Candida Krusei Isolates Research Articles

Biology and genetic diversity of Candida krusei isolates from fermented vegetables and clinical samples in China

ABSTRACT Candida krusei, also known as Pichia kudriavzevii, is an emerging non-albicans Candida (NAC) species causing both superficial and deep-seated infections in humans. This fungal pathogen is inherently resistant to the first-line antifungal drug, fluconazole, and is widely distributed in natural environments such as soil, foods, vegetables, and fruits. In this study, we collected 86 C. krusei strains from clinical settings and traditional fermented vegetables from different areas of China. Compared to C. krusei strains from fermented vegetables, clinical isolates exhibited a higher ability to undergo filamentation and biofilm development, which could facilitate its host colonization and infections. Isolates from fermented vegetables showed higher resistance to several antifungal drugs including fluconazole, voriconazole, itraconazole, amphotericin B, and caspofungin, than clinical strains, while they were more susceptible to posaconazole than clinical strains. Although C. krusei has been thought to be a diploid organism, we found that one-fourth of clinical strains and the majority of isolates from fermented vegetables (87.5%) are triploid. Whole-genome sequencing and population genetic analyses demonstrated that isolates from clinical settings and fermented food are genetically associated, and distributed across a wide range of genetic clusters. Additionally, we found that six nucleotide substitutions at the promoter region of the ABC11 gene, encoding a multidrug efflux pump, could play a critical role in antifungal resistance in this species. Given the ubiquitous distribution of C. krusei strains in fermented vegetables and their genetic association with clinical strains, a One Health approach will be necessary to control the prevalence of this pathogen.

Antifungal susceptibility pattern of Candida species isolated from pregnant women.

Candidaspecies, opportunistic yeast, are the second most common cause of female vulvovaginal candidiasis. This study aimed to evaluate the antifungal susceptibility profile of the isolatedCandidaspecies in pregnant women in Hajjah governorate, Yemen. A hospital-based cross-sectional study was conducted among 396 pregnant women attending Authority AL-Gumhorri Hospital Hajjah between February and July 2023. Vaginal swabs were collected, andCandidaspecies were isolated and identified based on the standard laboratory method. Furthermore, the antifungal drug susceptibility ofCandidaspecies was determined by the Kirby-Bauer technique. The prevalence of vaginal Candida infection among pregnant women was 61.4%. Candida albicanswas the most predominant species (59.26%), followed by Candida krusei(13.58%), Candida Tropicalis (11.12%), Candida Grabata (9.87%), and Candida dubliniensis (6.17%). The highest rate ofCandidainfections was among women aged 24-30 years (71.9%) who finished primary school (77.8%), with the third trimester (80%), multigravida (66.1%), and recurrent infection (67.7%) showing significant differences (P< 0.05). The Candida albicans isolates were resistant to clotrimazole and itraconazole at 34.7% and 23.6%, respectively.In addition, the resistance of Candida krusei, Candida tropicalis, Candida glabrata, and Candida dublinensis isolates to fluconazole, voriconazole, voriconazole, and nystatin was 57.6%, 63%, 43.8%, and 60%, respectively. Additionally, approximately 46.2% of isolated Candida albicans exhibited one kind of antifungal drug resistance, whereas 38.7% of isolated non-albicans exhibited resistance to three different antifungal agents. According to the above findings, Candida infection is highly prevalent in Yemen and quite widespread. Interventions in health education are advised to increase women's knowledge of vaginitis and its prevention. The antifungal susceptibility test may also be helpful in determining the best medication for each patient.

Comparative pharmacodynamics and dose optimization of liposomal amphotericin B against Candida species in an in vitro pharmacokinetic/pharmacodynamic model.

