O'Brien F G, Botterill C I, Endersby T G, Lim R L, Grubb W B, Gustafson J E
Microbiology Group, School of Biomedical Sciences, Curtin University of Technology, Perth, Australia.
Pathology. 1998 Aug;30(3):299-303. doi: 10.1080/00313029800169486.
Fusidic acid resistance expression in a methicillin susceptible Staphylococcus aureus strain (WBG1576), which carries fusidic acid resistance on plasmid pUB101, and a prevalent Western Australian methicillin-fusidic acid resistant strain (WBG8287) were compared. WBG8287 carries fusidic acid resistance on the chromosome and its plasmid content has no effect on the levels of this resistance. WBG1576 and WBG8287 exhibited similar heterogeneous populations in respect to fusidic acid resistance levels in population analyses. A high-level fusidic acid resistant mutant of WBG1576 (BE8) had alterations in Smal chromosomal profiles, but not in plasmid size or resistance expression. Mutations causing increased fusidic acid resistance in WBG1576 are chromosomally located. A high-level fusidic acid resistant mutant of WBG8287 (BE3) had no alterations in Smal chromosomal profiles, or plasmid content and resistances. Comparison of resistance levels to kanamycin and spectinomycin, between high-level resistant colonies of WBG8287 and WBG8287, indicate that mutations in the chromosomal gene fusA, which encodes elongation factor-G, are probably the cause of the increased resistance levels observed in these mutant strains.
对一株携带pUB101质粒上的夫西地酸抗性的甲氧西林敏感金黄色葡萄球菌菌株（WBG1576）和一株西澳大利亚流行的甲氧西林 - 夫西地酸抗性菌株（WBG8287）的夫西地酸抗性表达进行了比较。WBG8287在染色体上携带夫西地酸抗性，其质粒含量对这种抗性水平没有影响。在群体分析中，WBG1576和WBG8287在夫西地酸抗性水平方面表现出相似的异质群体。WBG1576的一个高水平夫西地酸抗性突变体（BE8）在Smal染色体图谱上有改变，但质粒大小或抗性表达没有改变。导致WBG1576中夫西地酸抗性增加的突变位于染色体上。WBG8287的一个高水平夫西地酸抗性突变体（BE3）在Smal染色体图谱、质粒含量和抗性方面没有改变。WBG8287的高水平抗性菌落之间对卡那霉素和壮观霉素的抗性水平比较表明，编码延伸因子 - G的染色体基因fusA中的突变可能是这些突变菌株中观察到的抗性水平增加的原因。
