TRANSDUCTION OF METHICILLIN RESISTANCE IN STAPHYLOCOCCUS-AUREUS DEPENDENT ON AN UNUSUAL SPECIFICITY OF RECIPIENT STRAIN
TRANSDUCTION OF METHICILLIN RESISTANCE IN STAPHYLOCOCCUS-AUREUS DEPENDENT ON AN UNUSUAL SPECIFICITY OF RECIPIENT STRAIN
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DOI：
10.1128/jb.104.3.1158-1167.1970
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发表时间：
1970-01-01
影响因子：
3.2
通讯作者：
SWEENEY, HM
中科院分区：
文献类型：
--
作者：
COHEN, S;SWEENEY, HM
对甲氧西林的耐药性通过噬菌体80或53从两种天然存在的金黄色葡萄球菌甲氧西林耐药菌株转导到甲氧西林敏感的受体菌株，频率为10− 7至10−9。转导噬菌体的紫外线照射和转导后在30 ℃下孵育对于有用的转导频率是必不可少的。作为该转导的受体的有效性是高度特异性的。菌株NCTC 8325（PS47）在其天然状态下是无效的受体，但在通过转导接受几种青霉素酶质粒之一后变得有效。在大多数情况下，通过溴化乙锭治疗消除质粒后，这种获得的有效性仍保留。与供体菌株一样，后代对甲氧西林的抗性程度是异质的，当孵育温度从37 ℃降低到30 ℃时，表现为较高比例的细胞。单独的转导子在通过转导获得的抗性程度上变化很大。甲氧西林耐药性在供体和转导菌株中是稳定的。我们倾向于这样的解释，即我们菌株的甲氧西林耐药性是由单个染色体基因决定的，尽管不能排除它是由两个或更多紧密连锁的基因决定的可能性。
Resistance to methicillin was transduced by phage 80 or 53 from two naturally occurring methicillin-resistant strains ofStaphylococcus aureusto methicillin-susceptible recipient strains at frequencies of 10−7to 10−9. Ultraviolet irradiation of transducing phage and posttransductional incubation at 30 C were essential for useful frequencies of transduction. Effectiveness as a recipient for this transduction was highly specific. Strain NCTC 8325 (PS47) in its native state was an ineffective recipient but became effective after it had received by transduction one of several penicillinase plasmids. This acquired effectiveness was retained in most cases after elimination of the plasmid by ethidium bromide treatment. Like the donor strain, the progeny were heterogeneous in the degree of their resistance to methicillin, which was expressed by a higher proportion of cells as the temperature of incubation was lowered from 37 to 30 C. Separate transductants varied widely in the degree of resistance acquired by transduction. Methicillin resistance was stable in the donor and transductant strains. We favored the interpretation that methicillin resistance in our strains was determined by a single chromosomal gene, although the possibility that it was determined by two or more closely linked genes could not be excluded.