scholarly journals In vitro effects of glycyrrhetinic acid and hyaluronic acid on the growth of vulvovaginal Candida albicans and other yeasts

2017 ◽  
Vol 32 (4) ◽  
Author(s):  
Martina Stevan ◽  
Eleonora Fusato ◽  
Decio Armanini ◽  
Giulio Bertoloni ◽  
Francesco De Seta ◽  
...  

Aims. The present study aimed to test the in vitro activity against Candida albicans and non-albicans strains of 18-β glycyrrhetinic acid (18-β GA) and hyaluronic acid (HA), both alone and in combination. This antimicrobial activity was assessed using the National Committee for Clinical Laboratory Standards (NCCLS) method on Candida strains that were isolated from patients with recurrent vulvovaginal candidiasis (RVVC). Results. Our results demonstrate that the anti-Candida activity is independent from antifungal susceptibility level and the fact that the growth inhibition is stronger at acidic pH level makes the two drugs a promising biological alternative for the topical treatment of vulvovaginal candidiasis (VVC) and RVVC. Conclusions. Furthermore, the reduction of both budding cells formation and germ tube elongation, on mammalian cell monolayers, may explain the observed growth inhibition and suggest a decreased virulence, respectively.

1996 ◽  
Vol 40 (9) ◽  
pp. 1998-2003 ◽  
Author(s):  
J L Rodríguez-Tudela ◽  
J Berenguer ◽  
J V Martínez-Suárez ◽  
R Sanchez

The National Committee for Clinical Laboratory Standards has proposed a reference broth macrodilution method for in vitro antifungal susceptibility testing of yeasts (the M27-P method). This method is cumbersome and time-consuming and includes MIC endpoint determination by visual and subjective inspection of growth inhibition after 48 h of incubation. An alternative microdilution procedure was compared with the M27-P method for determination of the amphotericin B, flucytosine, and fluconazole susceptibilities of 8 American Type Culture Collection strains (6 of them were quality control or reference strains) and 50 clinical isolates of candida albicans. This microdilution method uses as culture medium RPMI 1640 supplemented with 18 g of glucose per liter (RPMI-2% glucose). Preparation of drugs, basal medium, and inocula was done by following the recommendations of the National Committee for Clinical Laboratory Standards. The MIC endpoint was calculated objectively from the turbidimetric data read at 24 h. Increased growth of C. albicans in RPMI-2% glucose and its spectrophotometric reading allowed for the rapid (24 h) and objective calculation of MIC endpoints compared with previous microdilution methods with standard RPMI 1640. Nevertheless, good agreement was shown between the M27-P method and this microdilution test. The MICs obtained for the quality control or reference strains by the microdilution method were in the ranges published for those strains. For clinical isolates, the percentages of agreement were 100% for amphotericin B and fluconazole and 98.1% for flucytosine. These data suggest that this microdilution method may serve as a less subjective and more rapid alternative to the M27-P method for antifungal susceptibility testing of yeasts.


1997 ◽  
Vol 41 (3) ◽  
pp. 575-577 ◽  
Author(s):  
M Ruhnke ◽  
A Schmidt-Westhausen ◽  
M Trautmann

The susceptibility of Candida albicans to a new antifungal triazole, voriconazole (UK-109,496), was investigated in 105 isolates obtained from the oral cavities of patients with human immunodeficiency virus (HIV) infection to study this drug's activity against fluconazole-susceptible and -resistant isolates. MICs were determined by a broth microdilution technique according to document M27-T from the National Committee for Clinical Laboratory Standards and by using a broth microdilution technique and a synthetic high-resolution medium. These antifungal susceptibility testing methods showed high levels of agreement (93% for fluconazole and 86% for voriconazole). Data from in vitro studies showed that voriconazole has good activity against fluconazole-susceptible and -resistant C. albicans isolates; the MICs at which 90% of all isolates were inhibited were 0.19 to 0.39 microgram/ml. We found that for isolates for which fluconazole MICs were high, voriconazole MICs were proportionally higher than those for fluconazole-susceptible C.albicans (P < 0.001). Pretreatment isolates from six patients with fluconazole-refractory esophageal candidiasis were included in the study. For these isolates the MICs were < or = 0.39 microgram/ml, and all patients responded to voriconazole. These results suggest that voriconazole is effective even in the treatment of fluconazole-refractory esophageal candidiasis and should be studied further to determine its clinical relevance in patients with HIV infection.


