scholarly journals Oral Candida colonization in HIV-infected patients in Londrina-PR, Brazil: antifungal susceptibility and virulence factors

2015 ◽  
Vol 9 (12) ◽  
pp. 1350-1359 ◽  
Author(s):  
Suelen Balero De Paula ◽  
Alexandre Tadachi Morey ◽  
Jussevania Pereira Santos ◽  
Pollyanna M. C. Dos Santos ◽  
Danielle G. Gameiro ◽  
...  
Keyword(s):  
Candida Species ◽  
Biofilm Formation ◽  
Fungal Infections ◽  
Antifungal Susceptibility ◽  
Cell Surface Hydrophobicity ◽  
Candida Colonization ◽  
Hydrophobic Property ◽  
Predisposing Factor ◽  
Oral Candida

Introduction: Host colonization by Candida species is an important predisposing factor to candidiasis, which seems to be more frequent in human immunodeficiency virus (HIV)-infected patients. Knowledge about the distribution, antifungal susceptibility, and virulence of oral Candida isolates is important for effective management of candidiasis. Methodology: Oral rinses were collected from 242 HIV-infected patients without clinical evidence of candidiasis seen at the AIDS referral center in Londrina, Brazil. Species were identified by standard phenotypic and molecular methods, and characterized in vitro according to antifungal susceptibility, cell surface hydrophobicity, biofilm formation, and enzyme activities. Results: Oral Candida colonization was detected in 50.4% of patients and combined use of antiretroviral therapy and protease inhibitor had a protective effect against colonization. Candida albicans (75.2%) was the most prevalent species. A high proportion of Candida spp. (39.9%) showed decreased susceptibility to fluconazole. Five isolates were resistant to nystatin. Protease and phospholipase activities were detected in 100% and 36.8% of isolates, respectively. Most isolates displayed a hydrophobic property that was associated with biofilm formation ability. Conclusions: A significant number of oral Candida species exhibiting decreased susceptibility to fluconazole were isolated from colonized HIV-infected individuals. Furthermore, all isolates expressed potential virulence attributes in vitro. Given the high incidence and severity of fungal infections in HIV-infected individuals, the results of this study reinforce the importance of antifungal susceptibility testing, which contributes to therapeutic strategies and highlights the need for continuous surveillance of Candida colonization in this population.

scholarly journals Symbiotic NCR Peptide Fragments Affect the Viability, Morphology and Biofilm Formation of Candida Species

2021 ◽  
Vol 22 (7) ◽  
pp. 3666
Author(s):  
Bettina Szerencsés ◽  
Attila Gácser ◽  
Gabriella Endre ◽  
Ildikó Domonkos ◽  
Hilda Tiricz ◽  
...  
Keyword(s):  
Candida Species ◽  
Biofilm Formation ◽  
Therapeutic Potential ◽  
Fungal Infections ◽  
Combined Treatment ◽  
Antimicrobial Activities ◽  
Dilution Method ◽  
Model Legume ◽  
Anticandidal Activity

The increasing rate of fungal infections causes global problems not only in human healthcare but agriculture as well. To combat fungal pathogens limited numbers of antifungal agents are available therefore alternative drugs are needed. Antimicrobial peptides are potent candidates because of their broad activity spectrum and their diverse mode of actions. The model legume Medicago truncatula produces >700 nodule specific cysteine-rich (NCR) peptides in symbiosis and many of them have in vitro antimicrobial activities without considerable toxicity on human cells. In this work we demonstrate the anticandidal activity of the NCR335 and NCR169 peptide derivatives against five Candida species by using the micro-dilution method, measuring inhibition of biofilm formation with the XTT (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) assay, and assessing the morphological change of dimorphic Candida species by microscopy. We show that both the N- and C-terminal regions of NCR335 possess anticandidal activity as well as the C-terminal sequence of NCR169. The active peptides inhibit biofilm formation and the yeast-hypha transformation. Combined treatment of C. auris with peptides and fluconazole revealed synergistic interactions and reduced 2-8-fold the minimal inhibitory concentrations. Our results demonstrate that shortening NCR peptides can even enhance and broaden their anticandidal activity and therapeutic potential.

