Effect of low temperature on growth and ultra-structure of Staphylococcus spp.
Effect of low temperature on growth and ultra-structure of Staphylococcus spp.
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DOI：
10.1371/journal.pone.0029031
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Roberts TK
中科院分区：
文献类型：
--
作者：
Onyango LA;Dunstan RH;Gottfries J;von Eiff C;Roberts TK
温度波动的影响是细菌生长的一个重要因素，特别是对于病原体，如葡萄球菌，它们必须在宿主之间潜在的苛刻和长期的转移条件下保持活力。本研究的目的是探讨S.金黄色葡萄球菌、epidermidis和S. lugdunensis在长时间暴露于低温（4°C）下时的生长特性，以及该因素如何影响其随后的生长、菌落形态、细胞超微结构和非细胞质水解产物部分中的氨基酸组成。临床分离株在最佳条件下生长，然后在4°C条件下培养8周。在透射电子显微镜（TEM）下评估冷应激和参考对照样品，以确定潜在的超微结构变化。为了确定氨基酸组成的变化，将细胞破碎以除去脂质和细胞质组分，并水解剩余的结构组分。然后通过使用主成分分析（PCA）分析水解级分的氨基酸谱的变化。暴露的三个葡萄球菌长时间的低温应力导致形成的小菌落变异（SCV）表型的比例增加。透射电镜显示，SCV细胞的细胞壁比相应的WT样品明显更厚，更弥散。金黄色葡萄球菌和epidermidis，而S. lugdunensis。在冷处理的细胞中也观察到结构水解产物部分的氨基酸组成的实质性物种特异性改变。这些数据表明，葡萄球菌在长时间的冷应激处理中通过转化为SCV群体而做出反应。所观察到的超微结构和氨基酸的变化，提出了代表的反应机制，葡萄球菌生存在恶劣的条件下，从而保持物种的生存能力，直到有利的条件再次出现。
The effect of temperature fluctuation is an important factor in bacterial growth especially for pathogens such as the staphylococci that have to remain viable during potentially harsh and prolonged transfer conditions between hosts. The aim of this study was to investigate the response of S. aureus, S. epidermidis, and S. lugdunensis when exposed to low temperature (4°C) for prolonged periods, and how this factor affected their subsequent growth, colony morphology, cellular ultra-structure, and amino acid composition in the non-cytoplasmic hydrolysate fraction. Clinical isolates were grown under optimal conditions and then subjected to 4°C conditions for a period of 8 wks. Cold-stressed and reference control samples were assessed under transmission electron microscopy (TEM) to identify potential ultra-structural changes. To determine changes in amino acid composition, cells were fractured to remove the lipid and cytoplasmic components and the remaining structural components were hydrolysed. Amino acid profiles for the hydrolysis fraction were then analysed for changes by using principal component analysis (PCA). Exposure of the three staphylococci to prolonged low temperature stress resulted in the formation of increasing proportions of small colony variant (SCV) phenotypes. TEM revealed that SCV cells had significantly thicker and more diffuse cell-walls than their corresponding WT samples for both S. aureus and S. epidermidis, but the changes were not significant for S. lugdunensis. Substantial species-specific alterations in the amino acid composition of the structural hydrolysate fraction were also observed in the cold-treated cells. The data indicated that the staphylococci responded over prolonged periods of cold-stress treatment by transforming into SCV populations. The observed ultra-structural and amino acid changes were proposed to represent response mechanisms for staphylococcal survival amidst hostile conditions, thus maintaining the viability of the species until favourable conditions arise again.
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影响因子：
--
作者：
Noskin, GA;Rubin, RJ;Gemmen, E
通讯作者：
Gemmen, E
影响因子：
9.4
作者：
Kipp, F;Becker, K;von Eiff, C
通讯作者：
von Eiff, C
影响因子：
5.2
作者：
Hanaki, H;Labischinski, H;Hiramatsu, K
通讯作者：
Hiramatsu, K
DOI：
10.1016/s0924-8579(99)00170-3
发表时间：
2000-01-01
影响因子：
10.8
作者：
McNamara, PJ;Proctor, RA
通讯作者：
Proctor, RA
影响因子：
6.4
作者：
BADDOUR, LM;SIMPSON, WA;CHRISTENSEN, GD
通讯作者：
CHRISTENSEN, GD