scholarly journals Isolation, identification and antifungal susceptibility of Candida in patients with fungal sepsis

Author(s):  
Bilal Ahmad Wani ◽  
Mohd Rafiq Lone ◽  
Najmus Saqib

Background: In this study, our aim was to identify and isolate Candida species from patients admitted in ICU,s of our hospital and to determine their susceptibilities to various antifungal agents so as to find the local resistance pattern and guide for empirical treatment.Methods: In our study 37 strains of candida were isolated (4 Candida albicans, 33 Non-albicans Candida strains). Candida species were identified by conventional, biochemical and molecular methods. Antifungal susceptibility tests for amphotericin B, fluconazole, itraconazole, ketoconazole and voriconazole were performed with broth microdilution method and E- tests as described by National Committee for Clinical Laboratory Standards (NCCLS).Results: Out of 37 Candida strains, the most prevalent species were C. tropicalis (43.2%), C. parapsilosis (24.3%), C. krusei (16.2%), C. albicans (10.8%), and C. glabrata (2.7%). Among all strains four strains (10.8 %) were resistant, two Candida albicans where found resistant to fluconazole one Candida krusei and one Candida parapsilosis were found to be resistant to all azoles.Conclusions: Candidemia continues to be associated with substantial morbidity and mortality and non albicans Candida species are the commonly isolated pathogen from those patients admitted in tertiary care hospitals in Indian scenario. Thus, it is imperative to perform antifungal susceptibility to select appropriate and effective antifungal therapy.

Author(s):  
Parvez Anwar Khan ◽  
Nazish Fatima ◽  
Haris Manzoor Khan ◽  
Midhat Ali Khan ◽  
Asim Azhar ◽  
...  

Candidiasis is recognized as a significant cause of morbidity, especially in immunocompromised individuals. An epidemiologic change in Candida species and emergence of resistance can impact the usage of antifungal agents as empirical therapy for Candidiasis in patients with or without AIDS. The present study was done to find out: i) The species of Candida isolated from H.I.V. and Non-HIV infected patients. ii) The resistance pattern of these Candida isolates to antifungal agents. A total of 160 Candida species isolates (80 isolates each from H.I.V. and Non-HIV infected patients) were characterized. Identification of yeast isolates was made by standard procedures including morphology (Staib agar, cornmeal agar, CHROMagar), germ tube test, fermentation, and assimilation of sugars and growth at 42°C. In addition, sensitivity testing was done using the broth microdilution method (M27-A2) as per the C.L.S.I. guidelines against amphotericin B, nystatin, voriconazole, fluconazole, ketoconazole, and itraconazole. In both the groups, i.e., H.I.V. and Non-HIV infected patients, Candida albicans was the most common species (61.2 % and 85 % respectively), followed by Candida guilliermondi (16.2 % and 5 %), Candida tropicalis (5 % and 3.7 %), Candida krusei (5% and 2.5 %), Candida dubliniensis 1(5 % and 1.2 %) and others. Among HIV infected patients fluconazole resistance was 16.25%, ketoconazole 13.5%, clotrimazole 12.5%, itraconazole 6.25 %. In the non-HIV infected group, fluconazole resistance was 8.75% and itraconazole 1.25%. For the appropriate treatment of Candida infections, antifungal susceptibility has become an essential tool, especially in the present scenario of increasing resistance.


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.


2004 ◽  
Vol 46 (5) ◽  
pp. 239-241 ◽  
Author(s):  
Ana Graciela Ventura Antunes ◽  
Alessandro Comarú Pasqualotto ◽  
María Cristina Diaz ◽  
Pedro Alves d'Azevedo ◽  
Luiz Carlos Severo

Recent studies have shown differences in the epidemiology of invasive infections caused by Candida species worldwide. In the period comprising August 2002 to August 2003, we performed a study in Santa Casa Complexo Hospitalar, Brazil, to determine Candida species distribution associated with candidemia and their antifungal susceptibility profiles to amphotericin B, fluconazole and itraconazole. Antifungal susceptibility was tested according to the broth microdilution method described in the NCCLS (M27A-2 method). Only one sample from each patient was analyzed (the first isolate). Most of the episodes had been caused by species other than C. albicans (51.6%), including C. parapsilosis (25.8%), C. tropicalis (13.3%), C. glabrata (3.3%), C. krusei (1.7%), and others (7.5%). Dose-dependent susceptibility to itraconazole was observed in 14.2% of strains, and dose-dependent susceptibility to fluconazole was found in 1.6%. Antifungal resistance was not found, probably related to low use of fluconazole. Further epidemiological surveillance is needed.


1999 ◽  
Vol 37 (3) ◽  
pp. 591-595 ◽  
Author(s):  
A. Espinel-Ingroff ◽  
M. Pfaller ◽  
S. A. Messer ◽  
C. C. Knapp ◽  
S. Killian ◽  
...  

