scholarly journals Influence of biosynthesized silver nanoparticles on keratinase activity and mycelialgrowth of dermatophytes

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Adnan Hamad Uobeed Al Hamadani ◽  
Balsam Miri Mizher Al Muhna
Keyword(s):  
Silver Nanoparticles ◽  
Aspergillus Niger ◽  
Antifungal Drugs ◽  
Toxic Waste ◽  
Morphological Alteration ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Activity Comparison ◽  
Cell Free Filtrate

Among different nanomaterial,the silver nanoparticles (SNPs) exhibited high antifungal potency compared with other types of nanoparticles (NPs),and this property is often very helpful,particularly against fungi resistant to conventional antifungal agents. However synthesis of SNPs can generate toxic waste during the preparation process. Accordingly,new technique using non-toxic routs have been researched for synthesis of SNPs using cell-free filtrate of Aspergillus niger and evaluate their effect against some dermatophytes spp.The proposal of our study was to biosynthesize SNPs using cell-free filtrate of Aspergillus niger as reducing agent. The characterization of biosynthesized SNPs were carried out by UV-Visible spectroscopy,Fourier transform infrared spectroscopic analysis (FTIR) and scanning electron microscopy (SEM).The antifungal effect of the NPs against dermatophytes was also evaluated. The minimum inhibitory concentration (MIC) was determined by broth microdilution method. pherical NPs 15-50 nm in size were obtained.The biosynthesized SNPs exerted pronounced morphological alteration in the fungal mycelia.Additionally,the inhibition of keratinase activity of the tested dermatophytes was also recorded.The results indicate that SNps can be synthesized in ecofriendly,inexpensive and promising technique by fungal strain of A.niger,and it has considerable antifungal activity comparison with other antifungal drugs.

scholarly journals Evaluation of semisolid agar method for antifungal susceptibility test of T. rubrum

2016 ◽  
Vol 7 (1) ◽  
pp. 11
Author(s):  
Sultana Razia ◽  
Shahida Anwar ◽  
Md. Ruhul Amin Miah ◽  
Najmun Nahar ◽  
Ripon Barua
Keyword(s):  
Antifungal Agents ◽  
Antifungal Susceptibility ◽  
Antifungal Drugs ◽  
Test Method ◽  
Susceptibility Test ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Antifungal Susceptibility Test ◽  
Mic Value

<p><strong>Background:</strong> With increasing fungal disease many newer antifungal drugs are available with different spectrum of activ­ity. Antifungal susceptibility test will help clinicians for selection of effective drug and thereby treatment of patient.<strong> </strong></p><p><strong>Objective:</strong> The study was undertaken to perform a simple screening drug susceptibility test of T. rnbrum by Semi Solid Agar Antifungal Susceptibility (SAAS) <strong></strong></p><p><strong>Method:</strong> Perfonnance of susceptibility method was assessed by comparing the MICs of three commonly prescribed antifungal agents namely- tluconazole (FCZ), itraconazole (ITZ) and terbinafine (TER) to the CLSI (Clinical and Laboratory Standard Institute) recommended M-38, a broth microdilution method. <strong></strong></p><p><strong>Results:</strong> In SAAS method, among twenty nine T. rubrum, twenty five (86.2%) were susceptible (MIC range 0.5-64 µg/ml) to Fluconazole (FCZ) and four (13.7%) were resistant (MIC value &gt;64 µg/ml). In broth microdilution method, among twenty nine T. rubrum, twenty six (89.6%) were susceptible (MIC range 0.3-64 µg/ml) to FCZ and three (10.3%) were resistant (MIC value &gt;64 µg/ml). In case of both ITZ and TER, all were susceptible (MIC range 0.3-64 µg/ml) to both methods. The SAAS method demonstrated the susceptibility pattern of T. rubrum against FCZ, ITZ and TER usually within 72 to 96 hours after organism isolation and results were concordance with the results of CLSI broth microdilution method. <strong></strong></p><p><strong>Conclusion:</strong> Though it is a newer method with proper standardization of the test method, SAAS method is simple and easily applicable screening method for susceptibility testing of antifungal agents against dermatophytes in any microbiology laboratories.</p>

scholarly journals Antifungal Susceptibility of Dermatophytes Isolated From Cutaneous Fungal Infections: The Vietnamese Experience

2019 ◽  
Vol 7 (2) ◽  
pp. 247-249
Author(s):  
Chau Van Tro ◽  
Khuong Ho Thi Ngoc ◽  
Thuong Nguyen Van ◽  
Khang Tran Hau ◽  
Marco Gandolfi ◽  
...  
Keyword(s):  
Fungal Infections ◽  
Antifungal Susceptibility ◽  
Antifungal Drugs ◽  
Broth Microdilution ◽  
Direct Examination ◽  
Sensitivity Testing ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Vietnamese Population

