In vitro antifungal activity of phenothiazines and their combination with amphotericin B against different Candida species

Candidiosis is a mycosis that is currently increasingly affecting the population in consequence of its frequency and the severity of its complications, especially among immunocompromised hosts. In this work, the in vitro anticandidal activities of two phenothiazines (PTZs), chlorpromazine (CPZ) and trifluoperazine (TFP), and their combinations with amphotericin B (AMB) were tested against 12 different Candida strains representing 12 species (Candida albicans, Candida glabrata, Candida guillermondii, Candida inconspicua, Candida krusei, Candida lusitaniae, Candida lypolitica, Candida norvegica, Candida parapsilosis, Candida pulcherrima, Candida tropicalis and Candida zeylanoides). When used alone, both tested PTZs exerted antifungal effects against these strains. In their combinations, these PTZs and AMB mainly acted antagonistically at higher concentrations, but additively and synergistically at lower concentrations as concerns the clinically most important species (C. albicans and C. parapsilosis). For C. albicans, only synergistic interactions were revealed between CPZ and AMB. Synergistic, additive or no interactions were demonstrated between the investigated compounds for the most PTZ-susceptible (C. glabrata to TFP and C. krusei to CPZ) and insusceptible strains (C. glabrata to CPZ and C. lypolitica to TFP).     

An investigation on the anticandidal activity of some traditional medicinal plants in Turkey

Methanol and chloroform extracts obtained from eight plant species belonging to six families, which were selected depending on their use in Turkish folk medicine, including Mentha longifolia L . (Labiatae), Mentha piperita L . Hudson (Labiatae), Prongos ferulaceae (Umbelliferae), Galium verum L . (Rubiaceae), Salvia limbata C. A Meyer (Labiatae), Artemisia austriaca Jacq. (Artemiceae), Plantago lanceolata L. (Plantaginaceae) and Urtica dioica L. (Urticaceae) were evaluated for their in vitro anticandidal activity. The anticandidal activity of extracts against 99 human pathogenic clinical isolates belonging to 35 Candida albicans , 33 Candida tropicalis and 31 Candida glabrata and standard strains of Candida spp. ( C. albicans ATCC 10231, C. glabrata ATCC 80030 and C. tropicalis ATCC 22019) were tested by disc diffusion method and the active extracts were assayed for the minimal inhibitory concentration (MIC). Chloroform extracts of plants have no inhibitory effect against both clinical and standard strains of Candida spp., whereas methanol extracts exhibited good activity. Among the plants tested, M. piperita showed the highest anticandidal activity with 12.3 mm inhibition zone and 1.25 mg ml⁻¹ MIC value against C. albicans , M. longifolia , P. lanceolata and A. austriaca also displayed activity against C. albicans and C. tropicalis .     

Etiology of fungaemia and catheter colonisation in Argentinean paediatric patients

Yeast strains obtained from blood cultures and catheters from intensive care units (ICU) and hospitalised oncology paediatrics were studied. Yeast were the first cause of catheter colonisation (51/627), and the third cause of bloodstream infection (44/6065). In catheter, the most frequent species were Candida albicans (34%), C. parapsilosis (27.7%) and C. tropicalis (15%). In blood, C. albicans (40.8%), C. parapsilosis (26.6%), C. tropicalis (15%). Malassezia furfur and Malassezia sympodialis were isolated from catheters from ICU patients. All isolates were susceptible to amphotericin B, 88.8% to itraconazole and 91.9% to fluconazole. Candida albicans and C. tropicalis strains resistant to fluconazole and itraconazol were detected. These results reveal a change in the predominant role of C. albicans as cause of candidemia in hospitalised children and the emergence of antifungal resistant species. These variations emphasise the importance of performing a permanent surveillance to observe and assess them.     

