RESUMO Neobenedenia melleni (MacCallum, 1927) (Monogenea) é um patógeno amplamente distribuído em cultivo de teleósteos marinhos no mundo. Com o crescimento da piscicultura marinha no Brasil, faz-se necessário um maior cuidado em relação à identificação e ao tratamento das principais patologias nesse tipo de cultivo. Este estudo relata a primeira ocorrência de Neobenedenia melleni em dentão (Lutjanus jocu) no oeste do Atlântico Sul. Também são sugeridos procedimentos adotados para eliminação desse parasito em peixes cultivados em laboratório.

Abstract The species Waltheria viscosissima A.St.–Hil, Malvaceae, which is known as ‘malva-branca', is traditionally used in the Brazilian northeast for the treatment of coughs. This research looks towards reporting the isolation of phytoconstituents of W. viscosissima, as well as the quantification of its phenolics, total flavonoid content, and free radical scavenging potential, along with an evaluation of its larvicidal activity against Aedes aegypti larvae. Chromatographic techniques were used to isolate the compounds and a structural elucidation was performed by 1D and 2D NMR. The quantification of total phenolics and flavonoids and the DPPH˙ radical scavenging activity was determined through spectrophotometric methods. Consequently, the phytochemical investigation led to the identification of fourteen compounds from the aerial parts of the W. viscosissima: steroids, triterpenes, alkaloids, and eight flavonoids previously reported in the literature. The quantification of compounds showed that the aerial parts extract possessed high concentration of flavonoids, while the roots extract were rich in other phenolic compounds. At the DPPH˙ free radical scavenging assay, the roots extract presented EC50 = 77.32 ± 4.37 µg/ml and the aerial parts extracts showed EC50 = 118.10 ± 1.21 µg/ml. W. viscosissima roots extract showed the most potent larvicidal activity against Ae. aegypti (LC50 = 4.78 mg/ml), with the potential of being used in effective and economically viable preparations that can be catered for domestic use towards controlling the vector insect of severe diseases, such as dengue and Zika.

Durante o levantamento de fungos anamórficos associados à folhas em decomposição de diferentes plantas na região semi-árida do Estado da Bahia, 23 espécies, pertencentes a 19 gêneros foram encontradas. Dessas, uma espécie constitui novo registro para a Bahia e três para o Brasil, respectivamente: Drechslera victoriae (F. Meehan & H.C. Murphy) Subram. & B.L. Jain, Ochroconis crassihumicola (Matsush.) de Hoog & Arx, Pyricularia caffera Matsush. e Tretopileus sphaerophorus (Berk & M.A. Curtis) Hughes & Deighton. Descrições, comentários e ilustrações são apresentados para essas espécies.

During a survey of the anamorphic fungi associated with leaf litter of different plants from the semi-arid region of Bahia state, 23 species belonging to 19 genera were found. One species is recorded for the first time for Bahia and three for Brazil, respectively: Drechslera victoriae (F. Meehan & H.C. Murphy) Subram. & B.L. Jain, Ochroconis crassihumicola (Matsush.) de Hoog & Arx, Pyricularia caffera Matsush. and Tretopileus sphaerophorus (Berk & M.A. Curtis) Hughes & Deighton. Descriptions, comments and illustrations are provided for these species.

The opportunistic bacterium Proteus mirabilis secretes a metalloprotease, ZapA, considered to be one of its virulence factors due to its IgA-degrading activity. However, the substrate specificity of this enzyme has not yet been fully characterized. In the present study we used fluorescent peptides derived from bioactive peptides and the oxidized ß-chain of insulin to determine the enzyme specificity. The bradykinin- and dynorphin-derived peptides were cleaved at the single bonds Phe-Ser and Phe-Leu, with catalytic efficiencies of 291 and 13 mM/s, respectively. Besides confirming already published cleavage sites, a novel cleavage site was determined for the ß-chain of insulin (Val-Asn). Both the natural and the recombinant enzyme displayed the same broad specificity, demonstrated by the presence of hydrophobic, hydrophilic, charged and uncharged amino acid residues at the scissile bonds. Native IgA, however, was resistant to hydrolysis by ZapA.

The protease ZapA, secreted by Proteus mirabilis, has been considered to be a virulence factor of this opportunistic bacterium. The control of its expression requires the use of an appropriate methodology, which until now has not been developed. The present study focused on the replacement of azocasein with fluorogenic substrates, and on the definition of enzyme specificity. Eight fluorogenic substrates were tested, and the peptide Abz-Ala-Phe-Arg-Ser-Ala-Ala-Gln-EDDnp was found to be the most convenient for use as an operational substrate for ZapA. A single peptide bond (Arg-Ser) was cleaved with a Km of 4.6 µM, a k cat of 1.73 s-1, and a catalytic efficiency of 376 (mM s)-1. Another good substrate for ZapA was peptide 6 (Abz-Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg-Gln-EDDnp) which was cleaved at a single bond (Phe-Ser) with a Km of 13.6 µM, a k cat of 3.96 s-1 and a catalytic efficiency of 291 (mM s)-1. The properties of the amino acids flanking the scissile bonds were also evaluated, and no clear requirement for the amino acid residue at P1 was found, although the enzyme seems to have a preference for a hydrophobic residue at P2.