含硫氰酸根离子的乳过氧化物酶-I^--H_2O_2系统对Pg和Fn生长的影响

Susceptibilities of Porphyromonas gingivalis and Fusobacterium nucleatum to lactoperoxidease-I^--H_2O_2 system with SCN-

目的研究含生理浓度硫氰酸根离子(SCN-)的乳过氧化物酶(LP)-I--H2O2抗菌系统对牙龈卟啉单胞菌(Pg)和具核梭杆菌(Fn)生长的影响。方法Pg和Fn各分5组每组含Pg(6.0×108/ml)或Fn(1.0×108/ml)菌悬液、含不同浓度I-的LP-I-系统、SCN-,在37℃震荡水浴分别培养0min(加H2O2前)和30min,5μlDTT终止反应,10倍浓度系列稀释,接种于BHI-S琼脂培养基,厌氧培养4d,并计数CFU。结果I-浓度增加至大于等于500μmol/L时,LP-I-抗菌系统抑菌作用明显高于单独的LP-SCN--系统(P<0.05)。结论生理浓度SCN-存在时,通过增加I-的浓度可达到显著提高LP-I-抗菌系统抑制Pg和Fn生长的作用。

Objective To examine the antibacterial effect of different halide combinations with different concentration of SCN- and I- as substrates of lactoperoxidease (LP).Methods The bacteria were grown in BHI-S agar plate and the colonial forming units were numerated.Five groups were divided according the I- concentration with each type strain (Pg and Fn).Each group contained Pg(6.0×108/ml) or Fn (1.0×108/ml) suspension and LP system with different combination of SCN- and I-.After incubating on a shaking water bath at 37 ℃ for 1 hour,add 5 μl DTT to abolish the oxidation.Sample were taken immediately before the addition of H_2O_2 (0 min) and after incubation for 30 min,and ten-fold dilution were made before plated on the BHI-S agar plate for enumeration of CFU.Results The antibacterial effects of LP-I- system with average concentration of SCN- was significantly higher than that of LP-SCN- system alone when I- concentration was over 500 μmol/L(P<0.05).Conclusions With the increment of I- concentration to a certain degree,it would greatly enhance the antibacterial effects of LP-I- system with average concentration of SCN-.