Antifungal activity of extracts from Atacama Desert fungi againstParacoccidioides brasiliensis and identification ofAspergillus felis as a promising source of natural bioactive compounds

Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the extracts showed minimum inhibitory concentration (MIC) values≤ 125.0 µg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 µg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 µg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity.

Eugenol as an anesthetic for juvenile common snook

The objective of this work was to evaluate the efficacy of eugenol as an anesthetic for juvenile common snook, and to determine the minimum effective concentration for use in handling procedures. In the first trial, juvenile common snook were subjected to immersion baths at 25, 50, 75, 100, 125, and 150 mg L-1 eugenol concentrations, after which induction and recovery times were evaluated. In the second experiment, the lethal exposure time (LT50) at 75 mg L-1 was estimated. Minimum effective eugenol concentration was 50 mg L-1, andthe stage of deep anesthesia and recovery were, respectively, reached at 126.3 and 208.8 s. At 75 mg L-1, LT50 was 1,314 s, and induction time and recovery were also satisfactory; however, fish cannot tolerate over 229 s exposure.

Synthesis and antitubercular activity of isoniazid condensed with carbohydrate derivatives

A series of 13 compounds analogous of isoniazid condensed with carbohydrate was synthesized and evaluated for their in vitro antibacterial activity against Mycobacterium tuberculosis H37Rv using Alamar Blue susceptibility test and the activity expressed as the minimum inhibitory concentration (MIC90) in μg/mL. Several compounds exhibited antitubercular activity (0.31-3.12 μg/mL) when compared with first line drugs such as isoniazid (INH) and rifampicin (RIP) and could be a good starting point to develop new compounds against tuberculosis.

Isolamento e seleção de micro-organismos resistentes e capazes de volatilizar mercúrio

Mercury (Hg) occurs in the environment as a natural and anthropogenic element, and through the years the accumulation of mercury has affected the integrity of ecosystems and human health. This study presents a screening of microorganisms resistant to organic and inorganic mercury, the determination of the minimum inhibitory concentration of Hg, the estimation of the mercury volatilization by selected microorganisms and the dynamics of volatilization. Eight Gram-negative bacteria resistant to high concentrations of mercury (60 to 210 mg L-1) were selected, and these isolates showed ability to volatilize the metal. The dynamics of the volatilization of the Proteus mirabilis M50C demonstrated that in only 4 h of incubation it was possible to volatilize 72% of the mercury present in the culture. The results showed promising application for bioremediation strategies.

Screening of antibacterial extracts from plants native to the Brazilian Amazon Rain Forest and Atlantic Forest

More than 20% of the world's biodiversity is located in Brazilian forests and only a few plant extracts have been evaluated for potential antibacterial activity. In the present study, 705 organic and aqueous extracts of plants obtained from different Amazon Rain Forest and Atlantic Forest plants were screened for antibacterial activity at 100 µg/ml, using a microdilution broth assay against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli. One extract, VO581, was active against S. aureus (minimum inhibitory concentration (MIC) = 140 µg/ml and minimal bactericidal concentration (MBC) = 160 µg/ml, organic extract obtained from stems) and two extracts were active against E. faecalis, SM053 (MIC = 80 µg/ml and MBC = 90 µg/ml, organic extract obtained from aerial parts), and MY841 (MIC = 30 µg/ml and MBC = 50 µg/ml, organic extract obtained from stems). The most active fractions are being fractionated to identify their active substances. Higher concentrations of other extracts are currently being evaluated against the same microorganisms.

Clonal dissemination of VanA-type glycopeptide-resistant Enterococcus faecalis between hospitals of two cities located 100 km apart

Nosocomial dissemination of glycopeptide-resistant enterococci represents a major problem in hospitals worldwide. In Brazil, the dissemination among hospitals in the city of São Paulo of polyclonal DNA profiles was previously described for vancomycin-resistant Enterococcus faecium. We describe here the dissemination of VanA phenotype E. faecalis between two hospitals located in different cities in the State of São Paulo. The index outbreak occurred in a tertiary care university hospital (HCUSP) in the city of São Paulo and three years later a cluster caused by the same strain was recognized in two patients hospitalized in a private tertiary care hospital (CMC) located 100 km away in the interior of the state. From May to July 1999, 10 strains of vancomycin-resistant E. faecalis were isolated from 10 patients hospitalized in the HCUSP. The DNA genotyping using pulsed-field gel electrophoresis (PFGE) showed that all isolates were originated from the same clone, suggesting nosocomial dissemination. From May to July 2002, three strains of vancomycin-resistant E. faecalis were isolated from two patients hospitalized in CMC and both patients were colonized by the vancomycin-resistant Enterococcus in skin lesions. All isolates from CMC and HCUSP were highly resistant to vancomycin and teicoplanin. The three strains from CMC had minimum inhibitory concentration >256 µg/ml for vancomycin, and 64 (CMC 1 and CMC 2) and 96 µg/ml (CMC 3) for teicoplanin, characterizing a profile of VanA resistance to glycopeptides. All strains had the presence of the transposon Tn1546 detected by PCR and were closely related when typed by PFGE. The dissemination of the E. faecalis VanA phenotype among hospitals located in different cities is of great concern because E. faecalis commonly colonizes the gastrointestinal tract of patients and healthy persons for periods varying from weeks to years, which, together with the persistence of vancomycin-resistant Enterococcus in hospital rooms after standard cleaning procedures, increases the risk of the dissemination and reservoir of the bacteria.

