Activity of Amphotericin B and Anidulafungin Combined with Rifampicin, Clarithromycin, Ethylenediaminetetraacetic Acid, N-Acetylcysteine, and Farnesol against Candida tropicalis Biofilms.

Marcelo Fernández-Rivero,Araceli De Diego,Javier Pemán,José Del Pozo,Amparo Valentín,Emilia Cantón

doi:10.3390/jof3010016

Abstract

We evaluated the activity of (1) amphotericin-B (AMB), combined with rifampicin (RIF), clarithromycin (CLA), N-acetylcysteine (NAC), ethylenediaminetetraacetic acid (EDTA), and farnesol (FAR) (1000, 1000, 1000, 4000, and 30,000 mg/L, and 300 µM, respectively), against Candida tropicalis biofilms formed on polytetrafluoroethylene (PTFE) and (2) anidulafungin (ANF) combined with the same compounds at 8, 10, 5, 40, and 30 mg/L, and 30 µM, respectively, against biofilms formed on titanium. Biofilm growth kinetics were performed in a CDC Biofilm Reactor (CBR). PTFE or titanium disks were removed from the CBR at 24, 48, 72, and 96 h to determine the Log10CFU/cm2. Killing kinetics were performed by adding the drugs to 24-h-mature biofilms (time 0). Disks were removed after 24, 48, and 72 h of drug exposure to determine Log10CFU/cm2. Viable cells in biofilms were 4.73 and 4.29 Log10CFU/cm2 on PTFE and titanium, respectively. Maximum Log10 decreases in CFU/cm2 depend on the combination and were: 3.53 (AMB + EDTA), 2.65 (AMB + RIF), 3.07 (AMB + NAC), 2.52 (AMB + CLA), 1.49 (AMB + FAR), 2.26 (ANF + EDTA), 2.45 (ANF + RIF), 2.47 (ANF + NAC), 1.52 (ANF + CLA), and 0.44 (ANF + FAR). In conclusion, EDTA, NAC, RIF, and CLA improve the activity of AMB and ANF against biofilms developed on both surfaces, which could be an effective strategy against C. tropicalis biofilm-related infections.

Highlights

Biomedical devices are essential for treatment of a number of diseases, substantially improving the quality of life and survival of patients
The aim of our study was to evaluate the activity of amphotericin B (AMB) and anidulafungin (ANF) alone and combined with RIF, CLA, NAC, ethylenediaminetetraacetic acid (EDTA), and FAR, against C. tropicalis biofilms formed on PTFE and titanium, using the CDC Biofilm Reactor (CBR) as an in vitro model
Biofilm growth kinetics curves showed that C. tropicalis was able to colonize both PTFE and titanium surfaces

Summary

Introduction

Biomedical devices are essential for treatment of a number of diseases, substantially improving the quality of life and survival of patients. Several materials are commonly used in the manufacture of these devices. Plastic polymers such as polytetrafluoroethylene (PTFE, commercially known as Teflon® ). Are hydrophobic materials commonly used for the manufacture of catheters. About 80% of hip and knee prostheses are manufactured using metallic biomaterials such as titanium (a hydrophilic surface), which, due to its excellent biocompatibility, has gained importance in the last few years. Candida spp. are able to attach to biomaterials and tissues, and once an organism. J. Fungi 2017, 3, 16; doi:10.3390/jof3010016 www.mdpi.com/journal/jof

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