Antimicrobial Activity of Cultivable Endophytic Fungi Associated with Hancornia Speciosa Gomes Bark.

INTRODUCTION: In this study, we evaluated the antimicrobial potential of cultivable endophytic fungi associated with Hancornia speciosa Gomes stem bark. METHODS AND MATERIALS: Plant samples were collected in rainy (July 2010) and dry (January 2011) seasons. In total, 116 endophytic fungi strains were isolated from 90 fragments (64.4% frequency of colonization). Higher fungi frequency was observed in the rainy season (84.4%). The strains were grouped into 14 species; the most frequent were Phoma cava (13.8%), Colletotrichum gloeosporioides (12.1%), and Lasiodiplodia theobromae (11.2%). Fungal diversity was similar in both the seasons. Among the 116 strains, 39 (33.6%) showed antimicrobial activity in preliminary screening. The ten most active isolates were subjected to semi-solid fermentation using rice or corn as substrates. Methanolic extracts were obtained from each fermentation medium and the minimum inhibitory (MIC) and minimum microbicide concentrations (MMC) were determined. RESULTS: The best antimicrobial results (MIC < 100 µg/mL) were observed for fungi strains grown in rice medium: Aspergillus niger FHS061 against Proteus mirabilis (MIC = 19 µg/mL) and Staphylococcus aureus (MIC = 39 µg/mL). These strains also showed good results when cultivated in corn medium against P. mirabilis (MIC = 78 µg/mL). CONCLUSION: Thus, the stem bark of H. speciosa harbors diverse endophytic fungi with antimicrobial potential.

Antimicrobial Activity and Phytochemical Analysis of Organic Extracts from Cleome spinosa Jaqc.

Due to the use of Cleome spinosa Jacq. (Cleomaceae) in traditional medicine against inflammatory and infectious processes, this study evaluated the in vitro antimicrobial potential and phytochemical composition of extracts from its roots and leaves. From leaves (L) and roots (R) of C. spinosa different extracts were obtained (cyclohexane: ChL and ChR; chloroform: CL and CR; ethyl acetate: EAL and EAR, methanol: ML and MR). The antimicrobial activity was evaluated by the broth microdilution method to obtain the minimum inhibitory (MIC) and microbicidal (MMC) concentrations against 17 species, including bacteria and yeasts. Additionally, antimicrobial and combinatory effects with oxacillin were assessed against eight clinical isolates of Staphylococcus aureus. All C. spinosa extracts showed a broad spectrum of antimicrobial activity, as they have inhibited all tested bacteria and yeasts. This activity seems to be related to the phytochemicals (flavonoid, terpenoids and saponins) detected into the extracts of C. spinosa. ChL and CL extracts were the most actives, with MIC less than 1 mg/mL against S. aureus, Bacillus subtilis, and Micrococcus luteus. It is important to note that these concentrations are much lower than their 50% hemolysis concentration (HC50) values. Strong correlations were found between the average MIC against S. aureus and their phenolic (r = -0.89) and flavonoid content (r = -0.87), reinforcing the possible role of these metabolite classes on the antimicrobial activity of C. spinosa derived extracts. Moreover, CL and CR showed the best inhibitory activity against S. aureus clinical isolates, they also showed synergistic action with oxacillin against all these strains (at least at one combined proportion). These results encourage the identification of active substances which could be used as lead(s) molecules in the development of new antimicrobial drugs.

Antibacterial activity of endophytic fungi from leaves of Indigofera suffruticosa Miller (Fabaceae).

Endophytic fungi were isolated from healthy leaves of Indigofera suffruticosa Miller, a medicinal plant found in Brazil which is used in folk medicine to treat various diseases. Among 65 endophytic fungi isolated, 18 fungi showed activity against at least one tested microorganism in preliminary screening, and the best results were obtained with Nigrospora sphaerica (URM-6060) and Pestalotiopsis maculans (URM-6061). After fermentation in liquid media and in semisolid media, only N. sphaerica demonstrated antibacterial activity (in Potato Dextrose Broth-PDB and in semisolid rice culture medium). In the next step, a methanolic extract from rice culture medium (NsME) and an ethyl acetate extract (NsEAE) from the supernatant of PDB were prepared and both exhibited antimicrobial activity against Gram-negative and Gram-positive bacteria. The best result was observed against Staphylococcus aureus, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 1.56 mg/mL and 6.25 mg/mL, respectively, for NsME and MIC and MBC values of 0.39 mg/mL and 3.12 mg/mL, respectively, for NsEAE. This study is the first report about the antimicrobial activity of endophytic fungi residing in I. suffruticosa leaves, in which the fungus N. sphaerica demonstrated the ability to produce bioactive agents with pharmaceutical potential, and may provide a new lead in the pursuit of new biological sources of drug candidates.

