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1.
Braz. j. med. biol. res ; 55: e11831, 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1394125

ABSTRACT

Candida albicans is the most frequently isolated opportunistic pathogen in the female genital tract, with 92.3% of cases in Brazil associated with vulvovaginal candidiasis (VVC). Linalool is a monoterpene compound from plants of the genera Cinnamomum, Coriandrum, Lavandula, and Citrus that has demonstrated a fungicidal effect on strains of Candida spp., but its mechanism of action is still unknown. For this purpose, broth microdilution techniques were applied, as well as molecular docking in a predictive manner for this mechanism. The main results of this study indicated that the C. albicans strains analyzed were resistant to fluconazole and sensitive to linalool at a dose of 256 µg/mL. Furthermore, the increase in the minimum inhibitory concentration (MIC) of linalool in the presence of sorbitol and ergosterol indicated that this molecule possibly affects the cell wall and plasma membrane integrity of C. albicans. Molecular docking of linalool with proteins that are key in the biosynthesis and maintenance of the cell wall and the fungal plasma membrane integrity demonstrated the possibility of linalool interacting with three important enzymes: 1,3-β-glucan synthase, lanosterol 14α-demethylase, and Δ 14-sterol reductase. In silico analysis showed that this monoterpene has theoretical but significant oral bioavailability, low toxic potential, and high similarity to pharmaceuticals. Therefore, the findings of this study indicated that linalool probably causes damage to the cell wall and plasma membrane of C. albicans, possibly by interaction with important enzymes involved in the biosynthesis of these fungal structures, in addition to presenting low in silico toxic potential.

2.
Braz. j. infect. dis ; 25(1): 101041, jan., 2021. tab, graf
Article in English | LILACS | ID: biblio-1249290

ABSTRACT

ABSTRACT Objectives: Candida spp. has been reported as one of the common agents of nosocomial bloodstream infections and is associated with a high mortality. Therefore, this study evaluated the clinical findings, local epidemiology, and microbiological aspects of candidemia in eight tertiary medical centers in the state of Parana, South of Brazil. Methods: In this study, we reported 100 episodes of candidemia in patients admitted to eight different hospitals in five cities of the state of Parana, Brazil, using data collected locally (2016 and 2017) and tabulated online. Results: The incidence was found to be 2.7 / 1000 patients / day and 1.2 / 1000 admissions. C. albicans was responsible for 49% of all candidemia episodes. Cancer and surgery were the two most common underlying conditions associated with candidemia. The mortality rate within 30 days was 48%, and removal of the central venous catheter (p = 0.029) as well as empirical or prophylactic exposure to antifungals were both related to improved survival (p = 0.033). Conclusions: This study highlights the high burden and mortality rates of candidemia in hospitals from Parana as well as the need to enhance antifungal stewardship program in the enrolled medical centers.


Subject(s)
Humans , Cross Infection/drug therapy , Cross Infection/epidemiology , Incidence , Candidemia/drug therapy , Candidemia/epidemiology , Brazil/epidemiology , Candida , Antifungal Agents/therapeutic use
3.
Article in English | WPRIM | ID: wpr-921330

ABSTRACT

Objective@#This study aimed to evaluate the epidemiological, clinical and mycological characteristics of invasive candidiasis (IC) in China.@*Methods@#A ten-year retrospective study including 183 IC episodes was conducted in a tertiary hospital in Beijing, China.@*Results@#The overall incidence of IC from 2010-2019 was 0.261 episodes per 1,000 discharges. Candidemia (71.0%) was the major infective pattern; 70.3% of the patients tested positive for @*Conclusion@#The incidence of IC has declined in the recent five years.


Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Antifungal Agents/pharmacology , Candidiasis, Invasive/microbiology , Child , Child, Preschool , China/epidemiology , Drug Resistance, Fungal , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Retrospective Studies , Tertiary Care Centers/statistics & numerical data , Young Adult
4.
Article in Chinese | WPRIM | ID: wpr-912067

ABSTRACT

Candida auris ( C. auris) is a recently emerged multidrug-resistant fungal pathogen, featured by difficulty in identification, high mortality and easy spread in hospital environments. Furthermore, C. auris is resistant to various frontline antifungals. However, the mechanisms governing drug resistance remain unclear. This review summarized the mechanisms of triazole resistance in C. auris, including ERG11 missense mutations or overexpression, the activity of efflux pumps, missense mutations in TAC1 B, the gain of an extra copy of chromosomeⅤ, the role of Hsp90 and biofilm formation. In addition, the factors associated with the resistance to other drugs including echinocandins, polyenes, nucleoside analogues and acrylamide were also reviewed.

