Salivary immunoglobulin levels in juvenile autoimmune hepatitis.

AIMS: The aim of the present study was to investigate the presence of immunoglobulins (Ig) in whole saliva from patients affected by autoimmune hepatitis (AIH). DESIGN: Twelve individuals with AIH and 12 healthy individuals without (CON) autoimmune hepatitis, aged 8-18 years, participated in this study. Non-stimulated whole saliva was collected and centrifuged. Supernatants were separated and lyophilized. Salivary pH was measured and immunoglobulins were analyzed through ELISA technique. RESULTS: Salivary pH (CON, 7.17 ±â€¯0.45; AIH, 6.92 ±â€¯0.43) did not differ between groups (p = 0.183). Measurable levels of IgG, IgA, IgM and IgE were detected on all patients. IgG levels were higher in AIH individuals (CON, 1.058 ±â€¯0.386; AIH, 1.635 ±â€¯0.373; p = 0.001), whereas IgA (CON, 0.915 ±â€¯0.187; AIH, 0.995 ±â€¯0.235; p = 0.362), IgM (CON, 0.683 ±â€¯0.147, AIH, 0.646 ±â€¯0.161; p = 0.561) and IgE levels (CON, 1.241 ±â€¯0.378; AIH, 1.312 ±â€¯0.412; p = 0.664) did not present differences between groups. CONCLUSIONS: The results of the present study suggest differences in salivary IgG levels between individuals with and without AIH. Thus, saliva has the potential of becoming an important diagnostic tool for the assessment of AIH.

Lingual Frenulum Phenotypes in Brazilian Infants With Congenital Zika Syndrome.

OBJECTIVE: The present study aimed to evaluate lingual frenulum in children affected by congenital Zika syndrome (CZS) and to analyze the association of lingual frenulum phenotypes with other variables. DESIGN: This present work had a cross-sectional, descriptive study design. SETTING: This study was carried out in Fortaleza (Brazil). The health professionals provided tertiary level of care. Data collection occurred during a multidisciplinary task force for evaluating infants affected by CZS in December 2 to 3, 2016. PATIENTS: Fifty-four patients with CZS (1-12 months old; 32 girls and 22 boys) were recruited from a population of 70 infants. INTERVENTIONS: A multidisciplinary group comprised of speech-language pathologist/audiologists and pediatric dentists evaluated all patients through an intraoral examination and a specific tongue maneuver protocol for infants. MAIN OUTCOME MEASURES: Lingual frenulum visibility was the primary outcome measure. Before initiating the study, we hypothesized that children with CZS had an absent lingual frenulum. RESULTS: Lingual frenula were visible in 34 (63%) infants, whereas in 20 (37%) infants lingual frenula visibility required a specific maneuver to retract the tongue. Six of 20 infants presented posteriorly positioned lingual frenula that were visible after maneuver. Lingual frenula were covered by mucous tissue in 14 infants. Presence of posterior frenulum was associated with dysphagia ( P = 0.038). However, the presence of dysphagia in a multivariate model did not associate with the presence of a posterior lingual frenulum ( P = .069) or neurologic symptoms ( P = .056). CONCLUSION: Children with CZS showed predominance of a posterior lingual frenula covered by an overlapping curtain-like mucous membrane.

Promethazine improves antibiotic efficacy and disrupts biofilms of Burkholderia pseudomallei.

Efflux pumps are important defense mechanisms against antimicrobial drugs and maintenance of Burkholderia pseudomallei biofilms. This study evaluated the effect of the efflux pump inhibitor promethazine on the structure and antimicrobial susceptibility of B. pseudomallei biofilms. Susceptibility of planktonic cells and biofilms to promethazine alone and combined with antimicrobials was assessed by the broth microdilution test and biofilm metabolic activity was determined with resazurin. The effect of promethazine on 48 h-grown biofilms was also evaluated through confocal and electronic microscopy. The minimum inhibitory concentration (MIC) of promethazine was 780 mg l-1, while the minimum biofilm elimination concentration (MBEC) was 780-3,120 mg l-1. Promethazine reduced the MIC values for erythromycin, trimethoprim/sulfamethoxazole, gentamicin and ciprofloxacin and reduced the MBEC values for all tested drugs (p<0.05). Microscopic analyses demonstrated that promethazine altered the biofilm structure of B. pseudomallei, even at subinhibitory concentrations, possibly facilitating antibiotic penetration. Promethazine improves antibiotics efficacy against B. pseudomallei biofilms, by disrupting biofilm structure.

