Wright C J, Jerse A E, Cohen M S, Cannon J G, Seifert H S
Department of Microbiology-Immunology, Northwestern University Medical School, Chicago, Illinois 60611.
J Clin Microbiol. 1994 Feb;32(2):464-8. doi: 10.1128/jcm.32.2.464-468.1994.
PCR amplification and DNA sequencing of the expression locus from Neisseria gonorrhoeae contained in urine sediments collected from experimentally infected human subjects produced two observations. First, different pilin sequences were obtained when separate aliquots of the same sample were amplified and sequenced. In contrast, the same pilin sequence was obtained when repeated amplifications were performed on individual colonies grown from the clinical samples. Second, mixed sequences (i.e., more than one nucleotide at variable positions in the pilin gene sequence) were observed in both the direct clinical isolates and individual cultures grown from the isolates. These results suggest that when clinical samples are directly examined by PCR amplification and sequencing, multiple amplifications may be required to detect sequence variants in the sample and minority variant sequences will not always be detected.
对从实验感染人类受试者收集的尿液沉积物中所含淋病奈瑟菌的表达位点进行聚合酶链反应（PCR）扩增和DNA测序，得出了两个观察结果。首先，当对同一样品的不同等分试样进行扩增和测序时，获得了不同的菌毛蛋白序列。相比之下，对从临床样品中生长的单个菌落进行重复扩增时，获得了相同的菌毛蛋白序列。其次，在直接临床分离株和从分离株生长的单个培养物中均观察到混合序列（即菌毛蛋白基因序列中可变位置有一个以上核苷酸）。这些结果表明，当通过PCR扩增和测序直接检查临床样品时，可能需要进行多次扩增以检测样品中的序列变异，并且少数变异序列并非总能被检测到。
