Drug susceptibility testing of Mycobacterium tuberculosis by the broth microdilution method with 7H9 broth

ABSTRACTMalasseziais a genus of lipid-dependent yeasts. It is associated with common skin diseases such as pityriasis versicolor and atopic dermatitis and can cause systemic infections in immunocompromised individuals. Owing to the slow growth and lipid requirements of these fastidious yeasts, convenient and reliable antifungal drug susceptibility testing assays forMalasseziaspp. are not widely available. Therefore, we optimized a broth microdilution assay for the testing ofMalasseziathat is based on the CLSI and EUCAST assays forCandidaand other yeasts. The addition of ingredients such as lipids and esculin provided a broth medium formulation that enabled the growth of allMalasseziaspp. and could be read, with the colorimetric indicator resazurin, by visual and fluorescence readings. We tested the susceptibility of 52 strains of 13Malasseziaspecies to 11 commonly used antifungals. MIC values determined by visual readings were in good agreement with MIC values determined by fluorescence readings. The lowest MICs were found for the azoles itraconazole, posaconazole, and voriconazole, with MIC90values of 0.03 to 1.0 μg/ml, 0.06 to 0.5 μg/ml, and 0.03 to 2.0 μg/ml, respectively. AllMalasseziaspp. were resistant to echinocandins and griseofulvin. SomeMalasseziaspp. also showed high MIC values for ketoconazole, which is the most widely recommended topical antifungal to treatMalasseziaskin infections. In summary, our assay enables the fast and reliable susceptibility testing ofMalasseziaspp. with a large panel of different antifungals.

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Susceptibility testing of Mycobacterium tuberculosis by broth microdilution method: a rapid alternative method

Diagnostic Microbiology and Infectious Disease ◽

10.1016/j.diagmicrobio.2006.10.001 ◽

2007 ◽

Vol 57 (4) ◽

pp. 447-449 ◽

Cited By ~ 4

Author(s):

Sunil Sethi ◽

Jharna Mandal ◽

Parveen Kumar ◽

Shiv Kumar ◽

Sandeep Meharwal ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Susceptibility Testing ◽

Broth Microdilution ◽

Microdilution Method ◽

Alternative Method ◽

Broth Microdilution Method

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Comparative analysis of Etest and broth microdilution method (AFST-EUCAST) for trends in antifungal drug susceptibility testing of Brazilian Cryptococcus neoformans isolates

Journal of Medical Microbiology ◽

10.1099/jmm.0.46789-0 ◽

2006 ◽

Vol 55 (12) ◽

pp. 1693-1699 ◽

Cited By ~ 14

Author(s):

Amanda L. T. Dias ◽

Flavia E. Matsumoto ◽

Marcia S. C. Melhem ◽

Eriques G. da Silva ◽

Marcos E. Auler ◽

...

Keyword(s):

Cryptococcus Neoformans ◽

Amphotericin B ◽

Susceptibility Testing ◽

Antifungal Susceptibility ◽

Correlation Coefficients ◽

Drug Susceptibility ◽

Drug Susceptibility Testing ◽

Microdilution Method ◽

Broth Microdilution Method

A prospective study was performed to evaluate the correlation between the proposed standard of the Antifungal Susceptibility Testing Subcommittee of the European Committee on Antibiotic Susceptibility Testing (AFST-EUCAST) (document 7.1) and the commercial system Etest for determining the MICs of flucytosine, amphotericin B, fluconazole, itraconazole and voriconazole for a collection of 100 clinical and environmental isolates of Cryptococcus neoformans. The agreements among Etest MICs within ±2 log2 dilutions of AFST-EUCAST standard MICs were greater for flucytosine, fluconazole and voriconazole (76, 78 and 88 %, respectively) than for amphotericin B (5 %), the lowest agreement, and itraconazole (67 %). Overall, the correlation coefficients were statistically significant (P<0.05), and it is suggested that the Etest and AFST-EUCAST method are reliable alternatives and present good correlation for all drugs evaluated except amphotericin B. However, the observed differences related to MICs for susceptible, susceptible dose dependent and resistant strains between the methods suggest that it will be necessary to carry out further studies, including assessment of interlaboratory agreement and correlation of MICs by different methods with in vivo response.

