A disc test of antifungal susceptibility

Diagnostic laboratories are frequently requested to perform antifungal susceptibility tests on isolates recovered from systemic infections. A standard reference procedure of broth dilution was proposed by the Clinical and Laboratory Standards Institute (CLSI), but it is too labour-intensive for most clinical laboratories. CLSI also suggested a disc diffusion method, which is a cost-effective alternative method and simple to use in diagnostic microbiology laboratories. However, the method does not deal satisfactorily with the difficulty in interpretation of inhibitory zones on disc testing of those strains that show a ?trailing effect? on minimum inhibitory concentration (MIC) determination of the azole group of antifungals. Although disconcerting, trailing is regarded as an in vitro phenomenon and these strains are generally regarded as susceptible. We present a disc diffusion test for use with available antifungals, based on the Calibrated Dichotomous Sensitivity (CDS) method, used in antibiotic susceptibility testing of bacteria. The disc testing was done under predetermined optimal condition of growth, that overcame the problem of the ill-defined inhibitory zones of the azoles.

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Physical Properties, Chemical Analysis, and Evaluation of Antimicrobial Response of New Polylactide/Alginate/Copper Composite Materials

Marine Drugs ◽

10.3390/md18120660 ◽

2020 ◽

Vol 18 (12) ◽

pp. 660

Author(s):

Marcin H. Kudzin ◽

Maciej Boguń ◽

Zdzisława Mrozińska ◽

Anna Kaczmarek

Keyword(s):

Antifungal Susceptibility ◽

Attenuated Total Reflection ◽

Composite Fibers ◽

Protection Factor ◽

Average Pore ◽

Ultraviolet Protection Factor ◽

Susceptibility Tests ◽

Copper Composite

In recent years, due to an expansion of antibiotic-resistant microorganisms, there has been growing interest in biodegradable and antibacterial polymers that can be used in selected biomedical applications. The present work describes the synthesis of antimicrobial polylactide-copper alginate (PLA–ALG–Cu2+) composite fibers and their characterization. The composites were prepared by immersing PLA fibers in aqueous solution of sodium alginate, followed by ionic cross-linking of alginate chains within the polylactide fibers with Cu(II) ions to yield PLA–ALG–Cu2+ composite fibers. The composites, so prepared, were characterized by scanning electron microscopy (SEM), UV/VIS transmittance and attenuated total reflection Fourier-transform infrared spectroscopy ATR-FTIR, and by determination of their specific surface area (SSA), total/average pore volumes (through application of the 5-point Brunauer–Emmett–Teller method (BET)), and ability to block UV radiation (determination of the ultraviolet protection factor (UPF) of samples). The composites were also subjected to in vitro antimicrobial activity evaluation tests against colonies of Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria and antifungal susceptibility tests against Aspergillus niger and Chaetomium globosum fungal mold species. All the results obtained in this work showed that the obtained composites were promising materials to be used as an antimicrobial wound dressing.

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In vitro antifungal resistance profile of Candida strains isolated from Saudi women suffering from vulvovaginitis

European Journal of Medical Research ◽

10.1186/s40001-019-0399-0 ◽

2020 ◽

Vol 25 (1) ◽

Cited By ~ 5

Author(s):

Mohamed T. Yassin ◽

Ashraf A. Mostafa ◽

Abdulaziz A. Al-Askar ◽

Rashad Bdeer

Keyword(s):

Antifungal Agents ◽

Health Hazard ◽

Antifungal Susceptibility ◽

Public Health Problem ◽

Diffusion Method ◽

Its Sequencing ◽

Disc Diffusion ◽

Disc Diffusion Method ◽

Resistance Profile

Abstract Background Vulvovaginal candidiasis (VVC) represents a universal health hazard that contributes to significant morbidity in women. Resistance of Candida to antifungal therapy has been reported as a public health problem. So, the objective of our current study is to detect resistance profile of different candidal strains. Methods In this study, isolated Candida strains were identified by conventional methods, confirmed by internal transcribed spacer (ITS) sequencing, and phylogenetically analyzed with reference strains in GenBank. Also, sensitivity of different Candida strains to common antifungal agents was evaluated by disc diffusion method. Results Candida albicans was identified as the most frequent strain (63%) followed by non-albicans strains, such as C. glabrata (20%), C. tropicalis (13%), and C. krusei (4%). Sensitivity of Candida strains (C. albicans, C. tropicalis and C. glabrata) to commonly used antifungal agents was evaluated through the disc diffusion method. C. glabrata was the most resistant strain and considered to be a multidrug-resistant pathogen, while both, C. albicans and C. tropicalis showed high susceptibility to terbinafine. In contrast, C. albicans showed resistance to fluconazole, clotrimazole, and nystatin, while C. tropicalis, considered as the most sensitive strain, was susceptible to all the antifungal agents tested except nystatin. Terbinafine was the most effective antifungal agent against both C. tropicalis and C. albicans, and hence its minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) for C. albicans and C. tropicalis were evaluated. MICs of terbinafine against C. albicans and C. tropicalis were 5 μg/ml and 2.5 μg/ml, while their MFCs were 10 μg/ml and 5 μg/ml, respectively. Conclusion The emergence of resistant Candida strains necessitates conduction of the antifungal susceptibility test prior to deciding the medication regime.