Isolation of filamentous fungi from public telephones of the Metropolitan region of the city of Recife, PE, Brazil

Fungi can inhabit our organism without causing any harm, but they show themselves when the immunological system is compromised. In this study, a survey of the occurrence of filamentous fungi was carried out in public telephones of the Metropolitan Region of the City of Recife, PE, Brazil. This showed the public phones as a possible mean of transmission of fungal diseases among humans. Samples from the environment, audios, speakers and keyboards were taken at the airport, mall, subway and bus station in the months of October/2003 (dry season) and June/2004 (rainy season), totaling 120 samples. The procedure of identification of species was carried out through conventional taxonomy. Thirty-four genera were isolated, totaling 73 species, the majority belonging to the anamorphic fungi (91.78 percent), followed by the Ascomycota (6.85 percent) and the Zygomycota (1.37 percent). There was no significant difference in the proportion of species between the dry and rainy seasons, with 46 and 53 species identified, respectively. Due to the lack of maintenance, or inadequate cleaning of public telephones, the fungi present in these appliances may cause mycosis in the users as these telephones are used by people from different social classes and variable habits, both healthy and immunocompromised.

Os fungos podem circular pelo nosso organismo sem causar qualquer mal, mas manifestam-se quando o sistema imunológico está comprometido. Neste estudo foi realizada uma análise da ocorrência de fungos filamentosos em telefones públicos da Região Metropolitana da Cidade do Recife, PE, Brasil. Apresentando-os como possível meio de transmissão de doenças de natureza fúngica entre os indivíduos. Amostras dos ambientes, áudios, bocais e teclas foram obtidas no aeroporto, shopping, metrô e rodoviária nos meses de outubro/2003 (período seco) e junho/2004 (período chuvoso), totalizando 120 amostras. O procedimento de identificação das espécies ocorreu através da taxonomia convencional. Trinta e quatro gêneros foram isolados, totalizando 73 espécies, a maioria pertencente aos fungos anamórficos (91,78 por cento), seguido de Ascomycota (6,85 por cento) e Zygomycota (1,37 por cento). Não houve diferença significativa quanto a proporção de espécies entre os períodos seco e chuvoso, com 46 e 53 espécies identificadas, respectivamente. Por falta de manutenção ou limpeza inadequada dos telefones públicos, os fungos presentes podem vir a provocar micoses nos usuários, pois esses aparelhos são utilizados por pessoas de diferentes classes sociais e hábitos variados, tanto sadias quanto imunocomprometidas.

Comparación morfológica in vitro de cercospora caribaea ciferri & chupp y c. henningsii allescher en diferentes medios de cultivo / In vitro morphological comparison of cercospora caribaea ciferri & chupp and c. henningsii allescher in different culture media

Se comparó el desarrollo de cultivos de cercospora caribaea c.henningsii en 8 diferentes medios, incubados a 22ºC durante 20 días, para verificar su influencia sobre el crecimiento radial de ambas especies. Posteriormente se estableció una curva de crecimiento basada en el peso seco de la masa micelial de estos hongos, en el medio que expresó el mayor diámetro de las colonias. Las colonias de c. caribaea, lo alcanzaron (19 mm), en el medio de agar extracto de hoja de mandioca adicionado de extracto vitaminizado piam, mientras las colonias de c. henningsii, lo obtuvieron (12 mm), en el medio agar extracto de hoja de mandioca adicionado de extracto de malta compuesto. El peso seco de la masa micelial de ambas especies obtenida en medio líquido (extracto de hoja de mandioca adicionado con extracto de malta compuesto), demostró después de un periódo lag de 3 días, un crecimiento exponencial hasta el día 12 y una fase de desaceleración hasta el último día de observación (día 36). No se observó en el periódo de tiempo de estudio, la fase estacionaria