Bezanson G, Khakhria R, Lacroix R
Can J Microbiol. 1982 Sep;28(9):993-1001. doi: 10.1139/m82-149.
Strains resistant to the action of sulfa drugs and tetracycline were predominant among the antibiotic-resistant Salmonella typhimurium phagovar 204 isolated in Canada. Plasmid DNA was detected in cellular extracts of all strains examined. A number of these plasmids could be placed in specific incompatibility and size classes. Both resistance coding and cryptic plasmids were involved in determining phagovar 204. In one instance, phagovar 204 was derived from phagovar 36 in a two-step conjugation involving independent sulfadiazine and tetracycline resistance plasmids. In another, phagovar 204 was derived directly from phagovar 49 through the introduction of a single tetracycline-streptomycin R plasmid. The phagovar-determining plasmids ranged in size from 3.4 to 72 megadaltons.
在加拿大分离出的抗药性鼠伤寒沙门氏菌204噬菌型中，对磺胺类药物和四环素作用具有抗性的菌株占主导地位。在所检测的所有菌株的细胞提取物中均检测到了质粒DNA。其中许多质粒可归为特定的不相容性和大小类别。抗性编码质粒和隐蔽质粒都参与了噬菌型204的确定。在一个实例中，噬菌型204是在涉及独立的磺胺嘧啶和四环素抗性质粒的两步接合过程中从噬菌型36衍生而来。在另一个实例中，噬菌型204是通过引入单个四环素-链霉素R质粒直接从噬菌型49衍生而来。决定噬菌型的质粒大小范围为3.4至72兆道尔顿。
