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目的艰难梭菌是医院获得性感染性腹泻的主要原因。有些抗生素能够诱导和促进艰难梭菌相关性腹泻(CDAD)。本研究探讨治疗CDAD的一线药物甲硝唑和万古霉素的亚最小抑菌浓度(MIC)剂量对中国艰难梭菌A-B+高分离株BJ08生长、毒力基因转录和毒素分泌的影响。方法 BJ08菌株分别生长在含有1/4MIC的甲硝唑或万古霉素以及无抗生素的BHI液体培养基中。每4h通过检测其OD值以确定其生长曲线;通过实时荧光定量PCR检测其毒力基因的表达;通过ELISA检测上清和细胞内B毒素的表达。结果实验发现BJ08在1/4MIC剂量的甲硝唑和万古霉素存在的情况为,到达指数生长期的时间延迟;毒力基因及其毒素的表达增高且提前;但甲硝唑和万古霉素对其影响的程度不同。结论实验证明中国株A-B+在亚MIC剂量抗生素存在的情况下,其生长延迟,毒力基因和毒素表达提前且升高。本实验为临床规范治疗CDAD与合理用药提供一定的参考价值。
Purpose Clostridium difficile is the leading cause of hospital-acquired infectious diarrhea. Some antibiotics can induce and promote C. difficile-associated diarrhea (CDAD). This study was to investigate the effects of sub-minimal inhibitory concentrations (MICs) of metronidazole and vancomycin, the first-line drugs for treating CDAD, on the growth, virulence gene transcription and toxin secretion of the Chinese Clostridium difficile A-B + isolate BJ08. Methods BJ08 strains were grown in metronidazole or vancomycin containing 1 / 4MIC and BHI liquid medium without antibiotics, respectively. The OD value was determined every 4 h to determine the growth curve. The virulence gene expression was detected by real-time fluorescence quantitative PCR. The expression of B toxin in the supernatant and intracellular was detected by ELISA. Results The results showed that the presence of metronidazole and vancomycin at a dose of 1 / 4MIC for BJ08 was a delay in reaching the exponential growth phase; the expression of virulence genes and toxins increased and advanced; but metronidazole and vancomycin The degree of impact on them is different. Conclusion Experiments show that the Chinese strain A-B + in the presence of submicrobial doses of antibiotics, the growth delay, virulence genes and toxins in advance and increased. This experiment provides a certain reference value for clinical treatment of CDAD and rational drug use.