding (ie fingerprinting). 100 pairs of pre-treatment isolates and chemotherapy during the last culture strains or recurrence during the first isolate and second isolates paired comparison, 15 pairs with different types; of which 4 pairs of review found to be due to reading error To (error rate of 1.5%), the remaining 11 pairs (11%) significantly different banding. Of the 42 relapsed patients, fingerprints of five (12%) recurrent isolates differed significantly from pre-treatment isolates. In contrast, in the pairwise comparisons of 40 pairs of isolated positive culture strains after chemotherapy with the original isolate, there were significant differences in fingerprints of 36 pairs (90%). It is impossible to determine how much of the remaining 10-12% of the fingerprints are due to clinical mixed infection and how much is due to laboratory cross-contamination. Of 84 consecutive isolates of patients, 7 (8%) showed an increase or decrease in one or two bands, suggesting the evolution of the fingerprinting pattern. RELP fingerprinting as a means of identifying strains is clearly superior to phage typing.