scholarly journals Identification of Cryptic Species of Four Candida Complexes in a Culture Collection

2019 ◽  
Vol 5 (4) ◽  
pp. 117
Author(s):  
Gustavo Fontecha ◽  
Kathy Montes ◽  
Bryan Ortiz ◽  
Celeste Galindo ◽  
Sharleen Braham
Keyword(s):  
Cryptic Species ◽  
Candida Species ◽  
Fungal Infections ◽  
Sensu Stricto ◽  
Culture Collection ◽  
Antifungal Drugs ◽  
Correct Identification ◽  
Candida Spp ◽  
Simple Method ◽  
First Report

Candida spp. are one of the most common causes of fungal infections worldwide. The taxonomy of Candida is controversial and has undergone recent changes due to novel genetically related species. Therefore, some complexes of cryptic species have been proposed. In clinical settings, the correct identification of Candida species is relevant since some species are associated with high resistance to antifungal drugs and increased virulence. This study aimed to identify the species of four Candida complexes (C. albicans, C. glabrata, C. parapsilosis, and C. haemulonii) by molecular methods. This is the first report of six cryptic Candida species in Honduras: C. dubliniensis, C. africana, C. duobushaemulonii, C. orthopsilosis, and C. metapsilosis, and it is also the first report of the allele hwp1-2 of C. albicans sensu stricto. It was not possible to demonstrate the existence of C. auris among the isolates of the C. haemulonii complex. We also propose a simple method based on PCR-RFLP for the discrimination of the multi-resistant pathogen C. auris within the C. haemulonii complex.

scholarly journals Identification of Cryptic Species of Four Candida Complexes in a Culture Collection

2019 ◽  
Author(s):  
Gustavo Fontecha ◽  
Kathy Montes ◽  
Bryan Ortiz ◽  
Celeste Galindo ◽  
Sharleen Braham
Keyword(s):  
Cryptic Species ◽  
Candida Species ◽  
Fungal Infections ◽  
Sensu Stricto ◽  
Culture Collection ◽  
Antifungal Drugs ◽  
Correct Identification ◽  
Candida Spp ◽  
Simple Method ◽  
First Report

Candida spp. are the most common cause of fungal infections worldwide. The taxonomy of Candida is controversial and has undergone recent changes due to novel genetically related species. Therefore, some complexes of cryptic species have been proposed. In clinical settings, the correct identification of Candida species is relevant since some species are associated with high resistance to antifungal drugs and increased virulence. This study aimed to identify the species of four Candida complexes (C. albicans, C. glabrata, C. parapsilosis, and C. haemulonii) by molecular methods. This is the first report of six cryptic Candida species in Honduras: C. dubliniensis, C. africana, C. duobushaemulonii, C. orthopsilosis, and C. metapsilosis, and it is also the first report of the allele hwp1-2 of C. albicans sensu stricto. It was not possible to demonstrate the existence of C. auris among the isolates of the C. haemulonii complex. We also propose a simple method based on PCR-RFLP for the discrimination of the multi-resistant pathogen C. auris within the C. haemulonii complex.

scholarly journals Trends on Aspergillus Epidemiology—Perspectives from a National Reference Laboratory Surveillance Program

2021 ◽  
Vol 7 (1) ◽  
pp. 28
Author(s):  
Raquel Sabino ◽  
Paulo Gonçalves ◽  
Aryse Martins Melo ◽  
Daniela Simões ◽  
Mariana Oliveira ◽  
...  
Keyword(s):  
Cryptic Species ◽  
Environmental Samples ◽  
Reference Method ◽  
Sensu Stricto ◽  
Antifungal Drugs ◽  
Surveillance Program ◽  
Azole Resistance ◽  
Correct Identification ◽  
Reference Laboratory ◽  
Minimal Inhibitory Concentrations