As comparative pharmacokinetic/pharmacodynamic (PK/PD) studies of liposomal amphotericin B (L-AMB) against Candida spp. are lacking, we explored L-AMB pharmacodynamics against different Candida species in an in vitro PK/PD dilution model. Eight Candida glabrata, Candida parapsilosis, and Candida krusei isolates (EUCAST/CLSI AMB MIC 0.125-1 mg/L) were studied in the in vitro PK/PD model simulating L-AMB Cmax = 0.25-64 mg/L and t1/2 = 9 h. The model was validated with one susceptible and one resistant Candida albicans isolate. The Cmax/MIC-log10CFU/mL reduction from the initial inoculum was analyzed with the Emax model, and Monte Carlo analysis was performed for the standard (3 mg/kg with Cmax = 21.87 ± 12.47 mg/L) and higher (5 mg/kg with Cmax = 83 ± 35.2 mg/L) L-AMB dose. A ≥1.5 log10CFU/mL reduction was found at L-AMB Cmax = 8 mg/L against C. albicans, C. parapsilosis, and C. krusei isolates (MIC 0.25-0.5 mg/L) whereas L-AMB Cmax ≥ 32 mg/L was required for C. glabrata isolates. The in vitro PK/PD relationship followed a sigmoidal pattern (R2 ≥ 0.85) with a mean Cmax/MIC required for stasis of 2.1 for C. albicans (close to the in vivo stasis), 24/17 (EUCAST/CLSI) for C. glabrata, 8 for C. parapsilosis, and 10 for C. krusei. The probability of target attainment was ≥99% for C. albicans wild-type (WT) isolates with 3 mg/kg and for wild-type isolates of the other species with 5 mg/kg. L-AMB was four- to eightfold less active against the included non-C. albicans species than C. albicans. A standard 3-mg/kg dose is pharmacodynamically sufficient for C. albicans whereas our data suggest that 5 mg/kg may be recommendable for the included non-C. albicans species.

The fungicidal effectiveness of 2-Chloro-3-hydrazinylquinoxaline, a newly developed quinoxaline derivative, against Candida species.

Candida represents a prevalent fungal infection, notable for its substantial implications on morbidity and mortality rates. In the landscape of prospective treatments, quinoxaline derivatives emerge as a category of compact compounds exhibiting notable potential in addressing infections. These derivatives showcase promising antimicrobial efficacy coupled with favorable pharmacokinetic and safety characteristics. The central aim of this investigation was to examine the antifungal characteristics of 2-Chloro-3-hydrazinylquinoxaline against diverse strains of Candida and Aspergillus in vitro. Additionally, we endeavored to assess the in vivo efficacy of 2-Chloro-3-hydrazinylquinoxaline using a murine model for oral candidiasis induced by C. albicans cells ATCC 10231. 2-Chloro-3-hydrazinylquinoxaline demonstrated noteworthy effectiveness when tested against various reference strains of Candida species. It exhibited heightened efficacy, particularly against Candida krusei isolates. However, its performance against Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, and Candida auris isolates exhibited variability. Notably, 2-Chloro-3-hydrazinylquinoxaline manifests variable efficacy against Aspergillus fumigatus, Aspergillus niger, Aspergillus terreus and Aspergillus flavus and no effect against Aspergillus brasiliensis. In a murine model, 2-Chloro-3-hydrazinylquinoxaline exhibited significant efficacy in combating the C. albicans cells ATCC 10231 strain, underscoring its potential as a viable treatment option. 2-Chloro-3-hydrazinylquinoxaline has demonstrated substantial potential in effectively addressing various Candida and Aspergillus species, showcasing dual attributes of antifungal and anti-inflammatory properties. However, to attain a more comprehensive understanding of its therapeutic capabilities, further investigations, incorporating additional tests and experiments, are imperative.

Antifungal Activity and Type of Interaction of Melissa officinalis Essential Oil with Antimycotics against Biofilms of Multidrug-Resistant Candida Isolates from Vulvovaginal Mucosa.

(1) Background: Vulvovaginal candidosis (VVC) is a major therapy issue due to its high resistance rate and virulence factors such as the ability to form biofilms. The possibility of combining commonly used antifungals with natural products might greatly improve therapeutic success. (2) Methods: A total of 49 vulvovaginal isolates, causative agents of recurrent VVC, were tested for their susceptibility to fluconazole, nystatin, and Melissa officinalis essential oil (MOEO). This examination included testing the antibiofilm potential of antifungals and MOEO and the determination of their types of interaction with mature biofilms. (3) Results: Antimicrobial testing showed that 94.4% of the Candida albicans isolates and all the Candida krusei isolates were resistant to fluconazole, while all strains showed resistance to nystatin. The same strains were susceptible to MOEO in 0.156-2.5 mg/mL concentrations. Additionally, the results revealed very limited action of fluconazole, while nystatin and MOEO reduced the amount of biofilm formed by as much as 17.7% and 4.6%, respectively. Testing of the combined effect showed strain-specific synergistic action. Furthermore, the lower concentrations exhibited antagonistic effects even in cases where synergism was detected. (4) Conclusions: This study showed that MOEO had a very good antibiofilm effect. However, combining MOEO with antimycotics demonstrated that the type of action depended on the choice of antifungal drugs as well as the applied concentration.