1999 ◽  
Vol 45 (10) ◽  
pp. 871-874 ◽  
Author(s):  
Eric Dannaoui ◽  
Florence Persat ◽  
Marie-France Monier ◽  
Elisabeth Borel ◽  
Marie-Antoinette Piens ◽  
...  

A comparative study of visual and spectrophotometric MIC endpoint determinations for antifungal susceptibility testing of Aspergillus species was performed. A broth microdilution method adapted from the National Committee for Clinical Laboratory Standards (NCCLS) was used for susceptibility testing of 180 clinical isolates of Aspergillus species against amphotericin B and itraconazole. MICs were determined visually and spectrophotometrically at 490 nm after 24, 48, and 72h of incubation, and MIC pairs were compared. The agreement between the two methods was 99% for amphotericin B and ranged from 95 to 98% for itraconazole. It is concluded that spectrophotometric MIC endpoint determination is a valuable alternative to the visual reference method for susceptibility testing of Aspergillus species.Key words: antifungal, susceptibility testing, Aspergillus, spectrophotometric reading.


2000 ◽  
Vol 44 (8) ◽  
pp. 2081-2085 ◽  
Author(s):  
Beth A. Arthington-Skaggs ◽  
David W. Warnock ◽  
Christine J. Morrison

ABSTRACT MIC end point determination for the most commonly prescribed azole antifungal drug, fluconazole, can be complicated by “trailing” growth of the organism during susceptibility testing by the National Committee for Clinical Laboratory Standards approved M27-A broth macrodilution method and its modified broth microdilution format. To address this problem, we previously developed the sterol quantitation method (SQM) for in vitro determination of fluconazole susceptibility, which measures cellular ergosterol content rather than growth inhibition after exposure to fluconazole. To determine if SQM MICs of fluconazole correlated better with in vivo outcome than M27-A MICs, we used a murine model of invasive candidiasis and analyzed the capacity of fluconazole to treat infections caused by C. albicansisolates which were trailers (M27-A MICs at 24 and 48 h, ≤1.0 and ≥64 μg/ml, respectively; SQM MIC, ≤1.0 μg/ml), as well as those which were fluconazole sensitive (M27-A and SQM MIC, ≤1.0 μg/ml) and fluconazole resistant (M27-A MIC, ≥64 μg/ml; SQM MIC, 54 μg/ml). Compared with the untreated controls, fluconazole therapy increased the survival of mice infected with a sensitive isolate and both trailing isolates but did not increase the survival of mice infected with a resistant isolate. These results indicate that the SQM is more predictive of in vivo outcome than the M27-A method for isolates that give unclear MIC end points due to trailing growth in fluconazole.


2006 ◽  
Vol 19 (2) ◽  
pp. 435-447 ◽  
Author(s):  
M. A. Pfaller ◽  
D. J. Diekema ◽  
D. J. Sheehan