Identification of Aspergillus to species level is important since sibling species may display variable susceptibilities to multiple antifungal drugs and also because correct identification contributes to improve the knowledge of epidemiological studies. Two retrospective laboratory studies were conducted on Aspergillus surveillance at the Portuguese National Mycology Reference Laboratory. The first, covering the period 2017–2018, aimed to study the molecular epidemiology of 256 Aspergillus isolates obtained from patients with respiratory, subcutaneous, or systemic infections and from environmental samples. The second, using our entire collection of clinical and environmental A. fumigatus isolates (N = 337), collected between 2012 and 2019, aimed to determine the frequency of azole-resistant A. fumigatus isolates. Aspergillus fumigatus sensu stricto was the most frequent species in both clinical and environmental samples. Overall, and considering all Aspergillus sections identified, a high frequency of cryptic species was detected, based on beta-tubulin or calmodulin sequencing (37% in clinical and 51% in environmental isolates). Regarding all Fumigati isolates recovered from 2012–2019, the frequency of cryptic species was 5.3% (18/337), with the identification of A. felis (complex), A. lentulus, A. udagawae, A. hiratsukae, and A. oerlinghauensis. To determine the frequency of azole resistance of A. fumigatus, isolates were screened for azole resistance using azole-agars, and 53 possible resistant isolates were tested by the CLSI microdilution reference method. Nine A. fumigatus sensu stricto and six Fumigati cryptic isolates showed high minimal inhibitory concentrations to itraconazole, voriconazole, and/or posaconazole. Real-time PCR to detect cyp51A mutations and sequencing of cyp51A gene and its promoter were performed. The overall frequency of resistance to azoles in A. fumigatus sensu stricto was 3.0%. With this retrospective analysis, we were able to detect one azole-resistant G54R mutant A. fumigatus environmental isolate, collected in 2015. The TR34/L98H mutation, linked to environmental transmission route of azole resistance, was the most frequently detected mutation (N = 4; 1.4%). Our findings underline the demand for correct identification and susceptibility testing of Aspergillus isolates.

Opportunistic yeast pathogen Candida spp.: Secreted and membrane-bound virulence factors

2021 ◽  
Author(s):  
Si Jie Lim ◽  
Mohd Shukuri Mohamad Ali ◽  
Suriana Sabri ◽  
Noor Dina Muhd Noor ◽  
Abu Bakar Salleh ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Drug Targets ◽  
Fungal Infections ◽  
Antifungal Drugs ◽  
Host Immune System ◽  
Structural Studies ◽  
Candida Spp ◽  
Structural Investigations ◽  
Membrane Bound ◽  
Aspartyl Proteinases

Abstract Candidiasis is a fungal infection caused by Candida spp. especially Candida albicans, C. glabrata, C. parapsilosis and C. tropicalis. Although the medicinal therapeutic strategies have rapidly improved, the mortality rate due to candidiasis has continuously increased. The secreted and membrane-bound virulence factors (VFs) are responsible for fungal invasion, damage and translocation through the host enterocytes besides the evasion from host immune system. VFs such as agglutinin-like sequences (Als), heat shock protein 70, phospholipases, secreted aspartyl proteinases (Sap), lipases, enolases and phytases are mostly hydrolases which degrade the enterocyte membrane components except for candidalysin, the VF acts as a peptide toxin to induce necrotic cell lysis. To date, structural studies of the VFs remain underexplored, hindering their functional analyses. Among the VFs, only secreted aspartyl proteinases and agglutinin-like sequences have their structures deposited in Protein Data Bank (PDB). Therefore, this review scrutinizes the mechanisms of these VFs by discussing the VF-deficient studies of several Candida spp. and their abilities to produce these VFs. Nonetheless, their latest reported sequential and structural analyses are discussed to impart a wider perception of the host-pathogen interactions and potential vaccine or antifungal drug targets. This review signifies that more VFs structural investigations and mining in the emerging Candida spp. are required to decipher their pathogenicity and virulence mechanisms compared to the prominent C. albicans. Lay Abstract Candida virulence factors (VFs) including mainly enzymes and proteins play vital roles in breaching the human intestinal barrier and causing deadly candidiasis. Limited VFs’ structural studies hinder deeper comprehension of their mechanisms and thus the design of vaccines and antifungal drugs against fungal infections.

scholarly journals Susceptibility Pattern of Caspofungin-Coated Gold Nanoparticles against Clinically Important Candida Species

2020 ◽  
Author(s):  
Zahra Salehi ◽  
Azam Fattahi ◽  
Ensieh lotfali ◽  
Abdolhassan Kazemi ◽  
Ali Shakeri-Zadeh ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Cell Wall ◽  
Candida Species ◽  
Spherical Shape ◽  
Sem Analysis ◽  
Antifungal Drugs ◽  
Wall Structure ◽  
Candida Spp ◽  
Average Size

