In Brazil, 4.5% of the AIDS-related opportunistic infections are caused by Cryptococcus neoformans. This pathogen is a ubiquitous environmental basidiomycetous encapsulated yeast, commonly found in soil and avian excreta. The present study investigates further the population structure of clinical and environmental C. neoformans isolates from south Brazil. One hundred five clinical and 19 environmental (pigeon excreta and Eucalyptus spp.) isolates from the Brazilian state Rio Grande do Sul were characterized based on morphological, biochemical, molecular and serological data. The majority of the clinical and environmental isolates analyzed belonged to C. neoformans var. grubii serotype A (89.5 and 52.6%, respectively), were mating type alpha (98.1 and 94.7%, respectively) and were phospholipase-positive (94.3 and 73.7%, respectively). PCR-fingerprinting with the microsatellite-specific primer M13 and the minisatellite-specific primer (GACA)(4) grouped the majority of the isolates into the molecular type VNI (89.5 of the clinical and 52.6% of the environmental isolates). Our results add considerable new information to the few available data on ecology, molecular biology and epidemiology of C. neoformans in the southern region of Brazil.

In the present study, the antifungal activity of selected essential oils obtained from plants used as spices was evaluated against both fluconazole-resistant and fluconazole-susceptible Candida spp. The Candida species studied were Candida albicans, Candida dubliniensis, Candida tropicalis, Candida glabrata, and Candida krusei. For comparison purposes, they were arranged in groups as C. albicans, C. dubliniensis, and Candida non-albicans. The essential oils were obtained from Cinnamomum zeylanicum Breyn, Lippia graveolens HBK, Ocimum basilicum L., Origanum vulgare L., Rosmarinus officinalis L., Salvia officinalis L., Thymus vulgaris L., and Zingiber officinale. The susceptibility tests were based on the M27-A2 methodology. The chemical composition of the essential oils was obtained by gas chromatography-mass spectroscopy and by retention indices. The results showed that cinnamon, Mexican oregano, oregano, thyme, and ginger essential oils have different levels of antifungal activity. Oregano and ginger essential oils were found to be the most and the least efficient, respectively. The main finding was that the susceptibilities of fluconazole-resistant C. albicans, C. dubliniensis, and Candida non-albicans to Mexican oregano, oregano, thyme, and ginger essential oils were higher than those of the fluconazole-susceptible yeasts (P<0.05). In contrast, fluconazole-resistant C. albicans and Candida non-albicans were less susceptible to cinnamon essential oil than their fluconazole-susceptible counterparts (P<0.05). A relationship between the yeasts' susceptibilities and the chemical composition of the essential oils studied was apparent when these 2 parameters were compared. Finally, basil, rosemary, and sage essential oils did not show antifungal activity against Candida isolates at the tested concentrations.

Mexican oregano (Lippia graveolens) is a plant found in Mexico and Central America that is traditionally used as a medicinal herb. In the present study, we investigated the antiviral activity of the essential oil of Mexican oregano and its major component, carvacrol, against different human and animal viruses. The MTT test (3-4,5-dimethythiazol-2yl)-2,5-diphenyl tetrazolium bromide) was conducted to determine the selectivity index (SI) of the essential oil, which was equal to 13.1, 7.4, 10.8, 9.7, and 7.2 for acyclovirresistant herpes simplex virus type 1 (ACVR-HHV-1), acyclovir-sensitive HHV-1, human respiratory syncytial virus (HRSV), bovine herpesvirus type 2 (BoHV-2), and bovine viral diarrhoea virus (BVDV), respectively. The human rotavirus (RV) and BoHV-1 and 5 were not inhibited by the essential oil. Carvacrol alone exhibited high antiviral activity against RV with a SI of 33, but it was less efficient than the oil for the other viruses. Thus, Mexican oregano oil and its main component, carvacrol, are able to inhibit different human and animal viruses in vitro. Specifically, the antiviral effects of Mexican oregano oil on ACVR-HHV-1 and HRSV and of carvacrol on RV justify more detailed studies.

