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Biomedical subjects

J Guarro

Publications and source records attributed to J Guarro.

At least 19 recordsLinked to original sources

Effect of inoculum form on in vitro antifungal susceptibilities of Aspergillus spp.

The effect of inoculum form, i.e. ungerminated conidia, germinated conidia and hyphae on the in vitro antifungal susceptibility of 12 strains belonging to Aspergillus spp. was compared using a broth microdilution method. The isolates were tested three times on different days against amphotericin B, itraconazole and ketoconazole. There were no significant differences between MICs obtained with the three types of inoculum (P > 0.05) for any antifungal tested. The degree of reproducibility of the tests was high (>or=75%) for all antifungals with each type of inoculum, except for itraconazole (58.3%) when the inoculum was prepared with ungerminated conidia.

Amphotericin B↗

In vitro activities of four novel triazoles against Scedosporium spp.

In order to develop new approaches to the treatment of the severe and usually fatal infections caused by Scedosporium spp., the in vitro antifungal activities of four novel triazoles (posaconazole, ravuconazole, voriconazole, and UR-9825) and some current antifungals (amphotericin B, ketoconazole, itraconazole, and nystatin) were determined. The latter group was clearly ineffective against the two species tested. The four new antifungals showed activity against Scedosporium apiospermum, and UR-9825 and voriconazole were active against S. prolificans.

Antifungal Agents↗

In vitro activities of 10 antifungal drugs against 508 dermatophyte strains.

We have tested 508 strains belonging to 24 species of dermatophytes against 10 antifungal drugs following mainly the NCCLS (M38-P) standard for filamentous fungi. However, several important factors, such as the temperature (28 versus 35 degrees C) and time of incubation (4 to 10 days versus 21 to 74 h), have been modified. The antifungals used were itraconazole, ketoconazole, miconazole, clotrimazole, voriconazole, terbinafine, amphotericin B, fluconazole, UR-9825, and G-1. In general, with the exception of fluconazole and G-1, all antifungals were shown to be highly effective.

Antifungal Agents↗

In vitro antifungal activities of the new triazole UR-9825 against clinically important filamentous fungi.

We used a modified reference microdilution method (the M-38P method) to evaluate the in vitro activities of the new triazole UR-9825 in comparison with those of amphotericin B against 77 strains of opportunistic filamentous fungi. UR-9825 was clearly more active than amphotericin B against all fungi except Fusarium solani and Scytalidium spp. Notably, UR-9825 had low MICs for Aspergillus fumigatus and Paecilomyces lilacinus (MICs at which 90% of isolates are inhibited, 0.125 microg/ml for both species).

Antifungal Agents↗

Cutaneous infection caused by Aspergillus ustus, an emerging opportunistic fungus in immunosuppressed patients.

We report a case of primary cutaneous infection by the emerging fungus Aspergillus ustus in an immunosuppressed patient after a domestic accident. The patient failed to respond to itraconazole and died before receiving a new treatment with amphotericin B. There have been eight other cases reported since 1973, and only two patients survived the infection. In vitro susceptibility testing of seven antifungal drugs showed that terbinafine and the new azole derivative UR-9825 were the most active against this fungus.

Aged↗

Phaeohyphomycotic cyst caused by Colletotrichum crassipes.

A case of phaeohyphomycosis is reported in a male renal transplant recipient with a nodular lesion in the right leg who was treated with immunosuppressing drugs. The lesion consisted of a purulent cyst with thick walls. The cyst was excised surgically, and the patient did not receive any antifungal therapy. One year later he remains well. Histological study of the lesion showed a granulomatous reaction of epithelioid and multinucleate giant cells, with a central area of necrosis and pus. Fontana-Masson staining demonstrated the presence of pigmented hyphal elements. The fungus Colletotrichum crassipes was grown in different cultures from the cyst. The in vitro inhibitory activities of eight antifungal drugs against the isolate were tested. Clotrimazole and UR-9825 were the most active drugs. This case represents the first known reported infection caused by this rare species.

Adult↗

Comparison of the minimum fungicidal concentration of amphotericin B determined in filamentous fungi by macrodilution and microdilution methods.

Minimum fungicidal concentration (MFC) determination could be useful in severe fungal infections in immunocompromised patients. No reference tests to determine the MFC are available, and both macro- and microdilution methods are commonly used. In this study, discrepancies between minimum inhibitory concentrations (MICs) and MFCs of amphotericin B against 58 isolates of filamentous fungi other than Aspergillus (46 Fusarium spp., six Paecilomyces spp. and six Scopulariopsis spp.), obtained with macro- and microdilution methods, were evaluated. Additionally, the agreement between MFCs obtained by both methods were analyzed. In general MFCs were higher than the corresponding MICs overall using the macrodilution method. MFCs were more than one dilution higher than MICs in 52.3% of the cases in the macrodilution test and in 20.5% of the cases in microdilution test. The degree of agreement between MFCs obtained with the two methods was of 70.4% (Kappa coefficient of 0.5). In general, the macrodilution method showed higher MFC values than the microdilution method. Differences of up to six drug dilutions were observed between MFCs obtained by both methods.

Amphotericin B↗

Emerging pathogens.

