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Biofilm Formation and Susceptibility to Amphotericin B and Fluconazole in Candida albicans.

Zarei Mahmoudabadi A, Zarrin M, Kiasat N - Jundishapur J Microbiol (2014)

Bottom Line: The results indicated that 100% of C. albicans isolates from different sources had the ability to form biofilms in vitro.Our results showed that 65.0% of the tested isolates are sensitive to amphotericin B at amounts lower than 10 µg/mL, while only 26.7% are sensitive to fluconazole (had MBIC < 10 µg/mL).In addition, there were differences in the MBIC against the two examined antifungals, amphotericin B and fluconazole.

View Article: PubMed Central - PubMed

Affiliation: Health Research Institute, Infectious and Tropical Diseases Research Centre, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran ; Department of Medical Mycology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.

ABSTRACT

Background: The ability of Candida albicans to form biofilms and adhere to host tissues and biomaterial surfaces is an important factor in its pathogenesis. One of the main characteristics of biofilms is their resistance to broad-spectrum anti-microbial drugs.

Objectives: In the present study the formation of biofilm by C. albicans from different sources was evaluated. In addition, the minimum biofilm inhibitory concentration (MBIC) for two antifungals was evaluated.

Materials and methods: In total, 120 isolates of C. albicans from different sources (patients with vaginitis, patients with candiduria, bucal cavity and environmental surfaces) were collected. Biofilm formation was determined by the 96-well micro-titeration plate method. MBIC testing was also performed, using the calorimetric indicator resazurin for amphotericin B and fluconazole.

Results: The results indicated that 100% of C. albicans isolates from different sources had the ability to form biofilms in vitro. Amongst these isolates, 83.3% of isolates had the maximum potential (4+) to form biofilms, while only one (0.9%) of isolates had the minimum ability (1+) to form biofilms. Our results showed that 65.0% of the tested isolates are sensitive to amphotericin B at amounts lower than 10 µg/mL, while only 26.7% are sensitive to fluconazole (had MBIC < 10 µg/mL).

Conclusions: Although biofilm formation was detected in all tested isolates, there were differences in the ability to form biofilms between isolates from different sources. In addition, there were differences in the MBIC against the two examined antifungals, amphotericin B and fluconazole.

No MeSH data available.


Related in: MedlinePlus

Resazurin Dye TestResazurin dye test for determining MBIC of amphotericine B and fluconazole to C. albicans at serial concentrations from 1280 to 10 µL/mL, C1AMB, C. albicans (No. 1) amphotericine B; C1FLC, C. albicans (No. 1) fluconazole; C2AMB, C. albicans (No. 2) amphotericine B; C2FLC, C. albicans (No. 2) fluconazole.
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fig11529: Resazurin Dye TestResazurin dye test for determining MBIC of amphotericine B and fluconazole to C. albicans at serial concentrations from 1280 to 10 µL/mL, C1AMB, C. albicans (No. 1) amphotericine B; C1FLC, C. albicans (No. 1) fluconazole; C2AMB, C. albicans (No. 2) amphotericine B; C2FLC, C. albicans (No. 2) fluconazole.

Mentions: Minimum biofilm inhibitory concentration test: the minimum biofilm inhibitory concentration (MBIC) test was performed by a technique using the calorimetric indicator resazurin (5, 13). Firstly, 90 µL of SDB supplemented with 8% glucose was added to each well of the microplate. Secondly, 10 µL of yeast suspension was also added and incubated at 37°C for 48 hours. All media were removed from wells and wells washed three times with 0.9% NaCl. Serial dilutions of each antifungal agent were prepared from 1280-10 µL/mL in RPMI 1640. Next, 100 µL of each antifungal agent was added to each well and incubated at 37°C for 24 hours. A series of wells without antifungal drugs and un-inoculated wells served as positive and negative controls, respectively. All experiments were done in triplicates. When active cells of yeast (live cells) were present in wells, they produced a pinkish color, resorufin from resazurin indicator. The lowest concentration of the antifungal drug that maintained the blue color of the calorimetric indicator determined the MBIC (Figure 1).


