Dupuy B, Daube G, Popoff M R, Cole S T
Unité de Génétique Moléculaire Bactérienne, Institut Pasteur, Paris, France.
Infect Immun. 1997 Jun;65(6):2313-20. doi: 10.1128/iai.65.6.2313-2320.1997.
Although many bacteria are ureolytic, and in some cases urease acts as a virulence factor, the urease phenotype has not been analyzed in the anaerobic pathogen Clostridium perfringens. In this study, approximately 2% of C. perfringens strains, representing the principal biotypes, were found to harbor the urease structural genes, ureABC, and these were localized on large plasmids that often encode, in addition, the lethal epsilon or iota toxins or the enterotoxin. This represents the first report of a plasmid-encoded urease in a gram-positive bacterium. The C. perfringens enzyme was highly similar to the ureases of other bacteria and cross-reacted with antibodies raised against the urease purified from Helicobacter pylori. Urease production was inhibited by urea and induced under growth conditions where the availability of nitrogen sources was limiting. To date, this form of regulation has been observed only for chromosomal ureABC genes.
尽管许多细菌都具有尿素分解能力，在某些情况下脲酶还作为一种毒力因子，但尚未对厌氧病原体产气荚膜梭菌的脲酶表型进行分析。在本研究中，发现代表主要生物型的约2%的产气荚膜梭菌菌株含有脲酶结构基因ureABC，这些基因位于大型质粒上，这些质粒通常还编码致死性的ε毒素或ι毒素或肠毒素。这是革兰氏阳性菌中质粒编码脲酶的首次报道。产气荚膜梭菌的酶与其他细菌的脲酶高度相似，并与针对从幽门螺杆菌纯化的脲酶产生的抗体发生交叉反应。脲酶的产生受到尿素的抑制，并在氮源可用性受限的生长条件下被诱导。迄今为止，这种调控形式仅在染色体ureABC基因中观察到。