In-vitro and In-vivo Anti-Candidal Effect of Cnidoscolus aconitifolius Leaves Extracts

Candidiasis is an opportunistic infection caused by pathogens of the genus Candida. Due to the increase in antifungal resistance by Candida species, there is a need for alternatives in its treatment. Cnidoscolus aconitifolius is a medicinal plant with vast nutritional and antimicrobial properties. This study evaluated the in-vitro and in-vivo anti-candidal effect of Cnidoscolus aconitifolius (spinach tree) leaves extract. Clinical isolates of Candida albicans, Candida krusei, Candida tropicalis, Candida dublinensis, Candida glabrata, and Candida parapsilosis were used in this study and Cold maceration technique was employed in the plant extraction process, to obtain its ethanolic, methanolic, and aqueous extract. The agar well diffusion method and 2-fold dilution process -to obtain 250 mg/ml to 15.625mg/ml of the extracts -were used for the antimicrobial sensitivity test and three weeks old female Wistar rats infected with 20µl of standardized C. albicans were used for the in-vivo evaluation. Statistical analysis was done using Statistical package for Social Sciences (SPSS) version 22. In-vitro assay revealed ethanolic extract as the most potent extract with the highest inhibition zone diameter of 12.67±1.15c, 11.67±1.15c, and 12.33±0.58c at 250mg/ml against C. tropicalis, C. krusei2, and C. parapsilosis respectively. C. parapsilosis was the most sensitive to all the extracts. In-vivo, the disappearance of disease symptoms and progressive decrease in rats Candida burden- from 6.35×103 CFU/ml obtained after infection to 2.15×103CFU/ml after treatment revealed the ability of the plant to treat candidiasis. The study suggests that extract of Cnidoscolus aconitifolius leaves could act individually or synergistically as effective drug candidates in the treatment of candidiasis; thus if its individual antifungal constituents are purified, this plant could be the next major anti-candidal agent.

The Spectrum of Pathogenic Yeast Infection in a Tertiary Care Hospital in Assam, India.

In view of the growing incidence of pathogenic yeast infection all over the world, this study was undertaken to understand its etiology and epidemiology in Assam. To characterize and study the antifungal susceptibility pattern of the pathogenic yeasts from the clinical samples. The study was a hospital-based cross-sectional study. 150 patients were enrolled in the study and from which clinical samples were collected. A total of 83 samples showing the growth of yeast in culture were included in the study. The yeasts were identified by conventional and BioMerieux ID 32C and VITEK 2TM. Antifungal susceptibility test was done by disk diffusion method as per Clinical and Laboratory Standards Institute (CLSI), M44-A2. Data was analyzed using statistical software Epi-Info 7.1.2.0 (2013; CDC, Atlanta, USA). For comparison of categorical data, the Chi-square test or Fisher exact test was used. A value of p less than 0.05 was considered statistically significant. The most affected population was the age group of ≤10 years (32.5%) with male preponderance (67.5%). Yeasts were mostly isolated bloodstream infections (49.3%). The major risk factorwas prolonged antibiotic intake. Predominant yeast isolates were Candida albicans (43.4%) followed by Candida tropicalis (19.3%). Emerging yeasts like Kodaemea ohmeri (4.8%), Pichia anomala (2.4%), and Candida auris (1.2%) were also isolated. Amphotericin B was effective against all yeast isolates. All the isolates of Candida krusei were resistant to all the azoles. The study reflects that there is a growing incidence of emerging yeast infections and efforts are to be made for their identification and antifungal susceptibility testing for the initiation of appropriate therapy.

