Van der Auwera Géraldine A, Timmery Sophie, Mahillon Jacques
Laboratory of Food and Environmental Microbiology, Université Catholique de Louvain, Croix du Sud, 2/12, B-1348 Louvain-la-Neuve, Belgium.
Plasmid. 2008 Mar;59(2):134-8. doi: 10.1016/j.plasmid.2007.11.007. Epub 2008 Feb 12.
Recent characterisations of plasmids related to the anthrax virulence plasmids pXO1 and pXO2 in clinical isolates of Bacillus cereus and Bacillus thuringiensis have contributed to the emerging picture of a virulence-associated plasmid pool in the B. cereus sensu lato group. The family of pXO2-like plasmids includes the conjugative plasmid pAW63 from the biopesticide strain B. thuringiensis subsp. kurstaki HD73 and the heretofore cryptic plasmid pBT9727 from the clinical strain B. thuringiensis subsp. konkukian 97-27. Comparative sequence analysis of these three plasmids suggested that they were derived from an ancestral conjugative plasmid, with pAW63 retaining its self-transfer capabilities, and pXO2 having lost them through genetic drift. Such properties had not been investigated in pBT9727, but sequence homologies led us to predict that it may possess self-transfer capabilities. Here, we report that pBT9727 is indeed conjugative, and is able to promote its own transfer as well as that of small mobilisable plasmids.
近期对蜡状芽孢杆菌和苏云金芽孢杆菌临床分离株中与炭疽病毒力质粒pXO1和pXO2相关的质粒的表征，有助于揭示蜡状芽孢杆菌广义组中与毒力相关的质粒库的新情况。pXO2样质粒家族包括来自生物杀虫剂菌株苏云金芽孢杆菌亚种kurstaki HD73的接合质粒pAW63，以及来自临床菌株苏云金芽孢杆菌亚种konkukian 97-27的此前未知功能的质粒pBT9727。对这三种质粒的比较序列分析表明，它们源自一个祖先接合质粒，pAW63保留了自身转移能力，而pXO2则通过遗传漂变失去了这种能力。pBT9727尚未对此类特性进行研究，但序列同源性使我们预测它可能具有自我转移能力。在此，我们报告pBT9727确实具有接合性，并且能够促进自身以及小型可移动质粒的转移。
