scholarly journals Absence of Amphotericin B-Tolerant Persister Cells in Biofilms of Some Candida Species

2008 ◽  
Vol 52 (5) ◽  
pp. 1884-1887 ◽  
Author(s):  
Rawya S. Al-Dhaheri ◽  
L. Julia Douglas
Keyword(s):  
Drug Resistance ◽  
Candida Albicans ◽  
Amphotericin B ◽  
Candida Glabrata ◽  
Candida Parapsilosis ◽  
Candida Krusei ◽  
Cell Populations ◽  
Planktonic Cells ◽  
Persister Cells ◽  
Tolerant Cell

ABSTRACT Biofilms and planktonic cells of five Candida species were surveyed for the presence of persister (drug-tolerant) cell populations after exposure to amphotericin B. None of the planktonic cultures (exponential or stationary phase) contained persister cells. However, persisters were found in biofilms of one of two strains of Candida albicans tested and in biofilms of Candida krusei and Candida parapsilosis, but not in biofilms of Candida glabrata or Candida tropicalis. These results suggest that persister cells cannot solely account for drug resistance in Candida biofilms.

scholarly journals Antifungal Resistance Pattern of Candida Species Isolated from High Vaginal Swabs of Women Attending a Hospital in Enugu State, Nigeria

2020 ◽  
pp. 62-72
Author(s):  
Joachim Ohiakwu Ezeadila ◽  
Ikechukwu Okoli ◽  
Christie Amaechi Oyeka
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Candida Tropicalis ◽  
Candida Species ◽  
Candida Glabrata ◽  
Candida Parapsilosis ◽  
Inhibition Zone ◽  
Candida Krusei ◽  
Antifungal Resistance ◽  
Resistance Pattern

There is an increase in non-albicans Candida (NAC) vulvovaginal candidiasis which is attributed to overuse of antifungal therapy and this has led to antifungal resistance. This study was aimed at determining the antifungal resistance pattern of some clinical isolates of Candida species. Eighty-eight (88) isolates were used which included Candida tropicalis (34), Candida Parapsilosis (21), Candida albicans (20), Candida krusei (7) and Candida glabrata (6). The drugs used were Fluconazole (25µg), Ketoconazole (10µg), Voriconazole (1µg), Nystatin (100Units), Amphotericin B (20µg), Flucytosine (1µg), Clotrimazole (10µg) and Itraconazole (50µg). The susceptibility testing was carried out using the M44-A standard method for yeast disk diffusion testing. Results showed that the percentages of Candida species resistant to Fluconazole, Ketoconazole, Voriconazole, Amphotericin B, Flucytosine, Clotrimazole and Itraconazole and Nystatin were 52.3%, 61.9%, 35.2%, 19.3%, 86.4%, 34.1%,  45.5% and 44.3%,  with inhibition zone diameters ≤14mm, ≤20mm, ≤13mm, <10mm, ≤11mm, ≤11mm, ≤13mm and no inhibition zone diameter respectively. Candida krusei was the most resistant species with 100% resistance to each of Fluconazole, Ketoconazole and Flucytosine. Candida tropicalis was the species with the highest susceptibility (79.4%) to Amphotericin B followed by Candida parapsilosis with inhibition zone diameters ≥15mm. While Candida glabrata showed 100% resistance to each of Flucytosine and Itraconazole, Candida albicans showed 100% resistance to Flucytosine only. Candida glabrata was the only Candida species with 0% resistance to Amphotericin B. The drug to which most of the Candida species were susceptible was Amphotericin B followed by Voriconazole while Flucytosine was the drug with the highest resistance followed by Ketoconazole and Fluconazole. The highest number of susceptible-dose dependent Candida isolates was observed with Ketoconazole (25%), followed by Clotrimazole and Itraconazole, each recording 23.9%. Based on the findings of the present study, Voriconazole is recommended for vaginal candidiasis especially in the study area and also especially for infections caused by Fluconazole-resistant Candida species. This suggests that routine sensitivity testing is pertinent to guiding the choice of antifungal therapy. Thus, indiscriminate use of antifungal drugs should be avoided to reduce the development and spread of resistance.

scholarly journals Aspectos micológicos e suscetibilidade in vitro de leveduras do gênero Candida em pacientes HIV-positivos provenientes do Estado de Mato Grosso