Biofilm Formation and Susceptibility to Amphotericin B and Fluconazole in Candida albicans.

Zarei Mahmoudabadi A, Zarrin M, Kiasat N - Jundishapur J Microbiol (2014)

Resazurin Dye TestResazurin dye test for determining MBIC of amphotericine B and fluconazole to C. albicans at serial concentrations from 1280 to 10 µL/mL, C1AMB, C. albicans (No. 1) amphotericine B; C1FLC, C. albicans (No. 1) fluconazole; C2AMB, C. albicans (No. 2) amphotericine B; C2FLC, C. albicans (No. 2) fluconazole.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4216586&req=5

fig11529: Resazurin Dye TestResazurin dye test for determining MBIC of amphotericine B and fluconazole to C. albicans at serial concentrations from 1280 to 10 µL/mL, C1AMB, C. albicans (No. 1) amphotericine B; C1FLC, C. albicans (No. 1) fluconazole; C2AMB, C. albicans (No. 2) amphotericine B; C2FLC, C. albicans (No. 2) fluconazole.
Mentions: Minimum biofilm inhibitory concentration test: the minimum biofilm inhibitory concentration (MBIC) test was performed by a technique using the calorimetric indicator resazurin (5, 13). Firstly, 90 µL of SDB supplemented with 8% glucose was added to each well of the microplate. Secondly, 10 µL of yeast suspension was also added and incubated at 37°C for 48 hours. All media were removed from wells and wells washed three times with 0.9% NaCl. Serial dilutions of each antifungal agent were prepared from 1280-10 µL/mL in RPMI 1640. Next, 100 µL of each antifungal agent was added to each well and incubated at 37°C for 24 hours. A series of wells without antifungal drugs and un-inoculated wells served as positive and negative controls, respectively. All experiments were done in triplicates. When active cells of yeast (live cells) were present in wells, they produced a pinkish color, resorufin from resazurin indicator. The lowest concentration of the antifungal drug that maintained the blue color of the calorimetric indicator determined the MBIC (Figure 1).

Bottom Line: The results indicated that 100% of C. albicans isolates from different sources had the ability to form biofilms in vitro.Our results showed that 65.0% of the tested isolates are sensitive to amphotericin B at amounts lower than 10 µg/mL, while only 26.7% are sensitive to fluconazole (had MBIC < 10 µg/mL).In addition, there were differences in the MBIC against the two examined antifungals, amphotericin B and fluconazole.

View Article: PubMed Central - PubMed

Affiliation: Health Research Institute, Infectious and Tropical Diseases Research Centre, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran ; Department of Medical Mycology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.

ABSTRACT

Background: The ability of Candida albicans to form biofilms and adhere to host tissues and biomaterial surfaces is an important factor in its pathogenesis. One of the main characteristics of biofilms is their resistance to broad-spectrum anti-microbial drugs.

Objectives: In the present study the formation of biofilm by C. albicans from different sources was evaluated. In addition, the minimum biofilm inhibitory concentration (MBIC) for two antifungals was evaluated.

Materials and methods: In total, 120 isolates of C. albicans from different sources (patients with vaginitis, patients with candiduria, bucal cavity and environmental surfaces) were collected. Biofilm formation was determined by the 96-well micro-titeration plate method. MBIC testing was also performed, using the calorimetric indicator resazurin for amphotericin B and fluconazole.

Results: The results indicated that 100% of C. albicans isolates from different sources had the ability to form biofilms in vitro. Amongst these isolates, 83.3% of isolates had the maximum potential (4+) to form biofilms, while only one (0.9%) of isolates had the minimum ability (1+) to form biofilms. Our results showed that 65.0% of the tested isolates are sensitive to amphotericin B at amounts lower than 10 µg/mL, while only 26.7% are sensitive to fluconazole (had MBIC < 10 µg/mL).

Conclusions: Although biofilm formation was detected in all tested isolates, there were differences in the ability to form biofilms between isolates from different sources. In addition, there were differences in the MBIC against the two examined antifungals, amphotericin B and fluconazole.

No MeSH data available.


Related in: MedlinePlus