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Isolation, Identification and Antifungal Susceptibility of Dermatophytes Isolated from Clinically Suspected Cases of Tinea Infections in Pakistan

Microbiology Research Journal International ◽

10.9734/mrji/2019/v29i530178 ◽

2019 ◽

pp. 1-11

Author(s):

Shumaila Shakir ◽

Sidrah Saleem ◽

Wajhiah Rizvi ◽

Waheed Aslam ◽

Javid Iqbal

Keyword(s):

Correct Diagnosis ◽

Antifungal Susceptibility ◽

Cost Effective ◽

Trichophyton Mentagrophytes ◽

Diffusion Method ◽

Fungal Culture ◽

Disk Diffusion Method ◽

Zones Of Inhibition ◽

In Vitro Antifungal Susceptibility

Dermatophytosis or tinea is a type of cutaneous infection caused by keratinophilic fungi, infecting the skin, nails and hair. A correct diagnosis is important for epidemiological purposes and initiating appropriate treatment. An increase in the prevalence of fungal infection worldwide is due to abuse of antibiotics, immunosuppressive treatments and numerous medical conditions. Aim: To isolate, identify, and examine the in-vitro antifungal susceptibility of dermatophytes in clinically suspected cases of tinea infections. Methodology: After taking informed consent, we took 65 patients suspected of tinea infection and obtained samples from skin, hair and nail, under aseptic precautions, at Department of Microbiology, University of Health Sciences (UHS), Lahore, Pakistan. The identification of dermatophytes was performed using potassium hydroxide (KOH) mounts and culture on Sabouraud Dextrose Agar (SDA) and Dermatophyte Test Medium (DTM). The cultures were incubated at 30ºC for up to 4 weeks in case of SDA and 2 weeks in case of DTM. Lactophenol cotton blue (LCB) stain was used to identify the species morphologically. Susceptibility test was done by agar diffusion method using antifungal disks and zones of inhibition were measured. Results: More females (55.38%) than males (44.61%) were observed in the study. Most of the cases belonged to the age categories of 1-10 years and 21-30 years. Tinea corporis was the most common clinical type found (27.69%) followed by Tinea capitis (21.53%) and Tinea cruris (12.30%).Trichophyton mentagrophytes was the commonest species isolated (32%) followed by Trichophyton violaceum (28%) and Trichophyton rubrum (12%). Terbinafine was seen to be the most effective drug against the isolates, followed by clotrimazole. Fluconazole showed least activity. Conclusion: Fungal culture remains the gold standard in identifying the causative species. Terbinafine promises to be a potent antifungal, whereas fluconazole has low efficacy against such organisms. Disk diffusion method adopted for antifungal susceptibility is cost effective and easily performable in small laboratories not having an established mycology bench.

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Bloodstream infections caused by Magnusiomyces capitatus and Magnusiomyces clavatus: epidemiological, clinical and microbiological features of two emerging yeast species

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01834-21 ◽

2021 ◽

Author(s):

Janina Noster ◽

Martin Köppel ◽

Marie Desnos-Olivier ◽

Maria Aigner ◽

Oliver Bader ◽

...