Terpinen-4-ol, tyrosol, and ß-lapachone as potential antifungals against dimorphic fungi

Abstract This study aimed to evaluate the in vitro antifungal activity of terpinen-4-ol, tyrosol, and β-lapachone against strains of Coccidioides posadasii in filamentous phase (n = 22) and Histoplasma capsulatum in both filamentous (n = 40) and yeast phases (n = 13), using the broth dilution methods as described by the Clinical and Laboratory Standards Institute, to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of these compounds. The mechanisms of action of these compounds were also investigated by analyzing their effect on cell membrane permeability and ergosterol synthesis. The MIC and MFCf these compounds against C. posadasii, mycelial H. capsulatum, and yeast-like H. capsulatum, were in the following ranges: 350-5720 µg/mL, 20-2860 µg/mL, and 40-1420 µg/mL, respectively for terpinen-4-ol; 250-4000 µg/mL, 30-2000 µg/mL, and 10-1000 µg/mL, respectively, for tyrosol; and 0.48-7.8 µg/mL, 0.25-16 µg/mL, and 0.125-4 µg/mL, respectively for β-lapachone. These compounds showed a decrease in MIC when the samples were subjected to osmotic stress, suggesting that the compounds acted on the fungal membrane. All the compounds were able to reduce the ergosterol content of the fungal strains. Finally, tyrosol was able to cause a leakage of intracellular molecules.

Terpinen-4-ol, tyrosol, and ß-lapachone as potential antifungals against dimorphic fungi.

This study aimed to evaluate the in vitro antifungal activity of terpinen-4-ol, tyrosol, and ß-lapachone against strains of Coccidioides posadasii in filamentous phase (n=22) and Histoplasma capsulatum in both filamentous (n=40) and yeast phases (n=13), using the broth dilution methods as described by the Clinical and Laboratory Standards Institute, to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of these compounds. The mechanisms of action of these compounds were also investigated by analyzing their effect on cell membrane permeability and ergosterol synthesis. The MIC and MFCf these compounds against C. posadasii, mycelial H. capsulatum, and yeast-like H. capsulatum, were in the following ranges: 350-5720µg/mL, 20-2860µg/mL, and 40-1420µg/mL, respectively for terpinen-4-ol; 250-4000µg/mL, 30-2000µg/mL, and 10-1000µg/mL, respectively, for tyrosol; and 0.48-7.8µg/mL, 0.25-16µg/mL, and 0.125-4µg/mL, respectively for ß-lapachone. These compounds showed a decrease in MIC when the samples were subjected to osmotic stress, suggesting that the compounds acted on the fungal membrane. All the compounds were able to reduce the ergosterol content of the fungal strains. Finally, tyrosol was able to cause a leakage of intracellular molecules.

Antiretroviral drugs saquinavir and ritonavir reduce inhibitory concentration values of itraconazole against Histoplasma capsulatum strains in vitro

Abstract Recent studies have shown that some drugs that are not routinely used to treat fungal infections have antifungal activity, such as protease inhibitor antiretroviral drugs. This study investigated the in vitro susceptibility of Histoplasma capsulatum var. capsulatum to saquinavir and ritonavir, and its combination with the antifungal itraconazole. The susceptibility assay was performed according to Clinical and Laboratory Standards Institute guidelines. All strains were inhibited by the protease inhibitor antiretroviral drugs. Saquinavir showed minimum inhibitory concentrations ranging from 0.125 to 1 μg mL−1 for both phases, and ritonavir presented minimum inhibitory concentrations ranging from 0.0312 to 4 μg mL−1and from 0.0625 to 1 μg mL−1 for filamentous and yeast phase, respectively. Concerning the antifungal itraconazole, the minimum inhibitory concentration values ranged from 0.0019 to 0.125 μg mL−1 and from 0.0039 to 0.0312 μg mL−1 for the filamentous and yeast phase, respectively. The combination of saquinavir or ritonavir with itraconazole was synergistic against H. capsulatum, with a significant reduction in the minimum inhibitory concentrations of both drugs against the strains (p < 0.05). These data show an important in vitro synergy between protease inhibitors and itraconazole against the fungus H. capsulatum.

