环磷酸腺苷受体蛋白调控子对细菌毒力及生物膜形成的影响

Effects of cAMP receptor protein regulator on bacterial virulence and biofilm formation

目的探讨肺炎克雷伯菌环磷酸腺苷受体蛋白(CRP)调控子对细菌毒力及生物膜形成的影响。方法 2012年8月到2014年2月,选择120株肺炎克雷伯菌进行CRP调控子的PCR阳性表达检测,同时选择哌拉西林、哌拉西林+他唑巴坦、阿米卡星、头孢他啶、头孢曲松、头孢哌酮+舒巴坦、左氧氟沙星等进行耐药性与生物膜形成实验。结果 PCR检测CRP调控子阳性率为33.3%。而CRP调控子阳性株对于头孢曲松、左氧氟沙星、阿米卡星与头孢他啶有更高的耐药性,与CRP调控子阴性株对比差异有统计学意义(P<0.05)。2组生物被膜培养组CRP调控子表达量为0.28±0.04,普通液相培养组CRP调控子表达量为0.08±0.05,2组对比差异有统计学意义(P<0.05)。结论肺炎克雷伯菌CRP调控子的阳性表达有利于降低细菌毒力与促进生物膜形成,从而提高相关抗菌药物的耐药性。

Objective To discuss the effects of cAMP receptor protein（ CRP） regulator on the virulence and biofilm formation for the Klebsiella pneumoniae. Methods From August 2012 to February 2014,selected120 Klebsiella pneumoniae strains for PCR detecting expression of CRP regulators,while selected piperacillin,piperacillin ＋ tazobactam,amikacin,ceftazidime,ceftriaxone,cefoperazone ＋ sulbactam,levofloxacin and other antibacterial drugs for the resistance testing and analysis. In the biofilm formation experiment,were given the detailed analyzed of the regulation of relative positive expression strains in ordinary liquid culture and biofilm state situation. Results PCR detection positive rate of CRP regulators were 33. 3%,while the CRP regulatory sequences flanking PCR positive strains also amplified target sequence. The resistance of CRP regulator positive strains for ceftriaxone,levofloxacin,amikacin and ceftazidime were higher than the CRP regulators negative strains that difference were statistically significant（ P〈0. 05）. The CRP regulator expression in the biofilm culture group was 0. 28 ± 0. 04,so that was0. 08 ± 0. 05 in the ordinary liquid culture group,the difference between two groups was statistically significant（ P〈0. 05）. Conclusion The expression of CRP regulators for the Klebsiella pneumoniae is favor of reducing the bacterial virulence and promote biofilm formation,therebyincrease resistance to drugs-related antimicrobial.