Ayhan Yücel

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

Summary.u2003 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.

Case report. Isolation of Cladosporium cladosporioides from cerebrospinal fluid

Summary.u2003 Cladosporium cladosporioides was isolated from three subsequent cerebrospinal fluid specimens and from a brain biopsy specimen of a human patient. Susceptibility testing of the isolate was performed against seven antifungal agents.

Paecilomyces variotii central nervous system infection in a patient with cancer

Paecilomyces variotii was isolated from two subsequent cerebrospinal fluid (CSF) specimens of a cancer patient. Identification was confirmed through β‐tubulin and rDNA ITS sequencing. MICs were determined for seven antifungal agents; the isolate was found to be susceptible to amphotericin B (AMB), itraconazole (ITZ), ketaconazole (KTZ) and 5‐fluorocytosine (5FC) but resistant to fluconazole (FLZ) and miconazole (MCZ). Despite antimycotic therapy, the infection proved to be fatal.

Fatal Trichoderma harzianum infection in a leukemic pediatric patient.

We report the repeated isolation for Trichoderma.harzianum, a rare opportunistic pathogen from three sets of each of the following clinical samples; blood serum, skin lesions, sputum and throat of a pediatric ALL patient with neutropenia. The definition of invasive fungal infection requires evidence of the presence of fungal elements in tissue samples, in addition to the isolation of suspected etiologic agent in culture. However, invasive procedures are not always applicable due to several factors, as for example in our case, the poor general status of the individual patient or thrombocytopenia. The present paper also emphasizes the problems encountered in obtaining appropriate samples and diagnosing invasive fungal disease in immunocompromised patient populations, including those with hematological malignancy. Three cases involving T. harzianum, including this one, have been described thus far in the literature. All were fatal and the fungus was resistant to antifungal therapy. A critical review of the other two cases of Trichoderma infections in humans is provided.

Central nervous system infection due to Penicillium chrysogenum.

Penicillium chrysogenum was isolated from three subsequent cerebrospinal fluid (CSF) specimens of a 73‐year‐old male patient without immunological compromise. The isolated was tested against five antifungal agents according to the NCCLS M38‐P macrodilution method. MICs were determined as follows: amphotericin B (AMB), 2u2003μgu2003ml−1; fluconazole (FLZ), 8u2003μgu2003ml−1; itraconazole (ITZ), 1u2003μgu2003ml−1; flucytosine (5FC), 0.125u2003μgu2003ml−1; and terbinafine (TRB), 0.06u2003μgu2003ml−1. The patient has been cured with FLZ.

Subcutaneous cryptococcosis due to Cryptococcus diffluens in a patient with sporotrichoid lesions case report, features of the case isolate and in vitro antifungal susceptibilities

Environmental fungi, in particular primary pathogens and Cryptococcus spp. can be responsible for skin lesions mimicking sporotrichosis. In this paper, we report a case of subcutaneous cryptococcosis in an apparently healthy, young male patient due to a non-C. neoformans Cryptococcus species, C. diffluens. The isolate showed in vitro phenotypic switching that may affect virulence and host inflammatory and immune responses, and in vitro resistance to amphotericin B and 5-flucytosin. This species shares several phenotypic traits with C. neoformans, and, therefore, decisive diagnosis should be based on biopsy and culturing results followed by molecular identification.

Cryptococcal parotid involvement: an uncommon localization of Cryptococcus neoformans

We describe a cryptococcal infection localized in the parotid gland of an otherwise healthy 72-year-old woman. The patient presented with a painful, approximately 4.5 cm diameter mass in the anterior region of her right ear. Her symptoms were mild and uncharacteristic. The patient had previously fallen on her face in her garden, causing the loss and breakage of her dentures. Since the soil of the garden contained chicken droppings, it is quite likely that the oral prothesis became contaminated on contacting the soil. The fungus probably entered the parotid gland through the traumatization of the posterior lateral wall of her oral cavity by her broken denture. Numerous intra- and extracellular cryptococcal yeast cells were observed in both histopathological and mycological slide preparations. The yeastlike fungus was recovered in cultures inoculated with tissue collected through three biopsies of her parotid region. The isolates were identified as Cryptococcus neoformans by classical mycology methods and found to be susceptible, in vitro, to fluconazole, amphotericin B and flucytosine. Fluconazole treatment (400 mg/d, for 6 months) was started and the patients facial swelling resolved and the pain significantly reduced within 5 weeks of the initiation of treatment. While fungal infection of the parotid gland have been reported, to our knowledge, this is the first description of a non-disseminated primary parotid infection due to C. neoformans.

Susceptibility testing of Cryptococcus diffluens against amphotericin B, flucytosine, fluconazole, itraconazole, voriconazole and posaconazole

Cryptococcus diffluens is a recently re-established species that shares several phenotypic features with Cryptococcus neoformans. We evaluated the application of the Clinical Laboratory Standards Institute (CLSI, formerly NCCLS) macro- and microbroth dilution methods and the E-test agar diffusion method to determine the in vitro susceptibilities of known strains of C. diffluens against amphotericin B (AMB), flucytosine (5-FC), fluconazole (FLC), itraconazole (ITC) and the novel triazoles, voriconazole (VRC) and posaconazole (PSC). Seven strains were found to be resistant in vitro to AMB (MICs >/=2 microg/ml), five were resistant to 5-FC (MICs of >/=32 microg/ml), four were resistant to FLC (MICs of FLC >/=32 microg/ml) and nine were resistant to ITC (MICs of ITC >1 microg/ml). In contrast, VRC and PSC showed good in vitro activity against C.diffluens strains, even those with elevated MICs to amphotericin B and/or established azoles. Most of the isolates were inhibited by 0.5 microg/ml of both VRC and PSC. A clinical isolate showing phenotypic switching exhibited elevated MICs to both agents, i.e., VRC (>16 microg/ml) and PSC (>8 microg/ml).

A Rhizopus oryzae strain isolated from resected bone and soft tissue specimens from a sinonasal and palatal mucormycosis case. Report of a case and in vitro experiments of yeastlike cell development

We report a histologically and mycologically proven sinonasal mucormycosis case causing palatal necrosis in a nondiabetic patient with renal failure. Mycological examination of Giemsa stained imprinted tissue preparations revealed abundant yeast-like cells besides the typical mucoraceous hyphae. The fungus was isolated from surgical specimens and identified as Rhizopus oryzae by phenotypic and genotypic tests. Laboratory studies were performed to investigate the association of the yeast-like cells observed in tissue specimens and the fungus recovered in culture. In vitro induced yeast-like cell development of the case isolate was found under certain growth conditions and documented by photomicrographs.