Enterobacteria and Vibrio from Macrobrachium amazonicum prawn farming in Fortaleza, Ceará, Brazil.

OBJECTIVE: To investigate the isolation of enterobacteria associated with Macrobrachium amazonicum (M. amazonicum) farming and evaluate the in vitro antimicrobial susceptibility of Vibrio strains. METHODS: Strains were isolated from female M. amazonicum prawns and environmental and hatchery water. Biochemical assays were used to identify bacterial genera and those belonging to the genus Vibrio were submitted to further analyses for species identification, through Vitek 2 automated system and serotyping. Susceptibility test was performed according to Clinical Laboratory Standards Institute. RESULTS: The following genera of enterobacteria were recovered: Enterobacter (n = 11), Citrobacter (n = 10), Proteus (n = 2), Serratia (n = 2), Kluyvera (n = 2), Providencia (n = 2), Cedecea (n = 1), Escherichia (n = 1), Edwardsiella (n = 1) and Buttiauxella (n = 1). As for Vibrio, three species were identified: Vibrio cholerae non-O1/non-O139 (n = 4), Vibrio vulnificus (V. vulnificus) (n = 1) and Vibrio mimicus (n = 1). Vibrio spp. showed minimum inhibitory concentrations values within the susceptibility range established by Clinical Laboratory Standards Institute for almost all antibiotics, except for V. vulnificus, which presented intermediate profile to ampicillin. CONCLUSIONS: Enterobacteria do not seem to be the most important pathogens associated with M. amazonicum farming, whereas the recovery of Vibrio spp. from larviculture, with emphasis on Vibrio cholerae and V. vulnificus, deserves special attention due to their role as potentially zoonotic aquaculture-associated pathogens. Furthermore, the intermediate susceptibility of V. vulnificus to ampicillin reflects the importance of monitoring drug use in prawn farming.

Antiretroviral drugs saquinavir and ritonavir reduce inhibitory concentration values of itraconazole against Histoplasma capsulatum strains in vitro.

Recent studies have shown that some drugs that are not routinely used to treat fungal infections have antifungal activity, such as protease inhibitor antiretroviral drugs. This study investigated the in vitro susceptibility of Histoplasma capsulatum var. capsulatum to saquinavir and ritonavir, and its combination with the antifungal itraconazole. The susceptibility assay was performed according to Clinical and Laboratory Standards Institute guidelines. All strains were inhibited by the protease inhibitor antiretroviral drugs. Saquinavir showed minimum inhibitory concentrations ranging from 0.125 to 1µgmL(-1) for both phases, and ritonavir presented minimum inhibitory concentrations ranging from 0.0312 to 4µgmL(-1)and from 0.0625 to 1µgmL(-1) for filamentous and yeast phase, respectively. Concerning the antifungal itraconazole, the minimum inhibitory concentration values ranged from 0.0019 to 0.125µgmL(-1) and from 0.0039 to 0.0312µgmL(-1) for the filamentous and yeast phase, respectively. The combination of saquinavir or ritonavir with itraconazole was synergistic against H. capsulatum, with a significant reduction in the minimum inhibitory concentrations of both drugs against the strains (p<0.05). These data show an important in vitro synergy between protease inhibitors and itraconazole against the fungus H. capsulatum.

Evidence of Fluconazole-Resistant Candida Species in Tortoises and Sea Turtles.

The aim of this study was to evaluate the antifungal susceptibility of Candida spp. recovered from tortoises (Chelonoidis spp.) and sea turtles (Chelonia mydas, Caretta caretta, Lepidochelys olivacea, Eretmochelys imbricata). For this purpose, material from the oral cavity and cloaca of 77 animals (60 tortoises and 17 sea turtles) was collected. The collected specimens were seeded on 2% Sabouraud dextrose agar with chloramphenicol, and the identification was carried out by morphological and biochemical methods. Sixty-six isolates were recovered from tortoises, out of which 27 were C. tropicalis, 27 C. famata, 7 C. albicans, 4 C. guilliermondii and 1 C. intermedia, whereas 12 strains were obtained from sea turtles, which were identified as Candida parapsilosis (n = 4), Candida guilliermondii (n = 4), Candida tropicalis (n = 2), Candida albicans (n = 1) and Candida intermedia (n = 1). The minimum inhibitory concentrations for amphotericin B, itraconazole and fluconazole ranged from 0.03125 to 0.5, 0.03125 to >16 and 0.125 to >64, respectively. Overall, 19 azole-resistant strains (14 C. tropicalis and 5 C. albicans) were found. Thus, this study shows that Testudines carry azole-resistant Candida spp.

