Grant R B, Bannatyne R M, Shapiey A J
J Infect Dis. 1976 Oct;134(4):354-61. doi: 10.1093/infdis/134.4.354.
Combined resistance to chloramphenicol and ampicillin in Salmonella typhimurium is appearing in Canada. Five cases of this type of infection have been noted. The isolates are resistant to streptomycin, sulfonamides, and tetracycline, in addition to ampicillin and and chloramphenicol; four isolates are also resistant to kanamycin. In each isolate the determinant for chloramphenicol resistance is linked to a conjugative plasmid. Four of the chloramphenicol plasmids appear to be related in resistance pattern, level of antibiotic resistance mediated, and temperature sensitivity of mating ability. The same four plasmids are associated in the primary isolates of Salmonella with three different kinds of genetic units mediating resistance to ampicillin. In only one of the five strains are the genes for chloramphenicol and ampicillin resistance linked in the same plasmid.
在加拿大，鼠伤寒沙门氏菌对氯霉素和氨苄青霉素的联合耐药性正在出现。已发现5例这种类型的感染。这些分离株除对氨苄青霉素和氯霉素耐药外，还对链霉素、磺胺类药物和四环素耐药；4个分离株也对卡那霉素耐药。在每个分离株中，氯霉素耐药决定簇与一个接合质粒相连。4种氯霉素质粒在耐药模式、介导的抗生素耐药水平以及交配能力的温度敏感性方面似乎有关联。相同的4种质粒在沙门氏菌的原始分离株中与3种不同的介导氨苄青霉素耐药的遗传单位相关联。在这5个菌株中，只有1个菌株的氯霉素和氨苄青霉素耐药基因位于同一质粒中。
