[Show abstract][Hide abstract] ABSTRACT: Opportunistic yeasts and yeast-like fungi have been recognized as important pathogens in high-risk patients. This study aimed to evaluate the presence of these microorganisms in the microbiota of captive rheas and to investigate the antifungal susceptibility of the isolated strains. Isolates representing Magnusiomyces capitatus (Geotrichum capitatum, n = 11), Trichosporon mucoides (n = 11), Trichosporon asteroides (n = 5), Rhodotorula mucilaginosa (n = 4), Trichosporon asahii (n = 3), Trichosporon cutaneum (n = 3), and Trichosporon ovoides (n = 3) were obtained from the oropharynx, cloaca, and feces of 58 animals. Most of the isolates were susceptible to antifungals in vitro; however, resistance against fluconazole (n = 1) and itraconazole (n = 2) was detected among T. mucoides. This study indicates that healthy rheas can be reservoirs of opportunistic pathogens. Primary resistance to azoles in T. mucoides obtained from these animals demonstrates the potential risk to humans.
Full-text · Article · Aug 2013 · Canadian Journal of Microbiology
[Show abstract][Hide abstract] ABSTRACT: The State of Ceará in north-eastern Brazil has one of the highest rates in the world of relapse and death due to disseminated histoplasmosis (DH) in acquired immunodeficiency syndrome (AIDS) patients. The objective of this study is to characterise the relapse and mortality of DH in AIDS cases residents in Ceará. We performed a retrospective analysis of the medical records of AIDS patients who had a first episode of DH from 2002 to 2008. We analysed the outcomes until December 31, 2010. A total of 145 patients participated in the study. The mean clinical follow-up duration was 3.38 years (SD = 2.2; 95% CI = 3.01-3.75). The majority of the subjects were male with a mean age of 35 years (SD = 2.2; 95% CI = 3.01-3.75) and were born in the capital of Ceará. DH was the first manifestation of AIDS in 59% of the patients. The relapse rate was 23.3%, with a disseminated presentation in 90% of these patients. The overall mortality during the study period was 30.2%. The majority of patients who relapsed or died had irregular treatment with antifungals or highly active antiretroviral therapy and did not have active clinical follow-up. High rates of recurrence and mortality were found in AIDS-associated DH in this area of the country.
[Show abstract][Hide abstract] ABSTRACT: There is growing interest in breeding rheas (Rhea americana) in Brazil. However, there are no data on the gastrointestinal microbiota of yeasts in this species. Therefore, the aim of this work was to isolate Candida spp. from the digestive tract of rheas and to evaluate in vitro the antifungal sensitivity and secretion of phospholipases of the fungi encountered. For this purpose, 58 rheas from breeding operations in the cities of Fortaleza and Mossoro, northeastern Brazil, were used. Samples were gathered from the oropharynx and cloaca of the animals, using sterile swabs. Stool samples were collected from their pens, by scraping with a scalpel. For the primary isolation, the material was seeded onto 2% Sabouraud dextrose agar plus chloramphenicol (0.5 g/L). The fungi were identified by macro and micromorphological characteristics as well as by culturing on CHROMagar-Candida medium and biochemical profiling. After identification, all the strains were submitted to antifungal sensitivity testing by the standard method defined by the Clinical Laboratory Standards Institute (document M27-A3), using broth microdilution, against amphotericin B, itraconazole and fluconazole. The capacity of the Candida spp. strains to secrete phospholipases was also tested, by culturing on egg yolk agar. Candida spp. were isolated from at least one anatomical site in 36/58 of the birds (14/17 juveniles and 22/41 adults) and in 6/10 fecal samples. In the large majority of cases, only a single species was isolated from each site (36/56 positive sites), with up to three species being observed only in four cases (4/56). A total of 77 isolates were obtained, belonging to the species C. parapsilosis (19/77), C. albicans (18/77), C. tropicalis (13/77), C. guilliermondii (12/77), C. krusei (10/77) and C. famata (5/77). There was greater presence of C. albicans in the oropharynx of the juvenile rheas than in the adults (p<0.001). No resistance was observed to amphotericin B, but 16 strains were simultaneously resistant to the two azole derivatives (11/18 C. albicans, 1/10 C. krusei, 2/19 C. parapsilosis and 2/13 C. tropicalis). There was particularly high resistance of C. albicans strains to fluconazole (15/18) and to itraconazole (13/18). Finally, 23/77 strains secreted phospholipases. In summary, the digestive tract of healthy rheas (Rhea americana) contains potentially pathogenic Candida spp. because of resistance to the azole derivatives and the secretion of phospholipases.