Yeast microbiota of natural cavities of manatees (Trichechus inunguis and Trichechus manatus) in Brazil and its relevance for animal health and management in captivity.

The aim of this study was to characterize the yeast microbiota of natural cavities of manatees kept in captivity in Brazil. Sterile swabs from the oral cavity, nostrils, genital opening, and rectum of 50 Trichechus inunguis and 26 Trichechus manatus were collected. The samples were plated on Sabouraud agar with chloramphenicol and incubated at 25 °C for 5 days. The yeasts isolated were phenotypically identified by biochemical and micromorphological tests. Overall, 141 strains were isolated, of which 112 were from T. inunguis (Candida albicans, Candida parapsilosis sensu stricto, Candida orthopsilosis, Candida metapsilosis, Candida guilliermondii, Candida pelliculosa, Candida tropicalis, Candida glabrata, Candida famata, Candida krusei, Candida norvegensis, Candida ciferri, Trichosporon sp., Rhodotorula sp., Cryptococcus laurentii) and 29 were from T. manatus (C. albicans, C. tropicalis, C. famata, C. guilliermondii, C. krusei, Rhodotorula sp., Rhodotorula mucilaginosa, Rhodotorula minuta, Trichosporon sp.). This was the first systematic study to investigate the importance of yeasts as components of the microbiota of sirenians, demonstrating the presence of potentially pathogenic species, which highlights the importance of maintaining adequate artificial conditions for the health of captive manatees.

Virulence and antimicrobial susceptibility of clinical and environmental strains of Aeromonas spp. from northeastern Brazil.

The aims of the present study were to isolate and identify clinical and environmental strains of Aeromonas spp. by means of biochemical tests and the automated method VITEK 2 and to investigate the presence of the virulence genes cytotoxic enterotoxin (act), hemolysin (asa-1), and type III secretion system (ascV), and also the in vitro antimicrobial susceptibility of the strains. From the clinical isolates, 19 Aeromonas hydrophila, 3 Aeromonas veronii bv. sobria, and 1 Aeromonas caviae were identified, while from the environmental strains, 11 A. hydrophila, 22 A. veronii bv. sobria, 1 A. veronii bv. veronii, and 1 A. caviae were recovered. The gene act was detected in 69.5% of clinical isolates, asa-1 in 8.6%, and ascV in 34.7%. In the environmental strains, the detection rates were 51.4%, 45.7%, and 54.2% for the genes act, asa-1, and ascV, respectively. Resistance to amoxicillin-clavulanate and piperacillin-tazobactam was observed in 15 and 3 clinical strains, respectively, and resistance to ceftazidime, meropenem, imipenem, ciprofloxacin, and trimethoprim-sulfamethoxazole was observed in 1 strain for each drug. Resistance to amoxicillin-clavulanate and piperacillin-tazobactam was detected in 17 and 1 environmental strain, respectively. Higher resistance percentages were observed in clinical strains, but environmental strains also showed this phenomenon and presented a higher detection rate of virulence genes. Thus, it is important to monitor the antimicrobial susceptibility and pathogenic potential of the environmental isolates.

Easy storage strategies for Sporothrix spp. strains.

The present study evaluated the maintenance of Sporothrix spp. (6 Sporothrix brasiliensis; 6 S. schenckii; 5 S. mexicana, and 3 S. globosa) in saline at 4°C, and in 10% glycerol plus either 10% lactose or 10% sucrose, at -20°C and -80°C. Viability was assessed after 3, 6, and 9 months of storage, through the recovery of strains on potato dextrose agar and analysis of macro- and micromorphological features. Conidium quantification was performed before and after storage, at 3, 6 and 9 months. 100% viability was observed, regardless of storage conditions or time period. Storage at 4°C and at -20°C did not alter the number of conidia, but lower conidium counts were observed at -80°C. This study shows that the combination of glycerol with lactose or sucrose is effective to maintain Sporothrix spp. at freezing temperatures.

Histoplasma capsulatum in planktonic and biofilm forms: in vitro susceptibility to amphotericin B, itraconazole and farnesol.