In Vitro Susceptibilities of Worldwide Isolates of Intrapulmonary Aspergillus Species and Important Candida Species in Sterile Body Sites against Important Antifungals: Data from the Antimicrobial Testing Leadership and Surveillance Program, 2017-2020.

To understand the changes of resistance in clinically commonly encountered fungi, we used the Antimicrobial Testing Leadership and Surveillance (ATLAS) database to explore in vitro antifungal susceptibilities against clinically important isolates of Aspergillus and Candida species (collected from intrapulmonary and sterile body areas, respectively). We applied the CLSI antifungal 2020 and the EUCAST antifungal 2020 guidelines. From 2017 to 2020, isolates of intrapulmonary Aspergillus fumigatus (n = 660), Aspergillus niger (n = 107), Aspergillus flavus (n = 96), Aspergillus terreus (n = 40), and Aspergillus nidulans species complex (n = 26) and sterile site-originated isolates of Candida albicans (n = 1,810), Candida glabrata (n = 894), Candida krusei (n = 120), Candida dubliniensis (n = 107), Candida lusitaniae (n = 82), Candida guilliermondii (n = 28), and Candida auris (n = 7) were enrolled in this study. Using the EUCAST 2020 breakpoints, it was demonstrated that amphotericin B and posaconazole displayed poor in vitro susceptibility rates against A. fumigatus isolates (<50% and 18.9%, respectively). In contrast, isavuconazole and itraconazole showed high in vitro potency against most Aspergillus isolates (>92%). Most intrapulmonary Aspergillus isolates exhibited MICs of ≤0.06 μg/mL to anidulafungin. Furthermore, intrapulmonary A. fumigatus isolates collected from Italy and the United Kingdom exhibited lower in vitro susceptibility to isavuconazole (72.2% and 69%, respectively) than those in the remaining ATLAS participant countries (>85%). Higher isavuconazole MIC90s against C. auris and C. guilliermondii (1 and 4 μg/mL, respectively) were observed compared to the other five Candida species. Despite the aforementioned MICs and susceptibilities against fungi, research needs to consider the pharmacokinetic (PK) profiles, pharmacodynamic (PD) parameters, and clinical treatment experience with antifungals against specific Aspergillus species. IMPORTANCE In addition to monitoring the antifungal susceptibilities of clinically important fungi, reviewing the PK/PD indices and the clinical therapy experience of antifungals under evaluation are important to guide an appropriate antifungal prescription. The efficacies of liposomal amphotericin B complex and anidulafungin for the treatment of pulmonary aspergillosis caused by different Aspergillus species need to be periodically evaluated in the future.

S2.4d Combination antifungal effects of eugenol with voriconazole against Candida tropicalis and Candida krusei strains isolated from the genital tract of mares

S2.4 Veterinary mycology research, September 21, 2022, 3:00 PM - 4:30 PM ObjectivesThe objective of the current study was to investigate the possibility that eugenol synergizes the antifungal effects of voriconazole on genital isolates of Candida krusei and Candida tropicalis from mares.MethodsThe antifungal activity of eugenol and voriconazole was evaluated using the broth microdilution assay (CLSI- M27-A3). The synergism of eugenol and voriconazole against genital Candida isolates was evaluated by the microdilution checkerboard method.ResultsMinimum inhibitory concentration (MIC) values for eugenol and voriconazole ranged from 400 to 800 μg/ml and 1 to 8 μg/ml, respectively, for C. tropicalis isolates, and from 200 to 400 μg/ml for eugenol and 2 to 16 μg/ml for voriconazole against C. krusei isolates. Eugenol decreased the arithmetic mean of MIC for voriconazole against C. tropicalis and C. krusei isolates from 2.66 to 0.46 μg/ml and 7.77 to 0.41 μg/ml respectively. The fractional inhibitory concentration index (FICI) values for the eugenol voriconazole combination ranged from 0.25 to 0.88 and 0.19 to 0.63 for C. tropicalis and C. krusei isolates respectively. A synergistic effect of eugenol in combination with voriconazole was observed for 83.3% of C. tropicalis and 77.7% of C. krusei isolates. The antagonistic activity was not seen in any of the isolates tested.ConclusionsEugenol showed fungistatic and fungicidal effects against genital Candida isolates and, in combination, synergized the antifungal effects of voriconazole. The eugenol-voriconazole combination can lay the foundation for a therapeutic approach against isolates in which azole resistance has increased over time.