Full-text · Article · Mar 2013 · Journal of Medical Microbiology
[Show abstract][Hide abstract] ABSTRACT: This research aimed at investigating the cryoprotectant action of glucose and lactose on strains of Malassezia spp. and zygomycetes immobilised in sodium alginate. Twelve strains of Malassezia spp. (nine M. furfur, two M. globosa and one M. sympodialis) and 12 zygomycetes (five Rhizopus oryzae and seven Mucor hiemales) were immobilised in sodium alginate, within plastic beads, maintained in appropriate media containing glucose and lactose at concentrations of 9% and 23% and preserved at temperatures of -20 and -80 °C. Strain viability was evaluated from 15 to 270 days of storage, through the observation of macro-micromorphologic characteristics. The Malassezia spp. strains were only viable until 90 days of storage, whereas for zygomycetes, viable strains were observed until after 270 days of storage at -80 °C, in the media containing 23% glucose or lactose. The use of 23% glucose or lactose at -80 °C in a sodium alginate cell immobilisation system is efficient for cryopreserving zygomycetes. This research creates perspectives for the use of glucose and lactose in sodium alginate cell immobilisation systems for the preservation of fungi with low viability.
[Show abstract][Hide abstract] ABSTRACT: This study evaluated the in vitro interaction between ciprofloxacin (CIP) and classical antifungals against Histoplasma capsulatum var. capsulatum in mycelial (n = 16) and yeast-like forms (n = 9) and Coccidioides posadasii in mycelial form (n = 16). This research was conducted through broth microdilution and macrodilution, according to Clinical Laboratory Standards Institute. Inocula were prepared to obtain from 0.5 × 10(3) to 2.5 × 10(4) cfu ml(-1) for H. capsulatum and from 10(3) to 5 × 10(3) cfu ml(-1) for C. posadasii. Initially, minimum inhibitory concentration (MIC) for each drug alone was determined. Then, these MICs were used as the highest concentration for each drug during combination assays. The procedures were performed in duplicate. For all combination assays, MICs were defined as the lowest concentration capable of inhibiting 80% of visible fungal growth, when compared to the drug-free control. Drug interaction was evaluated by paired sample t-Student test. The obtained data showed a significant MIC reduction for most tested combinations of CIP with antifungals, except for that of CIP and voriconazole against yeast-like H. capsulatum. This study brings potential alternatives for the treatment of histoplasmosis and coccidioidomycosis, raising the possibility of using CIP as an adjuvant antifungal therapy, providing perspectives to delineate in vivo studies.
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to evaluate the antifungal activity of farnesol and its interaction with traditional antifungals against drug-resistant strains of Candida species. To do so, we studied the minimum in vitro inhibitory concentration (MIC) of amphotericin B (AMB), fluconazole (FLC), itraconazole (ITC), caspofungin (CAS) and farnesol against 45 isolates of Candida spp., i.e., 24 C. albicans, 16 C. parapsilosis and 5 C. tropicalis through the use of the broth microdilution method. Then, the isolates were tested with the combination of farnesol plus drugs to which they were previously found to be resistant. Additionally, the strains were pre-incubated at sub-inhibitory farnesol concentrations and their antifungal susceptibilities were re-evaluated. We found the MIC values for farnesol varied from 4.68-150 µM for Candida spp., with 19 isolates having a MIC > 1 mg/l, 18 a MIC ≥ 64 mg/l, 35 having a MIC ≥ 1 mg/l and 6 isolates a MIC ≥ 2 mg/l or were resistant to AMB, FLC, ITC and CAS, respectively. Significant MIC reductions were observed when farnesol and antifungal drugs were combined (P < 0.05) and when Candida strains were incubated with farnesol (P < 0.05). We conclude that the in vitro effects of farnesol improved the activity of traditional antifungals to which the Candida spp. isolates were resistant. These results support further investigation of the role of farnesol in the balance of the sterol biosynthetic pathway and how it interferes with cell viability.
Full-text · Article · Jun 2012 · Medical mycology: official publication of the International Society for Human and Animal Mycology
[Show abstract][Hide abstract] ABSTRACT: Candida meningitis is a rare condition that occurs more frequently in premature infants, immunocompromised patients or patients after neurosurgery. We describe a case of a previously healthy 41-year-old man with Candida parapsilosis meningitis associated with oropharyngeal candidiasis as the first manifestation of AIDS.
Preview · Article · May 2011 · Journal of Medical Microbiology