No abstract

Casein pancreatic digest is the basic bacterial growth medium used for diphtheria, botulinumand tetanus toxin vaccine production. It is known that the variation in the peptide content of thecasein digest directly affects final toxin yields. In this study, the identification and sequences ofeight peptides, four to eight amino acids in length, of casein pancreatic digestion, which seem tobe involved in the enhancement of tetanus toxin production, are described. They all contain one ortwo residues of proline/molecule and a predominance of hydrophobic amino acid residues. Themost active peptides show a general structure of Pro‐aromatic‐Pro, and this pattern resembled themotif displayed by bradykinin‐potentiating peptides found in snake venoms. By analogy with themechanism of bradykinin potentiation through inhibition of the proteolytic degradation ofbradykinin, it is suggested that the six peptides identified here could protect the tetanus toxin fromproteolysis, once secreted by the bacteria.

RESUMO:Os microrganismos patogênicos multirresistentes apresentam-se como grandes responsáveis por milhões de mortes em todo o mundo, principalmente Pseudomonas aeruginosa e Staphylococcus aureus, responsáveis por grande parte das infecções hospitalares. A preocupação com estas espécies faz com que novas pesquisas busquem alternativas para controlar estes microrganismos de uma forma mais eficiente e também mais econômica. Os extratos fitoterápicos são alternativas promissoras para este fim, visto que são uma imensa fonte de compostos de ação biológica. O objetivo do trabalho foi a elucidação da atividade antimicrobiana do extrato de Lafoensia pacari A. St.-Hil., Lythraceae, frente a linhagens de bactérias multirresistentes (P. aeruginosa, S. aureus) isoladas de pacientes com múltiplas infecções internados na Unidade de Emergência de Maceió. Os testes de atividade antibacteriana foram avaliados pelo método de difusão em meio sólido (Kirby-Bauer) modificado. De acordo com os ensaios in vitro, foi constatado que 96,4% das linhagens de bactérias utilizadas na pesquisa apresentaram-se sensíveis ao extrato da folha da planta, demonstrando atividade antibacteriana. Halos de inibição de crescimento de até 26 mm foram encontrados. Dessa forma, conclui-se que o extrato de Lafoensia pacari apresenta possibilidades de se encontrar substâncias úteis no combate a bactérias multirresistentes.Unitermos: Infecção hospitalar, bactérias multirresistentes, Lafoensia pacari, Lythraceae.ABSTRACT: "Antibacterial activity of the hydro-alcoholic extracts of Lafoensia pacari Saint Hil. against multiresistant bacterial strains from hospital source". Multiresistant pathogenic microorganisms are responsible for million of death all the world, mainly Pseudomonas aeruginosa and Staphylococcus aureus that are responsible for great part of hospital infections. The concern with this species does new researches to find out alternatives to control these microorganisms in the way more efficient and more economic. The phytoterapic extracts are promissory alternatives for that purpose because they are an immense source of biological action. The objective of this study was to evaluate the antimicrobial activity of Lafoensia pacari A. St.-Hil., Lythraceae, extract on multiresistant bacterial strains (P. aeruginosa, S. aureus) that have been isolated from patients with multiple infections occupying an Emergency Unit from Maceió in Brazil. The antibacterial activity experiments were evaluated by agar diffusion tests. Agreeable us experiments in vitro, ascertain that 96,4% of bacterial strains utilized in this research have showed susceptible to the plant's leaf extract, it means an excellent antibacterial activity. Halos of bacterial inhibition until 26 mm were observed. Thus, it can be concluded that the Lafoensia pacari extract has showed as an excellent product to combat multiresistant bacterial.

"Phytochemistry and microbiological assay of the bark extracts of Maytenus rigida Mart. (Celastraceae)". Maynetus rigida Mart (Celastraceae), known as "Bom-homem", "Bom-nome", "Cabelo-de-negro", "Casca-grossa" and "Pau-de-colher", is a small tree. The stem bark is used by the population in the northeast of Brazil to treat aches, infections and inflammations in general. The present work evaluated both the phytochemistry of M. rigida Mart by an analytical routine, and the antimicrobial activity of the bark extracts by the KirbyBauer modified method. Our results showed the aqueous, methanol, chloroform, ethyl acetate and hydroalcoolic extracts of M. rigida Mart has antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, while the hexane extract does not have any activity. Catechins, quinones, steroids, triterpenes, saponins, flavonoids and phenolic compounds were detected by the phytochemical analysis.

Cyanobacteria (Microcystis aeruginosa), which produce powerful hepatotoxic cyclopeptides, were collected and submitted to the determination of toxicity through intraperitoneal injections made in 30 and 90 days-old Swiss albino mice. The liver and the spleen were histopathologically analyzed and the weight and vital signs development were monitored. Test of toxicity resulted in a LD 50 of 154.28 mg.Kg -1 . M. aeruginosa represented 95% of the analyzed biomass. The ratios between liver weight and body weight in the animal inoculated with a single dose were 6.0% and 7.2%, with multi doses 7.0% and 7.5% and in the control animals 4.0% and 5.0%, for adult and young animals, respectively. There was an accentuated increase in the volume and weight of the spleen, and the animals inoculated with a single dose showed a ratio between spleen weight and body weight of 0.67% and 0.37%, with multidoses 1.22% and 1.05% and the control animals the ratio was 0.12% and 0.15%, for adult and young animals, respectively. The young animals inoculated with single and multi doses had an increase of 150% and 407% in the spleen size while the adults increased, 607% and 845%, respectively, in relation to the control. The histopathological analysis showed strong differences in the structure of the hepatic parenchyme in control animals and in those exposed to the M. aeruginosa extract. The main alterations were the congestive aspect, including the sinusoid, and intrahepatic haemorrhagia. The histopathological analysis showed considerable increase in the number of multinuclear giant cells in the spleen of the animals intoxicated by M. aeruginosa.