In Vitro Antifungal Activity of Saperconazole (R 66905) Against Candida and Torulopsis Die antimyzetische Aktivität von Saperconazol (R 66905) in vitro gegen Candida und Torulopsis

The susceptibility of several strains of Candida and Torulopsis to saperconazole, a new triazole antifungal compound, was compared to that of ketoconazole. The MICs of the two antifungal agents were determined against 70 strains of Candida albicans, 10 strains of C. guilliermondii, 10 strains of C. krusei, 10 strains of C. parapsilosis, 10 strains of C. pseudotropicalis, 10 strains of C. tropicalis and 15 strains of Torulopsis glabrata. The fungistatic activity was evaluated by the agar dilution method using BHI and casitone media after incubation for 48 hours at 28-30 degrees C. The in vitro activity of saperconazole was similar to that of ketoconazole for most of the Candida spp. tested except for C. krusei in particular. An MIC of less than or equal to 3.12 micrograms/ml for saperconazole was found with 92% of the C. albicans strains tested. In contrast, T. glabrata was more susceptible to ketoconazole.     

Preparation and characterization of a monoclonal antibody against mannoprotein of Candida albicans

BALB/c mice were immunized via injection with whole cell of Candida albicans serotype A. The spleens were fused with myeloma cells of SP2/0 origin. A mannoprotein-reactive monoclonal antibody (MAb) was selected and characterized by ELISA technique. This MAb reacted with strains of Candida such as C. albicans, C. tropicalis, and C. albicans of the Persian Type Culture Collection (PTCC). However, our antibody did not react with other Candida species such as C. parapsilosis, C. glabrata, C. stellatoidae, C. lusitania, C. krusei, and S. cervisiae. These antibodies also did not recognize extracts of other fungal species such as Aspergillus fumigatus and Aspergillus flavus, and bacterial strains such as Staphylococcus aureus and Pseudomonas aeruginosa. Polyclonal antibody produced in this study could not differentiate the above species and was reactive towards all fungal species mentioned above except bacterial strains of S. aureus and P. aeruginosa. Western blot analysis of ligand affinity-purified mannoproteins of C. albicans wall protein using this MAb showed reactivity toward a single protein band in the region of 55-65 kDa molecular weight. The same antibody, when examined with unpurified C. albicans extract, reacted with a broad band in the region of 55-105 kDa, which we concluded was due to a possible different glycosylation pattern of mannoprotein in crude extract in which the higher molecular weight protein was eliminated by ligand-binding affinity purification.     

Phospholipase and protease activities in clinical Candida isolates with reference to the sources of strains

The present study was aimed at determining in vitro phospholipase and protease activities in 95 clinical isolates of various Candida species (C. albicans, C. glabrata, C. guilliermondii,C.kefyr, C. krusei, C. lipolytica, C. lusitaniae, C. parapsilosis, C.rugosa and C. tropicalis). 59 (62.1%) of isolates examined were phospholipase positive and 75 (78.9.9%) were protease positive. 56 (93.3%) of C.albicans isolates tested were phospholipase producers - however only a few strains of C. glabrata and C. kefyr behaved in the same way. Protease activity was detected in 57 (95%) of C. albicans strains tested and in a few strains of C. kefyr, C.lipolytica, C. parapsilosis and C. tropicalis- the remaining isolates were negative. 56 strains of C.albicans and 2 strains of C. kefyr tested produced both phospholipase and protease.     

Screening of Thai medicinal plants for anticandidal activity

Medicinal plants are often used in the treatment of various ailments. In this study, 23 of Thai medicinal plants were screened for their anticandidal activity against six pathogenic Candida species: C. albicans , C. glabrata , C. guilliermondii , C. krusei , C. parapsilosis and C. tropicalis. The methanol extract of Hibiscus sabdariffa L. fruit, Trigonostemon reidioides (Kurz) Craib root, Usnea siamensis Vain whole plant, Boesenbergia rotunda (L.) Mansf. rhizome, and Albizia myriophylla Benth. stem showed anticandidal activity against one or more species of Candida . Among them, A. myriophylla Benth. showed broad anticandidal activity. The susceptibility tests of A. myriophylla Benth. extract, in terms of minimal inhibitory concentrations (MIC) and minimal fungicidal concentration (MFC), were performed by the broth microdilution techniques as described by the Clinical Laboratory Standard Institute. MICs of A. myriophylla Benth. extract to all Candida species was ranged 100–500 μg ml⁻¹. The killing activity of A. myriophylla Benth. extract was fast acting against all Candida tested; the reduction in the number of CFU ml⁻¹ was >3 log₁₀ units (99.9%) in 2 h. This study indicates that A. myriophylla Benth. extract has considerable anticandidal activity, deserving further investigation for clinical applications for the treatment of candidiasis.     

