Rabbit model of Candida albicans biofilm infection: liposomal amphotericin B antifungal lock therapy.
Catheter-related infections due to Candida albicans biofilms are a leading cause of fungal nosocomial bloodstream infection. In this paper, we describe the development of a model of catheter-associated infection with C. albicans biofilms and show that antifungal lock therapy with liposomal amphotericin B is an effective treatment strategy for these infections. Silicone catheters surgically placed in New Zealand White rabbits were infected with C. albicans, and the rabbits were randomized into three groups: (i) untreated controls, (ii) liposomal amphotericin B lock, and (iii) fluconazole lock. Upon completion of therapy, blood cultures were obtained and the catheters were removed for quantitative culture and scanning electron microscopic analyses. Quantitative cultures revealed that catheters treated with liposomal amphotericin B yielded 0 CFU, which was significant compared to the untreated controls (P < 0.001) and the fluconazole-treated group (P = 0.0079). Although fluconazole treatment tended to have lower CFU compared to untreated controls, there was no difference in mean colony counts between these two groups (1.128 +/- 0.764 and 1.841 +/- 1.141 log(10) CFU/catheter segment, respectively; P = 0.297). Scanning electron microscopy revealed abundant biofilm in the control and fluconazole groups, while the liposomal amphotericin B group was virtually cleared. These findings suggest a possible treatment strategy for the successful salvage of catheters infected with C. albicans biofilms and describe an animal model that may play an important role in the further study of C. albicans biofilm pathogenesis and evaluation of potential antibiofilm agents.
Schinabeck
Matthew K
MK
Center for Medical Mycology and Mycology Reference Laboratory, Department of Dermatology, University Hospitals of Cleveland and Case Western Reserve University, Cleveland, Ohio 44106, USA.
Long
Lisa A
LA
Hossain
Mohammad A
MA
Chandra
Jyotsna
J
Mukherjee
Pranab K
PK
Mohamed
Sotohy
S
Ghannoum
Mahmoud A
MA
D000666:Amphotericin B / Q000008:administration & dosage / Q000627:therapeutic use*; D000818:Animals; D000935:Antifungal Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D018441:Biofilms; D002177:Candidiasis / Q000188:drug therapy* / Q000209:etiology*; D002405:Catheterization, Central Venous / Q000009:adverse effects*; D015169:Colony Count, Microbial; D004337:Drug Carriers; D025141:Drug Resistance, Fungal; D008081:Liposomes; D008855:Microscopy, Electron, Scanning; D011817:Rabbits
D000935:Antifungal Agents; D004337:Drug Carriers; D008081:Liposomes; D000666:Amphotericin B