scholarly journals 146. antifungal Susceptibility Patterns of candida Parapsilosis Bloodstream Isolates in the US, 2008–2018

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S203-S203
Author(s):  
Brenda L Tesini ◽  
Meghan Lyman ◽  
Brendan R Jackson ◽  
Anita Gellert ◽  
William Schaffner ◽  
...  
Keyword(s):  
Candida Species ◽  
Regional Variation ◽  
Antifungal Susceptibility ◽  
Bloodstream Infections ◽  
Emerging Infections ◽  
In Vitro Susceptibility ◽  
Fluconazole Resistance ◽  
The Us ◽  
Susceptibility Patterns

Abstract Background Multidrug resistant Candida is an increasing concern. C. parapsilosis in particular has decreased in vitro susceptibility to echinocandins. As a result, fluconazole had been favored for C. parapsilosis treatment. However, there is growing concern about increasing azole resistance among Candida species. We report on antifungal susceptibility patterns of C. parapsilosis in the US from 2008 through 2018. Methods Active, population-based surveillance for candidemia through the Centers for Disease Control and Prevention’s (CDC) Emerging Infections Program was conducted between 2008–2018, eventually encompassing 9 states (GA, MD,OR, TN, NY, CA, CO, MN, NM). Each incident isolate was sent to the CDC for species confirmation and antifungal susceptibility testing (AFST). Frequency of resistance was calculated and stratified by year and state using SAS 9.4 Results Of the 8,704 incident candidemia isolates identified, 1,471 (15%) were C. parapsilosis; the third most common species after C. albicans and C. glabrata. AFST results were available for 1,340 C. parapsilosis isolates. No resistance was detected to caspofungin (MIC50 0.25) or micafungin (MIC50 1.00) with only one (< 1%) isolate resistant to anidulafungin (MIC50 1.00). In contrast, 84 (6.3%) isolates were resistant to fluconazole and another 44 (3.3%) isolates had dose-dependent susceptibility to fluconazole (MIC50 1.00). Fluconazole resistance increased sharply from an average of 4% during 2008–2014 to a peak of 14% in 2016 with a subsequent decline to 6% in 2018 (see figure). Regional variation is also observed with fluconazole resistance ranging from 0% (CO, MN, NM) to 42% (NY) of isolates by site. Conclusion The recent marked increase in fluconazole resistance among C. parapsilosis highlights this pathogen as an emerging drug resistant pathogen of concern and the need for ongoing antifungal resistance surveillance among Candida species. Our data support the empiric use of echinocandins for C. parapsilosis bloodstream infections and underscore the need to obtain AFST prior to fluconazole treatment. Furthermore, regional variation in fluconazole resistance emphasizes the importance of understanding local Candida susceptibility patterns. Disclosures Lee Harrison, MD, GSK (Consultant)Merck (Consultant)Pfizer (Consultant)Sanofi Pasteur (Consultant)

scholarly journals Review of T-2307, an Investigational Agent That Causes Collapse of Fungal Mitochondrial Membrane Potential

2021 ◽  
Vol 7 (2) ◽  
pp. 130
Author(s):  
Nathan P. Wiederhold
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Candida Species ◽  
Mammalian Cells ◽  
Mitochondrial Membrane ◽  
Fungal Infections ◽  
Published Data ◽  
Candida Auris

Invasive infections caused by Candida that are resistant to clinically available antifungals are of increasing concern. Increasing rates of fluconazole resistance in non-albicans Candida species have been documented in multiple countries on several continents. This situation has been further exacerbated over the last several years by Candida auris, as isolates of this emerging pathogen that are often resistant to multiple antifungals. T-2307 is an aromatic diamidine currently in development for the treatment of invasive fungal infections. This agent has been shown to selectively cause the collapse of the mitochondrial membrane potential in yeasts when compared to mammalian cells. In vitro activity has been demonstrated against Candida species, including C. albicans, C. glabrata, and C. auris strains, which are resistant to azole and echinocandin antifungals. Activity has also been reported against Cryptococcus species, and this has translated into in vivo efficacy in experimental models of invasive candidiasis and cryptococcosis. However, little is known regarding the clinical efficacy and safety of this agent, as published data from studies involving humans are not currently available.