Purpose: The present study was performed to examine whether caspofungin-coated gold nanoparticles (CAS-AuNPs) may offer the right platform for sensitivity induction in resistant isolates. Methods: For the purpose of the study, a total of 58 archived Candida species were enrolled in the research. The identification of Candida spp. was performed using polymerase chain reaction-restriction fragment length polymorphism and HWP1 gene amplification approaches. The conjugated CAS-AuNPs were synthesized and then characterized using transmission electron microscopy (TEM) and Zetasizer system to determine their morphology, size, and charge. Furthermore, the efficacy of CAS, CAS-AuNPs conjugate, and AuNPs against Candida spp. was assessed based on the Clinical and Laboratory Standards Institute M60. Finally, the interaction of CAS-AuNPs with Candida element was evaluated via scanning electron microscopy (SEM). Results: According to the TEM results, the synthesized CAS-AuNPs had a spherical shape with an average size of 20 nm. The Zeta potential of CAS-AuNPs was -38.2 mV. Statistical analyses showed that CAS-AuNPs could significantly reduce the minimum inhibitory concentration against C. albicans (P=0.0005) and non-albicans Candida (NAC) species (P<0.0001). All isolates had a MIC value of ≥ 4 µg/ml for CAS, except for C. glabrata. The results of SEM analysis confirmed the effects of AuNPs on the membrane and cell wall structure of C. globrata exposed to CAS-AuNPs, facilitating the formation of pores on the cell wall and finally cell death. Conclusion: The findings revealed that CAS-AuNPs conjugates had significant antifungal effects against Candida spp. through the degradation of the membrane and cell wall integrity. Therefore, it can be concluded that the encapsulation of antifungal drugs in combination with NPs not only diminishes side effects but also enhances the effectiveness of the medications.

scholarly journals COVID-19-Associated Candidiasis (CAC): An Underestimated Complication in the Absence of Immunological Predispositions?

2020 ◽  
Vol 6 (4) ◽  
pp. 211 ◽  
Author(s):  
Amir Arastehfar ◽  
Agostinho Carvalho ◽  
M. Hong Nguyen ◽  
Mohammad Taghi Hedayati ◽  
Mihai G. Netea ◽  
...  
Keyword(s):  
Fungal Infections ◽  
Antibiotic Use ◽  
Multidrug Resistant ◽  
Molecular Techniques ◽  
Antifungal Drugs ◽  
Diagnostic Tools ◽  
Candida Spp ◽  
Comparative Performance ◽  
Number Of Patients ◽  
Clinical Awareness

The recent global pandemic of COVID-19 has predisposed a relatively high number of patients to acute respiratory distress syndrome (ARDS), which carries a risk of developing super-infections. Candida species are major constituents of the human mycobiome and the main cause of invasive fungal infections, with a high mortality rate. Invasive yeast infections (IYIs) are increasingly recognized as s complication of severe COVID-19. Despite the marked immune dysregulation in COVID-19, no prominent defects have been reported in immune cells that are critically required for immunity to Candida. This suggests that relevant clinical factors, including prolonged ICU stays, central venous catheters, and broad-spectrum antibiotic use, may be key factors causing COVID-19 patients to develop IYIs. Although data on the comparative performance of diagnostic tools are often lacking in COVID-19 patients, a combination of serological and molecular techniques may present a promising option for the identification of IYIs. Clinical awareness and screening are needed, as IYIs are difficult to diagnose, particularly in the setting of severe COVID-19. Echinocandins and azoles are the primary antifungal used to treat IYIs, yet the therapeutic failures exerted by multidrug-resistant Candida spp. such as C. auris and C. glabrata call for the development of new antifungal drugs with novel mechanisms of action.

scholarly journals Prevalence and Fluconazole Susceptibility Profile of Candida spp. Clinical Isolates in a Brazilian Tertiary Hospital in Minas Gerais, Brazil

2015 ◽  
Vol 87 (2 suppl) ◽  
pp. 1349-1359 ◽  
Author(s):  
Athayde Neves-Junior ◽  
Ana Carolina Cartágenes-Pinto ◽  
Débora A.S. Rocha ◽  
Leandro F. Reis de Sá ◽  
Maria de Lourdes Junqueira ◽  
...  
Keyword(s):  
Opportunistic Infections ◽  
Fungal Infections ◽  
Tertiary Hospital ◽  
Antifungal Drugs ◽  
Control Measures ◽  
Clinical Isolates ◽  
University Hospital ◽  
Effective Control ◽  
Candida Spp ◽  
Resistance Phenotype

Candidiasis has become an important concern for clinical practice, especially with the increasing incidence of immunocompromised patients. In this scenario, the development resistance to fluconazole presents a challenge for treating these opportunistic infections. The aim of this study was to evaluate some epidemiology features of Candidainfections in a Brazilian University Hospital using data, previously unavailable. We observed that 44% of the 93 clinical isolates tested, belonged to Candida albicansspecies and 56% belonged to non-Candida albicansspecies (mainly Candida tropicalis and Candida glabrata). Most strains were isolated from urine samples where C. albicans was predominantly detected. 29 strains presented a fluconazole resistance phenotype and of these, 22 were chemosensitised by FK506, a classical inhibitor of ABC transporters related to azoles resistance. These data suggest the probable role of efflux pumps in this resistance phenotype. Our study highlights the need for developing effective control measures for fungal infections, rational use of antifungal drugs and development of new molecules able to abrogate the active transport of antifungals.