5.
Article | IMSEAR | ID: sea-215352

ABSTRACT

Candidiasis is a common life-threatening condition with various clinical manifestations. It can cause significant morbidity and mortality, especially in critically ill patients. Though mainly caused by C. albicans, it has shown a change in the epidemiological pattern with an increase in the prevalence of non albicans Candida (NAC) in the recent years. This change has also reflected in the profile of antifungal susceptibility since many of these species show high level of antifungal resistance associated with treatment failures. Thus, it is important to know the regional distribution of Candida species and also find their antifungal susceptibility profile to the commonly used antifungal agents.METHODSThis is a descriptive study conducted for a period of two years on the clinical isolates of Candida species which satisfied the inclusion and exclusion criteria. Speciation was done by phenotypic methods which include germ tube test, chromogenic medium, corn meal agar and VITEK-2 system and by molecular methods using multiplex PCR. Antifungal susceptibility testing was done using automated method by VITEK-2 compact system.RESULTSAmong the 80 isolates studied, on speciation C .albicans 25(31.25%) was the most common, followed by C. tropicalis 23 (28.75%), C. parapsilosis 13 (16.25%), C. krusei 12 (15%), C. pelliculosa 4 (5%), C. auris 2 (2.5%) and C. glabrata 1 (1.25%). Most isolates were susceptible to almost all the antifungal agents tested, but C. krusei showed high level of resistance.CONCLUSIONSC. albicans was the commonest individual species, but there was an overall predominance of non-albicans Candida (NAC). Speciation of Candida isolates is important as there is wide variation in their antifungal resistance pattern. Knowledge about the prevalent species and their antifungal susceptibility will help in early initiation of appropriate treatment, thus reducing the morbidity and mortality associated with Candida infections.

6.
Rev. chil. infectol ; 36(6): 767-773, dic. 2019. tab, graf
Article in Spanish | LILACS | ID: biblio-1058109

ABSTRACT

Resumen Candida auris es una levadura multi-resistente emergente con rápida diseminación mundial. Desde el primer reporte el 2009, varios aislados a través de los cinco continentes han sido identificados como agentes de infecciones asociadas a la atención en salud. Brotes independientes y simultáneos por C. auris se han vuelto prioridad para la comunidad hospitalaria y científica. Además, los errores en identificación y los perfiles de multi-resistencia, raramente observados para otras especies de Candida, resultan en una difícil erradicación y fallas terapéuticas frecuentes en infecciones por C. auris. Presentamos el primer aislamiento de una cepa de C. auris en un hospital en Santiago, en un paciente proveniente de la India, que fue admitido para tratamiento de su pie diabético. La cepa fue recuperada de un cultivo de tejido e identificada por VITEK® 2 Compact. La identificación de C. auris fue confirmada por MALDI-TOF MS y secuenciación. El aislado fue resistente a fluconazol y susceptible a anfotericina y caspofungina, según puntos de corte recomendados por el CDC. La emergencia de C. auris es alarmante debido a que el modo de transmisión dentro del ambiente hospitalario no es claro y probablemente es multifactorial.


Candida auris is an emerging multi-drug-resistant fungus that is rapidly spreading worldwide. Since the first reports in 2009, many isolates across five continents have been identified as agents of hospital-associated infections. Independent and simultaneous outbreaks of C. auris are becoming a major concern for healthcare and scientific community. Moreover, laboratory misidentification and multi-drug-resistant profiles, rarely observed for other non-albicans Candida species, result in difficult eradication and frequent therapeutic failures of C. auris infections. In this article we present the first case of isolation of a strain of C. auris at a hospital in Santiago, in a patient coming from India, who was admitted for treatment of diabetic foot complications. The strain was recovered from a tissue culture and identified by VITEK® 2 Compact. The accurate identification of C. auris was confirmed by means of MALDI-TOF MS and DNA sequence analysis. The isolate was resistant to fluconazole, retaining only susceptibility to amphotericin and caspofungin with MIC breakpoints recommended by CDC. The emergence of C. auris is alarming because the mode of transmission within the healthcare environment is not clear and is likely to be multifactorial.


Subject(s)
Humans , Candida/genetics , Candidiasis/drug therapy , Microbial Sensitivity Tests , Chile , Antifungal Agents/therapeutic use , Antifungal Agents/pharmacology
7.
Article | IMSEAR | ID: sea-188957

ABSTRACT

Candida Species are normal flora of skin and mucosa of gastrointestinal tract (GIT) and genital region. Usually they invade host tissue and cause diseases in patients with impaired immunity. OBJECTIVE: The aim of this study is to determine virulence factors expressed by various clinical isolates of different Candida species and to correlate with their antifungal resistance pattern. Methods: A total of 120 Candida isolates obtained from different clinical samples and speciated by standard microbiological laboratory protocol. Haemolysin, phospholipase and esterase activities were detected by growth characteristics on SDA with blood, egg yolk agar medium and Tween- 80 opacity test medium respectively. Adherence was seen microscopically over buccal epithelial cell and biofilm formation was detected visually with 2% Safranin staining. Antifungal susceptibility was detected by disk diffusion method using Mueller Hinton Agar supplemented with glucose and methylene blue (As per CLSI guideline). Results: Out of 120 isolates, 51(42.50%) were C.albicans and 69 (57.5%) were Non albicans Candida (NAC) including C.tropicalis 32(26.67%), C. guilliermondii 21(17.50%), C. parapsilosis 12(10%) and C. glabrata 04(3.33%). Haemolysin, phospholipase and esterase activities were detected in 110 (91.67%), 95 (79.17%) and 82 (68.33%) respectively. Adherence seen in 98 (81.67%) and in 59 (49.17%) cases biofilm had formed. The antifungal susceptibility patterns revealed that 81 (67.5%) were susceptible to Fluconazole and 72 (60%) were susceptible to Itraconazole, whereas 100% were susceptible to Voriconazole and Amphotericin B. Conclusion: Detection of virulence factor will help in better understanding of the changing behavioural patterns of Candida isolates and open doorways to better management and assessing prognosis of the patients.