scholarly journals Eap1p, an Adhesin That Mediates Candida albicans Biofilm Formation In Vitro and In Vivo

2007 ◽  
Vol 6 (6) ◽  
pp. 931-939 ◽  
Author(s):  
Fang Li ◽  
Michael J. Svarovsky ◽  
Amy J. Karlsson ◽  
Joel P. Wagner ◽  
Karen Marchillo ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Cell Adhesion ◽  
Biofilm Formation ◽  
Fungal Infections ◽  
Gene Dosage ◽  
Venous Catheter ◽  
Flow Chamber ◽  
Dependent Manner

ABSTRACT Candida albicans is the leading cause of systemic fungal infections in immunocompromised humans. The ability to form biofilms on surfaces in the host or on implanted medical devices enhances C. albicans virulence, leading to antimicrobial resistance and providing a reservoir for infection. Biofilm formation is a complex multicellular process consisting of cell adhesion, cell growth, morphogenic switching between yeast form and filamentous states, and quorum sensing. Here we describe the role of the C. albicans EAP1 gene, which encodes a glycosylphosphatidylinositol-anchored, glucan-cross-linked cell wall protein, in adhesion and biofilm formation in vitro and in vivo. Deleting EAP1 reduced cell adhesion to polystyrene and epithelial cells in a gene dosage-dependent manner. Furthermore, EAP1 expression was required for C. albicans biofilm formation in an in vitro parallel plate flow chamber model and in an in vivo rat central venous catheter model. EAP1 expression was upregulated in biofilm-associated cells in vitro and in vivo. Our results illustrate an association between Eap1p-mediated adhesion and biofilm formation in vitro and in vivo.

scholarly journals Biofilm Formation by Pneumocystis spp.

2008 ◽  
Vol 8 (2) ◽  
pp. 197-206 ◽  
Author(s):  
Melanie T. Cushion ◽  
Margaret S. Collins ◽  
Michael J. Linke
Keyword(s):  
Biofilm Formation ◽  
Fungal Infections ◽  
Morphological Changes ◽  
Continuous Cultivation ◽  
Life Cycles ◽  
Mammalian Host ◽  
Intense Staining ◽  
In Vitro System ◽  
Major Surface

ABSTRACT Pneumocystis spp. can cause a lethal pneumonia in hosts with debilitated immune systems. The manner in which these fungal infections spread throughout the lung, the life cycles of the organisms, and their strategies used for survival within the mammalian host are largely unknown, due in part to the lack of a continuous cultivation method. Biofilm formation is one strategy used by microbes for protection against environmental assaults, for communication and differentiation, and as foci for dissemination. We posited that the attachment and growth of Pneumocystis within the lung alveoli is akin to biofilm formation. An in vitro system comprised of insert wells suspended in multiwell plates containing supplemented RPMI 1640 medium supported biofilm formation by P. carinii (from rat) and P. murina (from mouse).Dramatic morphological changes accompanied the transition to a biofilm. Cyst and trophic forms became highly refractile and produced branching formations that anastomosed into large macroscopic clusters that spread across the insert. Confocal microscopy revealed stacking of viable organisms enmeshed in concanavalin A-staining extracellular matrix. Biofilms matured over a 3-week time period and could be passaged. These passaged organisms were able to cause infection in immunosuppressed rodents. Biofilm formation was inhibited by farnesol, a quorum-sensing molecule in Candida spp., suggesting that a similar communication system may be operational in the Pneumocystis biofilms. Intense staining with a monoclonal antibody to the major surface glycoproteins and an increase in (1,3)-β-d-glucan content suggest that these components contributed to the refractile properties. Identification of this biofilm process provides a tractable in vitro system that should fundamentally advance the study of Pneumocystis.