scholarly journals The Trends in the Distribution of Candida species Causing Candidemia at a Community Hospital in 2005 and 2014

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S87-S87
Author(s):  
Celestine Ishiekwene ◽  
Maxine Seales Kasangana ◽  
Monica Ghitan ◽  
Margaret Kuhn-Basti ◽  
Edward Chapnick ◽  
...  
Keyword(s):  
New York ◽  
Antifungal Therapy ◽  
Candida Species ◽  
Fungal Infections ◽  
Medical Center ◽  
Retrospective Chart Review ◽  
Common Species ◽  
Published Data ◽  
Candida Spp ◽  
Common Cause

Abstract Background Candida remains the most common cause of invasive fungal infections, with an attributable morality of 15–35%. Although five Candida species (C. albicans, C. tropicalis, C. parapsilosis, C. glabrata, and C. krusei) account for 92% of cases of candidemia, Candida albicans remains the most common cause of candidemia. However, recent studies report that the frequency of non albicans species are increasing globally and the distribution of Candida spp. varies significantly among different geographic regions and hospitals units. Objective We determine the distribution of Candida species causing candidemia at an adult level 1 Trauma Center in Brooklyn, New York and compared the trends of Candida species between 2005 and 2014. The results were compared with trends of US data collected in 2004 and 2012. Knowledge of the frequency of causative species would facilitate appropriate selection of empiric antifungal therapy. Methods We performed a retrospective chart review of patients with candidemia who were admitted in 2005 and 2014. We determined the frequency of Candida species and compared 2005 data with those in 2014. Results In total, 226 and 109 patients with candidemia were admitted to our hospital in 2005 and 2014, respectively. Although, C. albicans was the most common species (43% of candidemia in 2005), its frequency decreased to 33% in 2014. The frequencies of C. glabrata and C. parapsilosis increased in 2014 compared with those in 2005 (24% vs. 16% and 33% vs. 26%, respectively). Figure 1 compared the proportion of Candida species in Maimonides Medical Center to National data. Conclusion Our finding of an increase in non-albicans spp. causing candidemia is consistent with published reports. We saw more cases of C. parapsilosis compared with published data. Our results may be used to inform empiric antifungal therapy. Disclosures All authors: No reported disclosures.

scholarly journals COMPARISON BETWEEN FOUR USUAL METHODS OF IDENTIFICATION OF Candida SPECIES

2015 ◽  
Vol 57 (4) ◽  
pp. 281-287 ◽  
Author(s):  
Margarida Neves SOUZA ◽  
Stéfanie Otowicz ORTIZ ◽  
Marcelo Martins MELLO ◽  
Flávio de Mattos OLIVEIRA ◽  
Luiz Carlos SEVERO ◽  
...  
Keyword(s):  
Candida Species ◽  
Germ Tube ◽  
Mortality Rates ◽  
Correct Identification ◽  
Kappa Index ◽  
Candida Spp ◽  
Chromogenic Medium ◽  
Tube Test ◽  
Automated Method ◽  
Manual Methods

SUMMARY Infection by Candidaspp. is associated with high mortality rates, especially when treatment is not appropriate and/or not immediate. Therefore, it is necessary to correctly identify the genus and species of Candida. The aim of this study was to compare the identification of 89 samples of Candida spp. by the manual methods germ tube test, auxanogram and chromogenic medium in relation to the ID 32C automated method. The concordances between the methods in ascending order, measured by the Kappa index were: ID 32C with CHROMagar Candida(κ = 0.38), ID 32C with auxanogram (κ = 0.59) and ID 32C with germ tube (κ = 0.9). One of the species identified in this study was C. tropicalis,which demonstrated a sensitivity of 46.2%, a specificity of 95.2%, PPV of 80%, NPV of 81.1%, and an accuracy of 80.9% in tests performed with CHROMagar Candida;and a sensitivity of 76.9%, a specificity of 96.8%, PPV of 90.9%, NPV of 91%, and an accuracy of 91% in the auxanogram tests. Therefore, it is necessary to know the advantages and limitations of methods to choose the best combination between them for a fast and correct identification of Candidaspecies.