8.
Arq. bras. med. vet. zootec. (Online) ; 71(3): 819-827, May-June 2019. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1011330

ABSTRACT

In this study, we described the antifungal activity of three Brazilian propolis extracts: brown, green and from jataí bees against Sporothrix brasiliensis. The extracts were obtained from ethanolic extraction and their chemical composition was determined by high-performance liquid chromatography coupled to mass spectrometry. The cellular toxicity was measured in MDBK (Madin-Darby Bovine Kidney) cells and quantified by the MTT assay (3- (4,5 dimethylthiazol-2yl -2,5-diphenyl-2H bromine tetrazolato). For antifungal activity, the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined by broth microdilution. The results showed that cell toxicity was not observed at lower concentrations (0.097 to 0.39μg/ml) for all extracts in comparison to cell control. Among the chemical compounds identified, caffeic acid, p-coumaric acid, chlorogenic acid, ferulic acid and rutin were quantified. In antifungal activity, green and jataí did not exhibit activity against the isolates (MIC and MFC greater than 0.78mg/ml). However, all isolates of S. brasiliensis were sensitive to brown propolis (MIC of 0.09 to 0.78mg/ml), including the standard strain (P<0.001). Among the Brazilian propolis studied, the brown propolis showed activity against the S. brasiliensis isolates and more studies should be undertaken in order to evaluate its promising use in the treatment of sporotrichosis.(AU)


Neste estudo, descreveu-se a atividade antifúngica de três extratos de própolis brasileiras: marrom, verde e de abelhas jataí (Tetragonisca angustula), contra Sporothrix brasiliensis. Os extratos foram obtidos de extração etanólica, e a sua composição química foi determinada por cromatografia líquida de alta eficiência, acoplada à espectrometria de massa. A toxicidade celular foi medida em células MDBK (Madin-Darby Bovine Kidney), avaliada por observação microscópica e quantificada pelo ensaio MTT (3- (4,5-dimetiltiazol-2-ilo -2,5-difenil-2H bromo tetrazolato). Para a atividade antifúngica, determinou-se a concentração inibitória mínima (CIM) e a concentração fungicida mínima (CFM) por meio de microdiluição em caldo. Os resultados mostraram que a toxicidade celular não foi observada em concentrações menores (0,097 a 0,39μg/ml). Entre os compostos químicos identificados, foram quantificados o ácido cafeico, ácido p-cumárico, ácido clorogênico, ácido ferúlico e a rutina. Na atividade antifúngica, as própolis verde e jataí não apresentaram atividade contra os isolados (CIM e CFM maior que 0,78mg/ml), porém todos os isolados de S. brasiliensis foram sensíveis à própolis marrom (CIM de 0,09 a 0,78mg/ml), incluindo a cepa padrão (P<0,001). Entre as própolis brasileiras estudadas, a marrom mostrou atividade contra S. brasiliensis, e mais estudos devem ser realizados para avaliar seu uso promissor no tratamento da esporotricose.(AU)


Subject(s)
Humans , Animals , Propolis/analysis , Propolis/therapeutic use , Sporothrix/isolation & purification , Itraconazole/therapeutic use , Drug Resistance, Fungal , Apitherapy/veterinary , Antifungal Agents/analysis
9.
Article | IMSEAR | ID: sea-202381

ABSTRACT

Introduction: Serious fungal infections particularly Candidainfection have increased in recent years.It is as a consequenceof increased immunosuppression associated with HIVinfection, organ and tissue transplant and aggressive treatmentfor neoplastic and autoimmune diseases. Study aimed toinvestigate biofilm formation among candida species isolatedfrom various clinical samples and its role in antifungalresistance.Material and methods: A retrospective observational studywas conducted from October 2017 to January 2019 in theDepartment of Microbiology, Jhalawar Medical College,Jhalawar. A total of 630 samples with suspected Candidainfections were collected and processed. A total of 313Candida isolates from various clinical samples were taken upfor the study. Samples were processed by Gram staining, KOHmount and culture on SDA and BHI agar. Isolated yeasts wereidentified and speciated by germ tube test, chlamydosporesformation on corn meal agar, color production on CHROMagar, sugar fermentation test and sugar assimilation test.Biofilm production was tested by Tube method and Tissueculture plate method. Antifungal susceptibility testing ofisolates was performed as per CLSI guidelines.Results: A total of 313 samples out 630 samples were positivefor candida infections. Out of 313 isolates, 157 (50.16%) werefound to be biofilm producers. Candida tropicalis (52.86%)was most common Candida species to be isolated as biofilmproducer followed by C. Parapsilosis (10.19%), C. glabrata(10.19%) and C. krusei (4.45%) while C. albicans was 35/157(22.29%). Antifungal resistant was found to be more in biofilmproducer and tissue culture plate method was found to be moresensitive than tube method for biofilm detection.Conclusion: There is increasing trend of antifungal resistanceamong candida isolates particularly in Non Albicans Candidaspecies. So, it is necessary to identify all yeast isolates up tospecies level and their potential for biofilm formation as it isone of the major virulence factors responsible for antifungalresistance. This will be helpful for efficient treatment,prevention of development of antifungal resistance and finally,the reduction of the treatment costs.