The Synergistic Activity of Eugenol and Fluconazole on the Induction of Necrosis and Apoptosis in Candida Krusei Isolates of HIV+ Patients With Oral Candidiasis

Aims: The oral cavity contains more than 200 microbial species. Candida species are also part of the fungal flora of the oral cavity. In recent years, Candida krusei, as a common oral candida in AIDS patients, has been shown resistant to some antifungal drugs. The emergence of multidrug-resistant fungi, especially in immunodeficient populations, is a major global problem. Today, medicinal plants and their pure compounds in treating infectious diseases have provided a new horizon. This study aimed to investigate the synergistic activity of eugenol and fluconazole on the necrosis and apoptosis of Candida krusei (C. krusei) isolates from HIV+ patients with oral candidiasis. Methods &amp; Materials: The antifungal susceptibility tests were performed using the broth microdilution (CLSI, M27-A2) method, and the synergy between eugenol and fluconazole was evaluated using the checkerboard method. Necrotic and apoptotic effects of different antifungal agents against C. krusei were analyzed using the flow cytometry method. Findings: In antifungal susceptibility tests by microdilution broth, the mean minimum inhibitory concentration (MIC) values of eugenol and fluconazole for C. krusei isolates were 755.06 and 60.1 µg/mL, respectively. According to the checkerboard test results, eugenol in combination with fluconazole exhibited significant synergistic effects against most of the yeast isolates tested (P&lt;0.05). Eugenol decreased approximately 81.81% of the MIC value of fluconazole in growth inhibition of C. krusei. The flow cytometry test results indicated that eugenol plus fluconazole has significant necrotic effects on C. krusei isolates compared with the control group (P&lt;0.05). In contrast, minor early and late apoptotic effects of this compound were observed. Conclusion: Eugenol can be used to reduce fluconazole dose, inhibit the growth of fluconazole-resistant C. krusei, and the necrosis of yeast cells.

Cinnamaldehyde and α-terpineol inhibit the growth of planktonic cultures of Candida albicans and non albicans

Agents based in natural products have been investigated for the treatment of oral candidiasis. This study aims to evaluate the antifungal effect of phytoconstituent cinnamaldehyde and α-terpineol in planktonic cultures of Candida albicans, Candida glabrata, Candida krusei and clinical isolates of C. albicans. Reference strains of C. albicans (ATCC 90028 and ATCC 60193), C. glabrata (ATCC 2001), C. krusei (ATCC 34135) and four clinical isolates were used. Nistatin 100,000UI was used as a positive control. After preparation of the inoculum (1 × 103 CFU / mL), serial microdilution technique was performed using RPMI 1640 medium. Results: in reference strains, the MIC for α-terpineol ranged from 312,5 μg / mL (C. albicans 90028) to 40 μg / mL (C. krusei); and the cinnamaldehyde ranged from 40 μg / mL (C. albicans 90028, C. albicans 60193 and C. glabrata) to 20 μg / mL (C. krusei). Whereas for clinical strains, the MIC for α-terpineol ranged from 156 μg / mL to 78 μg / mL and cinnamaldehyde ranged from 78 μg / mL to 40 μg / mL. Therefore, the cinnamaldehyde and α-terpineol present an inhibitory effect against planktonic cultures of Candida albicans and not albicans.

