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Snake venoms are recognized as a promising source of pharmacologically active substances and are potentially useful for the development of new antimicrobial drugs. This study aimed to investigate the antimicrobial activity of the venom from the rattlesnake Crotalus durissus terrificus against several bacteria. Antibacterial activity was determined by using the plate microdilution method and the activity on the bacterial envelope structure was screened by using the crystal violet assay. The proteins in crude venom were separated by electrophoresis and characterized regarding their proteolytic activity. C. d. terrificus venom exhibited antimicrobial action against gram-positive and gram-negative bacteria. MIC values were defined for Pseudomonas aeruginosa ATCC 27853 (62.5 µg/mL), Staphylococcus aureus ATCC 25923 (125 µg/mL), and Micrococcus luteus ATCC 9341 (≤500 µg/mL). For Salmonella enterica serovar typhimurium ATCC 14028 and Corynebacterium glutamicum ATCC 13032, the decrease in bacterial growth was not detected visually, but was statistically significant. The crystal violet assay demonstrated that the crude venom increased bacterial cell permeability and the secreted protein profile agreed with previous reports. The results suggest that the proteins with lytic activity against bacteria in C. d. terrificus venom deserve further characterization as they may offer reinforcements to the weak therapeutic arsenal used to fight microbial multidrug resistance.

Gene expression of CDKN1A, CDKN1B, and TP53, and immunostaining of p21, p27 and p53 were evaluated to verify the role of these cell cycle inhibitors in canine prostates with proliferative inflammatory atrophy-PIA and prostatic carcinoma-PC. Seventy samples, 15 normal, 30PIA and 25PC. Regarding number of p27 and p53 labeled cells, difference between normal and PIA and PC was observed, as well as between PIA and PC for p53. Immunostaining intensities of p21, p27 and p53 were different when comparing normal tissues to PIA and PC. Sixteen cDNA of canine prostatic FFPE tissue were subjected to RT-PCR and RT-qPCR, four normal, three PIA, and nine PC. CDKN1A mRNA was detected in four PC by RT-PCR, and it was overexpressed when compared to normal by RT-qPCR, in one PIA and six PC. CDKN1B mRNA was detected in three PC by RT-PCR and it was overexpressed in three PC and decreased in one PC. TP53 mRNA was overexpressed in one PIA and three PC. In conclusion, when overexpressed in canine prostate with premalignant and malignant, p21 and p27 play a role controlling cell proliferation, working as a protective factor in the evolution of PIA to PC, and in the PC development, even in the presence of altered p53. RESUMOA expressão gênica de CDKN1A, CDKN1B e TP53, assim como imunomarcação de p21, p27 e p53 foram realizadas a fim de verificar o papel desses inibidores do ciclo celular na próstata canina com atrofia inflamatória proliferativa (PIA) e carcinoma prostático (PC). Foram obtidas70 amostras de próstata canina, sendo 15 de tecido normal, 30 de PIA e 25 de PC. Quanto ao número de células imunomarcadas foi observada diferença entre amostras normais, com PIA e PC para p27 e p53, assim como entre PIA e PC para p53. Para a intensidade de imunomarcação houve diferença entre os tecidos normais e com PIA e PC para p21, p27 e p53. Foram obtidas dezesseis amostras de cDNA a partir de amostras de próstatas caninas embebidas em parafina para a realização da RT-PCR e RT-qPCR, sendo quatro normais, três com PIA, e nove com o PC. O gene CDKN1A foi detectado em quatro das amostras com PC por RT-PCR, e pela RT-qPCR este estava superexpresso em uma PIA e em seis PC quando da comparação com o tecido prostático normal. O CDKN1B foi detectado em três PC por RT-PCR e pela RT-qPCR estava superexpresso em três PC e reduzido em um PC. O TP53 foi detectado em todas as próstatas caninas com PIA e PC por RT-PCR, sendo também superexpresso em uma glândula com PIA e em três com PC. Concluiu-se que p21 e p27 quando superexpressas na próstata canina com lesões pré-malignas (PIA) e malignas (PC) desempenham ação no controle da proliferação celular, possivelmente atuando como fator de proteção na evolução da PIA para PC, e no desenvolvimento do PC, mesmo na presença de p53 alterada. Assim, o próximo passo é avaliar essas proteínas do ciclo celular em casos de PC canino com metástase. p27, p53, PIA, Recebido em 28 de setembro de 2016 Aceito em 15 de março de 2017 

Gene expression of ErbB1 and ErbB2, and immunostaining of EGFR (Her1) and Her2 (c-erbB-2) were evaluated in this study to ascertain whether these receptors are involved in the evolution of canine premalignant and malignant prostatic lesions, as proliferative inflammatory atrophy (PIA) and prostatic carcinoma (PC). With regards to the intensity of EGFR immunostaining, there was no difference between normal prostatic tissue and tissues with PIA or PC. In relation to Her2 immunostaining, there were differences between normal prostatic tissue and those with PIA and PC, as also differences between prostates with PIA and PC. There was no correlation between EGFR and Her2 immunostaining. ErbB1 gene product was detected in two normal tissue samples, in one with PIA, and in all samples with PC. ErbB2 mRNA was recorded in two canine samples with PIA, in all with PC, but was not detected in normal prostatic tissue. It was concluded that EGFR and Her2 play roles in canine PIA and PC, suggesting that those receptors may be involved in canine prostatic carcinogenesis.

Xylanases (EC 3.2.1.8) are hydrolytic enzymes, which randomly cleave the β-1,4-linked xylose residues from xylan. The synthetic gene xynBS27 from Streptomyces sp. S27 was successfully cloned and expressed in Pichia pastoris. The full-length gene consists of 729 bp and encodes 243 amino acids including 51 residues of a putative signal peptide. This enzyme was purified in two steps and was shown to have a molecular weight of 20 kDa. The purified r-XynBS27 was active against beechwood xylan and oat spelt xylan as expected for GH 11 family. The optimum pH and temperature values for the enzyme were 6.0 and 75 °C, respectively. The Km and Vmax were 12.38 mg/mL and 13.68 μmol min/mg, respectively. The r-XynBS27 showed high xylose tolerance and was inhibited by some metal ions and by SDS. r-XynBS27 was employed as an additive in the bread making process. A decrease in firmness, stiffness and consistency, and improvements in specific volume and reducing sugar content were recorded.