RESUMO
AIM: To characterize four novel autochthonous bifidobacteria isolated from monkey faeces and a Bifidobacterium lactis strain isolated from chicken faeces by evaluating their technological and biological/functional potential to be used as probiotics. Different stressors, including food process parameters and storage, can affect their viability and functionality. METHODS AND RESULTS: The resistance to frozen storage, tolerance to lyophilization and viability during storage, thermal, acidic and simulated gastric resistance, surface hydrophobicity and antimicrobial activity against pathogens were studied. Bifidobacterium lactis Bb12 and INL1 were used as reference strains. The results obtained demonstrated that the new isolates presented strain-dependent behaviour. Good results were obtained for thermal resistance, frozen storage at -80°C and lyophilized powders maintained at 5°C. Cell viability during refrigerated storage was higher when the strains were resuspended in milk at pH 5·0 than at 4·5. The surface hydrophobicity ranged between 7 and 98% depending on the strain. The simulated gastric resistance was improved for the strains incorporated in cheese. Regarding antimicrobial activity, bifidobacteria isolated from monkey presented higher inhibitory capacity than the reference strains. CONCLUSION: This research provides a deeper insight into new strains of bifidobacteria isolated from primates and chicken that have not been previously characterized for their potential use in dairy products and confirm the most robust stress tolerance of B. lactis. SIGNIFICANCE AND IMPACT OF THE STUDY: The possibility of expanding the available bifidobacteria with the potential to be added to a probiotic food necessarily implies characterizing them from different points of view, especially when considering unknown species. For monkey isolates (which showed higher antimicrobial activity against pathogens), more in-depth knowledge is needed before applying strategies to improve their performance. On the contrary, the chicken isolate B. lactis P32/1 showed similar behaviour to the references B. lactis strains; therefore, it could be considered as a potential probiotic candidate.
Assuntos
Bifidobacterium , Probióticos , Animais , Bifidobacterium/isolamento & purificação , Bifidobacterium/fisiologia , Queijo/microbiologia , Galinhas , Fezes/microbiologia , Haplorrinos , Concentração de Íons de Hidrogênio , Viabilidade MicrobianaRESUMO
The objective of this work were to isolate and identify strains of entomopathogenic fungi from ingurgitated female Boophilus microplus ticks, collected from the soil in the municipality of Paracambi, Rio de Janeiro State, Brazil. The ingurgitated females were inoculated in the selective medium oat dodine agar (oda), where 49 colonies of Beauveria bassiana (71%) and 20 of Metarhizium anisopliae var. anisopliae (29%) were isolated. These isolated strains characterize for the first time in Brazil the natural occurrence of these species of fungi in this tick, and will be used to conduct bioassays to evaluate the pathogenicity and virulence of these strains for ticks of the genus Boophilus microplus.
Assuntos
Hypocreales/isolamento & purificação , Carrapatos/microbiologia , Animais , Brasil , Meios de Cultura , Controle Biológico de Vetores , Microbiologia do Solo , Infestações por Carrapato/microbiologia , Infestações por Carrapato/prevenção & controleRESUMO
Craniopharyngioma is the most common childhood tumor and thought to arise from embryonic remnants of Rathke's pouch. The paucity of published data on the molecular basis of these tumors prompted us to examine 22 adamantinomatous craniopharyngiomas looking for genetic abnormalities. Using the X-linked polymorphic androgen receptor gene as a tool for X-chromosome inactivating analysis, we found that a subset of craniopharyngiomas are monoclonal and therefore are probably due to acquired somatic genetic defects. Thus, we investigated these tumours for mutations within three candidate genes, Gsalpha, Gi2alpha and patched (PTCH). Using single stranded conformational polymorphism (SSCP), denaturing gradient gel electrophoresis and direct sequencing, the presence of somatic mutations in these genes could not be demonstrated in any tumor. Our data indicate that a subset of craniopharyngiomas are monoclonal and the mutations in the PTCH, Gsalpha, and Gi2alpha contribute little if any to craniopharyngioma development.
Assuntos
Adenoma/genética , Neoplasias Encefálicas/genética , Craniofaringioma/genética , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Proteínas Proto-Oncogênicas/genética , Adenoma/patologia , Anticorpos Monoclonais , Neoplasias Encefálicas/patologia , Craniofaringioma/patologia , Primers do DNA , Éxons/genética , Subunidade alfa Gi2 de Proteína de Ligação ao GTP , Humanos , Mutação/genética , Polimorfismo Conformacional de Fita Simples , Desnaturação Proteica , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Parathyroid adenomas are usually benign uniglandular tumors, and inactivation of several tumor suppressor genes, notably the MEN 1 gene, or activation of oncogenes have been implicated in the tumorigenesis. Genomic instability, indicative of the involvement of DNA mismatch repair genes, has not been previously described in parathyroid adenomas. A single large parathyroid adenoma was resected from an 8.5-yr-old Brazilian patient with no personal or family history of other endocrinopathies. Analysis of paired tumor-nontumor DNA using 23 microsatellite markers, located on chromosomes 1, 10, and 11 was carried out. Microsatellite instability was detected in nine markers (D1S191, D1S212, D1S413, D1S2848, RET, D11S901, D11S903, INSR, and INT2), whereas no allelic loss was detected with any of the analyzed markers. Immunohistochemical analysis of retinoblastoma protein expression revealed low levels of expression, but no histopathological signs of malignancy. We conclude that in this single, apparently sporadic parathyroid adenoma, DNA mismatch repair genes might be involved in parathyroid tumorigenesis.
Assuntos
Adenoma/genética , Repetições de Microssatélites/genética , Neoplasias das Paratireoides/genética , Adenoma/complicações , Criança , DNA de Neoplasias/análise , DNA de Neoplasias/genética , Feminino , Humanos , Hiperparatireoidismo/etiologia , Imuno-Histoquímica , Neoplasias das Paratireoides/induzido quimicamente , Reação em Cadeia da PolimeraseRESUMO
The mycobiota of the sandy soil of Ipanema Beach, Rio de Janeiro, Brazil, was investigated in 144 sand samples collected at four different sites along the sea coast, divided into three subsites, for a period of one year. A total of 4285 yeast colonies and of 6956 of colonies filamentous fungi were isolated using conventional media and techniques. Representatives of the filamentous fungi corresponding to a total of 1334 colonies were identified and assigned to 34 genera and 170 species. The genera of highest incidence and their respective numbers of species were as follows: Aspergillus, 30.4%, 32 spp.; Penicillium, 16.2%, 35 spp.; Fusarium, 12,6%, 33 spp.; Trichoderma, 6.4%, 7 spp.; Paecilomyces, 3.7%, 10 spp.; Cladosporium, 3.1%, 8 spp. and Acremonium, 1.0%, 8 spp. Several other genera and species were detected at quite low occurrences. Non-sporulating fungi (18.3%) and Coelomycetes (Sphaeropsidales) (1.9%) were also detected. Most of the genera detected belonged to the Deuteromycotina, with fewer proportions belonging to the Ascomycotina and Zygomycotina. Moniliaceae was represented by the largest number of species and Dematiaceae was represented by the largest number of genera. In terms of seasonal distribution, the largest number of filamentous fungi was isolated during the winter and the smallest number the Summer.