Keyword(s):

Antifungal Susceptibility ◽

Bloodstream Infections ◽

Its Sequencing ◽

Intrinsic Resistance ◽

Columbia Blood Agar ◽

Maldi Tof ◽

Invasive Infections ◽

Few Data

Background: Magnusiomyces clavatus and Magnusiomyces capitatus are emerging yeasts with intrinsic resistance to many commonly used antifungal agents. Identification is difficult, and determination of susceptibility patterns with commercial and reference methods is equally challenging. For this reason, few data on invasive infections by Magnusiomyces spp. are available. Objectives: To determine the epidemiology and susceptibility of Magnusiomyces isolates from bloodstream infections (BSI) isolated in Germany and Austria from 2001-2020. Methods: In seven institutions a total of 34 Magnusiomyces BSI were identified. Identification was done by ITS sequencing and MALDI-TOF MS. Antifungal susceptibility was determined by EUCAST broth microdilution and gradient tests. Results: Of the 34 isolates, M. clavatus was more common (N=24) compared to M. capitatus (N=10). BSI by Magnusiomyces spp. were more common in men (62%) and mostly occurred in patients with haemato-oncological malignancies (79%). The highest in vitro antifungal activity against M. clavatus / M. capitatus was observed for voriconazole (MIC 50 0.03/0.125 mg/L), followed by posaconazole (MIC 50 0.125/0.25 mg/L). M. clavatus isolates showed overall lower MICs compared to M. capitatus . With the exception of amphotericin B, low essential agreement between gradient test and microdilution was recorded for all antifungals (0-70%). Both species showed distinct morphologic traits on ChromAgar Orientation and Columbia blood agar, which can be used for differentiation if no MALDI-TOF or molecular identification is available. Conclusion: Most BSI were caused by M. clavatus. The lowest MICs were recorded for voriconazole. Gradient tests demonstrated unacceptably low agreement and should preferably not be used for susceptibility testing of Magnusiomyces spp.

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Komposisi Minyak Atsiri dan Aktivitas Antimikroba Rimpang Temu Putih dan Jahe Gajah sebagai Fitobiotik Pakan Unggas

Jurnal Ilmu dan Teknologi Peternakan Tropis ◽

10.33772/jitro.v6i2.5560 ◽

2019 ◽

Vol 6 (2) ◽

pp. 181

Author(s):

Laila Nur Rohma ◽

Osfar Sjofjan ◽

M. Halim Natsir

Keyword(s):

Escherichia Coli ◽

Antimicrobial Activity ◽

Essential Oil ◽

Essential Oils ◽

Feed Additives ◽

Diffusion Method ◽

Disc Diffusion ◽

Activity Test ◽

Main Component

ABSTRAK Imbuhan pakan unggas dapat berasal dari bahan herbal yang mengandung berbagai komponen aktif yang bermanfaat bagi pertumbuhan ternak.Temu putih dan jahe gajah dapat dimanfaatkan sebagai imbuhan pakan karena mengandung minyak atsiri yang dapat berperan sebagai agen antibakteri. Penelitian ini bertujuan untuk mengetahui komponen penyusun minyak atsiri dan aktivitas antimikroba pada rimpang temu putih dan jahe gajah. Penelitian dilakukan dengan percobaan in vitro menggunakan temu putih dan jahe gajah yang diolah menjadi bentuk ekstrak minyak atsiri temu putih dan jahe gajah sebagai materi uji komposisi penyusun minyak atsiri serta bentuktepung dan enkapsulasi sebagai materi uji aktivitas antimikroba. Komposisi minyak atsiri temu putih terdiri dari lima komponen penyusun dengan cis-1,7-octadien-3-yl acetat sebagai komponen utama. Komposisi minyak atsiri jahe gajah terdiri dari tujuh komponen dan benzene,1-(1,5-dimethyl-4-hexenyl)-4-methyl-(CAS) ar-curcumene sebagai komponen utama. Minyak atsiri yang terkandung pada temu putih dan jahe gajah mempunyai peran dalam menghambat mikroba. Uji komposisi penyusun minyak atsiri menggunakan alat GC-MS dan uji aktivitas antimikroba menggunakan metode disc diffusion dan. Hasil dari uji aktivitas antimikroba menunjukkan bahwa temu putih dan jahe gajah dalam bentuk tepung dan enkapsulasi memiliki perbedaan yang sangat nyata (P<0,01) terhadap aktivitas antimikroba pada bakteri asam laktat, Escherichia coli dan Salmonella sp. Campuran temu putih dan jahe gajah (1:1) menunjukkan kemampuan terbaik dalam menghambat pertumbuhan bakteri patogen dengan diameter zona hambat 5,70±0,14 mm (Escherichia coli) dan 6,88±0,45 mm (Salmonella sp.).Kata Kunci : antimikroba, fitobiotik, jahe gajah, minyak atsiri, temu putihABSTRACTThe poultry feed additives can contain herbal ingredients that contain various beneficial components for livestock growth. White turmeric and giant ginger can be used as feed additives because they contain essential oils that can be used as antibacterial agents. This study aims to determine the constituent components of essential oils and antimicrobial activity in white turmeric and giant ginger rhizomes. The study was carried out by in vitro experiments using white turmeric and giant ginger which were processed into the form of essential oil extract as material for the composition of essential oils test, and powder and encapsulation form as antimicrobial activity test material. The composition of essential oils of white turmeric consists of five constituent components with cis-1,7-octadien-3-yl acetate as the main component. The composition of giant ginger essential oil consists of seven components with benzene, 1- (1,5-dimethyl-4-hexenyl) -4-methyl- (CAS) ar-curcumene as the main component. Essential oils contained in the white turmeric and giant ginger have a role in inhibiting microbes. The composition of the essential oil tested using GC-MS and the antimicrobial activity test used the disc diffusion method. The results of the antimicrobial activity test showed that white turmeric and giant ginger in powder and encapsulation form had significant differences (P <0.01) on antimicrobial activity in lactic acid bacteria, Escherichia coli and Salmonella sp. The mixture of white turmeric and giant ginger (1: 1) showed the best ability to inhibit the growth of pathogenic bacteria with inhibitory zone diameters of 5.70 ± 0.14 mm (Escherichia coli) and 6.88 ± 0.45 mm (Salmonella sp.).Keywords: antimicrobial, essential oil, giant ginger, phytobiotic, white turmeric

