摘要
目的体外培养铜绿假单胞菌(pseudomonas aeruginosa,PA),观察低浓度红霉素对铜绿假单胞菌蹭行运动(twitching motility)的影响。方法将铜绿假单胞菌 ATCC1244菌株接种于3组不同浓度红霉素(2.5 mg/L、0.5 mg/L、0.25 mg/L)的细菌培养基中,同时接种于未加红霉素的对照培养基中,采用肉眼观察、免疫荧光显微镜检查、免疫印迹实验、点杂交实验、电镜观察等方法观察铜绿假单胞菌蹭行运动的变化及鉴别其蹭行运动的分子组成。结果经过18～36 h 的孵育,LB 平板上不同浓度的红霉素对 PA 蹭行运动有抑制作用,细菌光晕(halation)直径与药物浓度呈反比;18 h 时细菌的平均光晕直径2.5 ms/L 组为(0.48±0.14)cm,0.5 mg/L 组为(0.64±0.20)cm,0.25 mg/L 组为(0.95±0.18)cm,对照组为(1.40±0.21)cm,组间比较差异有统计学意义(F=123.15,P<0.01);24 h时2.5 mg/L 组为(0.67±0.12)cm,0.5 mg/L 组为(0.82±0.23)cm,0.25 mg/L 组为(1.18±0.24)cm,对照组为(1.58±0.28)cm,组间比较差异有统计学意义(F=76.37,P<0.01);36 h 时2.5 mg/L 组为(0.91±0.17)cm,0.5 mg/L 组为(1.04±0.32)cm,0.25 mg/L 组为(1.49±0.31)cm,对照组为(2.07±0.38)cm,组间比较差异有统计学意义(F=54.75,P<0.01)。免疫荧光显微镜观察结果可见细菌菌体一端呈簇状突起,为Ⅳ型菌毛的位置所在,簇状突起的多少与药物浓度呈反比。免疫印迹实验结果显示,随着药物浓度的减少,Ⅳ型菌毛的主要成分 PilA 蛋白表达增加。点杂交实验结果显示在蹭行运动中起作用的 PilA 蛋白主要表达在光晕的最外周,但组间未见明显区别。电镜下可见红霉素作用后 PA 菌体一端的Ⅳ型菌毛较对照组减少,部分脱离菌体。结论低浓度红霉素对 PA 的蹭行运动有抑制作用,且与红霉素浓度呈正比。
Objective To observe the effects of low concentration of erythromycin on the twitching motility ofpseudomonas aerug/nosa. Methods Pseudomonas aeruginoa 1244（PA1244） was cultured in LB plate or LB broth with added erythromycin at different concentrations 2. 5,0. 5,0. 25 mg/L, and in cultures without erythromycin as the control. The changes of PA1244＇ s twitching motility was observed by naked eyes, immunofluorescence, Western blot, dot blot and electron microscope. Results SubMIC erythromycin inhibited the halation of twitching motility on the culture plates. The average diameters of bacterial halation after culture for 18 h were as below：group of 2.5 mg,/L was （0.48±0. 14） cm, group of0.5 mg/L was （0.64±0.20） cm, group of 0.25 mg,/L was （0.95±0. 18） cm; the control group was （1.40±0.21） cm （F=123. 15,P〈0.01）. After culture for24 h： group of 2.5mg/L was （0.67 ±0. 12） cm, group of 0.5 mg/L was （0.82±0.23） cm, group of 0.25 mg/L was （1.18±0.24） cm; the control group was （1.58±0.28） cm （F=76.37,P 〈0.01）. After culture for 36 h： group of 2.5 mg,/L was （0.91±0. 17） cm, group of 0. 5 mg,/L was （ 1.04±0. 32） cm, group of 0. 25 mg/L was （ 1.49 ±0. 31 ） cm; the control group was （2.07 ±0.38） cm （F =54.75,P 〈0.01）. Immunofluorescence showed that the key component of twitching motility was pilus Ⅵ located at the pole of the PA body. Western blot showed that the expression of pilus Ⅵ was increased with the decreasing concentration of erythromycin. Dot blot showed that pilus Ⅵ was expressed mostly at the outmost of the twitching zone and there was no significant difference between groups. Through transmission electron microscope, PA of the group of 2. 5 mg,/L had fewer pilus than the control group. Conclusion Diverse concentrations of erythromycin have inhibitory actions on the twitching motility of pseudomonas aeruginosa.
出处
《中华结核和呼吸杂志》
CAS
CSCD
北大核心
2007年第3期207-210,共4页
Chinese Journal of Tuberculosis and Respiratory Diseases
关键词
假单胞菌
铜绿
纤毛
细菌
红霉素
Pseudomonas aeruginosa
Fimbriae, bacterial
Erythromycin