Prevalence of Candida spp. in hospitalized patients and their risk factors

A total of 133 Candida spp. strains originating from a group of 100 patients from Santa Casa de Misericórdia of Belo Horizonte, Brazil, between March 1995 and December 1996, were first identified and classified into six different species: Candida albicans (51%), C. tropicalis (33%), C. parapsilosis (8%), C. glabrata (5%), C. krusei (2%) and C. guilliermondii (1%). All C. albicans strains were serotyped and 55% of these were found to belong to serotype A and 45% belonging to serotype B. The medical records of each patient were examined to characterise and survey the main risk factors associated with them. Most of the patients were between 60- and 80-years-old, 53% were males and 47% were females. Most patients were from the intensive care unit (ICU). Only 10 patients were not exposed to antimicrobial agents and 72 patients were not prescribed antifungal agents. Forty patients showed no other clinical condition and all showed some underlying disease that justified hospitalization. Eighty-seven patients had undergone some invasive procedure and 31 patients had been submitted to two different procedures simultaneously.     

Colony Variations in Candida Species

One hundred isolates of seven Candida species and three isolates of Saccharomyces cerevisiae were plated on phloxine B agar and examined for variations in the morphology or colour of colonies that developed. Colony variations were found in 9 of 12 C. parapsilosis isolates, 8 of 13 C. tropicalis isolates, 4 of 9 C. krusei isolates and 12 of 30 C. albicans isolates. None of 23 C. glabrata isolates grew on the test medium. Variant colonies often generated further different colony forms on secondary subculture. The rate of production of fimbriate and rhizoid colonies by two C. albicans isolates varied with agar thickness and the nutrient content of the medium. These results suggest that colony variation is a common property among isolates of many Candida species and that strict control of agar medium thickness and composition is essential for reproducible screening of isolates for colony variations.     

Fatty acid analysis of different Candida, species by capillary column gas-liquid chromatography

Gas-liquid chromatography was used to analyse the fatty acid composition of whole-cell hydrolysates of 40 yeast strains representing 5 Candida species and Torulopsis glabrata, T. glabrata could be easily distinguished from all other Candida spp. by the absence of C18:3. Candida albicans, C. krusei, C. parapsilosis, C. pseudotropicalis and C. tropicalis showed 10 major peaks in characteristic proportions. C. parapsilosis showed a high C16:0/C16:1 ratio (greater than 4.5), whereas C. pseudotropicalis was characterized by a C18:1/C16:0 ratio of less than 2.0. A high C18:3 concentration (greater than 10%) was typical for C. krusei (C18:2/C18:3 ratio less than or equal to 1.0). Our data reveal characteristic patterns of cellular fatty acid composition of T. glabrata, C. krusei, C. parapsilosis and C. pseudotropicalis which can be used for laboratory identification.     

Adherence of Candida strains isolated from the human gastrointestinal tract

The adherence of different Candida strains isolated from the human gastrointestinal tract was studied. The 23 Candida strains isolated from faeces were C. albicans (12), C. glabrata (2), C. krusei (2), C. parapsilosis (2), C. tropicalis (2), C. colliculosa (1), C. kefyr (1) and C. lusitaniae (1). Buccal epithelial cells from different healthy donors were used. Adherence values were maximal for C. albicans and minimal for C. krusei. A relation exists between yeast adherence capacity and the ability to colonize mucosal surfaces.     