2010 ◽  
Vol 43 (6) ◽  
pp. 673-677 ◽  
Author(s):  
Olivia Cometti Favalessa ◽  
Marilena dos Anjos Martins ◽  
Rosane Christine Hahn
Keyword(s):  
Candida Albicans ◽  
Candida Tropicalis ◽  
Candida Glabrata ◽  
Candida Parapsilosis ◽  
Candida Guilliermondii ◽  
Candida Krusei ◽  
Mato Grosso ◽  
Candida Sp

INTRODUÇÃO: A candidíase é uma das infecções fúngicas mais frequentes entre os pacientes infectados pelo vírus da imunodeficiência humana. O presente estudo objetivou a caracterização das leveduras do gênero Candida de distintas amostras clínicas, provenientes de pacientes HIV - positivos, assim como a determinação do perfil de suscetibilidade in vitro a cinco drogas antifúngicas. MÉTODOS: A caracterização dos isolados de Candida sp foi realizada através da metodologia clássica, testes bioquímicos (zimograma e auxanograma) e morfológicos (prova do tubo germinativo e microcultivo em lâmina). Também, foram realizadas a técnica genotípica (PCR) e identificação pelo método comercial API 20C AUX (BioMeriéux). Para a determinação do perfil de suscetibilidade in vitro, foram utilizadas cinco drogas antifúngicas (cetoconazol, fluconazol, itraconazol, voriconazol e anfotericina B), através do método comercialmente disponível - Etest. RESULTADOS: Foram identificados 105 isolados de leveduras do gênero Candida provenientes de 102 pacientes infectados pelo vírus HIV. Destes, foram caracterizadas 82 (78,1%) Candida albicans, 8 (7,6%) Candida parapsilosis, 8 (7,6%) Candida tropicalis, 4 (3,8%) Candida krusei, 2 (1,9%) Candida glabrata e 1 (1%) Candida guilliermondii. CONCLUSÕES: Considerando o perfil geral de sensibilidade, 60% dos isolados foram suscetíveis a todos os antifúngicos testados, porém as espécies C. tropicalis e C. krusei demonstraram uma tendência a valores mais elevados de CIMs para os azóis do que os encontrados paraC. albicans, sugerindo resistência.

Comparative evaluation of six chromogenic media for presumptive yeast identification

2017 ◽  
Vol 70 (12) ◽  
pp. 1074-1078 ◽  
Author(s):  
Alessandra Vecchione ◽  
Walter Florio ◽  
Francesco Celandroni ◽  
Simona Barnini ◽  
Antonella Lupetti ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Candida Tropicalis ◽  
Comparative Evaluation ◽  
Candida Glabrata ◽  
Candida Parapsilosis ◽  
Candida Krusei ◽  
Yeast Identification ◽  
Discrimination Ability ◽  
Candida Lusitaniae ◽  
Reference Strains

AimsThe present study was undertaken to evaluate the discrimination ability of six chromogenic media in presumptive yeast identification.MethodsWe analysed 108 clinical isolates and reference strains belonging to eight different species: Candida albicans,Candida dubliniensis, Candida tropicalis, Candida krusei, Candida glabrata, Candida parapsilosis,Candida lusitaniae and Trichosporon mucoides.ResultsC. albicans, C. tropicalis and C. krusei could be distinguished from one another in all the tested chromogenic media, as predicted by the manufacturers. In addition, C. albicans could be distinguished from C. dubliniensis on BBL CHROMagar Candida, Kima CHROMagar Candida and Brilliance Candida, and C. parapsilosis could be identified on CHROMATIC Candida agar, CHROMOGENIC Candida agar, and Brilliance Candida agar.ConclusionsBrilliance Candida provided the widest discrimination ability, being able to discriminate five out of the seven Candida species tested. Interestingly, C. tropicalis and C. krusei could be already distinguished from each other after 24 hours of incubation.

scholarly journals Atividade antifúngica de Cymbopogon citratus (DC) Stapf frente à leveduras do gênero Candida sp.