AIM: Evaluate the resistance of dermatophytes to systemic antifungal drugs in the Vietnamese population. METHODS: We enrolled 101 patients with cutaneous dermatophytosis at the Dermato-Venereology hospital in HCMC from August 2016 to March 2017. All the specimens were subjected to direct examination (10% KOH mount) and culture on Sabouraud dextrose agar. In vitro antifungal sensitivity testing was done on species isolated from a culture with broth microdilution method. RESULTS: Direct microscopy was positive for dermatophytes in all patients. However this pathogen was found in fungal cultures in only 61.38% of patients. The main causative agent isolated was Trichophyton spp. (90.3%), followed by Microsporum spp. (8%) and Epidermophyton spp. (1.7%). Trichophyton spp. Has shown resistance to fluconazole, griseofulvin, ketoconazole, and itraconazole in 92.9%, 46.4%, 5.4% and 1.8% of strains, respectively. All Microsporum spp. Strains were found resistant to fluconazole and griseofulvin while resistance to ketoconazole was demonstrated in only 20% of strains and none of them was resistant to itraconazole. Epidermophyton spp strains were all resistant to fluconazole, griseofulvin, ketoconazole while none of them was resistant to itraconazole. CONCLUSION: Based upon our results, Itraconazole shows the greatest probability of efficacy in the treatment of cutaneous dermatophytosis in Vietnamese patients.

scholarly journals Candida auris infection in the central catheter of a patient without sepsis symptoms

2019 ◽  
Vol 50 (4) ◽  
pp. 293-98
Author(s):  
Luz Angela Castro ◽  
María Inés Álvarez ◽  
Gustavo Giusiano ◽  
Ernesto Martínez
Keyword(s):  
Venous Catheter ◽  
Underlying Disease ◽  
Antifungal Drugs ◽  
Candida Auris ◽  
Great Ability ◽  
Ionization Time ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Candida Infections ◽  
Specific Technology

Background: Candida auris is an emerging yeast frequently reported as resistant to multiple antifungal drugs commonly used to treat Candida infections. This specie can colonize the patient’s skin and has great ability for producing outbreaks in hospitals. C. auris is phylogenetically related to other Candida species, can be misidentified using conventional biochemical or commercial methods and requires specific technology for its identification. Case report: We report the first isolate of C. auris in Cali, Colombia, from a central venous catheter in a 37-year-old patient with rheumatoid arthritis and endocarditis who did not have symptoms of sepsis. The yeast was initially misidentified as C. haemulonii using the Phoenix® system and subsequently identified as C. auris by matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry. The broth microdilution method was used to determine the minimum inhibitory concentration; the isolate was susceptible to fluconazole, itraconazole, voriconazole and amphotericin B. Conclusions: This report contributes to knowledge of the epidemiology of C. auris infections in individuals with underlying disease and describes an isolate with a behavior different from what is usually reported.

Biosynthesis and Characterization of Silver Nanoparticles from Aspergillus niger and its Antibacterial Activity

2018 ◽  
Vol 11 (12) ◽  
pp. 5282 ◽  
Author(s):  
Suresh Dhanaraj ◽  
P. Bharathiraja ◽  
R. Dhandapani ◽  
R. Subbaiya ◽  
A. K. Kathireshan
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Aspergillus Niger

scholarly journals Comparative Evaluation of a New Fluorescent Carboxyfluorescein Diacetate-Modified Microdilution Method for Antifungal Susceptibility Testing of Candida albicans Isolates

2002 ◽  
Vol 46 (10) ◽  
pp. 3236-3242 ◽  
Author(s):  
Robert S. Liao ◽  
Robert P. Rennie ◽  
James A. Talbot
Keyword(s):  
Candida Albicans ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Antifungal Drugs ◽  
Alamar Blue ◽  
Broth Microdilution ◽  
Modified Method ◽  
Microdilution Method ◽  
Growth Phenomenon ◽  
Broth Microdilution Method

ABSTRACT This report presents a fluorescent carboxyfluorescein diacetate (CFDA)-modified microdilution method used for the susceptibility testing of Candida albicans to amphotericin B, fluconazole, ketoconazole, itraconazole, voriconazole, and flucytosine. Four different broth microdilution susceptibility testing methods were simultaneously evaluated at 24 and 48 h. The MICs determined using the CFDA-modified method (MICcfda) were compared to those obtained by the standard broth microdilution method (MICvisual) and a procedure employing the indicator Alamar blue (MICalamar). The reference MIC was determined visually as recommended by the NCCLS M27-A protocol, and then quantified spectrophotometrically following agitation (MICspec). The CFDA-modified microdilution method was demonstrated to effectively determine the MICs for all the antifungal drugs tested at both 24 and 48 h. The results from both the MICspec and MICcfda methods yielded >80% agreement within ±1 dilution and >90% agreement within ±2 dilutions at 24 h in comparison to the reference MICvisual method, respectively. The trailing growth phenomenon that occurs with azole antifungal drugs and many strains of C. albicans did not inhibit the effectiveness of the MICspec and MICcfda methods. The MICspec and MICcfda methods shared 92.8% agreement within ±1 dilution at 24 h and 87.6% agreement within ±1 dilution at 48 h.