National Committee for Clinical Laboratory Standards (NCCLS) standard guidelines are available for the antifungal susceptibility testing of common Candida spp. and Cryptococcus neoformans, but NCCLS methods may not be the most efficient and convenient procedures for use in the clinical laboratory. MICs of amphotericin B, fluconazole, flucytosine, itraconazole, and ketoconazole were determined by the commercially prepared Sensititre YeastOne Colorimetric Antifungal Panel and by the NCCLS M27-A broth microdilution method for 1,176 clinical isolates of yeasts and yeast-like organisms, including Blastoschizomyces capitatus, Cryptococcus spp., 14 common and emerging species of Candida, Hansenula anomala,Rhodotorula spp., Saccharomyces cerevisiae,Sporobolomyces salmonicolor, and Trichosporon beigelii. Colorimetric MICs of amphotericin B corresponded to the first blue well (no growth), and MICs of the other agents corresponded to the first purple or blue well. Three comparisons of MIC pairs by the two methods were evaluated to obtain percentages of agreement: 24- and 48-h MICs and 24-h colorimetric versus 48-h reference MICs. The best performance of the YeastOne panel was with 24-h MICs (92 to 100%) with the azoles and flucytosine for all the species tested, with the exception of C. albicans (87 to 90%). For amphotericin B, the best agreement between the methods was with 48-h MIC pairs (92 to 99%) for most of the species tested. The exception was for isolates ofC. neoformans (76%). These data suggest the potential value of the YeastOne panel for use in the clinical laboratory.


1996 ◽  
Vol 40 (5) ◽  
pp. 1277-1279 ◽  
Author(s):  
J V Martinez-Suarez ◽  
J L Rodriguez-Tudela

Lipopeptide L-733,560 is a water-soluble derivative of pneumocandin B0 that exhibits enhanced anti-Candida activity. We investigated the in vitro activity of L-733,560 compared with those of amphotericin B, flucytosine, and itraconazole, against fluconazole-resistant (n = 44) and fluconazole-susceptible (n = 46) Candida albicans isolates. Tests were performed with a photometer-read broth microdilution method with RPMI-2% glucose and National Committee for Clinical Laboratory Standards reference strains. Except for those of itraconazole, MICs were not significantly different between the two groups of isolates, as expected for agents with different mechanisms of action. L-733,560 was the most active agent against C.albicans, with MICs for 50 and 90% of the strains tested of 0.01 and 0.06 microgram/ml, respectively.


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 (10) ◽  
pp. 2752-2758 ◽  
Author(s):  
Rama Ramani ◽  
Vishnu Chaturvedi

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.


2000 ◽  
Vol 44 (1) ◽  
pp. 226-229 ◽  
Author(s):  
Francesco Barchiesi ◽  
Daniela Arzeni ◽  
Annette W. Fothergill ◽  
Luigi Falconi Di Francesco ◽  
Francesca Caselli ◽  
...  

ABSTRACT A broth microdilution method performed in accordance with the National Committee for Clinical Laboratory Standards guidelines was used to compare the in vitro activity of the new antifungal triazole SCH 56592 (SCH) to that of fluconazole (FLC), itraconazole (ITC), and ketoconazole (KETO) against 257 clinical yeast isolates. They included 220 isolates belonging to 12 different species of Candida, 15 isolates each of Cryptococcus neoformans andSaccharomyces cerevisiae, and seven isolates ofRhodotorula rubra. The MICs of SCH at which 50% (MIC50) and 90% (MIC90) of the isolates were inhibited were 0.06 and 2.0 μg/ml, respectively. In general, SCH was considerably more active than FLC (MIC50 and MIC90 of 1.0 and 64 μg/ml, respectively) and slightly more active than either ITC (MIC50 and MIC90 of 0.25 and 2.0 μg/ml, respectively) and KETO (MIC50 and MIC90 of 0.125 and 4.0 μg/ml, respectively). Our in vitro data suggest that SCH has significant potential for clinical development.


1998 ◽  
Vol 36 (6) ◽  
pp. 1578-1583 ◽  
Author(s):  
Anna Maria Tortorano ◽  
Maria Anna Viviani ◽  
Francesco Barchiesi ◽  
Daniela Arzeni ◽  
Anna Lisa Rigoni ◽  
...  

Three susceptibility testing procedures were compared to determine fluconazole, itraconazole, and ketoconazole MICs against 47Candida albicans strains isolated sequentially from the oral cavities of five AIDS patients undergoing azole therapy. They included the broth microdilution method (BM), performed according to the National Committee for Clinical Laboratory Standards’ tentative standard, the agar dilution method (AD), and the Etest; the latter two tests were performed both in Casitone agar (AD-Cas and Etest-Cas) and in RPMI (AD-RPMI and Etest-RPMI). Twenty-four- and 48-h MICs obtained by AD and Etest were compared with 48-h MICs obtained by BM. The MICs of all the azoles determined by BM were usually lower than those obtained by the other methods, mainly due to different reading criteria. In order to assess the most appropriate way of evaluating the agreement of MICs obtained by different methods with those produced by the proposed reference method (BM), we used the mean differences calculated according to Bland and Altman’s method. Comparison of fluconazole MICs obtained by BM and AD-Cas yielded a mean difference of 3, and the percentages of agreement within ±2 dilutions were 98 and 100% at 24 and 48 h, respectively. For ketoconazole and itraconazole MICs, lower mean differences were noted, and agreement ranged from 96 to 100%. Agreement between the AD-RPMI and BM results was poor for all azoles, and an increase in MICs was always observed between the 1st- and 2nd-day readings. Similarly, Etest-Cas gave better agreement with BM than did Etest-RPMI for all the azoles. BM, AD-Cas, and Etest-Cas each demonstrated a progressive increase in fluconazole MICs against strains isolated sequentially from a given patient, in accordance with the decreased clinical response to fluconazole.


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