Cross-Reactivity of Pathogenic Candida Mannans Studied by Enzyme-Linked Immunosorbent Assay (ELISA) and Precipitin Methods/Untersuchungen zur Kreuzreaktivität von Mannanen pathogener Candida-Arten mittels ELISA und Präzipitationstesten

Summary: Cross-reactivity of mannans isolated from 7 medically most important Candida species was investigated by enzyme-linked immunosorbent assay (ELISA), quantitative precipitation and immunodiffusion in agar gel. It was found that mannans, in the basis of their reactions with rabbit anti- Candida albicans serotype B antiserum can be divided into three groups. The first group comprises the species C. albicans serotype A and B, C. tropicalis and C. stellatoidea showing very high cross-reactivity. To the second group belong the species C. parapsilosis, C. guilliermondii and C. pseudotropicalis which present moderate cross-reactivity. Mannan of C. krusei differing from the former species gave very low cross-reactivity. These investigations demonstrated a good correlation between enzyme-linked immunosorbent assay precipitin reactions of mannans.
Zusammenfassung: Es wurde die Kreuzreaktivität der Mannane der 7 medizinisch bedeutsamsten Candida -Arten mittels ELISA, quantitativer Präzipitation und Agargelimmundiffusion untersucht Auf Grand ihrer Reaktion mit einem Anti- Candida albicans Serotyp B-Antiserum vom Kaninchen können die Mannane in drei Gruppen eingeteilt werden. Die erste Gruppe umfaßt die Arten C. albicans Serotyp A und B, C. tropicalis und C. stettatoidea , die sehr hohe Kreuzreaktivität zeigen. Zur zweiten Gruppe gehören C. parapsilosis, C. guilliermondii und C. pseudotropicalis mit mäßiger Kreuzreaktivität Das Mannan von C. krusei unterscheidet sich von den vorher genannten Arten und ergab nur eine sehr geringe Kreuzreaktivität Die Untersuchungen zeigten eine gute übereinstimmung zwischen den ELISA- und den Präzipitationsreaktionen der Mannane.     

Yeasts species distribution in Neonatal Intensive Care Units in northeast Argentina

The aim of this study was to determine the distribution and antifungal susceptibility profile of yeast species isolated from neonates in Neonatal Intensive Care Units (NICU) in northeast of Argentina. With this purpose 92 strains isolated from 25 blood stream cultures, 20 venous catheters, 23 suprapubic aspirations and 24 rectal swabs were studied. Candida albicans and C. parapsilosis appeared with similar frequencies (36%) in blood stream isolates. Candida parapsilosis (50%) was the most frequent catheters colonizer and C. tropicalis (54.2%) was the most frequent yeast associated with gastrointestinal tract colonization. Candida krusei, C. glabrata and Trichosporon cutaneum appeared with a very low frequency. A high rate of susceptibility to amphotericin B, fluconazole, and itraconazole was observed.     

Oral yeast carriage in HIV-infected and non-infected populations in Rosario, Argentina

The objectives of the present study were: (i) to assess the frequency of oral colonisation by Candida species in HIV-positive patients and to compare it with a population of HIV-negative individuals, (ii) to determine the prevalence of C. dubliniensis in both populations and (iii) to determine the susceptibility of C. dubliniensis and other Candida species isolated from HIV-positive patients to the most commonly used antifungal agents. Oral samples were obtained from 101 HIV-positive and 108 HIV-negative subjects. For yeast identification, we used morphology in cornmeal agar, the API 20C Aux, growth at 45 °C, d -xylose assimilation, morphology in sunflower seed agar and PCR. The frequency of isolation of Candida in HIV-positive patients was: C. albicans , 60.7%; C. dubliniensis , 20.2%; C. glabrata , 5.6%; C. krusei , 5.6%; C. tropicalis , 4.5%; others, <5%. The frequency of isolation of Candida in HIV-negative patients was: C. albicans , 73.9%; C. tropicalis , 15.5%; C. dubliniensis , 2.1%; C. glabrata , 2.1%; C. parapsilosis , 2.1%; others, <5%. The oral colonisation by yeast in the HIV-positive patients was higher than that in the HIV-negative subjects. The susceptibilities of 42 Candida isolates to three antifungal agents were determined. All isolates of C. dubliniensis were susceptible to fluconazole, although several individuals had been previously treated with this drug. Out of the 42 Candida isolates, 10 presented resistance to fluconazole and 10 to itraconazole. The presence of Candida species, resistant to commonly used antifungal agents, represents a potential risk in immunocompromised patients.     