SUMMARY Developing interpretive breakpoints for any given organism-drug combination requires integration of the MIC distribution, pharmacokinetic and pharmacodynamic parameters, and the relationship between in vitro activity and outcome from both in vivo and clinical studies. Previously, the Subcommittee for Antifungal Testing of the Clinical and Laboratory Standards Institute (CLSI [formerly National Committee for Clinical Laboratory Standards]) proposed MIC interpretive breakpoints for fluconazole and Candida spp. These breakpoints were considered to be somewhat weak, because the clinical data supporting them came largely from mucosal infections and there were very few infections involving strains with elevated fluconazole MICs. We readdress the issue of fluconazole breakpoints for Candida by using published clinical and microbiologic data to provide further validation of the breakpoints proposed by the CLSI in 1997. We also address interpretive breakpoints for agar disk diffusion testing of fluconazole. The MIC distribution for fluconazole was determined with a collection of 13,338 clinical isolates. The overall MIC at which 90% of the isolates were inhibited was 8 μg/ml: 91% were susceptible (S) at a MIC of ≤8 μg/ml and 3% were resistant (R) (MIC ≥ 64 μg/ml). Similar results were obtained for 2,190 isolates from randomized clinical trials. Analysis of available data for 1,295 patient-episode-isolate events (692 represented mucosal infections and 603 represented invasive infections) from 12 published clinical studies demonstrated an overall success rate of 77%, including 85% for those episodes in which the fluconazole MIC was ≤8 μg/ml, 67% for those episodes in which the MIC was 16 to 32 μg/ml, and 42% for those episodes with resistant (MIC ≥ 64 μg/ml) isolates. Pharmacodynamic analysis demonstrated a strong relationship between MIC, fluconazole dose, and outcome. A dose/MIC ratio of ∼25 was supportive of the following susceptibility breakpoints for fluconazole and Candida spp.: S, MIC ≤ 8 μg/ml; susceptible-dose dependent (SDD), MIC = 16 to 32 μg/ml; R, MIC ≥ 64 μg/ml. The corresponding disk test breakpoints are as follows: S, ≥19 mm; SDD, 15 to 18 mm; R, ≤14 mm.


1998 ◽  
Vol 42 (5) ◽  
pp. 1057-1061 ◽  
Author(s):  
Neil S. Ryder ◽  
Sonja Wagner ◽  
Ingrid Leitner

ABSTRACT Terbinafine is active in vitro against a wide range of pathogenic fungi, including dermatophytes, molds, dimorphic fungi, and some yeasts, but earlier studies indicated that the drug had little activity against Candida albicans. In contrast, clinical studies have shown topical and oral terbinafine to be active in cutaneous candidiasis and Candida nail infections. In order to define the anti-Candida activity of terbinafine, we tested the drug against 350 fresh clinical isolates and additional strains by using a broth dilution assay standardized according to the guidelines of the National Committee for Clinical Laboratory Standards (NCCLS) M27-A assay. Terbinafine was found to have an MIC of 1 μg/ml for reference C. albicans strains. For 259 clinical isolates, the MIC at which 50% of the isolates are inhibited (MIC50) of terbinafine was 1 μg/ml (fluconazole, 0.5 μg/ml), and the MIC90 was 4 μg/ml (fluconazole, 1 μg/ml). Terbinafine was highly active against Candida parapsilosis(MIC90, 0.125 μg/ml) and showed potentially interesting activity against isolates of Candida dubliniensis,Candida guilliermondii, Candida humicola, andCandida lusitaniae. It was not active against theCandida glabrata, Candida krusei, andCandida tropicalis isolates in this assay.Cryptococcus laurentii and Cryptococcus neoformans were highly susceptible to terbinafine, with MICs of 0.06 to 0.25 μg/ml. The NCCLS macrodilution assay provides reproducible in vitro data for terbinafine against Candidaand other yeasts. The MICs for C. albicans and C. parapsilosis are compatible with the known clinical efficacy of terbinafine in cutaneous infections, while the clinical relevance of its activities against the other species has yet to be determined.


2001 ◽  
Vol 45 (6) ◽  
pp. 1854-1859 ◽  
Author(s):  
Gloria M. González ◽  
Rolando Tijerina ◽  
Laura K. Najvar ◽  
Rosie Bocanegra ◽  
Michael Luther ◽  
...  

ABSTRACT Caspofungin (Merck Pharmaceuticals) was tested in vitro against 25 clinical isolates of Coccidoides immitis. In vitro susceptibility testing was performed in accordance with the National Committee for Clinical Laboratory Standards document M38-P guidelines. Two C. immitis isolates for which the caspofungin MICs were different were selected for determination of the minimum effective concentration (MEC), and these same strains were used for animal studies. Survival and tissue burdens of the spleens, livers, and lungs were used as antifungal response markers. Mice infected with strain 98-449 (48-h MIC, 8 μg/ml; 48-h MEC, 0.125 μg/ml) showed 100% survival to day 50 when treated with caspofungin at ≥1 mg/kg. Mice infected with strain 98-571 (48-h MIC, 64 μg/ml; 48-h MEC, 0.125 μg/ml) displayed ≥80% survival when the treatment was caspofungin at ≥5 mg/kg. Treatment with caspofungin at 0.5, 1, 5, or 10 mg/kg was effective in reducing the tissue fungal burdens of mice infected with either isolate. When tissue fungal burden study results were compared between strains, caspofungin showed no statistically significant difference in efficacy in the organs of the mice treated with both strains. A better in vitro-in vivo correlation was noted when we used the MEC instead of the MIC as the endpoint for antifungal susceptibility testing. Caspofungin may have a role in the treatment of coccidioidomycosis.


