The Influence Of Pseudomonas Aeruginosa Biofilm Suspension And Alginate On Phagocytosis Function Of Macrophage In Mouse

Part 1 :The Influence of Pseudomonas aeruginosa Biofilm Suspension in Macrophage-depleted Mouse.【Objective】To explore the influence of P. aeruginosa biofilm on the function of macrophage in mouse.【Methods】The bacterial biofilm suspension of Pseudomonas aeruginosa was used to infect macrophage-depleted mouse and control mouse.The macrophage inhibition ratio in high inhibited group is 75%~85% and 8%~15% in low inhibited group.【Results】The high inhibited group compared to the control group, the bacterial count in tissue of lung was (4.16±3.36)×105CFU/ml to (5.15±1.92)×105CFU /ml,t=0.7211,P=0.483 , the bacterial count in tissue of liver was(6.88±3.74)×105CFU /ml to(2.97±1.57)×105CFU /ml,T=100.00a,P=0.0002 and the bacterial count in tissue of spleen was(9.63±3.95)×105CFU /ml to(5.80±2.06)×105CFU /ml,t=2.4268,P= 0.0293. In the low inhibited group compared to the control group, the bacterial count in tissue of lung was (1.85±0.889)×105CFU /ml to (2.06±1.198)×105CFU /ml,t=0.4026,P=0.6933;the bacterial count in tissue of liver was(2.00±0.900)×105CFU /ml to(1.76±1.0514)×105CFU /ml,t= 0.4837 , P=0.6361 and the bacterial count in tissue of spleen was( 6.67±2.15 )×105CFU /ml to ( 5.02±2.07 )×105CFU /ml , t= 1.5620,P=0.1406. The bacterial count in tissue of the lung,liver and spleen had no obviously difference in the low inhibited group compared to the control group. In the high inhibited group compared to the control group the bacterial count in tissue of the lung still hadn't increased. But the bacterial count in tissue of the liver and spleen were obviously higher than the control group and it indicated the bacteremia of the high inhibited group was more serious than the control group.【Conclusion】The macrophage could not have have active resistence in the acute lung infection by P.aeruginosa biofilm bacterium,but it could prevent the further dissemination of P.aeruginosa.Part 2: The Influence of Alginate on Phagocytosis Function of Macrophage in Mouse【Objective】To search the effective the alginate on macrophage function in mouse.【Methods】The macrophage was isolated from mouse .Then the P.aeruginosa dissociation bacteria ,the P.aeruginosa biofilm bacteria and the P.aeruginosa dissociation bacteria with alginate were added into the macrophage and phagocytosis rate was determined by the microscope. The capability of macrophage's phagocytosis also was detected by using neutral red method.【Results】The phagocytosis rate in P.aeruginosa biofilm bacteria group compared to the P.aeruginosa dissociation bacteria group was ( 13.82±4.71 ) % to ( 42.73±11.00 ) % , with significantly different(Q=12.3231,P<0.01). The phagocytosis rate in P.aeruginosa dissociation bacteria with alginate group compared to the the P.aeruginosa dissociation bacteria group was (22.91±6.20)% to(42.73±11.00)%,Q= 8.4465,also significantly different(Q= 8.4465,P<0.05). When the concentration of alginate were 0,25,50,75,100,125 and150μg/ml the absorbance D ( 540 ) ,which express the capability of macrophage phagocytosing neutral red in macrophage ,were ( 0.271±0.044 )( 0.456±0.062 )( 0.445±0.061 )( 0.551±0.065 )( 0.210±0.053 )(0.186±0.026)and(0.195±0.025)respectively. When≤75μg/ml of the alginate's concentration the capability of macrophage on phagocytosing neutral red was strengthen,P<0.05, compared to the 0μg/ml group ; When >75μg/ml of alginate's concentration the capability of phagocytosing neutral red in macrophage was degressive,P<0.05,compared to the 0μg/ml group.【Conclusion】P. aeruginosa biofilm could inhibit macrophage on phagocytosis and the alginate had significant contribution to the ability of inhibitation. And the alginate also could promote macrophage on phagocytosis when the dose of alginate≤75μg/ml of concentration but the larger dose of alginate inhibit may reversely decrease the effect of macrophage on phagocytosis.