Revista Fitos ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 22-31
Author(s):  
Luiz Francisley de Paiva ◽  
Sabrina de Alvarenga Domingues
Keyword(s):  
Candida Albicans ◽  
Candida Tropicalis ◽  
Candida Glabrata ◽  
Candida Utilis ◽  
Candida Parapsilosis ◽  
Candida Krusei ◽  
Candida Dubliniensis ◽  
Cymbopogon Citratus ◽  
Candida Sp

Candida sp. é um gênero de levedura que faz parte da microbiota do corpo humano e de animais. É considerado o principal grupo de fungos patógenos oportunistas. O uso de plantas medicinais é empregado cada vez mais nas diversas áreas. A planta Cymbopogon citratus (DC). Stapf é popularmente conhecida no Brasil por Capim-cheiroso, Capim-cidreira, Capim-santo, Capim-limão, Capim-cidró, Capim-cidrão. Este estudo teve como objetivo avaliar a atividade antifúngica do óleo essencial de Cymbopogon citratus frente a leveduras do gênero Candida sp.. O óleo essencial foi obtido por hidrodestilação das folhas pelo método do arraste a vapor. A atividade antifúngica foi verificada pelas técnicas de disco-difusão, concentração inibitória mínima e concentração letal mínima. Foram utilizadas as cepas padrão ATCC de Candida albicans, Candida dubliniensis, Candida tropicalis, Candida glabrata, Candida Krusei, Candida parapsilosis e Candida utilis. O óleo essencial apresentou atividade antifúngica frente a todas as espécies. A faixa de inibição varia de 0,281 µg/mL a 1,125 µg/mL e concentração letal varia de 0,562 µg/mL a 1,125 µg/mL. Esses achados contribuem para um futuro emprego da planta C. citratus como fitoterápico em tratamento preventivo ou alternativo contra infecções fúngicas.

scholarly journals Ação antifúngica de extratos e frações de Annona muricata L. sobre Candida spp.

2021 ◽  
Vol 10 (5) ◽  
pp. e28010514938
Author(s):  
Kellyane Karen Ferreira Aguiar Cesar ◽  
Anny Karoline Rodrigues Batista ◽  
Luciana Rocha Paula ◽  
Reginara Teixeira da Silva ◽  
Francisco Laurindo da Silva
Keyword(s):  
Candida Albicans ◽  
Candida Glabrata ◽  
Candida Parapsilosis ◽  
Candida Krusei ◽  
Annona Muricata ◽  
Candida Spp

Devido ao amplo potencial medicinal de Annona muricata, as pesquisas relacionadas às suas aplicações em diferentes áreas ligadas a saúde são de fundamental importância, principalmente no que se refere a microrganismos infecciosos com tendências a desenvolver mecanismos de resistência, que é o caso de algumas espécies do gênero Candida. Nesse sentido, a pesquisa tem como principal objetivo verificar a ação antifúngica de extratos metanólicos de Annona muricata sobre Candida albicans, Candida parapsilosis, Candida krusei e  Candida glabrata. Os órgãos utilizados para obtenção dos extratos metanólicos foram a folha e o fruto da Annona muricata. Para a realização da pesquisa, foram utilizadas cepas ATCC, que foram reativadas e cultivadas em Ágar Saboraud Dextrose. A determinação da atividade antifúngica dos extratos foi realizada pela técnica da difusão em ágar em poços. Na análise dos resultados, os valores de mensuração dos diâmetros dos halos indicaram uma ação mais significativa nos testes realizados com as espécies de C. krusei e C. albicans frente aos extratos brutos da folha e do fruto de A. muricata, com halo de 30mm e 22mm respectivamente. Em relação ao fracionamento químico realizado, os produtos obtidos a partir das frações butanólica e hexánica da folha sobre cepas de C. krusei, C. albicans e C. parapsilosis foram os que apresentaram resultados mais significativos. Dessa forma, comprovou-se que substancias presentes nesse vegetal podem ser utilizadas no controle cepas de Candida, contudo, estudos mais aprofundados são necessários para identificação e isolamento dos compostos biológicos ativos desses vegetais.

scholarly journals Atividade antifúngica de isolados clínicos de Candida não-albicans aos óleos essenciais de Syzygium aromaticum (cravo-da-índia) e Eucalyptus globulus (eucalipto-comum)