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Comparison of Proportion and Resistance Ratio Methods for Drug Susceptibility Testing of Mycobacterium tuberculosis Isolated from Patients Attending National Tuberculosis Centre, Nepal

SAARC Journal of Tuberculosis Lung Diseases and HIV/AIDS ◽

10.3126/saarctb.v5i1.3078 ◽

2010 ◽

Vol 5 (1) ◽

pp. 13-20

Author(s):

S Acharya ◽

P Ghimire ◽

DK Khadka ◽

S Nepali

Keyword(s):

Mycobacterium Tuberculosis ◽

Fluorescence Microscopy ◽

Susceptibility Testing ◽

Drug Susceptibility ◽

Drug Susceptibility Testing ◽

Resistance Ratio ◽

National Tuberculosis ◽

Smear Negative ◽

Culture Positive ◽

Good Agreement

Background: Tuberculosis (TB) is among the most serious infectious cause of global morbidity and mortality. Emergence of Multi-drug resistant tuberculosis (MDR-TB) is posing an increased threat to TB control programs. Drug susceptibility testing (DST) of Mycobacterium tuberculosis (M. tuberculosis) isolates is important for tackling such problems. Setting: National Tuberculosis Centre (NTC), Thimi, Bhaktapur, Nepal. Objectives: Comparative evaluation of two in vitro DST methods in determining susceptibility of M. tuberculosis isolates from patients attending NTC, to front-line anti-TB drugs: (Isoniazid-INH, Rifampicin-RFP, Streptomycin-SM, and Ethambutol-EMB). Methodology: This study was conducted from Sep 2006-Jun 2007. A total of 862 sputum samples (diagnosis or follow up cases) collected from patients (type of patients or their categories was not differentiated in this study) attending NTC bacteriology lab for sputum direct smear microscopy were analyzed using fluorescence microscopy. All smear positive samples, smear negative samples requested for culture were cultured. All culture positive samples confirmed as M. tuberculosis by biochemical tests were processed for DST by both proportion (PR) and resistance ratio (RR) methods. Results: Out of 862 sputum samples analyzed, 226 (26.2%) samples were positive for Acid Fast Bacilli (AFB) by fluorescence microscopy. Among 323 samples 226 smear positive samples and 97 smear negative samples requested for culture), 221 (68.4%) were culture positive, 92 (28.5%) were culture negative and 10 (3.1%) were contaminated. Out of 221 isolates of M. tuberculosis, 57.5% were resistant to one or more drugs by the PR method and 56.6% by the RR method. Similarly, MDR isolates were 29.9% and 29% by PR and RR methods respectively. On correlation analysis using Mc Nemar Chi-square test, no significant difference between the two tests were observed (p>0.05). The results showed high agreement between both methods and agreement rates to INH, RFP, SM and EMB were 93.2%, 93.7%, 93.2% and 94.1% respectively. Similarly, the agreement rates between both methods using kappa analysis showed kappa (k) value of 0.86, 0.85, 0.86 and 0.84 for INH, RFP, SM and EMB respectively, which is believed to be good agreement between both methods (k=0.80 to 1.00: Very good agreement). Conclusion: In conclusion, this study showed that both the Proportion and Resistance ratio methods are equally good for determining drug susceptibility of M. tuberculosis. Keywords: Mycobacterium tuberculosis; Drug Susceptibility Testing; Proportion Method; Resistance Ratio Method. DOI: 10.3126/saarctb.v5i1.3078 SAARC J. Tuber. Lung Dis. HIV/AIDS 2008 Vol.5(1) 13-20

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Comparison of the Performances of Two In-House Rapid Methods for Antitubercular Drug Susceptibility Testing

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00960-08 ◽

2008 ◽

Vol 53 (2) ◽

pp. 808-810 ◽

Cited By ~ 6

Author(s):

Agustina I. de la Iglesia ◽

Emma J. Stella ◽

Héctor R. Morbidoni

Keyword(s):

Drug Resistance ◽

Mycobacterium Tuberculosis ◽

Sensitivity And Specificity ◽

Susceptibility Testing ◽

Drug Susceptibility ◽

Drug Susceptibility Testing ◽

Antitubercular Drug ◽

Rapid Methods ◽

Resistance Assessment

ABSTRACT Resistance to rifampin (rifampicin), isoniazid, and streptomycin of 69 Mycobacterium tuberculosis isolates was analyzed by an in-house method based on mycobacteriophage D29 and a colorimetric micromethod. Both methods showed sensitivity and specificity values ranging from 93% to 100%. These simple methods offer an option for drug resistance assessment of M. tuberculosis.