scholarly journals DectiSomes: Glycan Targeting of Liposomal Drugs Improves the Treatment of Disseminated Candidiasis

2021 ◽  
Author(s):  
Suresh Ambati ◽  
Tuyetnhu Pham ◽  
Zachary A. Lewis ◽  
Xiaorong Lin ◽  
Richard B. Meagher
Keyword(s):  
Fungal Infections ◽  
Drug Efficacy ◽  
Antifungal Drugs ◽  
Outer Cell ◽  
Candida Spp ◽  
Fungal Burden ◽  
Disseminated Candidiasis ◽  
Binding Domains ◽  
One Year

Candida albicans causes life-threatening disseminated candidiasis. Individuals at greatest risk have weakened immune systems. An outer cell wall, exopolysaccharide matrix, and biofilm rich in oligoglucans and oligomannans help Candida spp. evade host defenses. Even after antifungal treatment, the one-year mortality rate exceeds 25%. Undoubtedly, there is room to improve drug performance. The mammalian C-type lectin pathogen receptors Dectin-1 and Dectin-2 bind to fungal oligoglucans and oligomannans, respectively. We previously coated amphotericin B-loaded liposomes, AmB-LLs, pegylated analogs of AmBisome, with the ligand binding domains of these two Dectins. DectiSomes, DEC1-AmB-LLs and DEC2-AmB-LLs, showed two distinct patterns of binding to the exopolysaccharide matrix surrounding C. albicans hyphae grown in vitro. Here we showed that DectiSomes were preferentially associated with fungal colonies in the kidneys. In a neutropenic mouse model of candidiasis, DEC1-AmB-LLs and DEC2-AmB-LLs delivering only one dose of 0.2 mg/kg AmB reduced the kidney fungal burden several fold relative to AmB-LLs. DEC1-AmB-LLs and DEC2-AmB-LLs increased the percent of surviving mice 2.5-fold and 8.3-fold, respectively, relative to AmB-LLs. Dectin-2 targeting of anidulafungin loaded liposomes, DEC2-AFG-LLs, and of commercial AmBisome, DEC2-AmBisome, reduced fungal burden in the kidneys several fold over their untargeted counterparts. The data herein suggest that targeting of a variety of antifungal drugs to fungal glycans may achieve lower safer effective doses and improve drug efficacy against a variety of invasive fungal infections.

scholarly journals The Inhibition of Non-albicans Candida Species and Uncommon Yeast Pathogens by Selected Essential Oils and Their Major Compounds

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4937
Author(s):  
Narcisa Mandras ◽  
Janira Roana ◽  
Daniela Scalas ◽  
Simonetta Del Re ◽  
Lorenza Cavallo ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Essential Oils ◽  
Candida Species ◽  
Fungal Infections ◽  
Biological Activities ◽  
Antifungal Drugs ◽  
Thymus Vulgaris ◽  
Foeniculum Vulgare ◽  
Lemon Balm ◽  
Wide Range

The epidemiology of yeast infections and resistance to available antifungal drugs are rapidly increasing, and non-albicans Candida species and rare yeast species are increasingly emerging as major opportunistic pathogens. In order to identify new strategies to counter the threat of antimicrobial resistant microorganisms, essential oils (EOs) have become an important potential in the treatment of fungal infections. EOs and their bioactive pure compounds have been found to exhibit a wide range of remarkable biological activities. We investigated the in vitro antifungal activity of nine commercial EOs such as Thymus vulgaris (thyme red), Origanum vulgare (oregano), Lavandula vera (lavender), Pinus sylvestris (pine), Foeniculum vulgare (fennel), Melissa officinalis (lemon balm), Salvia officinalis (sage), Eugenia caryophyllata (clove) and Pelargonium asperum (geranium), and some of their main components (α-pinene, carvacrol, citronellal, eugenol, γ-terpinene, linalool, linalylacetate, terpinen-4-ol, thymol) against non-albicans Candida strains and uncommon yeasts. The EOs were analyzed by GC-MS, and their antifungal properties were evaluated by minimum inhibitory concentration and minimum fungicidal concentration parameters, in accordance with CLSI guidelines, with some modifications for EOs. Pine exhibited strong antifungal activity against the selected non-albicans Candida isolates and uncommon yeasts. In addition, lemon balm EOs and α-pinene exhibited strong antifungal activity against the selected non-albicans Candida yeasts. Thymol inhibited the growth of all uncommon yeasts. These data showed a promising potential application of EOs as natural adjuvant for management of infections by emerging non-albicans Candida species and uncommon pathogenic yeasts.

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