scholarly journals A survey on the characterization and biological activity of isatin derivatives

2020 ◽  
Vol 85 (8) ◽  
pp. 979-1000
Author(s):  
Sasa Drmanic ◽  
Predrag Petrovic ◽  
Dominik Brkic ◽  
Aleksandar Marinkovic ◽  
Jasmina Nikolic
Keyword(s):  
Chemical Shifts ◽  
Biological Activities ◽  
Primary Amines ◽  
Geometrical Isomers ◽  
Linear Free Energy ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Energy Relationships ◽  
Popular Subject

The derivatives of isatin have already been known to display a variety of biological activities. Therefore, the studies on their activity and its relation to structure have recently become a popular subject for investigation. The examined compounds were synthesized by the reaction of isatin and substituted primary amines and characterized by spectroscopic methods. The investigation of the antimicrobial and antioxidative activity of the synthesized compounds was performed by broth microdilution method. As for the characterization of the investigated isatin based Schiff bases, the linear solvation energy relationships (LSER) were used to analyze the solvent influence on the UV absorption maxima shifts (?max), using the well known Kamlet?Taft model and taking geometrical isomers into consideration when possible. Linear free energy relationships (LFER) were used to analyze substituent effect on pKa, as well as NMR chemical shifts and ?max values. The antimicrobial activity and characterization were related using both experimental and theoretical methods.

scholarly journals Subinhibitory Concentrations of Biogenic Silver Nanoparticles Affect Motility and Biofilm Formation in Pseudomonas aeruginosa

2021 ◽  
Vol 11 ◽  
Author(s):  
Erika Kushikawa Saeki ◽  
Amanda Yaeko Yamada ◽  
Larissa Amianti de Araujo ◽  
Laís Anversa ◽  
Doroti de Oliveira Garcia ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Silver Nanoparticles ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Twitching Motility ◽  
Chronic Infections ◽  
Biogenic Silver Nanoparticles ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Subinhibitory Concentrations

Biogenic silver nanoparticles (bio-AgNPs) are increasingly recognized as an antibiofilm and antivirulence strategy against P. aeruginosa, a bacterium that causes chronic infections in immunocompromised and cystic fibrosis patients. This study aimed to investigate the effects of subinhibitory concentrations of bio-AgNPs on motility and biofilm formation in P. aeruginosa. Bio-AgNPs were synthesized via reduction of ionic silver catalyzed by cell-free culture filtrate from Fusarium oxysporum. A total of 17 P. aeruginosa isolates and strains were evaluated for swarming, swimming, and twitching motility in the presence and absence (control) of bio-AgNPs, including 10 clinical isolates from patients with and without cystic fibrosis, 5 environmental isolates obtained from the public water supply system, and 2 reference strains (PAO1 and PA14). Isolates were identified by biochemical and molecular methods. Minimum inhibitory concentrations (MICs) were determined by the broth microdilution method. Swarming, swimming, and twitching motility assays were performed in Petri dishes. Biofilm formation capacity was assessed quantitatively by the crystal violet method. MIC values ranged from 15.62 to 62.50 µM. The results showed that subinhibitory concentrations of bio-AgNPs (½ MIC, 7.81–31.25 µM) significantly increased (p &lt; 0.05) swarming, swimming, and twitching motility in 40.0, 40.0, and 46.7% of isolates, respectively. Subinhibitory bio-AgNP treatment enhanced (p &lt; 0.05) biofilm formation capacity in PA14 and a cystic fibrosis isolate (P11). It is concluded that subinhibitory concentrations of bio-AgNPs increased biofilm formation and swarming, swimming, and twitching motility in PA14 and some P. aeruginosa isolates. These virulence factors are directly involved with quorum-sensing systems. Further research should investigate the effects of AgNPs on P. aeruginosa quorum sensing to help elucidate their mechanism of action at subinhibitory concentrations.

Effects of calcineurin inhibitors, cyclosporine A and tacrolimus (FK506), on the activity of antifungal drugs against Candida spp.