Molecular diagnosis and antifungal resistance and biofilm production profiles among Candida species isolated from immunocompromised patients at Menoufia University Hospitals

2020 ◽  
Vol 29 (3) ◽  
pp. 37-45
Author(s):  
Mabrouk M Ghonaim ◽  
Azza Z. Labeeb ◽  
Alyaa I. Eliwa ◽  
Eman H. Salem
Keyword(s):  
Candida Species ◽  
Biofilm Formation ◽  
Antifungal Susceptibility ◽  
High Sensitivity ◽  
Antifungal Resistance ◽  
Common Source ◽  
Immunocompromised Patients ◽  
University Hospitals ◽  
Biofilm Production ◽  
Vitek 2

Background: Accurate and rapid identification of Candida species is necessary for proper diagnosis and treatment of candidiasis due to emergences of drug-resistant strains especially among immunocompromised patients. Objectives: Identification of Candida clinical isolates to the species level using different phenotypic and molecular methods. Biofilm-forming ability and antifungal resistance were also studied. Methodology: Sixty-nine Candida strains were isolated from 220 immunocompromised patients. Identification was performed using chromogenic Candida agar, VITEK 2 system and multiplex polymerase chain reaction (PCR). Biofilm formation was detected by the tube method and antifungal susceptibility was tested using the VITEK2 system. Results: The most common source of Candida isolates was from urine (33.3%) and ICUs (56.6%). VITEK 2 system detected 9 spp.: C. albicans (34.8%), C. tropicalis (21.7%), C. famata (8.7%), C. lusitaniae (7.2%), C. cruzi (7.2%), C. ciferri (5.8%), C. dubliniensis (5.8%), C. parapsilosis (5.8 %) and C. glabrata. Candida isolates showed high resistance to flucytocine (49.3%), and high sensitivity to fluconazole, micafungin, voriconazole and caspofungin (88.4%, 81.2% and 81.2 % respectively). Only 30.4% of all Candida isolates were biofilm producers. There was a positive relationship between antifungal resistance and biofilm formation among Candida isolates. Conclusion: C. albicans was the predominant species. Chromogenic Candida agar and VITEK 2 system were valuable tests compared to PCR in speciation of Candida isolates. Antifungal susceptibility was significantly related to biofilm production and its evaluation is important for proper treatment..

scholarly journals Biofilm Formation by and Antifungal Susceptibility of Candida Isolates from Urine

2007 ◽  
Vol 73 (6) ◽  
pp. 1697-1703 ◽  
Author(s):  
N. Jain ◽  
R. Kohli ◽  
E. Cook ◽  
P. Gialanella ◽  
T. Chang ◽  
...  
Keyword(s):  
Risk Factors ◽  
Growth Medium ◽  
Biofilm Formation ◽  
Chart Review ◽  
Antifungal Susceptibility ◽  
Retrospective Chart Review ◽  
Urine Samples ◽  
Rpmi Medium

ABSTRACT Biofilm formation (BF) in the setting of candiduria has not been well studied. We determined BF and MIC to antifungals in Candida spp. isolates grown from urine samples of patients and performed a retrospective chart review to examine the correlation with risk factors. A total of 67 Candida spp. isolates were grown from urine samples from 55 patients. The species distribution was C. albicans (54%), C. glabrata (36%), and C. tropicalis (10%). BF varied greatly among individual Candida isolates but was stable in sequential isolates during chronic infection. BF also depended on the growth medium and especially in C. albicans was significantly enhanced in artificial urine (AU) compared to RPMI medium. In nine of the C. albicans strains BF was 4- to 10-fold higher in AU, whereas in three of the C. albicans strains and two of the C. glabrata strains higher BF was measured in RPMI medium than in AU. Determination of the MICs showed that planktonic cells of all strains were susceptible to amphotericin B (AMB) and caspofungin (CASPO) and that three of the C. glabrata strains and two of the C. albicans strains were resistant to fluconazole (FLU). In contrast, all biofilm-associated adherent cells were resistant to CASPO and FLU. The biofilms of 14 strains (28%) were sensitive to AMB (MIC50 of <1 μg/ml). Correlation between degree of BF and MIC of AMB was not seen in RPMI grown biofilms but was present when grown in AU. A retrospective chart review demonstrated no correlation of known risk factors of candiduria with BF in AU or RPMI. We conclude that BF is a stable characteristic of Candida strains that varies greatly among clinical strains and is dependent on the growth medium. Resistance to AMB is associated with higher BF in AU, which may represent the more physiologic medium to test BF. Future studies should address whether in vitro BF can predict treatment failure in vivo.