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A study on Nalidixic Acid Resistant Salmonella among the patients attending Shree Birendra Hospital

Medical Journal of Shree Birendra Hospital ◽

10.3126/mjsbh.v10i2.6453 ◽

2012 ◽

Vol 10 (2) ◽

pp. 1-3 ◽

Cited By ~ 1

Author(s):

Raina Chaudhary ◽

Khagendra Sijapati ◽

Sunil Kumar Singh

Keyword(s):

Nalidixic Acid ◽

Salmonella Enterica ◽

Enteric Fever ◽

Brain Heart Infusion ◽

Public Health Problem ◽

Diffusion Method ◽

Disc Diffusion ◽

Diffusion Test ◽

Sensitivity Pattern

Introduction: Enteric fever is the commonest public health problem in developing countries like Nepal. Multi Drug Resistant Salmonella isolates are in vitro susceptible to Quinolone but exhibited a higher Minimum Inhibitory Concentration in vivo. Such phenomenon can be demonstrated by simple disc diffusion test of Nalidixic Acid which shows resistance. This study is conducted to determine prevalence of Nalidixic Acid Resistant Salmonella with their anti biotic sensitivity pattern at Shree Birendra Hospital, Chauni, kathmandu. Method: Of total 3945 blood samples from the patients suspected to have enteric fever were collected during the period of January 2011 to August 2011. Then it was mixed with Brain Heart Infusion , further processed according to standard methodology and their anti microbial susceptibility was performed by Kirby-Bauer disc diffusion method. Results: From 3945 samples, 280 (7.09%) showed positi ve growth, 114 (40.7%) Salmonella enterica serotype Typhi and 166 (59.2%) Salmonella enterica serotype Paratyphi A. a total of 221 (78.92%) were Nalidixic Acid Resistant Salmonella, all these strains were sensitive to Ciprofloxcin and Ofloxacin in disc diffusion test. Conclusion: Study showed a higher frequency of Nalidixic Acid Resistant Salmonella among the patients. screening of Nalidixic Acid disc diffusion test must be done as routine work for determination of low level resistance of Quinolone so as to decide the drug for the treatment of enteric fever. DOI: http://dx.doi.org/10.3126/mjsbh.v10i2.6453 Medical Journal of Shree Birendra Hospital July-Dec 2011 10(2) 1-3

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ESSENTIAL OILS AND METHYLGLYOXAL: A POSSIBLE ALTERNATIVE TREATMENT FOR ANTIBIOTIC RESISTANT BACTERIAL INFECTIONS

International Journal of Pharmacy and Pharmaceutical Sciences ◽

10.22159/ijpps.2016.v8i9.12242 ◽

2016 ◽

Vol 8 (9) ◽

pp. 107

Author(s):

Erin Cieslak ◽

James P. Mack ◽

Albert Rojtman

Keyword(s):

