Bandoh K, Watanabe K, Muto Y, Tanaka Y, Kato N, Ueno K
Institute of Anaerobic Bacteriology, Gifu University School of Medicine, Japan.
J Antibiot (Tokyo). 1992 Apr;45(4):542-7. doi: 10.7164/antibiotics.45.542.
Transfer of imipenem resistance in Bacteroides fragilis was studied. Clinical isolate B. fragilis 10-73 was highly resistant to imipenem. Imipenem resistance was transferred from 10-73 to B. fragilis strain TM4000 at a frequency of 10(-6)/input recipient by a filter mating technique. The resistance could also be retransferred. B. fragilis 10-73 and both primary and secondary transcipients produced an imipenem-hydrolyzing metallo-beta-lactamase. Acquisition of imipenem resistance correlated with the appearance of plasmid DNA with a size (ca. 13.6 kb) similar to that of the donor strain. TM4000 transformed by electroporation with purified DNA of the 13.6-kb plasmid pBFUK1 produced the metallo-beta-lactamase and was resistant to imipenem. Transfer was resistant to DNase treatment and no transfer was seen with a sterile filtrate of the donor culture. It is suggested that gene transfer in B. fragilis has the properties of a conjugation system rather than those of transformation or transduction.
对脆弱拟杆菌中亚胺培南耐药性的转移进行了研究。临床分离株脆弱拟杆菌10 - 73对亚胺培南高度耐药。通过滤膜交配技术，亚胺培南耐药性以10(-6)/输入受体的频率从10 - 73转移至脆弱拟杆菌菌株TM4000。该耐药性也可再次转移。脆弱拟杆菌10 - 73以及初次和二次转导受体均产生一种亚胺培南水解金属β-内酰胺酶。亚胺培南耐药性的获得与大小（约13.6 kb）与供体菌株相似的质粒DNA的出现相关。用13.6 kb质粒pBFUK1的纯化DNA通过电穿孔转化的TM4000产生金属β-内酰胺酶并对亚胺培南耐药。转移对DNA酶处理有抗性，并且用供体培养物的无菌滤液未观察到转移。提示脆弱拟杆菌中的基因转移具有接合系统的特性，而非转化或转导的特性。