2021 ◽  
Vol 70 (4) ◽  
Author(s):  
Sümeyye Şen Kaya ◽  
Nuri Kiraz ◽  
Ayşe Bariş ◽  
Deniz Turan ◽  
Yasemin Öz ◽  
...  
Keyword(s):  
Cyclosporine A ◽  
Fungal Infections ◽  
Immunosuppressive Agents ◽  
Calcineurin Inhibitors ◽  
Antifungal Drugs ◽  
Synergistic Activity ◽  
Candida Spp ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Time Kill

Introduction. The simultaneous use of antifungals with immunosuppressive agents has become a necessity for patients taking immunosuppressive therapy. However, antifungal drugs are problematic because of their limited target. Hypothesis. Scientists have been searching for new antifungals and some compounds with at least additive effects on antifungals. Calcineurin inhibitors used as immunosuppressive agents also attract attention due to their antifungal property. Aim. To evaluate the activity of two calcineurin inhibitors alone and in combination with amphotericin B (AMB), caspofungin (CAS), itraconazole (ITR), voriconazole (VOR) and fluconazole (FLU). Methodology. MICs of AMB, CAS, ITR, VOR, FLU and cyclosporine A (CsA) and tacrolimus (TAC) as calcineurin inhibitors were evaluated by the broth microdilution method against Candida albicans (n=13), C. krusei (n=7) and C. glabrata (n=10). Checkerboard and time-kill methods were performed to investigate the activity of combining calcineurin inhibitors with antifungal drugs. Results. The lowest MIC values were detected with VOR for all Candida isolates tested. Although we did not detect any inhibition for CsA or TAC alone at concentrations tested in this study, the combinations of CAS with CsA showed the highest synergistic activity (36.7%) by the checkerboard method, and CAS with CsA and ITR with TAC combinations exhibited apparent synergistic interaction by the time-kill method. However, the combinations of both CsA and TAC with AMB resulted in antagonistic interactions, especially against C. krusei isolate in time-kill testing. Conclusion. Synergistic interactions in the combinations of TAC or CsA with antifungal drugs, except for AMB, in many concentrations was found to be promising in terms of the treatment of patients with fungal infections.

scholarly journals In Vitro Antifungal Susceptibility and Molecular Characterization of Clinical Isolates of Fusarium verticillioides (F. moniliforme) and Fusarium thapsinum

2008 ◽  
Vol 52 (6) ◽  
pp. 2228-2231 ◽  
Author(s):  
Mónica Azor ◽  
Josepa Gené ◽  
Josep Cano ◽  
Deanna A. Sutton ◽  
Annette W. Fothergill ◽  
...  
Keyword(s):  
Active Drug ◽  
Fusarium Verticillioides ◽  
Antifungal Susceptibility ◽  
Antifungal Drugs ◽  
Clinical Isolates ◽  
Microdilution Method ◽  
Fusarium Thapsinum ◽  
In Vitro Antifungal Susceptibility

ABSTRACT A microdilution method was used to test 11 antifungal drugs against clinical isolates of Fusarium thapsinum and three different phylogenetic clades of Fusarium verticillioides that were characterized by sequencing a region of the β-tubulin gene. Terbinafine was the most-active drug against both species, followed by posaconazole against F. verticillioides.

scholarly journals Evaluation of susceptibility of Trichophyton mentagrophytes and Trichophyton rubrum clinical isolates to antifungal drugs using a modified CLSI microdilution method (M38-A)

2007 ◽  
Vol 56 (4) ◽  
pp. 514-518 ◽  
Author(s):  
Maria Elisabete da Silva Barros ◽  
Daniel de Assis Santos ◽  
Júnia Soares Hamdan
Keyword(s):  
Antifungal Agents ◽  
Susceptibility Testing ◽  
Incubation Temperature ◽  
Trichophyton Rubrum ◽  
Trichophyton Mentagrophytes ◽  
Antifungal Drugs ◽  
Standard Protocol ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method

Onychomycosis is a common adult human mycosis, and dermatophytes of the Trichophyton genera are the most common causative agent. Many antimycotic agents are safe and highly effective for the treatment of dermatophytosis, and are available for clinical practice. Successful treatment depends on the ability of antifungal drugs to eradicate the fungal isolates. The aim of this work was to determine the MICs of four antifungal drugs (fluconazole, itraconazole, terbinafine and griseofulvin) recognized for ungual dermatophytosis treatment caused by Trichophyton species, especially Trichophyton mentagrophytes and Trichophyton rubrum. MICs were determined using a broth microdilution method in accordance with Clinical and Laboratory Standards Institute approved standard M38-A with some modifications, such as an incubation temperature of 28 °C, an incubation time of 7 days and inocula constituted of only microconidia. The results showed that the activities of terbinafine and itraconazole were significantly higher (MICs of <0.007–0.031 and 0.015–0.25 μg ml−1, respectively) than other tested agents. All isolates had reduced susceptibility to fluconazole (1–64 μg ml−1). The MIC of griseofulvin varied among strains (MICs of 0.062–1 μg ml−1). The parameters adopted to perform susceptibility testing of T. rubrum and T. mentagrophytes to antifungal agents appeared to be suitable and reliable, and could contribute to the possible development of a standard protocol.

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