Pola Kepekaan Candida krusei Isolat Jakarta terhadap Flukonazol

Pendahuluan. Candida krusei menghuni tubuh manusia sebagai saprofit namun dapat berubah menjadi patogen dan menyebabkan mikosis. Candida krusei umumnya bersifat resisten primer terhadap flukonazol, namun data laboratorium di Jakarta menemukan adanya C. krusei yang bersifat sensitif terhadap flukonazol sehinga dilakukan studi prospektif mengenai hasil uji kepekaan C. krusei isolat Jakarta, memakai isolat C. krusei yang berbeda.&#x0D; Metode: Penelitian dilaksanakan tahun 2019-2020 di laboratorium parasitologi Fakultas Kedokteran Universitas Indonesia. Sebanyak 15 isolat C. krusei diuji dengan metode difusi cakram. Sebelum digunakan isolat uji disegarkan dan dipurifikasi sehingga diperoleh koloni tunggal.&#x0D; Hasil: Isolat yang digunakan berasal dari feses, sputum, broncho-alveolar lavage (BAL) dan satu isolat dari abses paru. Hasil uji kepekaan didapat sembilan isolat resisten, satu isolat intermediate dan lima isolat yang bersifat sensitif terhadap flukonazol.&#x0D; Kesimpulan: Secara in vitro, C. krusei isolat Jakarta tidak seluruhnya bersifat resisten primer terhadap flukonazol, namun sebagian peka.

Effect of chlorogenic and gallic acids combined with azoles on antifungal susceptibility and virulence of multidrug-resistant Candida spp. and Malassezia furfur isolates.

Chlorogenic acid (CHA) and gallic acid (GA) are safe natural phenolic compounds that are used as enhancers of some drugs in influencing antioxidant, anticancer, and antibacterial activities. Among fungi, Candida spp. and Malassezia spp. are characterized by an increasing prevalence of multidrug resistance phenomena and by a high morbidity and mortality of their infections. No data are available about the efficacy of CHA and GA combined with azoles on the antifungal susceptibility and on the virulence of both fungi. Therefore, their antifungal and antivirulence effects have been tested in combination with fluconazole (FLZ) or ketoconazole (KTZ) on 23 Candida spp. and 8M. furfur isolates. Broth microdilution chequerboard, time-kill studies, and extracellular enzymes (phospholipase and hemolytic) activities were evaluated, displaying a synergistic antifungal action between CHA or GA and FLZ or KTZ on C. albicans, C. bovina, and C. parapsilosis, and antagonistic antifungal effects on M. furfur and Pichia kudriavzevii (Candida krusei) isolates. The time-kill studies confirmed the chequerboard findings, showing fungicidal inhibitory effect only when the GA was combined with azoles on Candida strains. However, the combination of phenolics with azoles had no effect on the virulence of the tested isolates. Our study indicates that the combination between natural products and conventional drugs could be an efficient strategy for combating azole resistance and for controlling fungistatic effects of azole drugs.

Antifungal Activity of an Original Amino-Isocyanonaphthalene (ICAN) Compound Family: Promising Broad Spectrum Antifungals.

Multiple drug resistant fungi pose a serious threat to human health, therefore the development of completely new antimycotics is of paramount importance. The in vitro antifungal activity of the original, 1-amino-5-isocyanonaphthalenes (ICANs) was evaluated against reference strains of clinically important Candida species. Structure-activity studies revealed that the naphthalene core and the isocyano- together with the amino moieties are all necessary to exert antifungal activity. 1,1-N-dimethylamino-5-isocyanonaphthalene (DIMICAN), the most promising candidate, was tested further in vitro against clinical isolates of Candida species, yielding a minimum inhibitory concentration (MIC) of 0.04–1.25 µg/mL. DIMICAN was found to be effective against intrinsically fluconazole resistant Candida krusei isolates, too. In vivo experiments were performed in a severly neutropenic murine model inoculated with a clinical strain of Candida albicans. Daily administration of 5 mg/kg DIMICAN intraperitoneally resulted in 80% survival even at day 13, whereas 100% of the control group died within six days. Based on these results, ICANs may become an effective clinical lead compound family against fungal pathogens.

Effects of Culture Conditions (Microplate and Solvent) on in vitro Antifungal Activity of Caspofungin Against Candida Species.

Effects of the type of microplates and solvent for preparation of caspofungin (CPFG) on antifungal susceptibility testing of CPFG against clinical isolates of Candida albicans, Candida glabrata, and Candida krusei (20 strains each) by broth microdilution method according to the Clinical and Laboratory Standards Institute were evaluated. When CPFG was dissolved in water, MICs against the three Candida species decreased 3.1-6.0-fold in surface-untreated microplates compared to those in treated microplates. When CPFG was dissolved in dimethyl sulfoxide, MICs against the three Candida species decreased 1.3-2.5-fold in surface-untreated microplates compared to those in treated microplates. Differences in MICs according to the type of solvent did not exceed the difference for one dilution interval (0.5-2-fold MIC ratio) regardless of whether the microplate surface was treated or not. These findings suggest that differences in CPFG MICs may depend mainly on the type of surface treatment of assay microplates.