It is believed that most microbial infections are caused by pathogens organized in biofilms. Recently, it was shown that the dimorphic fungus Histoplasma capsulatum, estimated to be the most common cause of fungal respiratory diseases, is also able to form biofilm. Although the antifungal therapy commonly used is effective, refractory cases and recurrences have been reported. In the search for new compounds with antimicrobial activity, the sesquiterpene farnesol has gained prominence for its antifungal action. This study aimed to evaluate the in vitro susceptibility of H. capsulatum var. capsulatum to the antifungal agents itraconazole and amphotericin B, and farnesol alone and combined, as well as to determine the in vitro antifungal activity of these compounds against biofilms of this pathogen. The results show that farnesol has antifungal activity against H. capsulatum in the yeast and filamentous phases, with MIC values ranging from 0.0078 to 0.00312 µM. A synergistic effect (fractional inhibitory concentration index ≤0.5) between itraconazole and farnesol was found against 100 and 83.3 % of the isolates in yeast and mycelial forms, respectively, while synergism between amphotericin B and farnesol was only observed against 37.5 and 44.4 % of the isolates in yeast and filamentous forms, respectively. Afterwards, the antifungal drugs, itraconazole and amphotericin B, and farnesol alone, and the combination of itraconazole and farnesol, were tested against mature biofilms of H. capsulatum, through XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide) metabolic assay, and the itraconazole and amphotericin B showed lower antibiofilm activity when compared to farnesol alone and farnesol combined with itraconazole. In conclusion, farnesol showed promising results as an antifungal agent against H. capsulatum and also showed adjuvant action, especially when combined with itraconazole, increasing the fungal susceptibility to this drug.

In vitro inhibitory activity of terpenic derivatives against clinical and environmental strains of the Sporothrix schenkii complex.

Sporotrichosis is a subacute or chronic subcutaneous infection, caused by the fungus Sporothrix schenkii complex, occurring in human and animal tissues. Potassium iodide and itraconazole have been used as effective therapy for first-choice treatment, while amphotericin B may be indicated for disseminated infection. However, the adverse effects of potassium iodide and amphotericin B or the long duration of therapy with itraconazole often weigh against their use, leading to the search for alternatives for the treatment of severe infections. Terpinen-4-ol and farnesol are components of essential oils present in many plant species and have been described to have antifungal activity against microorganisms. In this study, 40 strains of Sporothrix spp. were tested for the susceptibility to terpinen-4-ol and farnesol. Changes in cytoplasmic membrane permeability were also investigated. Terpenes inhibited all Sporothrix strains with MIC values ranging from 87.9 to 1,429.8 µg/ml for terpinen-4-ol and from 0.003 to 0.222 µg/ml for farnesol. The MFC values ranged from 177.8 to 5,722.6 µg/ml and from 0.027 to 0.88 µg/ml, respectively, for terpinen-4-ol and farnesol. Farnesol was the most active compound for the Sporothrix strains. Significant loss of 260 and 280 nm-absorbing material did not occur after treatment with concentrations equivalent to the MIC and sub-MIC of the tested terpenes, when compared to corresponding untreated samples. The failure of terpenes to lyse Sporothrix cells suggests that their primary mechanism of action is not by causing irreversible cell membrane damage. Thus, new studies are needed to better understand the mechanisms involved in the antifungal activity.

A clinical multicenter study of orofacial features in 26 brazilian patients with different types of mucopolysaccharidosis.

PURPOSE: This study aimed to describe the orofacial features of 26 unrelated Brazilian patients with mucopolysaccharidosis and to verify any possible associations between these findings and specific types of mucopolysaccharidosis. METHODS: Patients were diagnosed with mucopolysaccharidosis and clinically evaluated. Following consent, a clinical assessment form was completed. Facial and intraoral examination was performed by evaluating facial pattern, malocclusions, dental caries, and tooth identification. RESULTS: Midface deficiency, increased lower facial third, anterior open bite, convex profile, macroglossia, gingival enlargement, and spaced arches were the most frequently observed features. These findings did not allow a differential diagnosis among the different types of mucopolysaccharidosis, except for pitting enamel, which significantly associated with mucopolysaccharidosis IVA (P < .001). Open bite was associated with mucopolysaccharidosis types I, II, III, and VI; however, only one patient with mucopolysaccharidosis IVA expressed this feature (P = .043). CONCLUSIONS: Our results suggest that pitted enamel in patients with mucopolysaccharidosis is most likely a feature of mucopolysaccharidosis type IVA; whereas, open bite is rarely observed in these patients. Orofacial features in mucopolysaccharidosis may help pediatric dentists recognize this disorder and minimize the delay between the initial signs/symptoms and diagnosis of the disease. Future studies should focus on the longitudinal manifestations, expression, and severity of mucopolysaccharidosis-associated orofacial anomalies.