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Standartization of broth microdilution method for Mycobacterium tuberculosis

Memórias do Instituto Oswaldo Cruz ◽

10.1590/s0074-02762000000100021 ◽

2000 ◽

Vol 95 (1) ◽

pp. 127-129 ◽

Cited By ~ 22

Author(s):

Clarice Queico Fujimura Leite ◽

Ana Laura Remédio Zeni Beretta ◽

Ivone Shizuko Anno ◽

Maria Alice da Silva Telles

Keyword(s):

Mycobacterium Tuberculosis ◽

Broth Microdilution ◽

Microdilution Method ◽

Broth Microdilution Method

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In Vitro Activities of the Novel Oxazolidinones DA-7867 and DA-7157 against Rapidly and Slowly Growing Mycobacteria

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00763-06 ◽

2006 ◽

Vol 50 (12) ◽

pp. 4027-4029 ◽

Cited By ~ 18

Author(s):

Lucio Vera-Cabrera ◽

Barbara A. Brown-Elliott ◽

Richard J. Wallace ◽

Jorge Ocampo-Candiani ◽

Oliverio Welsh ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Clinical Isolates ◽

Nontuberculous Mycobacterium ◽

The Novel ◽

Broth Microdilution ◽

Reference Species ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Aerobic Actinomycetes

ABSTRACT DA-7867 and DA-7157 are oxazolidinones active against pathogenic aerobic actinomycetes including Nocardia spp. and Mycobacterium tuberculosis. However, the activity of these drugs against nontuberculous mycobacterium (NTM) species is not known. In this work, we compared the susceptibilities of 122 clinical isolates and 29 reference species of both rapidly growing and slowly growing mycobacteria to linezolid, DA-7867, and DA-7157 by the broth microdilution method. The MICs for 50 and 90% of the strains tested (MIC50s and MIC90s, respectively) of DA-7867 and DA-7157 were lower than those of linezolid. In all of the cases, a MIC90 of <8 μg/ml was observed for all of the species tested in both groups of NTM. For M. kansasii and M. marinum isolates, the MIC90s of both DA-7867 and DA-7157 were less than 0.5 μg/ml. These results demonstrate the potential of these compounds to treat NTM infections.

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Susceptibility of Filamentous Fungi to Voriconazole in Malaysia Tested by Sensititre YeastOne and CLSI Microdilution Methods

10.21203/rs.3.rs-199013/v1 ◽

2021 ◽

Author(s):

Xue Ting Tan ◽

Stephanie Jane Ginsapu ◽

Fairuz binti Amran ◽

Salina binti Mohamed Sukur ◽

Surianti binti Shukor

Keyword(s):

Filamentous Fungi ◽

Susceptibility Testing ◽

Rhizopus Oryzae ◽

Antifungal Susceptibility ◽

Sporothrix Schenckii ◽

Rank Test ◽

Broth Microdilution ◽

Syncephalastrum Racemosum ◽

Microdilution Method ◽

Broth Microdilution Method

Abstract Background: Voriconazole is a trizaole antifungal to treat fungal infection. In this study, the susceptibility pattern of voriconazole against filamentous fungi was studied using Sensititre® YeastOne and Clinical & Laboratory Standards Institute (CLSI) M38 broth microdilution method. Methods: The suspected cultures of Aspergillus niger, A. flavus, A. fumigatus, A. versicolor, A. sydowii, A. calidoutus, A. creber, A. ochraceopetaliformis, A. tamarii, Fusarium solani, F. longipes, F. falciferus, F. keratoplasticum, Rhizopus oryzae, R. delemar, R. arrhizus, Mucor sp., Poitrasia circinans, Syncephalastrum racemosum and Sporothrix schenckii were received from hospitals. Their identification had been confirmed in our lab and susceptibility tests were performed using Sensititre® YeastOne and CLSI M38 broth microdilution method. The significant differences between two methods were calculated using Wilcoxon Sign Rank test.Results: Mean of the minimum inhibitory concentrations (MIC) for Aspergillus spp. and Fusarium were within 0.25 μg/mL-2.00 μg/mL by two methods except A. calidoutus, F. solani and F. keratoplasticum. Moreover, mean of MIC for S. schenkii were around 3.00 μg/mL by two methods. In contrast, mean of MIC for Rhizopus spp., Mucor sp., P. circinans and S. racemosum were ≥6.00 μg/mL by two methods. Generally, the MIC obtained by Sensititre YeastOne was one two-fold increase or decrease compared with the results obtained by CLSI method. The overall agreement between Sensititre YeastOne and CLSI methods to test susceptibility testing of voricaonazole was more than 70% except A. sydowii. The significant differences between two methods were significant when tested on A. niger, A. flavus, A. fumigatus, A. versicolor, A. sydowii, F. solani and S. schenkii. Conclusions: In conclusion, Sensititre YeastOne method appears to be an alternative procedure for antifungal susceptibility testing for some Malaysian moulds.

