Based on the previous study, in which nisin and bacterial cellulose were utilized, this new experiment loads nisin into bacterial cellulose (N-BC) and evaluates the morphological characteristics, cytotoxicity, antimicrobial activity and stability of the developed system. The load efficiency of nisin in BC was evaluated by an agar diffusion assay, utilizing , and total proteins. After having found the ideal time and concentration for the loading process, the system stability was evaluated for 100 days at 4, 25 and 37 °C against and .
View Article and Find Full Text PDFA synthetic version of the metal-regulated gene A (mrgA) promoter from Bacillus subtilis, which in this Gram-positive bacterium is negatively regulated by manganese, iron, cobalt, or copper turned out to promote high level of basal gene expression that is further enhanced by Co(II), Cd(II), Mn(II), Zn(II), Cu(II), or Ni(II), when cloned in the Gram-negative bacterium Cupriavidus metallidurans. Promoter activity was monitored by expression of the reporter gene coding for the enhanced green fluorescent protein (EGFP), and cellular intensity fluorescence was quantified by flow cytometry. Expression levels in C.
View Article and Find Full Text PDFMicrobes Infect
February 2008
The currently used pertussis vaccines are highly efficacious; however, neonates are susceptible to whooping cough up to the sixth month. In agreement, DTP-immunized neonate mice were not protected against intracerebral challenge with Bordetella pertussis. Neonate mice immunized with either DTP or a recombinant-BCG strain expressing the genetically detoxified S1 subunit of pertussis toxin do not show a humoral immune response against PT.
View Article and Find Full Text PDFSchistosomiasis affects 200 million individuals in underdeveloped and developing regions and is a growing concern for travelers worldwide. There has been evidence of resistance to the praziquantel-based therapy and reports of acute-disease manifestation; therefore, other drugs affecting different stages of the schistosome parasites life cycle and alternative therapeutic regimens should be developed and become accessible. The present review results from a comprehensive search in the scientific literature for substances and compounds tested in the past centennial for schistosomiasis therapy.
View Article and Find Full Text PDFBMC Public Health
April 2004
Background: Patients under haemodialysis are considered at high risk to acquire hepatitis B virus (HBV) infection. Since few data are reported from Brazil, our aim was to assess the frequency and risk factors for HBV infection in haemodialysis patients from 22 Dialysis Centres from Santa Catarina State, south of Brazil.
Methods: This study includes 813 patients, 149 haemodialysis workers and 772 healthy controls matched by sex and age.
Rev Inst Med Trop Sao Paulo
November 2003
There has been several studies worldwide on phylogenetics and genotype distribution of the GB-virus C / Hepatitis G virus (GBV-C/HGV). However, in their great majority, those investigations were based on some epidemiologically linked group, rather than on a representative sampling of the general population. The present is a continuation of the first study in Brazil with such a population; it addresses the GBV-C/HGV phylogenetics and genotype distribution based on samples identified among more than 1,000 individuals of the city of S o Paulo.
View Article and Find Full Text PDFThe prevalence of TT virus (TTV) infection was investigated by Polymerase Chain Reaction (PCR) in low- (blood donors and healthy children/adolescents) and high-risk (hemophiliacs) groups from São Paulo, Brazil. Primers based on the untranslated region (UTR) of the viral genome proved to be much more ubiquitous, leading to much higher frequencies for both groups (>or= 81%) than the earlier N22-PCR directed to the open reading frame 1 (blood donors, 5.5%, and hemophiliacs, 42.
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