In vitro susceptibility testing of Candida species isolated from blood stream infections to five conventional antifungal drugs

Candida is an opportunistic fungal pathogen which can cause fatal bloodstream infections (BSIs) in immunocompromised and immunodeficient persons. In this study, the susceptibility of 196 Candida species isolated from bloodstream infections (BSI) to 5 antifungal drugs were conducted from October 2014 through October 2017. The antifungal drugs used in this study were including fluconazole, itraconazole, voriconazole, Amphotericin B and Caspofungin. From 196 studied isolates, Candida albicans comprised 63.3% of the isolates, followed by C.parapsilosis (18.9 %), C. glabrata (8.7%), C. tropicalis (6.1%), C.krusei (2%) and C.gillermundii (1%). In this study, all isolates of Candida albicans and Candida non-albicans species were completely resistant to voriconazole and itraconazole. Of the 196 Candida isolates, 80 isolates with MIC of 32-16 μg/ml had a dose dependent susceptibility to fluconazole and 111 isolates showed resistance (MIC=64 μg / ml) and only 5 isolates were sensitive (MIC=8 μg / ml) to fluconazole. In this study, out of 196 isolates, 37 isolates were sensitive to amphotericin (MIC=1 μg/ml) and 159 isolates were resistant to amphotericin B (MIC&gt;1 μg/ml). Caspofungin was effective on 104 isolates (MIC&lt;2 μg/ml) and 92 isolates were non-susceptible (MIC&gt;2 μg / ml) to this drug. Out of 124 isolates of Candida albicans, 3 were susceptible, 61 susceptible dose dependent and 60 were resistant to fluconazole. Only 24 isolates were susceptible to amphotericin B and 100 isolates showed resistance to this antifungal drug. Eighty-eight isolates were sensitive to caspofungin and 36 isolates were insensitive. With respect to susceptibility to fluconazole, among 37 isolates of Candida parapsilosis, one was identified as susceptible, 13 isolates were susceptible dose dependent and 13 were resistant. Of these isolates, five were susceptible and 32 isolates were resistant to amphotericin B and caspofungin. Of 12 isolates of Candida tropicalis, 11 showed resistance and 1 was susceptible dose dependent to fluconazole. Of these isolates, 11 were resistant to amphotericin B and 1 isolate was sensitive. Ultimately, only 2 isolates showed susceptibility to caspofungin. Out of 17 isolates of Candida glabrata, 13 isolates were resistant, and 4 isolates had a dose-dependent sensitivity to fluconazole. Eight isolates were susceptible and 9 isolates were resistant to caspofungin. Seven isolates were susceptible and 10 isolates were resistant to amphotericin B. All four Candida krusei isolates showed resistance to the five drugs used in the study. Of the two Candida guilliermondii isolates, both were resistant to amphotericin B, but 1 was sensitive to fluconazole and 1 was identified to be dose-dependent susceptible. One isolate was resistant to and the other one was susceptible to caspofungin. Our findings shows the prevalence of resistant candida species to conventional treatments and indicate that candidemia caused by Candida resistant species is incrasing. Keywords: Candidiasis; Antifungal drugs; Candidemia; Iran

An Assessment of Alternative Therapeutic Options for the Treatment of Prolonged Zoonotic Fungal Infections in Companion Animals

Zoonotic disease is an ongoing issue, becoming more prominent as more microbial species display antimicrobial resistance. The role of companion animals in society is also increasing as therapy dogs become the mainstay for many special needs persons. In order to ensure public health safety, it is essent ial to determine the extent of resistance amongst zoonotic pathogens and where possible to suggest novel treatment options to counteract such resistance. Fungal species are increasingly recognised as the causative agent in numerous incidents of canine morb idity. Therefore, the development of new, safe and effective chemotherapeutic agents is essential to prevent and control mycotic disease. Chronic incidents of cutaneous candidiasis as diagnosed in the cases used for this study are particularly high risk fo r zoonotic transmission. Studies described herein evaluate the resistance of these canine isolates of Candida species to common antifungal agents and identify levels of resistance using recognised in vitro methods. Results show high levels of resistance to amphotericin B, fluconazole and caspofungin for Candida albicans and Candida krusei isolates. This clinical resistance was more prominent in isolated species compared to control species. Novel compounds namely phendione and Roussin Black salts show promis ing antifungal activity with minimum inhibitory concentrations determined.