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Why Phenotypic Drug Susceptibility Testing of Mycobacterium tuberculosis to First-Line Drugs is not Sufficient for Proper Management of Drug-Resistant and Multidrug-Resistant tuberculosis?

Journal of Bacteriology & Parasitology ◽

10.4172/2155-9597.1000e128 ◽

2017 ◽

Vol 09 (01) ◽

Author(s):

Suhail Ahmad

Keyword(s):

Mycobacterium Tuberculosis ◽

Susceptibility Testing ◽

Drug Susceptibility ◽

Multidrug Resistant ◽

Drug Susceptibility Testing ◽

Drug Resistant ◽

First Line ◽

Proper Management ◽

Resistant Tuberculosis ◽

Multidrug Resistant Tuberculosis

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Flow Cytometry Antifungal Susceptibility Testing of Pathogenic Yeasts other than Candida albicans and Comparison with the NCCLS Broth Microdilution Test

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.10.2752-2758.2000 ◽

2000 ◽

Vol 44 (10) ◽

pp. 2752-2758 ◽

Cited By ~ 44

Author(s):

Rama Ramani ◽

Vishnu Chaturvedi

Keyword(s):

Flow Cytometry ◽

Candida Albicans ◽

Amphotericin B ◽

Susceptibility Testing ◽

Antifungal Susceptibility ◽

Antifungal Susceptibility Testing ◽

Broth Microdilution ◽

Nitrogen Base ◽

Microdilution Method ◽

Broth Microdilution Method

ABSTRACT Candida species other than Candida albicansfrequently cause nosocomial infections in immunocompromised patients. Some of these pathogens have either variable susceptibility patterns or intrinsic resistance against common azoles. The availability of a rapid and reproducible susceptibility-testing method is likely to help in the selection of an appropriate regimen for therapy. A flow cytometry (FC) method was used in the present study for susceptibility testing ofCandida glabrata, Candida guilliermondii,Candida krusei, Candida lusitaniae,Candida parapsilosis, Candida tropicalis, andCryptococcus neoformans based on accumulation of the DNA binding dye propidium iodide (PI). The results were compared with MIC results obtained for amphotericin B and fluconazole using the NCCLS broth microdilution method (M27-A). For FC, the yeast inoculum was prepared spectrophotometrically, the drugs were diluted in either RPMI 1640 or yeast nitrogen base containing 1% dextrose, and yeast samples and drug dilutions were incubated with amphotericin B and fluconazole, respectively, for 4 to 6 h. Sodium deoxycholate and PI were added at the end of incubation, and fluorescence was measured with a FACScan flow cytometer (Becton Dickinson). The lowest drug concentration that showed a 50% increase in mean channel fluorescence compared to that of the growth control was designated the MIC. All tests were repeated once. The MICs obtained by FC for all yeast isolates except C. lusitaniae were in very good agreement (within 1 dilution) of the results of the NCCLS broth microdilution method. Paired ttest values were not statistically significant (P = 0.377 for amphotericin B; P = 0.383 for fluconazole). Exceptionally, C. lusitaniae isolates showed higher MICs (2 dilutions or more) than in the corresponding NCCLS broth microdilution method for amphotericin B. Overall, FC antifungal susceptibility testing provided rapid, reproducible results that were statistically comparable to those obtained with the NCCLS method.

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