Laboratório de Imunologia, Departamento de Imunofisiologia e Farmacologia, Instituto de Ciências Biomédicas de Abel Salazar - Universidade do Porto, Portugal.
Can J Microbiol. 2011 Oct;57(10):850-6. doi: 10.1139/w11-078. Epub 2011 Sep 27.
Staphylococcus epidermidis biofilms with different proportions of viable but nonculturable bacteria were used to show that SYBR green (SYBR) may be used as a probe to evaluate the bacterial physiological state using flow cytometry. Biofilms grown in excess glucose presented significantly higher proportions of dormant bacteria than biofilms grown in excess glucose with buffered pH conditions or with exponential-phase planktonic cultures. Bacteria obtained from biofilms with high or low proportions of viable but nonculturable cells were further cultured in broth medium and stained with SYBR at different time points. An association between bacterial growth and SYBR staining intensity was observed. In addition, bacteria presenting higher SYBR fluorescence intensity also stained more intensely with cyanoditolyl tetrazolium chloride, used as a probe to evaluate cellular metabolism. Accordingly, planktonic bacteria treated with rifampicin, an inhibitor of bacterial RNA transcription, presented lower SYBR and cyanoditolyl tetrazolium chloride staining intensity than nontreated bacteria. Overall, our results indicate that SYBR, in addition to being used as a component of LIVE/DEAD stain, may also be used as a probe to evaluate the physiological state of S. epidermidis cells.
使用不同比例活而不可培养细菌的表皮葡萄球菌生物膜来表明，SYBR 绿（SYBR）可被用作通过流式细胞术评估细菌生理状态的探针。在过量葡萄糖中生长的生物膜比在缓冲 pH 值条件下或处于指数期浮游培养物中生长的生物膜具有更高比例的休眠细菌。从具有高或低活而不可培养细胞比例的生物膜中获得的细菌进一步在肉汤培养基中培养，并在不同时间点用 SYBR 染色。观察到细菌生长与 SYBR 染色强度之间存在关联。此外，呈现较高 SYBR 荧光强度的细菌也用氰基二氢噻唑四唑氯化物（用于评估细胞代谢的探针）染色更深。因此，用利福平（一种细菌 RNA 转录抑制剂）处理的浮游细菌比未处理的细菌具有更低的 SYBR 和氰基二氢噻唑四唑氯化物染色强度。总的来说，我们的结果表明，SYBR 除了可用作 LIVE/DEAD 染色的组成部分外，还可用作评估表皮葡萄球菌细胞生理状态的探针。
