Sekizuka Tsuyoshi, Gondo Takayoshi, Murayama Ohoshi, Kato Yukio, Moore John E, Millar B Cherie, Matsuda Motoo
Laboratory of Molecular Biology, School of Environmental Health Sciences, Azabu University, Fuchinobe 1-17-71, Sagamihara 229-8501, Japan.
Res Microbiol. 2004 Apr;155(3):185-91. doi: 10.1016/j.resmic.2003.12.003.
A primer pair which was expected to generate an amplicon of the estimated size (approximately 1700 base pair (bp)) of the flaA gene for Campylobacter jejuni amplified products of approximately 1450 bp for 33 of the 44 isolates of urease-positive thermophilic Campylobacter (UPTC). The primer pair, however, failed to amplify fragments for 11 isolates of UPTC, for all of the 12 isolates of urease-negative C. lari and for one isolate of C. coli. Nevertheless, it successfully amplified fragments of approximately 1700 bp for five isolates of C. jejuni and for nine isolates of C. coli. Thus, the fragments of the flaA gene of UPTC were shorter than those of C. jejuni and C. coli. After PCR amplification and nucleotide sequencing of the flaA genes from five UPTC NCTC isolates, the putative open reading frames (ORFs) were found to range from 1461 to 1479 bp. The amino acid and nucleotide sequence alignments demonstrated that the PCR clones contained the flaA gene; however, our data indicated that this locus was markedly shorter in the UPTC organisms examined, as they were approximately 85 amino acid residues shorter, mainly corresponding to approximate residue numbers 390-470 of the large variable region of C. jejuni 81116. Heterogeneity was indicated in the molecular mass of the flagellin purified from the isolates examined. Flagellin of UPTC was demonstrated to be genotypically and phenotypically smaller than those of C. jejuni.
一对引物预期能扩增出空肠弯曲菌flaA基因估计大小（约1700碱基对（bp））的扩增子，对于44株脲酶阳性嗜热弯曲菌（UPTC）中的33株，该引物对扩增出了约1450 bp的产物。然而，该引物对未能扩增出11株UPTC、所有12株脲酶阴性的拉氏弯曲菌以及1株大肠弯曲菌的片段。尽管如此，它成功扩增出了5株空肠弯曲菌和9株大肠弯曲菌约1700 bp的片段。因此，UPTC的flaA基因片段比空肠弯曲菌和大肠弯曲菌的短。对5株UPTC NCTC分离株的flaA基因进行PCR扩增和核苷酸测序后，发现推定的开放阅读框（ORF）范围为1461至1479 bp。氨基酸和核苷酸序列比对表明，PCR克隆包含flaA基因；然而，我们的数据表明，在所检测的UPTC菌株中，该基因座明显较短，因为它们大约短85个氨基酸残基，主要对应于空肠弯曲菌81116大可变区的大约390 - 470位残基。从所检测的分离株中纯化的鞭毛蛋白分子量存在异质性。已证明UPTC的鞭毛蛋白在基因型和表型上比空肠弯曲菌的小。
