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采用琼脂稀释棋盘法,应用多点接种仪分别对Ceftazidime(CTD)单用或合用时抗菌活性进行测定。结果表明CTD对60株绿脓杆菌的抗菌活性最强,其MIC_(50)和MIC_(90)均为1μg/ml,对50株大肠杆菌的MIC_(50)为0.125μg/ml,MIC(90)为0.25μg/ml,优于实验中其它六种抗生素。 联合抗菌作用结果表明,CTD与妥布拉霉素及丁胺卡那霉素联合对20株绿脓杆菌,其协同率分别为15％、10％。CTD与哌拉西林联合协同率亦为15％,和CTD与妥布拉霉素联合时相同。CTD与丁胺卡那霉素联合对20株大肠杆菌也具有一定的协同作用(5％)。 形态学观察结果表明,光镜、电镜结果基本一致。 CTD2μg/ml(2MIC)作用4小时后,菌体拉长呈丝状,不见横膈形成; 20μg/ml(20MIC)作用后,细菌呈丝状及不规则型,胞壁、胞膜结构不完整,出现断裂和缺损。 CTD与哌拉西林各2MIC联合作用 4小时后,细菌呈多形性改变,胞壁破坏明显,胞内空泡形成。CTD与妥布拉霉素各2MIC联合作用4小时后,细菌形态以短小为主,可以见到收缩期横膈。 CTD与妥布拉霉素各20MIC联合作用后,细菌呈不规则形,有的可见菌体松解,有的则又浓缩变小,多数细菌胞壁结构不完整。
Agar dilution plate method, the use of multi-point inoculation instrument were Ceftazidime (CTD) antibacterial activity alone or in combination were determined. The results showed that the antibacterial activity of CTD against 60 P. aeruginosa strains was the strongest with MIC 50 and MIC 90 of 1 μg / ml, MIC 50 of 0.50 μg / ml and MIC 90 ) 0.25μg / ml, better than the other six antibiotics in the experiment. The results showed that the synergistic rates of CTD with tobramycin and amikacin on 20 strains of Pseudomonas aeruginosa were 15% and 10%, respectively. CTD and piperacillin joint synergistic rate was 15%, and CTD and tobramycin jointly when the same. CTD combined with amikacin had some synergistic effects on 20 strains of Escherichia coli (5%). Morphological observation results show that light and electron microscopy results are basically the same. After 4 hours treatment with CTD2μg / ml (2MIC), the bacterial cells grew into a filamentous shape with no diaphragms. After 20μg / ml (20micromol), the bacteria appeared filamentous and irregular with incomplete cell wall and cell membrane structure , There is fracture and defect. After 4 hours of combined action of CTD and piperacillin each 2MIC, the bacteria showed pleomorphic changes, cell wall destruction was obvious, and intracellular vacuoles formed. After 4 hours of combined action of CTD and tobramycin each 2MIC, the bacterial morphology was mainly short and the systolic diaphragms were seen. CTD and tobramycin 20MIC combined effect, the bacteria showed irregular shape, and some bacteria can be loose, while others are concentrated smaller, most bacteria cell wall structure is not complete.