10.
Article | IMSEAR | ID: sea-194191

ABSTRACT

Background: Isolation of two or more than two pathogenic fungi from the same body site in a patient is considered as a rare entity and very few cases have been reported in literature. These types of infections are called as mixed/ combined fungal infections. Author are enumerating ten cases of superficial mycoses in which two different dermatophytes were grown from the same focus.Methods: From clinically suspected cases of dermatophytosis, skin and hair samples were collected from the affected sites and examined by standard mycological procedures. Microscopy was done by using 10% KOH wet mount. Culture was put on Sabouraud’s dextrose agar with cyclohexamide medium. Growth was identified by lactophenol cotton blue mount.Results: Mixed dermatophytes were obtained from tinea corporis (five cases), tinea capitis (four cases) and tinea cruris (one case) patients. Fungal combinations from given cases involved two different species of genus Trichophyton which were as follows: T. violaceum+T. tonsurans, T. verrucosum+T. tonsurans, T. violaceum (violet) and T. violaceum (white), T. mentagrophytes+T. Violaceum, T. rubrum+T. tonsurans, T. violaceum+T. rubrum, T. rubrum+T. mentagrophytes, T. verrucosum+T. mentagrophytes, T. mentagrophytes+T. tonsurans, Malassezia+T. mentagrophytes.Conclusions: Inspite of the frequent occurrence of dermatophytic infections worldwide, reports on mixed dermatophytes are very few. With proper sample collection and proper identification procedures, more cases can be identified and added to the existing literature.

11.
Article in Korean | WPRIM | ID: wpr-816602

ABSTRACT

BACKGROUND: Candida auris was first isolated from the ears of Japanese and Korean patients. However, the prevalence of yeast isolates from ear cultures and their antifungal susceptibility profiles in these nations remain unclear.METHODS: We assessed yeast isolates recovered from ear cultures from a university hospital in Korea over a 4-year period from January 2014 to December 2017. Species identification was performed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and/or sequence analysis. Antifungal minimal inhibitory concentrations (MICs) were determined using the broth microdilution method of the Clinical and Laboratory Standards Institute.RESULTS: Among 81 non-duplicate isolates from ear cultures, Cadida parapsilosis was the most frequently detected yeast species (34.6%), followed by C. auris (28.4%), Candida metapsilosis (9.9%), Candida orthopsilosis (8.6%), Candida albicans (7.4%), and others (11.1%). The MICs of the isolates were 0.125 to > 64 µg/mL, ≤0.03 to 4 µg/mL, 0.25 to 1 µg/mL, 0.125 to 1 µg/mL, and ≤0.03 to 2 µg/mL for fluconazole, voriconazole, amphotericin B, caspofungin, and micafungin, respectively. Of the 81 isolates, 44.4% (36/81) showed decreased susceptibility to fluconazole (MIC ≥4 µg/mL). Of the 23 C. auris isolates, 19 (82.6%) had a fluconazole MIC of ≥32 µg/mL. None of the isolates showed resistance to amphotericin B or echinocandins. Most of these patients suffered from chronic otitis media (84%).CONCLUSION: Candida parapsilosis complex and C. auris were the yeast species identified most frequently from ear cultures and they exhibited a high rate of fluconazole non-susceptibility, particularly C. auris.


Subject(s)
Amphotericin B , Asians , Candida , Candida albicans , Ear , Echinocandins , Fluconazole , Humans , Korea , Mass Spectrometry , Methods , Otitis Media , Prevalence , Sequence Analysis , Voriconazole , Yeasts
12.
Rev. Soc. Bras. Med. Trop ; 51(5): 644-650, Sept.-Oct. 2018. tab, graf
Article in English | LILACS | ID: biblio-957457

