Dehydration Tolerance in Epidemic versus Nonepidemic MRSA Demonstrated by Isothermal Microcalorimetry.
Dehydration Tolerance in Epidemic versus Nonepidemic MRSA Demonstrated by Isothermal Microcalorimetry.
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DOI：
10.1128/spectrum.00615-22
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发表时间：
2022-10-26
影响因子：
3.7
通讯作者：
van Wamel, Willem J. B.
中科院分区：
文献类型：
--
作者：
Baede, Valerie O.;Tavakol, Mehri;Vos, Margreet C.;Knight, Gwenan M.;van Wamel, Willem J. B.
耐甲氧西林金黄色葡萄球菌（MRSA）簇根据其有效传播的能力被认为是流行病或非流行病。成功传播可能受到脱水耐受性的影响。目前测定脱水耐受性的方法缺乏准确性。在这里，使用等温微量热法（IMC）开发了一种气候控制的体外脱水试验，并与数学模型相关联，以确定来自法国、英国和荷兰的44种流行MRSA菌株与54种非流行MRSA菌株在脱水1周后的存活率。通过3个实验重复、3个不同的起始接种、脱水前后的IMC数据，推导出每个MRSA菌株第一生长期结束时间（tmax [h]）和最大指数生长率（μm）。如果最大指数增长率在预定范围内（平均值的±36%），则可以利用tmax与起始接种量之间的线性关系来预测单个菌株脱水后的对数降低。根据这些准则，可以对1764条热流曲线（数据集）中的1330条（75%）进行分析，计算脱水后接种量，从而计算98个菌株中90个菌株（92%）的脱水对数减少量。1周后总体减少约1 log。流行菌株和非流行菌株在脱水耐受性方面没有差异。对数降低与起始接种量呈负相关，表明接种量越高存活率越高。本研究提出了一个量化细菌存活的框架。MRSA菌株显示出在环境中持续存在的巨大能力，无论流行病学的成功与否。这一发现加强了有效的表面清洁以遏制MRSA传播的必要性。耐甲氧西林金黄色葡萄球菌（MRSA）是全球感染的主要原因。虽然一些MRSA集群已经在世界范围内传播，但其他集群尽管经常被引入，却无法成功地传播到某些地区以外。脱水耐受性通过增强在表面和污染物上的存活，促进了在医院环境中的传播，这可能解释了MRSA集群之间传播成功率的差异。不幸的是，目前可用的技术来确定像金黄色葡萄球菌这样的簇状形成细菌的脱水耐受性是劳动密集型的，并且由于它们依赖于定量培养而不可靠。在这项研究中，用一种新开发的等温微量热法来评估细菌的存活。利用这种技术，可以确定干燥的效果，而不存在定量培养的缺点。结合新开发的数学算法，我们以系统、无偏和稳健的方式确定了大量MRSA菌株的脱水耐受性。
Methicillin-resistant Staphylococcus aureus (MRSA) clusters are considered epidemic or nonepidemic based on their ability to spread effectively. Successful transmission could be influenced by dehydration tolerance. Current methods for determination of dehydration tolerance lack accuracy. Here, a climate-controlled in vitro dehydration assay using isothermal microcalorimetry (IMC) was developed and linked with mathematical modeling to determine survival of 44 epidemic versus 54 nonepidemic MRSA strains from France, the United Kingdom, and the Netherlands after 1 week of dehydration. For each MRSA strain, the growth parameters time to end of first growth phase (tmax [h]) and maximal exponential growth rate (μm) were deduced from IMC data for 3 experimental replicates, 3 different starting inocula, and before and after dehydration. If the maximal exponential growth rate was within predefined margins (±36% of the mean), a linear relationship between tmax and starting inoculum could be utilized to predict log reduction after dehydration for individual strains. With these criteria, 1,330 of 1,764 heat flow curves (data sets) (75%) could be analyzed to calculate the post-dehydration inoculum size, and thus the log reduction due to dehydration, for 90 of 98 strains (92%). Overall reduction was ~1 log after 1 week. No difference in dehydration tolerance was found between the epidemic and nonepidemic strains. Log reduction was negatively correlated with starting inoculum, indicating better survival of higher inocula. This study presents a framework to quantify bacterial survival. MRSA strains showed great capacity to persist in the environment, irrespective of epidemiological success. This finding strengthens the need for effective surface cleaning to contain MRSA transmission. IMPORTANCE Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of infections globally. While some MRSA clusters have spread worldwide, others are not able to disseminate successfully beyond certain regions despite frequent introduction. Dehydration tolerance facilitates transmission in hospital environments through enhanced survival on surfaces and fomites, potentially explaining differences in transmission success between MRSA clusters. Unfortunately, the currently available techniques to determine dehydration tolerance of cluster-forming bacteria like S. aureus are labor-intensive and unreliable due to their dependence on quantitative culturing. In this study, bacterial survival was assessed in a newly developed assay using isothermal microcalorimetry. With this technique, the effect of drying can be determined without the disadvantages of quantitative culturing. In combination with a newly developed mathematical algorithm, we determined dehydration tolerance of a large number of MRSA strains in a systematic, unbiased, and robust manner.
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影响因子：
168.9
作者：
DeLeo, Frank R.;Otto, Michael;Kreiswirth, Barry N.;Chambers, Henry F.
通讯作者：
Chambers, Henry F.
影响因子：
4.8
作者：
Braissant, O.;Bachmann, A.;Bonkat, G.
通讯作者：
Bonkat, G.
影响因子：
4.7
作者：
Braissant, Olivier;Keiser, Jennifer;Meister, Isabel;Bachmann, Alexander;Wirz, Dieter;Goepfert, Beat;Bonkat, Gernot;Wadso, Ingemar
通讯作者：
Wadso, Ingemar
DOI：
10.1099/00221287-6-1-2-95
发表时间：
1952-01-01
期刊：
JOURNAL OF GENERAL MICROBIOLOGY
影响因子：
--
作者：
DUTHIE, ES;LORENZ, LL
通讯作者：
LORENZ, LL
影响因子：
5.2
作者：
Baldan, Rossella;Rancoita, Paola Maria Vittoria;Cirillo, Daniela Maria
通讯作者：
Cirillo, Daniela Maria