2021 ◽  
Vol 54 (1) ◽  
pp. e168684
Author(s):  
Aryanna Kelly Pinheiro Souza ◽  
Rita Dâmaris Soares Dantas ◽  
Dálity Keffelen de Barros Rodrigues ◽  
Claudio José dos Santos Júnior
Keyword(s):  
Candida Albicans ◽  
Eucalyptus Globulus ◽  
Candida Glabrata ◽  
Candida Parapsilosis ◽  
Candida Krusei ◽  
Syzygium Aromaticum

Introdução: O gênero Candida infecta o ser humano com alta incidência, sendo a espécie Candida albicans a mais isolada em infecções invasivas e superficiais. Porém, tem sido relatado um aumento considerável de espécies de Candida não-albicans em infecções fúngicas. Os óleos essenciais, por serem voláteis, podem agir como sinais de comunicação química e arma de defesa. Objetivo: Avaliar a eficácia, in vitro, dos óleos essenciais de Syzygium aromaticum e Eucalyptus globulus na inibição do crescimento de espécies de Candida não-albicans. Métodos: Para avaliação da atividade antifúngica de S. aromaticum e de E. globulus e do efeito dos seus óleos essenciais sobre a micromorfologia das espécies Candida krusei, Candida parapsilosis e Candida glabrata, foram empregadas, nesta ordem, as técnicas de difusão em ágar e microcultivo para leveduras. Resultados: Na técnica de difusão, o óleo essencial de S. aromaticum apresentou formação de halo de inibição para Candida krusei, Candida parapsilosis e Candida glabrata. O óleo de E. globulus, por sua vez, não apresentou crescimento de halos de inibição em nenhuma das concentrações testadas frente as três espécies de Candida não-albicans. Todavia, com o microcultivo, ambos os óleos essenciais se provaram, in vitro, eficazes antimicrobianos tendo apresentado estruturas indicativas de atividade antifúngica na maior concentração dos óleos e diferentes graus de destruição celular nas demais concentrações. Conclusão: Nas condições deste estudo, concluiu-se que os produtos avaliados exerceram atividade antifúngica contra cepas de Candida não-albicans, destacando-se o óleo essencial de S. aromaticum que apresentou atividade antimicrobiana em ambas as metodologias.

scholarly journals In Vitro Activity of a New Polyene, SPA-S-843, against Yeasts

1998 ◽  
Vol 42 (11) ◽  
pp. 3012-3013 ◽  
Author(s):  
C. Rimaroli ◽  
T. Bruzzese
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Candida Tropicalis ◽  
Candida Glabrata ◽  
Fungicidal Activity ◽  
Candida Krusei ◽  
Water Soluble ◽  
Vitro Activity ◽  
In Vitro Activity

ABSTRACT The in vitro activity of a new water-soluble polyene, SPA-S-843, was evaluated against 116 strains of Candida,Cryptococcus, and Saccharomyces spp. and compared with that of amphotericin B. SPA-S-843 demonstrated better inhibitory activity against all of the yeasts examined and better fungicidal activity against Candida albicans, Candida glabrata, Candida krusei, and Candida tropicalis than did amphotericin B.

scholarly journals Apoptosis in Candida biofilms exposed to amphotericin B

2010 ◽  
Vol 59 (2) ◽  
pp. 149-157 ◽  
Author(s):  
Rawya S. Al-Dhaheri ◽  
L. Julia Douglas
Keyword(s):  
Amphotericin B ◽  
Antifungal Agents ◽  
Candida Parapsilosis ◽  
Candida Krusei ◽  
Clinical Use ◽  
Caspase Activity ◽  
Persister Cells ◽  
Specific Staining ◽  
General Inhibitor ◽  
Staining Methods