Antibacterial activity of indole alkaloids from Aspidosperma ramiflorum

We evaluated the antibacterial activities of the crude methanol extract, fractions (I-V) obtained after acid-base extraction and pure compounds from the stem bark of Aspidosperma ramiflorum. The minimum inhibitory concentration (MIC) was determined by the microdilution technique in Mueller-Hinton broth. Inoculates were prepared in this medium from 24-h broth cultures of bacteria (10(7) CFU/mL). Microtiter plates were incubated at 37ºC and the MICs were recorded after 24 h of incubation. Two susceptibility endpoints were recorded for each isolate. The crude methanol extract presented moderate activity against the Gram-positive bacteria B. subtilis (MIC = 250 µg/mL) and S. aureus (MIC = 500 µg/mL), and was inactive against the Gram-negative bacteria E. coli and P. aeruginosa (MIC > 1000 µg/mL). Fractions I and II were inactive against standard strains at concentrations of <=1000 µg/mL and fraction III displayed moderate antibacterial activity against B. subtilis (MIC = 500 µg/mL) and S. aureus (MIC = 250 µg/mL). Fraction IV showed high activity against B. subtilis and S. aureus (MIC = 15.6 µg/mL) and moderate activity against E. coli and P. aeruginosa (MIC = 250 µg/mL). Fraction V presented high activity against B. subtilis (MIC = 15.6 µg/mL) and S. aureus (MIC = 31.3 µg/mL) and was inactive against Gram-negative bacteria (MIC > 1000 µg/mL). Fractions III, IV and V were then submitted to bioassay-guided fractionation by silica gel column chromatography, yielding individual purified ramiflorines A and B. Both ramiflorines showed significant activity against S. aureus (MIC = 25 µg/mL) and E. faecalis (MIC = 50 µg/mL), with EC50 of 8 and 2.5 µg/mL for ramiflorines A and B, respectively, against S. aureus. These results are promising, showing that these compounds are biologically active against Gram-positive bacteria.

High prevalence of methicillin resistance and PVL genes amongStaphylococcus aureus isolates from the nares and skin lesions of pediatric patients with atopic dermatitis

Staphylococcus aureus is highly prevalent among patients with atopic dermatitis (AD), and this pathogen may trigger and aggravate AD lesions. The aim of this study was to determine the prevalence of S. aureus in the nares of pediatric subjects and verify the phenotypic and molecular characteristics of the isolates in pediatric patients with AD. Isolates were tested for antimicrobial susceptibility, SCCmectyping, and Panton-Valentine Leukocidin (PVL) genes. Lineages were determined by pulsed-field gel electrophoresis and multilocus sequence typing (MLST). AD severity was assessed with the Scoring Atopic Dermatitis (SCORAD) index. Among 106 patients, 90 (85%) presented S. aureus isolates in their nares, and 8 also presented the pathogen in their skin infections. Two patients had two positive lesions, making a total of 10 S. aureusisolates from skin infections. Methicillin-resistant S. aureus(MRSA) was detected in 24 (26.6%) patients, and PVL genes were identified in 21 (23.3%), including 6 (75%) of the 8 patients with skin lesions but mainly in patients with severe and moderate SCORAD values (P=0.0095). All 24 MRSA isolates were susceptible to trimethoprim/sulfamethoxazole, while 8 isolates had a minimum inhibitory concentration (MIC) to mupirocin >1024 μg/mL. High lineage diversity was found among the isolates including USA1100/ST30, USA400/ST1, USA800/ST5, ST83, ST188, ST718, ST1635, and ST2791. There was a high prevalence of MRSA and PVL genes among the isolates recovered in this study. PVL genes were found mostly among patients with severe and moderate SCORAD values. These findings can help clinicians improve the therapies and strategies for the management of pediatric patients with AD.