bWe have determined the in vitro activity of several antibacterial and antifungal drugs against Pythium insidiosum using broth microdilution (BMD), disk diffusion, and Etest methods. The largest zones of inhibition (disk diffusion) and the lowest BMD and Etest MICs were observed for azithromycin, clarithromycin, linezolid, mupirocin, doxycycline, minocycline, and tigecycline. The in vitro activities observed suggest that antibacterials, which act by inhibiting protein synthesis, are promising candidate therapies for the treatment of pythiosis. P ythiosis is a life-threatening and chronic pyogranulomatous disease caused by the fungus-like pathogen Pythium insidiosum, the main oomycete species capable of infecting humans and other animals (1, 2). Although there have been a few reports of clinical cures of cases of pythiosis with antifungal therapy (3, 4), the data from the literature on the clinical management of pythiosis patients with treatment by antifungals indicate that such therapy has been largely ineffective (2,5,6). The genus Pythium is unable to synthesize ergosterol, the active target of most antifungals, which partly explains why this class of drugs has been ineffective (2).Studies on the in vitro susceptibility of the clinical isolates of P. insidiosum to antifungal drugs have shown divergent results, and there are no international protocols approved for evaluating the in vitro susceptibility of P. insidiosum. Interestingly, previous studies have shown that P. insidiosum is quite sensitive to antibacterials belonging to the classes of macrolides, tetracyclines, and glycylcyclines (7,8) and that its combination with antifungal drugs can result in synergistic interactions in vitro (9). However, the effects of antibacterial agents that inhibit protein synthesis on P. insidiosum have not been studied extensively. Thus, the objective of this study was to compare the in vitro susceptibilities of P. insidiosum to a number of antibacterial and antifungal drugs using the Clinical and Laboratory Standards Institute (CLSI) M38-A2 broth microdilution, CLSI M51-A disk diffusion, and Etest methods.We evaluated the susceptibility of 25 Brazilian P. insidiosum strains isolated from equine pythiosis lesions. All of the isolates were identified using a PCR-based assay according to Botton et al. (10). The reference strains included P. insidiosum CBS 101555 from an equine pythiosis case and P. insidiosum CBS 119452 and Pythium aphanidermatum CBS 128995 from human pythiosis cases.The broth microdilution (BMD) reference assay was carried out following the CLSI M38-A2 guidelines (11), as previously described (12, 13). The final concentrations of the antimicrobial agents tested in the wells ranged from 1,024 to 0.5 g/ml for mupirocin and tobramycin and from 256 to 0.125 g/ml for azithromycin, clarithromycin, clindamycin, chloramphenicol, doxycycline, erythromycin, florfenicol, fluconazole, fusidic acid, lincomycin, linezolid, minocycline, roxithromycin, terbinafine, tetracycline, tigecycline, and tilmicosin. The final conce...

We studied 40 strains of the species complex formerly classified as the single species Sporothrix schenckii to identify new species within this complex and evaluate their antifungal susceptibility profiles. Based on phenotypic tests (ability to grow at 37°C, colony diameters, and pigmentation of the colonies, as well as assimilation of sucrose and raffinose) and molecular assays (amplification of a fragment of the calmodulin gene), here we report the identification of S. albicans, S. brasiliensis, S. luriei, and S. schenckii; two isolates of these species were detected as itraconazole-resistant strains.Sporotrichosis is a subcutaneous mycosis affecting humans and animals caused by Sporothrix schenckii. It has a worldwide distribution, especially in tropical and subtropical areas of Latin America, where areas of endemicity have been recognized (1,3,4,12). Recently, Marimon et al. (9,11). proposed that Sporothrix schenckii is a complex encompassing six cryptic species that had been previously identified by others (4). In this context, variation in the antifungal susceptibility profiles among these new species was hypothesized. The aim of this study was to explore a collection of 40 isolates formerly classified as Sporothrix schenckii in order to identify new species and evaluate their susceptibility to antifungal agents.The isolates were from cases of human (n ϭ 31) and animal (n ϭ 9) sporotrichosis diagnosed in the hinterlands of Rio Grande do Sul (Brazil) and were maintained in the Department of Microbiology of the Universidade Federal de Santa Maria (UFSM), Santa Maria, Brazil. Among the human-derived strains, 18 (58.06%) were from fixed cutaneous sporotrichosis and 13 (41.9%) were from the lymphocutaneous form of the mycosis. Of the strains isolated from animals (n ϭ 9), eight were from cats and one (S. luriei) was isolated from a dog with sporotrichosis. As proposed by Marimon et al. (9,11), the phenotypic tests included the ability/inability to grow at 37°C on potato dextrose agar (PDA; HiMedia, Mumbay, India), different colony diameters (mm) after 21 days of incubation at 30°C on PDA, the pigmentation of the colonies on cornmeal agar (CMA), and the assimilation of sucrose and raffinose. The susceptibility tests were conducted according the procedures proposed for the M38-A2 technique (2). For molecular identification, a fragment of the calmodulin (CAL) gene was amplified from genomic DNA using the degenerate primers CL1[5Ј-GA(GA)T(AT)CAAAGGAGGCCTTCTC-3Ј] and CL2A (5Ј-TTTTTGCATCATGACTTGGAC-3Ј) (9). DNA sequencing was performed on the purified amplicons using a MegaBace 500 automatic sequencer. The sequences were aligned against sequences available in GenBank with ClustalX (version 1.8) followed by manual adjustments with a text editor. The phylogenetic analysis was performed with MEGA (Molecular Evolutionary Genetic Analysis) software version 4.0 (17).Based on recently proposed procedures (9, 11), we phenotypically identified four species: Sporothrix schenckii (n ϭ 37), Sporothrix brasiliensis (n ϭ 1), Sporo...

The results showed that caspofungin has limited fungistatic activity against P. insidiosum. This work is the first study to analyse the susceptibility of this oomycete to inhibitors of beta-glucans of the cellular wall.

Antimicrobial activity of essential oils from oregano, thyme and cinnamon against Salmonella enterica sorovars from avian source RESUMO Avaliou-se a atividade antimicrobiana dos óleos essenciais de orégano (Origanum vulgare), tomilho (Thymus

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