Effects of Different Accumulation Culture Methods on the Titer of Phage PEf771
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摘要:
目的 对比3种不同富集培养方法对噬菌体PEf771的滴度影响，探讨有效提高噬菌体PEf771滴度的方法。 方法 通过噬菌体PEf771/粪肠球菌E. faecalis YN771比例法、挖斑法和丝裂霉素C诱导法在E. faecalis YN771不同生长时期加入PEf771原液进行富集，来获得较高的PEf771的滴度。 结果 PEf771/ E. faecalis YN771 = 1∶3和挖斑法得出的PEf771的滴度较高，将这2种方法扩大培养后无明显差异（P > 0.05），且在24 h滴度达108 pfu/mL。丝裂霉素C诱导法未能明显提高PEf771的滴度。通过在E. faecalis YN771生长早期（OD600 = 0.3）和对数期（OD600 = 1）加入PEf771进行富集培养，前者培养6 h滴度高达1010 pfu/ml，24 h滴度仍保持1010 pfu/ml，达到了理想滴度。 结论 在E. faecalis YN771培养早期（OD600 = 0.3）加入PEf771以噬菌体/菌 = 1∶3的方法或挖斑法富集培养可有效提高PEf771的滴度，为研究E. faecalis YN771的噬菌体PEf771治疗E. faecalis YN771引起的感染提供了实验材料和依据。 Abstract:Objective To compare the effects of three different enriching culture methods on the titer of phage PEf771, and discuss the methods to effectively improve the titer of phage PEf771. Methods Through phage PEf771/E. faecalis YN771 proportional method, spot digging method and mitomycin C induction method, phage PEf771 stock solution was added at E. faecalis YN771 different growth stages for enrichment to obtain a higher titer of phage PEf771. Results The titer of PEf771 obtained by PEf771/E. faecalis YN771 = 1∶3 and spot digging method was higher, there was no significant difference between the two methods after expanded culture （P > 0.05）, and the titer reached 108 pfu/mL in 24 hours. Mitomycin C induction method could not significantly improve the titer of PEf771.PEf771 was added in the early growth stage （OD600 = 0.3） and logarithmic stage （OD600 = 1） of E. faecalis YN771 for enrichment culture. The titer of the former was 1010 pfu/mL after 6 hours of culture, and remained 1010 pfu/mL after 24 hours, reaching the ideal titer. Conclusion Adding PEf771 in the early stage of E. faecalis YN771 culture （OD600 = 0.3） and enriching culture with PEf771/E. faecalis YN771 = 1∶3 or spot digging method can effectively improve the titer of PEf771. It provides experimental materials and basis for the study of phage PEf771 of E. faecalis YN771 in the treatment of infection caused by E. faecalis YN771. -
Key words:
- Bacteriophage /
- Enrichment /
- Titer
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表 1 不同方法富集噬菌体的滴度比较
Table 1. Comparison of titer of phage enriched by different methods
实验分组 噬菌体 对数期粪肠球菌
（OD = 1）（μL）新鲜BHI
（mL）噬菌体∶菌 24 h滴度
（pfu/mL）48 h滴度
（pfu/mL）72 h滴度
（pfu/mL）一 200 μL 250 5 4∶5 0.9×107 3.6×107 1.5×106 二 200 μL 500 5 1∶2.5 3.0×107 4.1×108 2.1×107 三 400 μL 500 5 4∶5 1.3×107 8.0×107 7.4×106 四 400 μL 250 5 8∶5 1.9×107 5.3×107 6.8×106 五 100 μL 300 5 1∶3 4.6×107 1.2×109 6.1×108 六 挖斑（2块） 1000 100 2.2×108 1.8×109 7.4×108 
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表 2 两种方法富集培养的滴度比较
Table 2. Comparison of enrichment culture by two methods
实验分组 噬菌体 对数期粪肠球菌
（OD = 1）（mL）新鲜BHI
（mL）24 h滴度
（pfu/mL）48 h滴度
（pfu/mL）72 h滴度
（pfu/mL）噬菌体：菌 = 1∶3 一组 10 mL 30 500 4.7×108 3.6×107 2.1×106 噬菌体：菌 = 1∶3 二组 10 mL 30 500 1.1×108 0.5×107 0.4×106 噬菌体：菌 = 1∶3 三组 10 mL 30 500 1.2×108 0.8×107 0.7×106 噬菌体：菌 = 1∶3 四组 10 mL 30 500 2.2×108 1.0×107 0.9×106 挖板法一组 挖斑（10块） 500 7.5×108 6.2×107 8.0×106 挖板法二组 挖斑（10块） 500 5.3×108 4.2×107 2.8×106 挖板法三组 挖斑（10块） 500 6.4×108 4.5×107 3.9×106 挖板法四组 挖斑（10块） 500 7.6×108 6.0×107 4.2×106
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表 3 丝裂霉素C诱导法对噬菌体滴度的影响
Table 3. Effects of mitonmycin C induction on phage titer
实验分组 24 h滴度（pfu/mL） 48 h滴度（pfu/mL） 加丝裂霉素C组 3.2×108 4.5×107 对照组 5.3×108 2.9×107
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表 4 E. faecalis YN771对数早期加入噬菌体富集
Table 4. Enrichment of PEf771 by E. faecalis YN771 at different culture phases
实验分组 6 h滴度（pfu/mL） 24 h滴度（pfu/mL） 对数生长早期组
（OD600 = 0.3）1.6×1010 1.3×1010 对数生长期组
（OD600 = 1）5.1×106 2.4×108
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