scholarly journals In-Vitro Activity of Nano Fluconazole and Conventional Flucon-azole against Clinically Important Dermatophytes

2020 ◽  
Author(s):  
Najmossadat MUSAVI BAFRUI ◽  
Seyed Jamal HASHEMI HAZAVEH ◽  
Mansour BAYAT
Keyword(s):  
Zeta Potential ◽  
Fungal Infections ◽  
Antifungal Susceptibility ◽  
Nano Particles ◽  
Medical Sciences ◽  
Particle Structure ◽  
Epidermophyton Floccosum ◽  
Dermatophyte Species ◽  
Better Than

Background: Dermatophytosis is one of the most common fungal infections in humans. Antifungals such as fluconazole are effectively used for treating dermatophytosis; however, drug resistance was observed in many cases. Therefore, a newer treatment strategy is essential. Methods: This study (Conducted in the Laboratory of the School of Public Health, Tehran University of Medical Sciences, Tehran, Iran in 2018) evaluated the antifungal susceptibility of nano fluconazole compared to conventional fluconazole on dermatophyte isolates using CLSI M38-A2guidelines. Dermatophyte species isolated from clinical cases of dermatophytosis were identified using PCR sequencing techniques. Zeta potential and size of the nano particles containing fluconazole were measured; scanning electron microscope (SEM) was used to determine nano particle structure. Results: The size of liposomal fluconazole obtained was 88.9  12.14 nm with –20.12  3.8 mV for zeta potential. The encapsulation rate for fluconazole was 75.1  4.2%. MIC50 for the three tested species was 32, 16, and 8 μg/ml for Trichophyton interdigitale, T. rubrum, and Epidermophyton floccosum isolates, respectively. The corresponding values for nano fluconazole were 8 μg/ml for the three tested species. Conclusion: MIC value for nano-fluconazole was lower than conventional fluconazole in all dermatophytes species tested; therefore, nano-fluconazole could inhibit the growth of dermatophytes better than fluconazole at a lower concentration of the drug.

scholarly journals Distribution and antifungal susceptibility of Candida species in patients with increased risk for fungal infections

2016 ◽  
Vol 62 (1) ◽  
pp. 65-76
Author(s):  
Gordana Mirchevska ◽  
Maja Jurhar Pavlova ◽  
Elena Trajkovska-Dokic ◽  
Zaklina Cekovska ◽  
Gordana Jankoska ◽  
...  
Keyword(s):  
Blood Culture ◽  
Amphotericin B ◽  
Critically Ill Patients ◽  
Candida Species ◽  
Antifungal Agents ◽  
Fungal Infections ◽  
Antifungal Susceptibility ◽  
Clinical Specimens ◽  
Fourth Group ◽  
Increased Risk