Identification of Candida species isolated from patients in intensive care unit and in vitro susceptibility to fluconazole for a 3-year period

Species level identification of Candida and antifungal susceptibility testing is not generally performed in routine laboratory practice. There is limited information about the distribution of Candida species and antifungal susceptibility in Turkey. In this study, we aimed at identifying Candida isolates to species level from various samples obtained from patients treated in an intensive care unit between 2002 and 2005 and to evaluate fluconazole susceptibilities of the isolates. A total of 320 Candida isolates obtained from 270 patients were identified by conventional methods and using API (Candida and/or 20C AUX) system. Antifungal susceptibility testing was performed by broth microdilution method. Candida albicans was isolated with the highest frequency (65.6%) followed by C. parapsilosis (11.3%), C. glabrata (8.8%) and C. tropicalis (7.8%). Of all the isolates, 92.9% revealed susceptibility to fluconazole. Susceptibility to fluconazole was highest for C. albicans followed by C. parapsilosis and C. glabrata. The MIC(90) values for C. albicans, C. parapsilosis, C. glabrata and C. tropicalis were 1, 2, 8 and 4 mug ml(-1) respectively. Fluconazole remains effective against both C. albicans and the majority of non-albicans Candida species. In this study, we determine the distribution of Candida species and evaluate the susceptibilities of the isolates, particularly for the azoles.     

Potent anti-microbial activity of traditional Chinese medicine herbs against Candida species

Anti-candidial activities of eight traditional Chinese medicinal (TCM) herbs were evaluated against six different Candida species. TCM preparations were screened for antifungal activity using a standard agar diffusion assay. Following identification of potential candidate herbs, their minimum inhibitory concentration (MIC) values were determined using the standardised NCCLS M-27A broth microdilution assay. Among TCM herbs, Rhizoma Coptidis had potent antifungal activity against Candida glabrata, Candida krusei and Candida tropicalis, but not against Candida albicans, Candida dubliniensis and Candida parapsolosis. The MIC values of the Rhizoma Coptidis against C. glabrata, C. krusei and C. tropicalis were 50, 50 and 100 microg ml(-1) respectively. We report here, for the first time, the potent antifungal activity of Rhizoma Coptidis and Cortex phellodendri Chinesis on three different non-albicans Candida species, C. glabrata, C. krusei and C. tropicalis and hence their possible use as therapeutic agents.     

Differentiation of Candida strains by lectin-mediated agglutination kinetics

The lectin-mediated agglutination kinetics of Candida albicans, Candida tropicalis, Candida glabrata, Candida krusei, Candida kefyr, and Candida parapsilosis strains isolated from immunocompromised patients was investigated. The rate of the lectin-induced cell agglutination depends on the physiological state of the yeast cell population. Therefore, the Candida strains have to be cultivated and investigated under identical conditions. Lentil lectin (prepared from Lens culinaris), castor lectin, and concanavalin A were used. Different yeast species showed different agglutination behaviour. Furthermore, the lectin-mediated rate of agglutination is a strain-specific property which makes it possible to distinguish between different yeast strains of the same species. It is concluded that the lectin-mediated agglutination kinetics allows reproducible differentiation of yeast strains of the same species.     

In vitro susceptibility of 545 isolates of Candida spp. to four antifungal agents

