The Effects Of Smake Venom Antimicrobial Peptide Cathelicidin On Rabbit Urinary Tract Infection Model Induced By E. Coli.

Objectives:The study was aimed to investigate the protective effects of the snake venom antimicrobial peptide Cathelicidin on rabbit urinary tract infection model induced by the cephalosporin-resistant E.coli and E. coli ATCC 25922.Methods:We did inhibitory tests in vitro and established a rabbit urinary tract infection model with the cephalosporin-resistant E.coli and E. coli ATCC 25922. The model was administered the snake venom antimicrobial peptide Cathelicidin and Cefoperazone and Sulbactam through urethral. The serum and urine was collected on the 1,5,10,14 days after the model establishment to determine the concentration of the IL-lα,IL-6,IL-10,TNF-a in serum using ELISA and to do urine culture. The animal was also sacrificed on the 14 day, the bladder tissue specimens were taken to observe by H-E staining light microscope and transmission electron microscope.Results:In vitro, E. coli ATCC 25922 were inhibited by both the snake venom antimicrobial peptide Cathelicidin and Cefoperazone and Sulbactam; The cephalosporin-resistant E.coli was inhibited only by the snake venom antimicrobial peptide Cathelicidin. There was not statistically significant in variation of cytokines. The snake venom antimicrobial peptide Cathelicidin reduced obviously the positve rate in urine culture of infectious animals induced both cephalosporin-resistant E.coli and the E. coli ATCC 25922. The Cefoperazone and Sulbactam could reduced the positive rate only with the E. coli ATCC 25922. (P<0.05) It was observed that less necrosis and degeneration and inflammatory cell infiltration in bladder tissue by H-E staining light microscope and transmission electron microscope in the groups with the snake venom antimicrobial peptide Cathelicidin.Conclutions:The snake venom antimicrobial peptide Cathelicidin has steadily activty to the cephalosporin-resistant E.coli and E. coli ATCC 25922 and protective effection to the rabbit urinary tract infection model induced the cephalosporin-resistant E.coli and E. coli ATCC 25922 in some degree.