Essential Oil ◽

Essential Oils ◽

Alternative Treatment ◽

Bacterial Infections ◽

Cost Effective ◽

Diffusion Method ◽

Antibiotic Resistant ◽

Medicinal Properties

Objective: Essential oils are of significant interest in today’s world of healthcare because these compounds have a variety of medicinal properties. In this study, we evaluated the in vitro antibiotic role of essential oils as a possible alternative treatment in combatting Methicillin-resistant Staphylococcus aureus (MRSA).Methods: In conjunction with carrier oils, three essential oils (cassia, cinnamon bark, and thyme), as well as methylglyoxal were tested on MRSA using the Kirby-Bauer disc diffusion method.Results: The minimum inhibitory concentration of each tested essential oil and methylglyoxal in carrier oil was determined to be 25% essential oil and 75% carrier oil mixture. This concentration worked much more effectively than the standard antibiotic, vancomycin, which is currently used to treat MRSA infections.Conclusion: Antibacterial emollients made from naturally occurring products like essential oils can be cost-effective alternatives to antibiotics. The results of this research show that these emollients are more effective against MRSA than standard antibiotics in cell culture.

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Essential Oil from Leaves of Lantana canescens and L. lopez-palacii Grown in Colombia

Natural Product Communications ◽

10.1177/1934578x1100600223 ◽

2011 ◽

Vol 6 (2) ◽

pp. 1934578X1100600

Author(s):

Andrés F. Peralta-Bohórquez ◽

Clara Quijano-Célis ◽

Mauricio Gaviria ◽

Consuelo Vanegas-López ◽

Jorge A. Pino

Keyword(s):

Essential Oil ◽

Volatile Compounds ◽

Diffusion Method ◽

Disc Diffusion ◽

Enterobacter Sakazakii ◽

Bacterial Strains ◽

Disc Diffusion Method ◽

Germacrene D ◽

In Vitro Antibacterial Activity

The chemical composition of the volatile compounds from the leaves of Lantana canescens Kunth (Verbenaceae) and L. lopez-palacii Moldenke grown in Colombia were analyzed by GC and GC/MS. One hundred and thirty-nine volatile compounds were identified in L. canescens, of which the major ones were β-caryophyllene (13.5%), germacrene D (10.3%) and 1-octen-3-ol (8.4%). In the oil obtained from L. lopez-palacii, eighty-three compounds were identified, of which the most prominent were 1-octen-3-ol (24.4%) and β-caryophyllene (15.2%). The in vitro antibacterial activity of the L. lopez-palacii essential oil was studied against three bacterial strains using the disc diffusion method. No antimicrobial activity was found against Escherichia coli, Enterobacter sakazakii and Listeria monocytogenes.

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In vitro sensitivity of Hungarian Actinobaculum suis strains to selected antimicrobials

Acta Veterinaria Hungarica ◽

10.1556/avet.51.2003.1.5 ◽

2003 ◽

Vol 51 (1) ◽

pp. 53-59 ◽

Cited By ~ 4

Author(s):

I. Biksi ◽

Andrea Major ◽

L. Fodor ◽

Keyword(s):

Type Strain ◽

Diffusion Method ◽

Resistance Pattern ◽

Disc Diffusion ◽

Disc Diffusion Method ◽

Antimicrobial Sensitivity ◽

Variable Sensitivity ◽

Agar Dilution ◽

Almost All

In vitro antimicrobial sensitivity of 12 Hungarian isolates and the type strain ATCC 33144 of Actinobaculum suis to different antimicrobial compounds was determined both by the agar dilution and by the disc diffusion method. By agar dilution, MIC50 values in the range of 0.05-3.125µg/ml were determined for penicillin, ampicillin, ceftiofur, doxycycline, tylosin, pleuromutilins, chloramphenicol, florfenicol, enrofloxacin and lincomycin. The MIC50 value of oxytetracycline and spectinomycin was 6.25 and 12.5µg/ml, respectively. For ofloxacin, flumequine, neomycin, streptomycin, gentamicin, nalidixic acid, nitrofurantoin and sulphamethoxazole + trimethoprim MIC50 values were in the range of 25-100µg/ml. With the disc diffusion method, all strains were sensitive to penicillin, cephalosporins examined, chloramphenicol and florfenicol, tetracyclines examined, pleuromutilins, lincomycin and tylosin. Variable sensitivity was observed for fluoroquinolones (flumequine, enrofloxacin, ofloxacin), most of the strains were susceptible to marbofloxacin. Almost all strains were resistant to aminoglycosides but most of them were sensitive to spectinomycin. A strong correlation was determined for disc diffusion and MIC results (Spearman's rho 0.789, p<0001). MIC values of the type strain and MIC50 values of other tested strains did not differ significantly. Few strains showed a partially distinct resistance pattern for erythromycin, lincomycin and ampicillin in both methods.

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