Presence of L701 M mutation in the FKS1 gene of echinocandin-susceptible Candida krusei isolates

Resistance of Candida krusei isolates to echinocandins, the recommended drugs to treat candidemia, has been associated with mutations in hot spot (HS) regions of the FKS1 gene or L701 M mutation in a region between HS1 and HS3 of FKS1. However, the role of L701 M mutation alone in causing reduced echinocandins susceptibility is still unclear. We analyzed a region between HS1 and HS3 of FKS1 of 25 C. krusei isolates from clinical samples. Susceptibility to echinocandins was determined by a commercial broth microdilution assay and by the microdilution method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST). The L701 M mutation was detected in 22/25 (88%) C. krusei isolates with low MIC values in the absence of other HS mutations. The presence of isolated L701 M mutation in C. krusei clinical isolates susceptible to echinocandins suggests that this mutation may be just associated to polymorphism in the C. krusei population.

In vitro susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole and the correlation between triazoles susceptibility: Results from a five-year study

Candida spp. is a common cause of invasive fungal disease. The aim of this study was to examine the susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole and explore the correlation between triazoles susceptibility. The antifungal susceptibility in the present study was measured by ATB Fungus 3 method, and the potential relationship was examined by obtaining the correlation of measured minimal inhibitory concentrations (MICs) of Candida spp. isolates. A total of 2099 clinical isolates of Candida spp. from 1441 patients were analyzed. The organisms included 1435 isolates of Candida albicans, 207 isolates of Candida glabrata, 65 isolates of Candida parapsilosis, 31 isolates of Candida krusei, 268 isolates of Candida tropicalis. Voriconazole and itraconazole were more active than fluconazole and against Candida spp. in vitro. The fluconazole, itraconazole and voriconazole MIC90 (MIC for 90% of the isolates) for all Candida spp. isolates was 4mg/L, 1mg/L and 0.25mg/L, respectively. There was a moderate correlation between the fluconazole MICs for Candida spp. isolates and this for voriconazole (R2=0.475; P<0.01) and itraconazole (R2=0.431; P<0.01). Voriconazole MICs for the Candida spp. isolates also correlated with those for itraconazole (R2=0.401; P<0.01). These observations suggest that the in vitro susceptibility of Candida spp. to fluconazole, itraconazole and voriconazole exhibits a moderate correlation.

Chemical composition and antifungal potential of Iranian propolis against Candida krusei strains

Propolis is known to have biological properties against numerous microorganisms of clinical interest. This is important, because all Candida krusei (C. krusei) isolates are resistant to azole drugs. The aims of this study were to determine the chemical composition and antifungal efficacy of Iranian propolis against C. krusei strains isolated from patients with cutaneous and mucosal candidiasis. Ethanolic extract of propolis (EEP) was prepared from propolis originating from Mazandaran province, and submitted to chemical analysis by high-resolution gas chromatography coupled to mass spectrometry. Additionally, the EEP was tested for its ability to inhibit yeasts by determination of the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) using broth microdilution method (M27-A3 protocol) with some modifications. Phenolic acids (78.2%) were the major components of Iranian propolis. The EEP exhibited MIC values ranging from 2 to 20 mg/ml and MFC values between 4 and 25 mg/ml. The most fungal susceptibility was associated with the nail isolates (mean MIC value: 7.8 mg/ml), followed by the oral isolates (mean MIC value: 9.7 mg/ml) and vaginal isolates (mean MIC value: 11.7 mg/ml). The results showed that Iranian propolis has strong anti-C. krusei activity and should be considered as a promising candidate to treat nail, oral and vaginal candidiasis.