The Frequency, Antifungal Susceptibility and Enzymatic Profiles of Candida Species Isolated from Neutropenic Patients

Abstract

BackgroundNeutropenia, as a predisposing factor for invasive candidiasis, is defined as a reduction in neutrophil count to less than 1500/mm3. It is a common condition in patients with hematological malignancy and cytostatic chemotherapy. Extensive chemotherapy and prophylaxis with antifungals have increased the resistance of Candida isolates to antifungal drugs. Although, Candida albicans is the most common causative agent among neutropenic patients, there is an increasing rate of non-albicans species. Extracellular enzymes activity pattern and antifungal agent sensitivity profiles are two important factors for spreading resistant strains.ObjectivesThe aim of the present study was to identify the Candida strains isolated from hospitalized neutropenic patients. The patterns of antifungal susceptibility of the causative agents to antifungals and the extracellular enzymes activity of the isolates were also evaluated.Patients and MethodsIn the present study, 243 urine and 243 oral swab samples were collected from neutropenic patients and inoculated on CHROMagar Candida. In addition, 100 blood samples were also inoculated in biphasic Brain Heart Infusion medium. Several yeast isolates were isolated from samples and identified by classical and molecular techniques. The profiles of extracellular enzymes and the susceptibility of recovered agents to amphotericin B, fluconazole and caspofungin were also evaluated.ResultsA total of 110 yeast strains isolated from urine and oral cavities were identified as C. albicans (51.8%), C. krusei (25.5%), C. glabrata (6.4%) and other yeasts (16.3%). No yeast species was isolated from blood samples. Our result showed that in 90% of the isolates, the range of secretion of extracellular enzymes was medium (2+) and high (3+), however only a few isolates were negative for this characteristic. All isolates were sensitive to caspofungin and fluconazole, whereas 54.7% of isolates were resistant to amphotericin B.ConclusionsWe found a marked increase in the incidence of non-albicans species (48.2%) among neutropenic patients. Only a few strains failed to produce extracellular enzymes. Finally, in addition to fluconazole, caspofungin can be considered as the first line treatment against Candida species among neutropenic patients.

Microsatellite Typing and Antifungal Susceptibility of Candida glabrata Strains Isolated From Patients With Candida Vaginitis

“…The in vitro antifungal susceptibility of 61 C. glabrata isolates to four azole drugs (fluconazole [32 mg/ml] [Serva, United States], itraconazole [2.5 mg/ml] [Sigma-Aldrich, Germany], posaconazole [1.75 mg/ml] [Sigma-Aldrich, Germany], and voriconazole [1.25 mg/ml] [Sigma-Aldrich, Germany]) was determined using the European Committee on Antimicrobial Susceptibility (EUCAST) broth microdilution method [EUCAST definitive document EDef 7.3.1 revision 2017 EUCAST (2017)]. This method was modified with colorimetric indicator Resazurin (Gharaghani et al, 2016) to read the MIC more easily. The MIC is defined as the lowest concentration of an antifungal drug that inhibits the fungal growth.…”

Genetic Analysis of Candida glabrata from Candiduric Patients Using Microsatellite Length Polymorphism, Antifungal Susceptibility, and Enzymatic Profiles

“…For accurate identification of isolates, genomic DNA was extracted and purified according to the method proposed by Looke et al (17). DNAs were subjected to PCR amplification with V9G (5'-TTACGTCCCTGCCCTTTGTA-3') and LS266 (5'-GCATTCCCAAACAACTCGACTC-3') primers (18). Then, the Cardiogenic Department of the Rajaie Cardiovascular, Medical, and Research Center, Tehran, Iran, sequenced PCR products.…”

“…Specific substrates, including egg yolk, bovine serum albumin agar (Merck, Germany), tween 80 (Merck, Germany), and sheep blood (Bahar Afshan, Iran), were used for phospholipase, proteinase, esterase, and hemolysin activity, respectively, according to the study by Gharaghani et al (18). Media were inoculated by the isolates and incubated at 37°C for one week for phospholipase, hemolysin, and proteinase activity.…”

Antifungal Susceptibility Profiles of Candida Species Isolated from Ahvaz Jundishapur Educational Hospitals

“…A standard suspension of an overnight culture of all tested organisms was prepared in 0.01% Resazurin (Sigma -Aldrich, Germany) RPMI 1640 (Bio IDEA, Iran), according to the CLSI protocol (21,22…”