Candida species are opportunistic yeasts that can be a serious threat for immunocompromised and critically ill patients, and a cause for increased morbidity and mortality in hospitalized patients. The aim of this study was to determine the frequency and distribution of different Candida species in clinical specimens in patients with increased risk for fungal infections, and to determine the antifungal susceptibility profile of invasive Candida species to antifungal agents. During a two year period, clinical specimens from 120 patients divided into 4 groups were analysed at the Institute of microbiology and parasitology, Faculty of Medicine, Skopje, Republic of Macedonia. Each of these 4 groups consisted of specimens from 30 patients, with primary immune deficiency, critically ill patients treated in the intensive care units (ICU), patients with mucosal candidiasis only, and patients with cystic fibrosis. All specimens were investigated with conventional mycological methods. Identification of Candida species was performed with VITEK-2 system (bioMérieux, France). E-test strips of fluconazole, voriconazole, amphotericin B and caspofungin (AB bioMerieux, France) were used for determination of the antifungal susceptibility profile. In this study, a total of 115 isolates of Candida species were confirmed in different clinical specimens (91 isolates from mucosal surfaces and 24 isolates from blood culture). Colonisation of mucosal membranes of gastrointestinal, respiratory and/or urinary tracts was registered in 56.67% (17/30), 56.67% (17/30), 90% (27/30) and 100% (30/30) of the specimens in the first, second, third and fourth group respectively. In all four groups of patients, the following Candida species were confirmed: C. albicans - 55%, C. glabrata - 17.6%, C. parapsilosis - 7.7%, C. tropicalis - 6.6%, unidentified Candida species - 4.4%, C. dubliniensis - 3.3%, C. kefyr - 2.2%, and one isolate of C. rugosa, C. pelliculosa and C. krusei each. Positive blood culture was registered in 23.33% specimens from the first group, 43.33% in the second group, 23.08% of the third group, and in one specimen of the fourth group. The most frequent isolates from blood culture were C. tropicalis and C. krusei, followed by C. albicans, C. parapsilosis and C. tropicalis, and in the second group C. albicans and C. pelliculosa were equally distributed, followed by C. parapsilosis and C. glabrata. All invasive isolates of Candida species were susceptible to amphotericin B, voriconazole and caspofungin. Resistance to fluconazole was registered in 8.3% (2/24) of all confirmed Candida species. Dose-dependent susceptibility to fluconazole was confirmed in 46% (11/24) of the isolates. Our study confirms high prevalence of colonisation and candidemia with non-albicans Candida species. Resistance to antifungal agents was registered only in two isolates of C. krusei. An epidemiological study is necessary for surveillance of dynamics of candidemia and antifungal susceptibility profile of invasive isolates of Candida species in our patients.

Identification and in Vitro Susceptibility Pattern of Fungal Pathogens in Immunocompromised Patients with invasive Fungal Infections

2021 ◽  
Vol 30 (3) ◽  
pp. 127-134
Author(s):  
Shaimaa A.S. Selem ◽  
Neveen A. Hassan ◽  
Mohamed Z. Abd El-Rahman ◽  
Doaa M. Abd El-Kareem
Keyword(s):  
Intensive Care ◽  
Fungal Infection ◽  
Fungal Pathogens ◽  
Fungal Infections ◽  
Antifungal Susceptibility ◽  
Invasive Fungal Infections ◽  
Immunocompromised Patients ◽  
University Hospitals ◽  
Vitek 2

Background: In intensive care units, invasive fungal infections have become more common, particularly among immunocompromised patients. Early identification and starting the treatment of those patients with antifungal therapy is critical for preventing unnecessary use of toxic antifungal agents. Objective: The aim of this research is to determine which common fungi cause invasive fungal infection in immunocompromised patients, as well as their antifungal susceptibility patterns in vitro, in Assiut University Hospitals. Methodology: This was a hospital based descriptive study conducted on 120 patients with clinical suspicion of having fungal infections admitted at different Intensive Care Units (ICUs) at Assiut University Hospitals. Direct microscopic examination and inoculation on Sabouraud Dextrose Agar (SDA) were performed on the collected specimens. Isolated yeasts were classified using phenotypic methods such as chromogenic media (Brilliance Candida agar), germ tube examination, and the Vitek 2 system for certain isolates, while the identification of mould isolates was primarily based on macroscopic and microscopic characteristics. Moulds were tested in vitro for antifungal susceptibility using the disc diffusion, and yeast were tested using Vitek 2 device cards. Results: In this study, 100 out of 120 (83.3%) of the samples were positive for fungal infection. Candida and Aspergillus species were the most commonly isolated fungal pathogens. The isolates had the highest sensitivity to Amphotericin B (95 %), followed by Micafungin (94 %) in an in vitro sensitivity survey. Conclusion: Invasive fungal infections are a leading cause of morbidity and mortality in immunocompromised patients, with Candida albicans being the most frequently isolated yeast from various clinical specimens; however, the rise in resistance, especially to azoles, is a major concern.

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