ABSTRACT

Abstract INTRODUCTION: The increase in the incidence of fungal infections, especially those caused by Candida albicans and other Candida species, necessitates the understanding and treatment of Candida-associated infections. In this study, we aimed to investigate the identification, distribution, and biofilm formation ability of different clinical Candida isolates and evaluate the distribution and antifungal susceptibilities of high biofilm-forming (HBF) Candida isolates. METHODS: For identification, carbohydrate fermentation, carbohydrate assimilation, and ChromAgar tests were used. Biofilm formation was assessed using crystal violet binding assay, while the susceptibility to antifungal agents was determined using ATBTM Fungus 3 test kits. RESULTS: The majority of Candida species were C. parapsilosis (31.3%; 31/99) and C. tropicalis (30.3%; 30/99). C. tropicalis was found to be the most frequently isolated species among all HBF Candida species. HBF Candida isolates were more frequently isolated from vaginal swab (35.7%; 10/28), tracheal aspirate (17.9%; 5/28), and urine (17.9%; 5/28). The majority of tested isolates were resistant to itraconazole and voriconazole, whereas no isolate was deemed resistant to 5-flucytosine. CONCLUSIONS: C. tropicalis displays the highest biofilm formation ability among all the Candida species evaluated, and HBF Candida isolates were more frequently seen in vaginal swab, tracheal aspirate, and urine samples. Our findings revealed that 5-flucytosine is the most efficient antifungal agent against HBF Candida isolates.


Subject(s)
Humans , Candida/drug effects , Biofilms/drug effects , Antifungal Agents/pharmacology , Candida/classification , Candida/physiology , Microbial Sensitivity Tests , Biofilms/growth & development
13.
Braz. J. Pharm. Sci. (Online) ; 54(4): e17858, 2018. tab, graf
Article in English | LILACS | ID: biblio-1001585

ABSTRACT

From drug repurposing studies, this work aimed to evaluate the activity of different pyrazinoic acid (POA) derivatives against Sporothrix brasiliensis. The POA esters were prepared and characterized as previously reported by classical esterification reactions, with good to excellent yields. Sporothrix brasiliensis isolates from cats (n=6) and standard strains of S. brasiliensis and S. schenckii were used to assess the antifungal activity of the POA derivatives through broth microdilution assay (CLSI M38-A2). Among the tested compounds, molecules 3 and 4 showed fungistatic and fungicidal activities against all Sporothrix spp. strains, and the obtained MIC and MFC values ranged from 2.12 to 4.24 mg/mL and from 1.29 to 5.15 mg/mL, respectively. Compound 2 and 5 were active as in vitro inhibitors of fungal growth, but showed weak fungicidal activity, while molecules 1 and POA itself were inactive. The results suggest the activity of POA derivatives against Sporothrix spp. may be dependent on the lipophilicity. In addition, the antifungal susceptibility of the isolates to itraconazole was performed, showing that two Sporothrix isolates from cats were itraconazole-resistant. Compounds 3 and 4 were also active against these itraconazole-resistant isolates, indicating a possible alternative route to the standard mode of action of itraconazole.


Subject(s)
Animals , Male , Female , Cats , Sporotrichosis/drug therapy , Sporothrix/classification , Prodrugs , Itraconazole/analysis , Antifungal Agents
14.
Article in Chinese | WPRIM | ID: wpr-609702

ABSTRACT

Objective:To investigate the prevalence of Candida spp.and the virulence factors of Candida albicans (C.albicans) isolated from external surfaces of blow flies collected from Mae Sot,Tak Province,Thailand,Methods:The blow flies were collected by sterile sweep nets from three areas in Mae Sot.Yeast isolation was first performed on Sabouraud dextrose agar (SDA) supplemented with chloramphenicol and cycloheximide.The yeast isolates were then identified by using chromogenic agar,a yeast identification test kit,a germ tube formation test and a carbohydrate utilization test.The β-hemolysis was determined on 7% sheep blood agar,while phospholipase activity was measured on SDA agar supplemented with 10% egg yolk suspension.Antifungal susceptibility testing was determined by broth micro-dilution testing against ketoconazole and amphotericin B.Results:The prevalence rate of Candida spp.on the external surfaces of the blow flies was 78.1%.All C.albicans isolated from the blow fly demonstrated β-hemolysin and potent phospholipase activities and 47.1% of C.albicans were resistant to ketoconazole with MIC values 128 μg/mL.Conclusions:The result s indicate that blow flies could play an essential role in the transmission of potentially pathogenic and antifungal resistant C.albicans into the environment.Further investigation on other virulence factors and genetic relatedness among isolates from the blow flies,the environment and clinical specimens is required to confirm this role.

15.
Rev. bioméd. (México) ; 27(3): 127-136, sep.-dic. 2016. graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1041932

ABSTRACT

Resumen Candida albicans es una levadura comensal capaz de causar una infección oportunista en hospederos susceptibles denominada candidiasis. El tratamiento para combatir la candidiasis puede ser tópico o sistémico según el tipo de infección, los antifúngicos más utilizados son los derivados imidazólicos (fluconazol, itraconazol, ketoconazol, miconazol etc.), sin embargo en la actualidad se observa una disminución en la efectividad de estos medicamentos, es decir, un fenómeno de resistencia de parte del microorganismo a estos fármacos, esto debido principalmente, al surgimiento de levaduras resistentes, a la aparición de nuevas especies patógenas, a la prescripción irracional de antimicóticos como profilaxis y al aumento de las dosis terapéuticas. Existen dos mecanismos por los que Candida puede adquirir resistencia a un azol. El primero es por mutaciones moleculares de la enzima diana del antifúngico, como la alteración de las enzimas relacionadas en la síntesis del ergosterol y el segundo por la alteración en las bombas de expulsión: ATP-binding cassette (ABC) y facilitadores mayores (MF). En este trabajo se resumen los principales mecanismos de resistencia en Candida y la importancia de hacer pruebas de susceptibilidad con el fin de brindar un tratamiento adecuado para este tipo de infecciones oportunistas.