Antibacterial and anti-inflammatory activities of an extract, fractions, and compounds isolated from Gochnatia pulchra aerial parts

This paper reports on the in vitro antibacterial and in vivo anti-inflammatory properties of a hydroethanolic extract of the aerial parts of Gochnatia pulchra (HEGP). It also describes the antibacterial activity of HEGP fractions and of the isolated compounds genkwanin, scutellarin, apigenin, and 3,5-O-dicaffeoylquinic acid, as evaluated by a broth microdilution method. While HEGP and its fractions did not provide promising results, the isolated compounds exhibited pronounced antibacterial activity. The most sensitive microorganism was Streptococcus pyogenes, with minimum inhibitory concentration (MIC) values of 100, 50 and 25 µg/mL for genkwanin and the flavonoids apigenin and scutellarin, respectively. Genkwanin produced an MIC value of 25 µg/mL against Enterococcus faecalis. A paw edema model in rats and a pleurisy inflammation model in mice aided investigation of the anti-inflammatory effects of HEGP. This study also evaluated the ability of HEGP to modulate carrageenan-induced interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), and monocyte chemoattractant protein-1 (MCP-1) production. Orally administered HEGP (250 and 500 mg/kg) inhibited carrageenan-induced paw edema. Regarding carrageenan-induced pleurisy, HEGP at 50, 100, and 250 mg/kg diminished leukocyte migration by 71.43%, 69.24%, and 73.34% (P<0.05), respectively. HEGP suppressed IL-1β and MCP-1 production by 55% and 50% at 50 mg/kg (P<0.05) and 60% and 25% at 100 mg/kg (P<0.05), respectively. HEGP abated TNF-α production by macrophages by 6.6%, 33.3%, and 53.3% at 100, 250, and 500 mg/kg (P<0.05), respectively. HEGP probably exerts anti-inflammatory effects by inhibiting production of the pro-inflammatory cytokines TNF-α, IL-1β, and MCP-1.

Chemical characterization and antimicrobial activity of essential oils of salvia L. species

In this work, the essential oils of S. officinalis, S. sclarea, S. lavandulifolia and S. triloba were chemically analyzed by gas chromatography coupled to a mass spectrometry detector (GC/MSD), and their antimicrobial activity was tested against 10 microorganisms using the disk diffusion method and the Minimum Inhibitory Concentration (MIC) technique. The following major compounds were identified in the essential oils: α - and β-thujone, camphor and 1,8-cineole, except in S. sclarea, where linalool, linalyl acetate and α-terpineol were the major constituents. The antimicrobial activity showed significant differences (p < 0.05) only when obtained by the MIC method. Gram-positive microorganisms presented larger sensitivity for the essential oils. The lowest MIC was observed when Staphylococcus aureus was exposed to 2.31 mg.mL-1 of S. lavandulifolia essential oil, while the highest MIC value was obtained when Shigella flexneri was exposed to 9.25 mg.mL-1 of the same essential oil, thus demonstrating that this essential oil may be effective as a bacteriostatic agent against Gram-positive microorganisms.

Inhibitory effect of the essential oil from Eugenia caryophyllata Thumb leaves on coalho cheese contaminating microorganisms

Coalho cheese (a firm but very lightweight cheese produced in Brazil) is widely produced and consumed in the Brazilian Northeast and its production has been mainly related to small farmers. This food has been frequently characterized as having high microbial load posing a risk for the health of consumers. This study aimed to indentify the chemical compounds of the essential oil from Eugenia caryophyllata leaves; to evaluate the inhibitory effect of the oil against coalho cheese contaminating microorganisms; and to assess its efficacy in inhibiting the autochthonous microflora of the cheese during refrigerated storage. Eugenol (74%) was found to be the most prevalent compound in the essential oil. Minimum Inhibitory Concentration (MIC) and Minimum Cidal Concentration (MCC) in laboratorial broth were in the range of 2.5-5 and 5-20 µg.mL-1, respectively. Vaccum packed coalho cheese added with 5, 10, and 20 µg.g-1 of oil showed a lower growth rate (like-static effect) against mesophilic bacteria during the time intervals evaluated. On the other hand, 2.5-10 µg.g-1 of oil provided a prominent decrease toward fungi count in cheese samples during storage. These results reveal the interesting antimicrobial property of the essential oil from E. caryophyllata leaves against a range of coalho cheese-related microorganisms in laboratorial media and in food matrix.

In vitro and in vivo antifungal activity of natural inhibitors against Penicillium expansum

Penicillium expansum is the causative agent of apple blue mold. The inhibitory effects of the capsaicin derived from Capsicum spp. fruits and yeast Hansenula wingei against P. expansum were evaluated in an in vitro and in in vivo assay using Fuji apples. The minimum inhibitory concentration of capsaicin determined using the broth micro-dilution method was 122.16 µg mL-1. Capsaicin did not reduce blue mold incidence in apples. However, it was able to delay fungal growth in the first 14 days of the in vivo assay. The in vivo effect of the yeast Hansenula wingei AM2(-2), alone and combined with thiabendazole at low dosage (40 µg mL-1), on the incidence of apple diseases caused by P. expansum was also described. H. wingei AM2(-2) combined with a low fungicide dosage (10% of the dosage recommended by the manufacturer) showed the best efficacy (100%) up to 7 days of storage at 21 ºC, later showing a non-statistically different decrease (p > 0.05) after 14 (80.45%) and 21 days (72.13%), respectively. These results contribute providing new options for using antifungal agents against Penicillium expansum.