1999 ◽  
Vol 37 (1) ◽  
pp. 195-198 ◽  
Author(s):  
Sanjay G. Revankar ◽  
Deanna A. Sutton ◽  
Stephen E. Sanche ◽  
Jyothi Rao ◽  
Marcus Zervos ◽  
...  

Metarrhizium anisopliae is a common pathogen of insects and has even been used to control insect populations. It is rarely isolated from human or animal sources, but recently, there have been three reported cases of disease, two in humans and one in a cat. We present our experience with five isolates from human sources, including two that were the apparent causes of two cases of sinusitis in immunocompetent hosts. The first patient was a 36-year-old male with frontal and ethmoid sinusitis, and the second was a 79-year-old female with chronic sinusitis. Both patients underwent surgery, and pathology of the surgical specimens revealed branching hyphae. Cultures grew onlyMetarrhizium species. Neither patient received antifungal therapy, and both did well postoperatively. The other three isolates were cultured from bronchoalveolar lavage specimens but were not felt to be clinically significant. Antifungal susceptibility testing using the National Committee for Clinical Laboratory Standards macrobroth method revealed that all isolates were resistant to amphotericin B, 5-flucytosine, and fluconazole. Itraconazole and newer azole compounds were more active. Metarrhizium species may cause disease in humans, even those without evidence of immunosuppression, and are apparently highly resistant to amphotericin B in vitro.


2014 ◽  
Vol 2 (1) ◽  
Author(s):  
K R Reddy ◽  
S Ram Reddy

Investigations on antifungal drug susceptibility were carried out on 90 clinical isolates of Trichophyton rubrum, and Trichophyton mentagrophytes with four antifungal drugs, namely griseofulvin, fluconazole, itraconazole and terbinafine as suggested by National Committee for Clinical Laboratory Standards (NCCLS) M27–A (1997) document by broth macrodilution method to standardize in vitro antifungal susceptibility testing and to find out the Minimum Inhibitory Concentration (MIC) of the drugs. In this study, terbinafine was found to be the most efficient drug for all isolates. Terbinafine had the lowest MIC range of 0.001 g/ml to 0.09 g/ml and MIC50 was low at 0.005 g/ml and MIC90 was also low at 0.04 g/ml against T.rubrum; and MIC range of 0.001μg/ml to 0.19μg/ml with a MIC50 of 0.01μg/ml and MIC90 at 0.09μg/ml against T.mentagrophytes. Itraconazole showed antifungal activity superior to that of fluconazole, with a MIC range of 0.04g/ml to 1.56g/ml, with MIC50 at 0.19μg/ml and MIC90 at 1.56g/ml against T.rubrum; and MIC range of 0.04μg/ml to 1.56μg/ml, with MIC50 at 0.19μg/ml and MIC90 at 0.78μg/ml against T.mentagrophytes. Griseofulvin appears to be still a potent drug for management of dermatophytoses. Griseofulvin had a MIC range of 0.15g/ml to 5.07 g/ml with MIC50 at1.26 g/ml and MIC90 at 2.53 g/ml against T.rubrum; and MIC range of 0.31μg/ml to 5.07μg/ml with MIC50 at 1.26μg/ml and MIC90 at 2.53μg/ml against T.mentagrophytes. Fluconazole showed a high MIC range of 0.19 g/ml to 50 g/ml and MIC50 was high at 1.56g/ml and MIC90 was also high at 12.5 g/ml against T.rubrum; and a high MIC range of 0.09μg/ml to 25.0μg/ml, with MIC50 at 1.56μg/ml and MIC90 at 12.5μg/ml towards T.mentagrophytes. The technique was found to be easy to perform and reliable with consistent results.


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