Summary. The in vitro susceptibility to amphotericin B, fluconazole, itraconazole and ketoconazole of 545 Candida strains from patients treated at the University Hospital of the Canaries was determined by means of a microdilution test. The distribution of the species was as follows: Candida albicans (342), Candida tropicalis (70), Candida glabrata (68), Candida parapsilosis (65). Of Candida albicans isolates, 8.5% and 7.6% showed resistance to itraconazole and fluconazole respectively. Of C. tropicalis isolates 34.3%, 27.1% and 2.9% were resistant to itraconazole, fluconazole and ketaconazole respectively. For C. glabrata , 10.3% and 4.4% of the isolates under study demonstrated resistance to fluconazole and itraconazole respectively. Only 4.6% and 1.5% of C. parapsilosis isolates demonstrated resistance to fluconazole and itraconazole respectively. C. tropicalis was the most resistant strain and C. parapsilosis the most sensitive. The greatest percentages of resistance in vitro were seen with the triazoles.
Zusammenfassung. Es wurde die Empfindlichkeit von 545 Candida -Stämmen für Amphotericin B, Fluconazol, Itraconazol und Ketoconazol in vitro in einem Mikrodilutionstest bestimmt. Bei den Stämmen handelte es sich um Isolate von Patienten, die in der Universitäts-Klinik der Kanarischen Inseln behandelt worden waren. Das Untersuchungsgut war wie folgt verteilt: 342 Candida albicans , 70 C. tropicalis , 68 C. glabrata , 65 C. parapsilosis. Bei C. albicans waren 8.5% gegen Itraconazol und 7.6% gegen Fluconazol resistent. Bei C. tropicalis wurden 34.3% resistent gegenüber Itraconazol befundet, 27.1% gegen Fluconazol und 2.9% gegen Ketoconazol. Bei C. glabrata waren 10.3% resistent gegen Fluconazol und 4.4% gegen Itraconazol. Candida parapsilosis wurde zu 4.6% gegen Fluconazol und zu 1.5% gegen Itraconazol als resistent befundet. Somit erwies sich C. tropicalis als die resistenteste und C. parapsilosis als die sensibelste Art.     

Zum Wachstum von Sproßpilzen auf actidionhaltigen Nährböden

Es wurden 74 verschiedene Sproßpilzarten auf ihr Vermögen hin untersucht, in Nährböden mit 400 bis 500 μg Actidion/ml zu wachsen. Von mehreren im klinischen Untersuchungsmaterial häufig vorkommenden Arten konnte jeweils eine größere Anzahl von Stämmen überprüft werden. Dabei zeigte sich, daß sich alle Stämme von Candida albicans, Candida guilliermondii, Candida lipolytica, Candida tropicalis, Candida pseudotropicalis, Trichosporen capitatum und Trichosporen cutaneum gut, hingegen Candida krusei, Candida parapsilosis und Cryptococcus neoformans nicht entwickeln konnten. Torulopsis candida, Torulopsis famata, Torulopsis glabrata und Torulopsis inconspicua sowie auch Candida mycoderma und Pichia membranaefaciens haben sowohl actidionempfindliche als auch -unenipfindliche Stämme.

Summary

Several strains (numbers varying from 1 to 60) of 74 different (individual) species of yeasts were cultivated on media (Mycoselagar, maltextract-agar) containing 400–500 μ/ml Actidione, to study infraspecific variation of Actidione-sensitivity. Among the yeasts of clinical importance in all the strains of Candida albicans (30), C. guilliermondii (30), C. lipolytica (20), C. tropicalis (25), C. pseudotropicalis (4), Trichosporon capitatum (5), and T. cutaneum (15), growth was not reduced, while all the strains of Candida krusei (25), C. parapsilosis (60), and Cryptococcus neoformans (6) more or less absolutely failed to grow under these conditions. Within the species Torulopsis candida, T. inconspicua, Candida mycoderma and Pichia membranaefaciens sensitive and insensitive strains were seen.     

Susceptibility of Candida Species to Cilofungin (LY-121019)

The antifungal activity of a new semi-synthetic lipopeptide named cilofungin (LY-121019) was studied in vitro on 102 strains of Candida and Torulopsis glabrata. A standardized protocol for susceptibility testing by means of a microtiter Sabouraud broth dilution was used. The minimal inhibitory concentrations of cilofungin for C. albicans (N = 50) ranged from 0.039 to 5.0 micrograms/ml with a geometric mean of 0.47 micrograms/ml. The same results were obtained with C. tropicalis but one strain showed higher resistance (40 micrograms/ml) suggesting an Eagle effect. The MIC for T. glabrata ranged from 5.0-40.0 micrograms/ml. C. parapsilosis and C. krusei were less susceptible (5.0-40.0 micrograms/ml). These results indicate that cilofungin exhibits a potent inhibitory action on C. albicans and C. tropicalis. This effect was lower against the other species of Candida and T. glabrata studied.