The carboxyl terminus of peptidoglycan stem peptides is a determinant for methicillin resistance in Staphylococcus aureus
The carboxyl terminus of peptidoglycan stem peptides is a determinant for methicillin resistance in Staphylococcus aureus
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DOI：
10.1128/aac.46.10.3151-3155.2002
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发表时间：
2002-10-01
影响因子：
4.9
通讯作者：
Xu, NX
中科院分区：
文献类型：
--
作者：
de Jonge, BLM;Gage, D;Xu, NX
在高浓度D-丝氨酸、D-苏氨酸和D-苯丙氨酸的存在下，培养出一株含有mecA的金黄色葡萄球菌。这些生长条件导致多肽末端(第五个)D-丙氨酸残基被生长介质中的D-氨基酸取代，在甲氧西林存在下生长能力降低。D-丝氨酸的效果最显著。在含有32 mM D-丝氨酸的情况下，在甲氧西林浓度为800µg/ml时仍能生长的菌株只能在低于50µg/ml的浓度下生长。这些结果还表明，在金黄色葡萄球菌中，通过掺入未终止于D-丙氨酰-D-丙氨酸的前体介导的万古霉素耐药性与mecA介导的甲氧西林耐药性的表达是互斥的。
A mecA-containing Staphylococcus aureus strain was grown in the presence of high concentrations of D-serine, D-threonine, and D-phenylalanine. These growth conditions resulted in the replacement of the carboxyl-terminal (fifth) D-alanine residue of peptidoglycan stem peptides with the D-amino acid present in the growth medium and a reduced ability to grow in the presence of methicillin. The most dramatic effect was seen with D-serine. With 32 MM D-serine, strains that had been able to grow in the presence of 800 mug of methicillin per ml were only able to grow in the presence of less than 50 mug/ml. The results also suggest that in S. aureus vancomycin resistance mediated through the incorporation of precursors not terminating in D-alanyl-D-alanine would be mutually exclusive with expression of mecA-mediated methicillin resistance.