Lethal Effect Of Antibiotics Combined With Antifungals On Acanthamoeba

Objective:Acanthamoeba spp. a widely-survivaled micro-organism, could lead to Acanthamoeba keratitis, granulomatous amoebic encephalitis, and skin infections. Currently, there are no specific drug for Acanthamoeba infections in the central nervous system, but drug combination had shown better effets. in this research, Acanthamoeba was cultivated, to explore the inbibitional effect of antifungal combined with antibiotic.Caspofungin acetate (caspofungin acetate, cancidas), as a inhibitor of fungal, could destruct the cellwall of fungus, thus, led microorganisms death through osmotic lysis. Amphotericin B (amphotericin B) could inhibit fungus through damaging cell metabolism. Azithromycin (Azithromycin).a macrolide antibiotic, had a Strong inhibitional effect on anaerobic bacteria. As different mechanisms to kill micro-oganism, to observe the changes of morphology, proliferation rate, inhibitional effect of Acanthamoeba in vitro, antifungal and antibiotic were combined in the experiment, further more to provide experimental evidence for clinical application.Method:Concentration of single-agent of Caspofungin was250μg/ml, Amphotericin B5μg/ml. Caspofungin and Amphotericin B combination was formed by250μg/ml of Caspofungin and5μg/ml of Amphotericin B or100μg/ml of Caspofungin and5μg/ml of Amphotericin B. Caspofungin and Azithromycin combination was formed by250μg/ml of Caspofungin and10mg/ml of Azithromycin or100μg/ml of Caspofungin and10mg/ml of Azithromycin. Amphotericin B and Azithromycin combination was formed by Amphotericin B at5μg/ml and Azithromycin at10mg/ml or Amphotericin B at1μg/ml and Azithromycin at10mg/ml. drugs were added in the Culture medium of Acanthamoeba, morphology and cell count were collected at4h、8h、24h、48h、72h under inverted microscope.Result:After Amphotericin B and Azithromycin combining5μg/ml and10mg/ml effecting for48h, the inhibit growth effect to Acanthamoeba was obvious (P<0.01). The combination of Caspofungin Acetate and Amphotericin B at250μg/ml and5μg/ml had an obvious effect at48h (P<0.01). The combination of Caspofungin Acetate and Azithromycin at 250μg/ml and10mg/ml had an obvious effect at8h (P<0.01). Combination of Amphotericin B at5μg/ml and Azithromycin at10mg/ml had a better effect compared with Amphotericin B alone at24h and after48-72h. Better effect had been showed by combination of Caspofungin at250μg/ml Amphotericin B at5μg/ml compared with single-agent of Caspofungin or Amphotericin B at8h and after48h. Increase effect had been showed by the combination of Caspofungin at250μg/ml and Azithromycin at10mg/ml compared with single agent of Caspofungin at4h,8h, and even better at24h.Conclusion:compared with single agent, the combination of Amphotericin B and Azithromycin at concentration of5μg/ml and10mg/ml showed a better effect at8h. the combination of Amphotericin B and Caspofungin at concentration of5μg/ml and250μg/ml showed a better effect at24h. the combination of Azithromycin and Caspofungin at concentration of10mg/ml and250μg/ml showed a better effect at8h. the inhibitional effect of combination was better than single agent.