Candida biofilms are resistant to a range of antifungal agents in current clinical use. The basis of this drug resistance is not clear, but in some cases it could be due to the presence of a small number of drug-tolerant or persister cells. In this study, specific staining methods were used to investigate the existence of persisters and apoptosis in Candida biofilms subjected to different concentrations of amphotericin B. Fluorescein diacetate staining revealed the presence of persisters in biofilms of one of two strains of Candida albicans tested, and in biofilms of Candida krusei and Candida parapsilosis. Caspase activity, indicative of apoptosis, was detected with SR-FLICA and (aspartyl)2-rhodamine 110 fluorochrome-based staining reagents in all of these biofilms. The general inhibitor of mammalian caspases, Z-VAD-FMK, when used at a low concentration (2.5 μM), increased the viability of drug-treated biofilms up to 11.5-fold (P <0.001 %). Seven specific caspase inhibitors had different effects on C. albicans biofilm viability, but inhibitors of caspases-1, −9, −5, −3 and −2 all significantly increased cell survival (40-fold, 8-fold, 3.5-fold, 1.9-fold and 1.7-fold, respectively). However, histone deacetylase (HDA) inhibitors enhanced the activity of amphotericin B for biofilms of all three Candida species. Sodium butyrate and sodium valproate, for example, when added concurrently with amphotericin B, completely eliminated biofilm populations of C. albicans. Overall, our results demonstrate an apoptotic process in amphotericin-treated biofilms of three Candida species. They also indicate that HDA inhibitors can enhance the action of the drug and in some cases even eradicate persister subpopulations, suggesting that histone acetylation might activate apoptosis in these cells.

scholarly journals In vitro kill curves of a new semisynthetic echinocandin, LY-303366, against fluconazole-sensitive and -resistant Candida species.

1997 ◽  
Vol 41 (11) ◽  
pp. 2576-2578 ◽  
Author(s):  
J A Karlowsky ◽  
G A Harding ◽  
S A Zelenitsky ◽  
D J Hoban ◽  
A Kabani ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Candida Species ◽  
Candida Glabrata ◽  
Candida Krusei ◽  
Clinical Isolates

In vitro killing by a new semisynthetic echinocandin, LY-303366, was characterized using clinical isolates of fluconazole-sensitive (Y58) and -resistant (Y180) Candida albicans as well as Candida glabrata (Y7) and Candida krusei (Y171). The 24-h kill curves for Y58 and Y180 demonstrated dose-independent killing of between 1 and 2 log10 with LY-303366 at concentrations of 0.1, 1, 10, 50, 100, and 1,000 times the MIC. Regrowth did not occur at 24 h with either C. albicans isolate at the aforementioned LY-303366 concentrations. At their MICs, LY-303366 and amphotericin B produced similar killing kinetics in cultures of Y58, Y180, Y7, and Y171, while all cultures exposed to fluconazole at its MIC demonstrated stasis or growth over 24 h.

Drug susceptibility and enzymatic activity of Candida isolated from mobile phone and hand surfaces

2017 ◽  
Vol 7 (2) ◽  
pp. 7-18
Author(s):  
A. Kordecka ◽  
E Krajewska-Kułak ◽  
C Łukaszuk ◽  
M. Kraszyński ◽  
B. Kraszyńska
Keyword(s):  
Drug Resistance ◽  
Candida Albicans ◽  
Enzymatic Activity ◽  
Mobile Phone ◽  
Mobile Phones ◽  
Candida Glabrata ◽  
Drug Susceptibility ◽  
Candida Krusei ◽  
Activity Of Enzymes

<b>Introduction</b>: Evaluation of susceptibility of isolated fungi as well as the type and activity of enzymes they release allows to determine their pathogenicity. <b>Purpose</b>; To assess potential correlations between drug susceptibility and enzymatic activity of strains isolated from mobile phone and hand surfaces <b>Materials and methods</b>: The mycological evaluation included 175 mobile phones and 175 hands of the phone owners. Drug susceptibility was assessed using the FUNGITEST; enzymatic activity was evaluated using the API ZYM test. <b>Results</b>: We found significant correlations between an increased resistance to 5-fluorocytosine, ketoconazole, fluconazole and higher activity of six selected enzymes for <i>Candida glabrata</i> strains isolated from hand surfaces. We found also significant correlations between an increased resistance to 5-fluorocytosine, ketoconazole, miconazole, itraconazole and higher activity of six selected enzymes for <i>Candida albicans</i> strains isolated from hand surfaces. We found significant correlations between an increased resistance to 5fluorocytosine, ketoconazole, itraconazole, fluconazole and higher activity of six selected enzymes for <i>Candida krusei</i> strains isolated from hand surfaces as well as an increased resistance to 5-fluorocytosine, ketoconazole, itraconazole, fluconazole and higher activity of five selected enzymes for strains isolated from phone surfaces. <b>Conclusions</i>: We found varying correlations between enzymatic activity and drug resistance depending on the site of isolation and the species/genus of fungi. The drugs to which the evaluated strains showed resistance were the same for hand and mobile phone isolates.

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