Influence of different systems of minimum ventilation on air quality in broiler houses

To maintain a competitive development of the Brazilian aviculture, some measures must be taken to enable the identification and reduction of risks to the health of birds, as well as for the physical environment. Therefore, the aim of this study was to evaluate the effectiveness of three different systems of minimum ventilation (positive pressure - SVMP, negative pressure - SVMN and natural ventilation - SVMNat) in the air quality during the first 21 days of life of broiler chicks, during winter. Three points were selected along the length to verify ammonia, carbon monoxide and oxygen concentrations at 3a.m., 9a.m., 3p.m. and 9p.m., by the respiration level of birds and workers. The averages of pollutant gases did not exceed the tolerance levels for the three minimum ventilation systems evaluated, which is 20 and 10ppm for the birds level and 20 and 39ppm for the workers level, for ammonia and carbon monoxide, respectively. It was evident that the minimum ventilation systems were appropriately sized for the required minimum ambient air renovation, in respect to ventilation rates applied for the SVMN and SVMP systems, and with air velocity at levels that do not stress the chicks, including for the SVMNat. The three studied systems of minimum ventilation allowed the birds to externalize their productive performance, with values close to the ones considered satisfactory for all evaluated parameters, in accordance with the Brazilian aviculture standards.

Peritoneal and serum interleukin-18 levels are not increased in women with minimum or mild endometriosis

Interleukin-18 (IL-18) is a cytokine that belongs to the IL-1 family. Endometriosis is strongly associated with sub-fertility, and affects about 15% of women of reproductive age. IL-18 may favor the progression of endometriosis. The objective of the present study was to determine the concentration of IL-18 in the serum and peritoneal fluid of infertile women with endometriosis. Forty infertile and 25 fertile women were screened in a teaching hospital. Thirty-four infertile patients with minimal or mild endometriosis and 22 fertile controls were enrolled in the study. The primary outcome was the estimate of IL-18 levels and the secondary outcome was the correlation between serum and peritoneal levels of IL-18. There were no differences between the two groups regarding age, body mass index and levels of peritoneal fluid IL-18 (mean ± SD): 290.85 ± 173.02 pg/mL for infertile women vs 374.21 ± 330.15 pg/mL for controls; or serum IL-18: 391.07 ± 119.71 pg/mL for infertile women vs 373.42 ± 129.11 pg/mL for controls. However, a positive association was found between serum and peritoneal IL-18 levels in patients with endometriosis: r = 0.794, P = 0.0001. All measurements were carried out at the same time by the Human IL-18 Immuno Assay ELISA kit (MBL Co. Ltd., Japan). The present study did not find evidence supporting the hypothesis that IL-18 levels are associated with infertility in women with minimal and mild endometriosis, although a positive correlation was detected in these women between peritoneal and serum levels of IL-18.

In vitro culture and characterization of alveolar bone osteoblasts isolated from type 2 diabetics

In order to understand the mechanisms of poor osseointegration following dental implants in type 2 diabetics, it is important to study the biological properties of alveolar bone osteoblasts isolated from these patients. We collected alveolar bone chips under aseptic conditions and cultured them in vitro using the tissue explants adherent method. The biological properties of these cells were characterized using the following methods: alkaline phosphatase (ALP) chemical staining for cell viability, Alizarin red staining for osteogenic characteristics, MTT test for cell proliferation, enzyme dynamics for ALP contents, radio-immunoassay for bone gla protein (BGP) concentration, and ELISA for the concentration of type I collagen (COL-I) in the supernatant. Furthermore, we detected the adhesion ability of two types of cells from titanium slices using non-specific immunofluorescence staining and cell count. The two cell forms showed no significant difference in morphology under the same culture conditions. However, the alveolar bone osteoblasts received from type 2 diabetic patients had slower growth, lower cell activity and calcium nodule formation than the normal ones. The concentration of ALP, BGP and COL-I was lower in the supernatant of alveolar bone osteoblasts received from type 2 diabetic patients than in that received from normal subjects (P < 0.05). The alveolar bone osteoblasts obtained from type 2 diabetic patients can be successfully cultured in vitro with the same morphology and biological characteristics as those from normal patients, but with slower growth and lower concentration of specific secretion and lower combining ability with titanium than normal ones.