5-FLUOROURACIL-RESISTANT BACTERIA AND METHOD FOR PRODUCTION THEREOF

摘要

Disclosed is a method for producing a cytosine deaminase(CD)-expressing, 5-fluorouracil(5-FU)-resistant bacterium which can grow in tumor tissues placed under anaerobic conditions, is capable of expressing CD, and has a resistance against 5-FU present in the concentration effective to exhibit antitumor activity or higher. More specifically, the method is a method (A) comprising performing subculture or acclimation culture of a CD-expressing bacterium which can grow in tumor tissues placed under anaerobic conditions, in the presence of 5-fluorocytosine (5-FC), or a method (B) comprising (1) performing subculture or acclimation culture of a bacterium which can grow in tumor tissues placed under anaerobic conditions but cannot express CD, in the presence of 5-FC to thereby produce a 5-FU-resistant bacterium and (2) introducing a CD gene into the 5-FU-resistant bacterium to transform the bacterium. Also disclosed are the CD-expressing, 5-FU-resistant bacterium and a pharmaceutical composition comprising the bacterium.