The Intervention In Endotracheal Tube-Associated Biofilms And Respiratory Infections Of Pseudomonas Aeruginosa By Using Inhalation Of Combination Erythromycin With Ciprofloxacin In Rats Model

PartⅠ: The intervention in endotracheal tube-associated biofilms and respiratory infections of Pseudomonas aeruginosa by using inhalation of combination Erythromycin with Ciprofloxacin in rats model【Objective】To research effect of inhalation of erythromycin combining ciprofloxacin against respiratory infection with endotracheal tube(ETT)-associated biofilm of Pseudomonas aeruginosa.【Methods】Rat model of P. aerudomonsa biofilm infection was established. The bacterial colony count from ETT biofilm and lung tissues were performed after intervention by follow 4 groups: control group (group1), erythromycin alone(group2), ciprofloxacin alone(group3)and combination of both(group4). Scanning electron microscopy (SEM) on biofilm after 7 days of intervention with above 4 groups respectively.【Results】After 7 days of intervention with above 4 groups respectively, The bacterial colony count from lung tissues(CFU/ml): the median in the four groups were 54, 74, 55 and 11 respectively. It were significantly different that the group1, group2 and group3 were compared with the group4 respectively.χ2 were 11.378, 11.361 and 10.662 respectively. all of the P values were 0.001. The bacterial colony count from ETT biofilm were as follows (×105CFU/ml): the median were 130.5, 103, 170.5 and 30.5 respectively. It were significantly different that the group1, group2 and group3 were compared with the group4 respectively,χ2 were 6.650, 9.956 and 7.489 respectively, P values were 0.010, 0.002 and 0.006 respectively. The matrixes of the ETT surface from group1, group2 and group3 were thicker than from group4 by using SEM.【Conclusion】Inhalation of erythromycin together with ciprofloxacin could decrease the P. aeruginosa biofilm and relevant respiratory infection.PartⅡ:Pathological change in hung tissues of tube-associated pneumonia after using inhalation of combination Erythromycin with Ciprofloxacin in rats model【Objective】To search the effect of inhalation of erythromycin combining ciprofloxacin against pneumonia with endotracheal tube(ETT)-associated biofilm of P. aeruginosa.【Methods】Rats model of P. aeruginosa biofilm infection was established. The bacterial colony count from lung tissues were performed after intervention by the follow 4 groups: control group(group1), erythromycin alone(group2), ciprofloxacin alone(group3) and combination of both(group4). Light microscope on the slice of lung tissues after 7days of intervention with above 4 groups respectively.【Results】After 7 days of intervention with above 4 groups respectively, the bacterial colony count from lung tissues(CFU/ml): the four groups'median were 54,74,55 and 11 respectively. It was significantly different that the group1,group2 and group3 were compared with the group4 respectively.χ2 were 11.378,11.361 and 10.662 respectively. All of the P values were less than 0.05. Observation of the slice of lung tissues by using light microscope shows that infection of lung tissues was very severe in the group1, group2 and group3, with a lot of inflammatory cells infiltration. Inflammation in lung tissues was not obviously in the group4 with few of inflammatory cells in lung tissues.【Conclusion】Inhalation of erythromycin together with ciprofloxacin could retard the pneumonia with ETT-associated biofilm of P. aeruginosa.PartⅢ:Effect of concentration in blood plasma after inhaling ciprofloxacin in rats model【Objective】To investigate concentration of ciprofloxacin in blood after using inhalation of ciprofloxacin in rats model.【Methods】Rats model of P. aeruginosa biofilm infection has been established. A 7 days of intervention with the follow 4 groups: control group(group1), erythromycin alone(group2), ciprofloxacin alone(group3) and combination of both(group4) had been done. Concentration of ciprofloxacin in rats model's blood plasma was measured by HPLC.【Results】The standard curve regression equation was y = 311.01x - 11.333 R2 = 0.9993. The linear range was 0.1~10μg/ml. The low limit of ciprofloxacin's quantitation was 0.1μg/ml. All of the with-day's and the between-day's degree of precision (RSD) of ciprofloxacin by HPLC were less than 10%. The recovery rates (RSD) in vivo were less than 5%. The foreign substance in blood plasma could been separated at the baseline (R>1.5). Concentration of ciprofloxacin in samples of blood plasma was less than 0.1ug/ml which was the standard curve'minimum value.【Conclusions】It was sensitive and good in reproducibility that using HPLC measured ciprofloxacin's concentration. Ciprofloxacin by inhalation almost didn't enter the blood circulation by across lung tissues.