Abstract Candida albicans is a commensal yeast capable of causing an opportunistic infection called candidiasis in susceptible hosts. Treatment to combat Candida may be topical or systemic according to the type of infection and the imidazole derivatives (fluconazole, itraconazole, ketoconazole, miconazole, etc.) are the antifungals most widely used. However, resistance to these drugs is observed by a decrement in their effectiveness. This is mainly due to the emergence of resistant yeasts and of new pathogenic species, as well as to the irrational prescribing of antifungal prophylaxis and the use of higher therapeutic doses. There are two mechanisms by which Candida can acquire an azole resistance, the first is by molecular mutations of antifungal target enzyme, as the alteration of enzymes related to the synthesis of ergosterols and the second by change in the efflux pumps, such as those of ATP-binding cassette and the higher facilitators. In this work the main mechanisms of resistance to Candida and the importance of performing susceptibility tests in order to provide an adequate treatment for this type of opportunistic infections are summarized.

16.
Braz. j. microbiol ; 47(4): 896-901, Oct.-Dec. 2016. tab, graf
Article in English | LILACS | ID: biblio-828210

ABSTRACT

Abstract The study aimed to evaluate the anti-Sporothrix sp. activity of the essential oil of Origanum majorana Linn. (marjoram), its chemical analysis, and its cytotoxic activity. A total of 18 fungal isolates of Sporothrix brasiliensis (n: 17) from humans, dogs and cats, and a standard strain of Sporothrix schenckii (n: 1) were tested using the broth microdilution technique (Clinical and Laboratory Standard Institute - CLSI M27-A3) and the results were expressed in minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC). The MIC50 and MIC90 of itraconazole against S. brasiliensis were 2 µg/mL and 8 µg/mL, respectively, and the MFC50 and MFC90 were 2 µg/mL and >16 µg/mL, respectively, with three S. brasiliensis isolates resistant to antifungal. S. schenckii was sensitive at MIC of 1 µg/mL and MFC of 8 µg/mL. For the oil of O. majorana L., all isolates were susceptible to MIC of ≤2.25-9 mg/mL and MFC of ≤2.25-18 mg/mL. The MIC50 and MIC90 were ≤2.25 mg/mL and 4.5 mg/mL, respectively, and the MFC50/90 values were twice more than the MIC. Twenty-two compounds were identified by gas chromatography with a flame ionization detector (CG-FID) and 1,8-cineole and 4-terpineol were the majority. Through the colorimetric (MTT) assay, the toxicity was observed in 70-80% of VERO cells between 0.078 and 5 mg/mL. For the first time, the study demonstrated the satisfactory in vitro anti-Sporothrix sp. activity of marjoram oil and further studies are needed to ensure its safe and effective use.


Subject(s)
Animals , Sporothrix/drug effects , Oils, Volatile/pharmacology , Antifungal Agents/pharmacology , Sporotrichosis/microbiology , Sporothrix/isolation & purification , Vero Cells , Oils, Volatile/chemistry , Microbial Sensitivity Tests , Zoonoses/microbiology , Cell Survival/drug effects , Chlorocebus aethiops , Drug Resistance, Fungal , Antifungal Agents/chemistry
17.
Arq. bras. med. vet. zootec ; 68(4): 991-999, jul.-ago. 2016. tab, graf
Article in English | LILACS, VETINDEX | ID: lil-792489

ABSTRACT

Rosmarinus officinalis L. (rosemary) and Origanum vulgare L. (oregano) are known to have antimicrobial properties, but studies on sporotrichosis are scarce. This study aimed to evaluate the anti-Sporothrix spp. activity of essential oils from commercial products and oils extracted from aerial parts of these plants and analyze their chemical constituents. S. schenckii complex and S. brasiliensis (n: 25) isolated from humans, cats, dogs, and environmental soil were tested through M27-A3 guidelines of CLSI with modification for phytotherapics. The essential oils of R. officinalis L. were similar for MIC50 and MFC50 ≤2.25mg/mL for extracted oil; and 4.5mg/mL and 9mg/mL, respectively, for commercial oil. Both products showed MIC90 of 18mg/mL and MFC90 of 36mg/mL. In O. vulgare L., the extracted oil had better activity with MIC50 and MFC50 ≤2.25mg/mL, and MIC90 and MFC90 of 4.5mg/mL, whereas the commercial oil showed MIC50 and MFC50 of 9mg/mL and MIC90 18mg/mL, respectively, and MFC90 of 36mg/mL. Through gas chromatography (CG/FID), thymol and α-terpinene were majority for extracted oil of O. vulgare L., and carvacrol and γ-terpinene made up the majority of the commercial oil. Both essential oils of R. officinalis L. showed 1,8-cineole and α-pinene as major. The fungal isolates were susceptible to all tested essential oils, including in itraconazole-resistant S. brasiliensis isolates. The extracted and commercial oils of the plants presented in vitro anti-Sporothrix spp. activity, and they are promising for treatment of sporotrichosis, including in cases refractory to itraconazole. More studies should be performed about toxicity and in vivo efficacy for its safe use.(AU)