Macrobrachium amazonicum: an alternative for microbiological monitoring of aquatic environments in Brazil / Macrobrachium amazonicum uma alternativa para o monitoramento microbiológico de ambientes aquáticos no Brasil

This study aimed to evaluate the role of the Amazon River prawn, Macrobrachium amazonicum, as carrier of Candida spp., by analyzing the correlation between Candida spp. from these prawns and their environment (surface water and sediment), through M13-PCR fingerprinting and RAPD-PCR. For this purpose, 27 strains of Candida spp. were evaluated. These strains were recovered from the gastrointestinal tract of adult M. amazonicum (7/27) from Catú Lake, Ceará State, Brazil and from the aquatic environment (surface water and sediment) of this lake (20/27). Molecular comparison between the strains from prawns and the aquatic environment was conducted by M13-PCR fingerprinting and RAPD-PCR, utilizing the primers M13 and OPQ16, respectively. The molecular analysis revealed similarities between the band patterns of eight Candida isolates with the primer M13 and 11 isolates with the primer OPQ16, indicating that the same strains are present in the digestive tract of M. amazonicum and in the aquatic environment where these prawns inhabit. Therefore, these prawns can be used as sentinels for environmental monitoring through the recovery of Candida spp. from the aquatic environment in their gastrointestinal tract.

Este estudo teve como objetivo avaliar o papel do camarão Macrobrachium amazonicum como carreador de Candida spp. do ambiente aquático, por meio da análise da correlação entre Candida spp. isoladas desse camarão e do seu ambiente (água de superfície e sedimento) através das técnicas de M13-PCR fingerprinting e RAPD-PCR. Para tanto, 27 cepas de Candida spp. foram avaliadas. Essas cepas foram recuperadas a partir do trato gastrointestinal de M. amazonicum adultos (7/27), oriundos da lagoa do Catú, Ceará, Brasil, e do meio aquático (águas superficiais e sedimentos) desse lago (20/27). A comparação molecular entre as cepas de camarões e o ambiente aquático foi conduzida por M13-PCR fingerprinting e RAPD-PCR, utilizando os iniciadores M13 e OPQ16, respectivamente. A análise molecular revelou semelhanças entre os padrões de bandas de oito isolados de Candida com o iniciador M13 e 11 isolados com o primer OPQ16, indicando que elas estão presentes no trato digestivo de M. amazonicum e no ambiente aquático, onde esses camarões habitam. Portanto, essa espécie de camarão pode ser usada como sentinela para monitoramento ambiental através da recuperação de Candida spp. do ambiente aquático, a partir do seu trato gastrointestinal.

Antifungal susceptibility and virulence attributes of animal-derived isolates of Candida parapsilosis complex.

This study aimed to identify strains of the Candida parapsilosis complex isolated from animals, as well as to assess their in vitro antifungal susceptibility profile and in vitro production of virulence attributes. We used 28 isolates of C. parapsilosis sensu lato recovered from clinically healthy animals. The strains were characterized phenotypically, followed by molecular identification of the species through PCR-restriction enzyme analysis. The susceptibility of the strains to amphotericin B, itraconazole, voriconazole, fluconazole and caspofungin was assessed through broth microdilution. Additionally, the ability of the strains to produce biofilm, phospholipases and proteases was analysed. Molecular analysis showed 13 C. parapsilosis sensu stricto, 10 Candida orthopsilosis and five Candida metapsilosis strains. In vitro resistance to fluconazole was observed in three strains of C. parapsilosis sensu stricto and two C. metapsilosis. All tested strains were able to form biofilms and 23/28 isolates presented protease production, whilst none was able to produce phospholipases. Our study showed that C. parapsilosis sensu stricto and C. orthopsilosis are the most common species of the C. parapsilosis species complex and that these cryptic species present no significant phenotypical differences.