The ever increasing numbers of immunosuppressed individuals has led to a significant increase in the incidence of opportunistic infections, particularly those caused by fungi. The epidemiology of infections caused by the common fungal pathogens such as Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus has been well documented. However, in addition to these, a number of species which have previously been unrecognized (e.g., C. dubliniensis) or have previously been assumed to be non-pathogenic (e.g., Saccharomyces cerevisiae, Scedosporium spp. and Fusarium spp.) have emerged as agents of human disease. Since these species have only been identified recently as human pathogens, their role in disease is poorly understood. In most cases, identification of these species is problematic and therefore their epidemiology has yet to be elucidated adequately. In addition, several of these species fail to respond to conventional antifungal therapies. In this article, we describe the emergence of two separate yeast species (C. dubliniensis and S. cerevisiae) and two separate groups of moulds (Scedosporium prolificans and Fusarium spp.), as human pathogens. It is apparent from what we already know, that much work has yet to be performed before we have a clear understanding of how these species cause disease and most importantly how they can be controlled.

Candida↗

Extended method for discrimination of Aeromonas spp. by 16S rDNA RFLP analysis.

A previously described molecular method, based on 16S rDNA RFLP analysis, for the identification of Aeromonas spp. was unable to separate the species Aeromonas salmonicida, Aeromonas bestiarum and the recently described Aeromonas popoffii. In this study, the method has been extended with endonucleases AIwNI and PstI for the identification of these species. A molecular frame for the identification of all known Aeromonas spp. is presented.

Aeromonas↗

Comparison of three methods of determining MICs for filamentous fungi using different end point criteria and incubation periods.

Three different methods were used to determine the in vitro activities of amphotericin B, ketoconazole, itraconazole, and flucytosine against 30 isolates of different genera of filamentous fungi. MICs were determined visually, with or without agitation, and spectrophotometrically by using a broth microdilution method. For amphotericin B, there was one end point reading criterion (the minimum concentration of antifungal that inhibited 100% of growth), but for azoles and flucytosine there were two (the minimum concentrations that inhibited 50 and 75% of fungal growth, respectively) after 48 and 72 h of incubation. All tests were performed in triplicate. An intraclass correlation coefficient (ICC) was used to evaluate the reproducibility of each of the methods and the correlation among them. The reproducibility of the three methods was very high (ICC of 0.808 to 0.992), particularly in the case of azoles and flucytosine. In general, the degree of reproducibility was highest for azoles and amphotericin B after 72 h of incubation and for flucytosine after 48 h of incubation. The degree of correlation among the three methods was very high (ICC of >0.98) with all of the antifungals under all the conditions tested. The end point reading criteria and the time of incubation affected neither the reproducibility of the methods nor their correlation, and their effect on MICs was statistically significant.

Antifungal Agents↗

Fungemia due to Fusarium sacchari in an immunosuppressed patient.

The fungus Fusarium sacchari was isolated repeatedly from the blood of an immunosuppressed host. The infection was treated successfully with a small dose of amphotericin B. The strain was resistant to this antifungal in vitro. MICs and minimum fungicidal concentrations of six antifungals for the clinical isolate are provided. To our knowledge, this is the first report involving this fungus in a case of fungemia.

Adult↗

Phaeoisaria clematidis as a cause of keratomycosis.

We report the first case of human infection by Phaeoisaria clematidis. This fungus caused a corneal ulcer in a Brazilian man who had previously suffered an eye injury. Diagnosis was established by positive direct examination and repeated cultures. The isolate was clearly resistant in vitro to the six antifungal agents tested.

Adrenal Cortex Hormones↗

Mixed infection caused by two species of Fusarium in a human immunodeficiency virus-positive patient.

We report on a case of mixed infection caused by two species of Fusarium in a human immunodeficiency virus-positive patient with lymphoma who was neutropenic due to chemotherapy. The patient showed the typical signs of a disseminated fusarial infection, with Fusarium solani isolated from skin lesions and F. verticillioides isolated from blood. The report discusses how difficult it is to make an accurate diagnosis when an immunosuppressed patient is infected with more than one fungal species, especially when the species are morphologically very similar.

AIDS-Related Opportunistic Infections↗

General assessment of the influence of a municipal landfill site and environmental factors on the occurrence of keratinolytic fungi in soil.

The study was to generally determine the influence of a municipal landfill site and environmental factors on the distribution of keratinolytic fungi in soil. The landfill site in Sosnowiec was selected for examination. Keratinolytic fungi occurred abundantly in soils of the landfill site examined and its surrounding area. Of 495 soil samples (Petri dishes) examined, 379 (76.56%) were found to be positive for keratinolytic fungi. Altogether, 1131 strains from 26 species were isolated from the samples. Among the fungi, some species with pathogenic properties (Microsporum racemosum, M. cookei, M. gypseum, Aphanoascus fulvescens and Scopulariopsis brevicaulis) were recorded. The influence of environmental factors on the qualitative and quantitative composition of keratinolytic fungi in the soils was complex. Among these factors, exchangeable acidity (pH in 1 M KCl, in particular), faecal bacterial contamination and the level of water deficit in soil were the most important. The conclusion has been drawn that municipal landfill sites are the sources of potentially pathogenic fungi with keratinolytic properties.

Environment↗