Rosmarinus officinalis L. (alecrim) e Origanum vulgare L. (orégano) são conhecidos pelas propriedades antimicrobianas, entretanto seus estudos na esporotricose são escassos. Este trabalho objetivou avaliar a atividade anti-Sporothrix spp. de óleos extraídos e comerciais dessas plantas e analisar seus constituintes químicos. Isolados do complexo S. schenckii e S. brasiliensis (n: 25) de humanos, gatos, cães e solo, foram testados pela diretriz M27-A3 do CLSI com modificações para fitoterápicos. Os óleos de R. officinalis L. foram similares com CIM50 e CFM50 ≤2.25mg/mL para extraído; e 4.5mg/mL e 9mg/mL, respectivamente, para comercial. Ambos os produtos demonstraram CIM90 de 18mg/mL e CFM90 de 36mg/mL. Em O. vulgare L., o óleo extraído apresentou melhor atividade com CIM50 e CFM50≤2.25mg/mL e CIM90 e CFM90 de 4.5mg/mL, ao passo que o óleo comercial mostrou CIM50 e CFM50 de 9mg/mL; e CIM90 de 18mg/mL e CFM90 de 36mg/mL. Por meio da cromatografia gasosa (CG/FID), timol e α-terpineno foram majoritários para o óleo extraído de O. vulgare L., e carvacrol e γ-terpineno para o comercial. Ambos os óleos de R. officinalis L. apresentaram 1,8-cineol e α-pineno como prevalentes. Os isolados foram sensíveis a todos os óleos essenciais testados, inclusive S. brasiliensis, resistentes ao itraconazol. Os óleos extraídos e comerciais de R. officinalis L. e O. vulgare L. apresentaram atividade anti-Sporothrix spp. in vitro e são promissores para o tratamento da esporotricose, inclusive em casos refratários ao itraconazol. Mais estudos devem ser realizados sobre toxicidade e eficácia in vivo para seu uso seguro.(AU)


Subject(s)
Humans , Animals , Cats , Dogs , Antifungal Agents/therapeutic use , Lamiaceae , Origanum , Rosmarinus , Sporotrichosis/prevention & control , Mycoses/prevention & control , Mycoses/veterinary
18.
Braz. j. microbiol ; 47(1): 33-38, Jan.-Mar. 2016. tab, graf
Article in English | LILACS | ID: lil-775105

ABSTRACT

Abstract Since, there is no study reporting the mechanism of azole resistance among yeasts isolated from aquatic environments; the present study aims to investigate the occurrence of antifungal resistance among yeasts isolated from an aquatic environment, and assess the efflux-pump activity of the azole-resistant strains to better understand the mechanism of resistance for this group of drugs. For this purpose, monthly water and sediment samples were collected from Catú Lake, Ceará, Brazil, from March 2011 to February 2012. The obtained yeasts were identified based on morphological and biochemical characteristics. Of the 46 isolates, 37 were Candida spp., 4 were Trichosporon asahii, 3 were Cryptococcus laurentii, 1 Rhodotorula mucilaginosa, and 1 was Kodamaea ohmeri. These isolates were subjected to broth microdilution assay with amphotericin B, itraconazole, and fluconazole, according to the methodology standardized by the Clinical and Laboratory Standards Institute (CLSI). The minimum inhibitory concentrations (MICs) of amphotericin B, itraconazole, and fluconazole were 0.03125–2 µg/mL, 0.0625 to ≥16 µg/mL, and 0.5 to ≥64 µg/mL, respectively, and 13 resistant azole-resistant Candida isolates were detected. A reduction in the azole MICs leading to the phenotypical reversal of the azole resistance was observed upon addition of efflux-pump inhibitors. These findings suggest that the azole resistance among environmental Candida spp. is most likely associated with the overexpression of efflux-pumps.


