Mahalingam S, Cheong Y M, Kan S, Yassin R M, Vadivelu J, Pang T
Institute of Advanced Studies, University of Malaya.
J Clin Microbiol. 1994 Dec;32(12):2975-9. doi: 10.1128/jcm.32.12.2975-2979.1994.
Isolates of Vibrio cholerae O1 El Tor from two well-defined cholera outbreaks in Malaysia were analyzed by using pulsed-field gel electrophoresis (PFGE). Isolates from sporadic cases occurring during the same time period were also studied. Digestion of chromosomal DNA from these isolates of V. cholerae O1 with restriction endonucleases NotI (5'-GCGGCCGC-3') and SfiI (5'-GGCCNNNN-3'), followed by PFGE, produced restriction endonuclease analysis (REA) patterns consisting of 13 to 24 bands (ranging in size from 46 to 398 kbp). Analysis of the REA patterns generated by PFGE after digestion with NotI and SfiI suggested the clonal nature and close genetic identity of the isolates obtained during each of the two outbreaks (Dice coefficient, 0.93 to 1.0). Although they had very similar REA patterns, the two outbreak clones were not identical. Isolates of V. cholerae O1 from sporadic cases, on the other hand, appeared to be much more heterogeneous (five different REA patterns detected in the five isolates tested; Dice coefficient, 0.31 to 0.81) than those obtained during the two outbreaks. We conclude that PFGE of V. cholerae O1 chromosomal DNA digested with infrequently cutting restriction endonucleases is a useful method for molecular typing of V. cholerae isolates for epidemiological purposes.
运用脉冲场凝胶电泳（PFGE）技术，对从马来西亚两次明确界定的霍乱疫情中分离出的霍乱弧菌O1 El Tor菌株进行了分析。同时，也对同一时期散发病例中分离出的菌株进行了研究。用限制性内切酶NotI（5'-GCGGCCGC-3'）和SfiI（5'-GGCCNNNN-3'）消化这些霍乱弧菌O1菌株的染色体DNA，随后进行PFGE，产生了由13至24条带（大小范围为46至398 kbp）组成的限制性内切酶分析（REA）图谱。对用NotI和SfiI消化后经PFGE产生 的REA图谱分析表明，在两次疫情中各自获得的分离株具有克隆性质且遗传关系密切（戴斯系数为0.93至1.0）。尽管这两个疫情克隆的REA图谱非常相似，但并不完全相同。另一方面，散发病例中的霍乱弧菌O1分离株似乎比两次疫情中获得的分离株具有更高的异质性（在测试的5株分离株中检测到5种不同的REA图谱；戴斯系数为0.31至0.81）。我们得出结论，用切割频率较低的限制性内切酶消化霍乱弧菌O1染色体DNA后的PFGE技术，是用于霍乱弧菌分离株分子分型以进行流行病学研究的一种有用方法。
