Nationwide survey shows that methicillin-resistant Staphylococcus aureus strains heterogeneously and intermediately resistant to vancomycin are not disseminated throughout Japanese hospitals
Nationwide survey shows that methicillin-resistant Staphylococcus aureus strains heterogeneously and intermediately resistant to vancomycin are not disseminated throughout Japanese hospitals
复制标题
DOI：
10.1128/jcm.39.12.4445-4451.2001
复制
发表时间：
2001-12-01
影响因子：
9.4
通讯作者：
Fujimoto, S
中科院分区：
文献类型：
--
作者：
Ike, Y;Arakawa, Y;Fujimoto, S
1997年11月至12月期间，从日本278家医院获得了总计6，625株耐甲氧西林金黄色葡萄球菌（MRSA）临床分离株，并使用Mueller欣顿（MH）、脑心浸液（BHI）、琼脂平板或肉汤微量稀释法检查了其对万古霉素的敏感性。MRSA菌株的浓缩接种物或使用高度富集的培养基，如BHI培养基，允许单个细胞在含有大于亲本菌株MIC的万古霉素浓度的琼脂平板上生长。然而，在含有较高万古霉素浓度的BHI琼脂平板上生长的菌落细胞并未获得高于亲本菌株的万古霉素耐药性水平，并且不是异质性万古霉素耐药性MRSA的亚群。这些菌落在较高浓度的万古霉素上生长的事实没有意义：在高于亲本菌株MIC的浓度下，没有一个菌落显示出对万古霉素的稳定耐药性，并且来自这些菌落的细胞没有显示出MIC与这些菌落在较高浓度的万古霉素上生长的能力之间的关系。对于来自这些集落的任何细胞，万古霉素MIC均不高于2 μ g/ml。未检测到Mu 3型异质耐药MRSA菌株，其组成性产生来自MRSA临床分离株的亚群，具有较高频率的中等万古霉素耐药性。在6，625株MRSA临床分离株中，MIC呈单极分布，范围为0.25 - 2 μ g万古霉素/ml，表明在临床分离株中不存在Mu 50型万古霉素中度耐药MRSA（MIC，8 μ g/ml，根据国家临床实验室标准委员会标准），也没有证据表明对万古霉素具有异质耐药的Mu 3型MRSA传播。
A total of 6,625 methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates obtained from 278 hospitals throughout Japan were obtained between November and December 1997 and were examined for their sensitivities to vancomycin using Mueller Hinton (MH), brain heart infusion (BHI), agar plates, or the broth microdilution method. A concentrated inoculum of an MRSA strain or the use of highly enriched medium, such as BHI medium, allows an individual cell to grow on agar plates containing a vancomycin concentration greater than the MIC for the parent strain. However, cells of the colonies which grew on BHI agar plates containing the higher vancomycin concentrations did not acquire a level of vancomycin resistance greater than that of the parent strain and were not subpopulations of heterogeneously vancomycin-resistant MRSA. There was no significance in the fact that these colonies grew on the higher concentration of vancomycin: none showed stable resistance to vancomycin at a concentration above the MIC for the parent strain, and no cell from these colonies showed a relationship between the MIC and the ability of these colonies to grow on higher concentrations of vancomycin. The vancomycin MIC was not above 2 mug/ml for any of the cells originating from these colonies. No Mu3-type heterogeneously resistant MRSA strains, which constitutively produce subpopulations from MRSA clinical isolates with intermediate vancomycin resistance at a high frequency, were detected. There was a unipolar distribution of the MICs ranging from 0.25 to 2 mug of vancomycin/ml among the 6,625 MRSA clinical isolates, indicating that there was no Mu50-type intermediately vancomycin-resistant MRSA (MIC, 8 mug/ml by National Committee for Clinical Laboratory Standards criteria) among the clinical isolates, and there was no evidence of dissemination of Mu3-type MRSA heteroresistant to vancomycin.