In vitro inhibitory effect of miltefosine against strains of Histoplasma capsulatum var. capsulatum and Sporothrix spp.

Miltefosine (MIL), originally developed for use in cancer chemotherapy, has been shown to have important antifungal activity against several pathogenic fungi. Our aim in this study was to determine the in vitro activity of MIL against the dimorphic fungi Histoplasma capsulatum and Sporothrix spp. This was done using the broth microdilution method. MIL had an in vitro inhibitory effect against all strains of H. capsulatum var. capsulatum and Sporothrix spp. analyzed. The minimal inhibitory concentrations (MIC) varied from 0.25 µg/ml to 2 µg/ml for H. capsulatum var. capsulatum in the filamentous phase and from 0.125 µg/ml to 1 µg/ml in the yeast phase. The MIC interval for Sporothrix spp. in the filamentous phase was 0.25-2 µg/ml. The minimal fungicidal concentrations (MFCs) were ≤4 µg/ml for isolates of both analyzed species. This study demonstrates that MIL has an antifungal effect in vitro against two potentially pathogenic fungi and that more studies should be performed in order to evaluate its applicability in vivo.

Species of Candida as a component of the nasal microbiota of healthy horses.

Respiratory infections are a common problem among equines and occur with variable rates of morbidity and mortality. Although some fungal species are considered primary agents of respiratory tract infections in several mammals, their relevance in respiratory diseases of equines is frequently neglected. In the present study, we performed an active search for Candida spp. in the nasal cavity of horses. The presence of Candida spp. was investigated through the use of nasal swabs that were streaked on culture media. These yeasts were identified through physiological testing and their in vitro antifungal susceptibility were also characterized. The analysis of the material from the nasal cavity of 97 randomly chosen horses resulted in the isolation of Candida spp. from 35 animals (36.08%), out of which 18 (32.14%) were C. famata, 14 (25%) C. parapsilosis, 12 (21.42%) Meyerozyma guilliermondii (C. guilliermondii), 11 (19.64%) C. tropicalis and 1 (1.78%) Wickerhamomyces anomalus (C. pelliculosa). The minimum inhibitory concentration (MIC) values ranged from 0.03125-1 µg/ml for amphotericin B; and from 0.03125-> 16 µg/ml and 0.125 to > 64 µg/ml for itraconazole and fluconazole, respectively. Resistance to fluconazole and itraconazole was observed among C. tropicalis (n = 3) and C. guilliermondii (n = 1). The data show a predominance of non-C. albicans Candida species in the nasal microbiota of healthy equines, including antifungal resistant isolates, reiterating the importance of monitoring fungal pathogens in these animals.

Effect of farnesol on growth, ergosterol biosynthesis, and cell permeability in Coccidioides posadasii.

Coccidioidomycosis is a systemic mycosis caused by the dimorphic fungi Coccidioides spp. The treatment for chronic and/or disseminated coccidioidomycosis can be prolonged and complicated. Therefore, the search for new drugs is necessary. Farnesol is a precursor in the sterol biosynthesis pathway that has been shown to present antifungal activity. Thus, the objective of this study was to evaluate the in vitro antifungal activity of farnesol alone and in combination with antifungal agents against clinical and environmental strains of Coccidioides posadasii as well as to determine their effect on the synthesis of ergosterol and on cell permeability. This study employed the broth macrodilution method to determine the MIC of farnesol against 18 strains of C. posadasii. Quantification of ergosterol was performed with 10 strains of C. posadasii after exposure to subinhibitory concentrations of farnesol. Finally, the activity of farnesol was evaluated in the presence of osmotic stress, induced by the addition of NaCl to the culture medium, during the susceptibility tests. The results showed that farnesol exhibited low MICs (ranging from 0.00171 to 0.01369 mg/liter) against all tested strains. The combination of farnesol with the antifungals showed synergistic effects (fractional inhibitory concentration index [FICI] ≤ 0.5). As for the ergosterol quantification, it was observed that exposure to subinhibitory concentrations of farnesol decreased the amount of ergosterol extracted from the fungal cells. Furthermore, farnesol also showed lower MIC values when the strains were subjected to osmotic stress, indicating the action of this compound on the fungal membrane. Thus, due to the high in vitro antifungal activity, this work brings perspectives for the performance of in vivo studies to further elucidate the effects of farnesol on the host cells.