Subject(s)
Antifungal Agents/metabolism , Azoles/metabolism , Candida/drug effects , Candida/isolation & purification , Drug Resistance, Fungal , Lakes/microbiology , Biological Transport, Active , Brazil , Microbial Sensitivity Tests
19.
Rev. argent. microbiol ; 48(1): 43-49, mar. 2016. ilus, tab
Article in English | LILACS | ID: biblio-843146

ABSTRACT

Candida africana taxonomical status is controversial. It was proposed as a separate species within the Candida albicans species complex; however, phylogenetic analyses suggested that it is an unusual variety of C. albicans. The prevalence of C. albicans-related species (Candida dubliniensis and C. africana) as vulvovaginal pathogens is not known in Argentina. Moreover, data on antifungal susceptibility of isolates causing vulvovaginal candidiasis is scarce. The aims of this study were to establish the prevalence of C. dubliniensis and C. africana in vaginal samples and to evaluate the antifungal susceptibilities of vaginal C. albicans species complex strains. We used a molecular-based method coupled with a new pooled DNA extraction methodology to differentiate C. dubliniensis and C. africana in a collection of 287 strains originally identified as C. albicans isolated from an Argentinian hospital during 2013. Antifungal susceptibilities to fluconazole, clotrimazole, itraconazole, voriconazole, nystatin, amphotericin B and terbinafine were evaluated by using the CLSI M27-A3 and M27-S4 documents. Of the 287 isolates, 4 C. dubliniensis and one C. africana strains (1.39% and 0.35% prevalence, respectively) were identified. This is the first description of C. africana in Argentina and its identification was confirmed by sequencing the ITS2 region and the hwp1 gene. C. dubliniensis and C. africana strains showed very low MIC values for all the tested antifungals. Fluconazole-reduced-susceptibility and azole cross-resistance were observed in 3.55% and 1.41% of the C. albicans isolates, respectively. These results demonstrate that antifungal resistance is still a rare phenomenon in this kind of isolates.


La clasificación taxonómica de Candida africana está en discusión, es considerada una nueva especie dentro del complejo C. albicans o una variedad inusual de C. albicans. La prevalencia de las especies relacionadas a C. albicans (C. dubliniensis y C. africana) como agentes de vulvovaginitis en Argentina se desconoce. Los objetivos de este trabajo fueron determinar la prevalencia de C. dubliniensis y C. africana en muestras vaginales y evaluar la sensibilidad a los antifúngicos de aislamientos vaginales de las especies del complejo C. albicans. Para diferenciar C. dubliniensis y C. africana utilizamos un método molecular asociado a un nuevo método de extracción de ADN. Se utilizó una colección de 287 cepas originalmente identificadas como C. albicans aisladas durante 2013 en un hospital de Argentina. Se evaluó la sensibilidad a fluconazol, clotrimazol, itraconazol, voriconazol, nistatina, anfotericina B y terbinafina utilizando los documentos M27-A3 y M27-S4 del CLSI. De los 287 aislamientos, se identificaron 4 C. dubliniensis y 1 C. africana (1,39 y 0,35% de prevalencia, respectivamente). Esta es la primera descripción de C. africana en Argentina. Su identificación fue confirmada por secuenciación de la región ITS2 y del gen hwp1. Las cepas identificadas como C. dubliniensis y C. africana mostraron valores de CIM muy bajos para todos los antifúngicos probados. En los aislamientos de C. albicans, la sensibilidad reducida al fluconazol y la resistencia cruzada a todos los azoles se observó en el 3,55% y el 1,41%, respectivamente. Estos resultados demuestran que la resistencia a los antifúngicos es todavía un fenómeno raro en este tipo de aislamientos.


Subject(s)
Humans , Female , Candida albicans/isolation & purification , Candida albicans/drug effects , Candidiasis, Vulvovaginal/drug therapy , Antifungal Agents/therapeutic use , Vulvovaginitis/microbiology , Candida albicans/classification
20.
Mem. Inst. Oswaldo Cruz ; 111(1): 51-58, Jan. 2016. tab, graf
Article in English | LILACS | ID: lil-771081

ABSTRACT

This study evaluated the antifungal susceptibility profile and the production of potential virulence attributes in a clinical strain of Candida nivariensis for the first time in Brazil, as identified by sequencing the internal transcribed spacer (ITS)1-5.8S-ITS2 region and D1/D2 domains of the 28S of the rDNA. For comparative purposes, tests were also performed with reference strains. All strains presented low planktonic minimal inhibitory concentrations (PMICs) to amphotericin B (AMB), caspofungin (CAS), and voriconazole. However, our strain showed elevated planktonic MICs to posaconazole (POS) and itraconazole, in addition to fluconazole resistance. Adherence to inert surfaces was conducted onto glass and polystyrene. The biofilm formation and antifungal susceptibility on biofilm-growing cells were evaluated by crystal violet staining and a XTT reduction assay. All fungal strains were able to bind both tested surfaces and form biofilm, with a binding preference to polystyrene (p < 0.001). AMB promoted significant reductions (≈50%) in biofilm production by our C. nivariensis strain using both methodologies. This reduction was also observed for CAS and POS, but only in the XTT assay. All strains were excellent protease producers and moderate phytase producers, but lipases were not detected. This study reinforces the pathogenic potential of C. nivariensis and its possible resistance profile to the azolic drugs generally used for candidiasis management.


Subject(s)
Humans , Antifungal Agents/pharmacology , Candida/drug effects , Candidiasis/microbiology , Brazil , Biofilms/drug effects , Candida/classification , Candida/isolation & purification , Candida/pathogenicity , Microbial Sensitivity Tests , Phenotype , Virulence
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