Hansen Bjarne Munk, Høiby Poul Erik, Jensen Gert Bolander, Hendriksen Niels Bohse
Department of Environmental Chemistry and Microbiology, National Environmental Research Institute, Frederiksborgvej 399, DK-4000, Roskilde, Denmark.
FEMS Microbiol Lett. 2003 Jun 6;223(1):21-4. doi: 10.1016/S0378-1097(03)00249-0.
Bacillus cereus is a known opportunistic human pathogen belonging to the B. cereus group. Establishment of the pathogenesis most likely involves several gene products. One of these gene products, a single gene component named bceT, has been cloned and described from B. cereus B-4ac [Agata et al., Microbiology 141 (1995) 983-988]. However, our sequences of the bceT region from 16 B. cereus group strains showed inconsistency with the published bceT sequence. Only part of the bceT sequence had homology to our sequences. This initiated a more thorough investigation of the bceT sequence. Restriction site search and database searches intimated that the cloned bceT was created by an incidental joining of four DNA fragments during ligation. One of these fragments had 93% homology to an open reading frame (ORF 101) located within the pathogenic island of the Bacillus anthracis pXO1 virulence plasmid. We suggest that the reported enterotoxic activity of the original cloned bceT construct could be due to either the fusion gene or the fragment with homology to ORF 101 in pXO1.
蜡样芽孢杆菌是一种已知的属于蜡样芽孢杆菌群的机会性人类病原体。发病机制的建立很可能涉及多种基因产物。其中一种基因产物，即一个名为bceT的单基因成分，已从蜡样芽孢杆菌B - 4ac中克隆并描述[阿加塔等人，《微生物学》141(1995)983 - 988]。然而，我们对16株蜡样芽孢杆菌群菌株的bceT区域序列分析显示，其与已发表的bceT序列不一致。只有部分bceT序列与我们的序列具有同源性。这引发了对bceT序列更深入的研究。限制性酶切位点搜索和数据库搜索表明，克隆得到的bceT是在连接过程中由四个DNA片段偶然拼接而成。其中一个片段与炭疽芽孢杆菌pXO1毒力质粒致病岛内的一个开放阅读框(ORF 101)具有93%的同源性。我们认为，最初克隆的bceT构建体所报道的肠毒素活性可能是由于融合基因或与pXO1中ORF 101具有同源性的片段所致。
