Giselle Cristina Silva

In vitro antibacterial effect of aqueous and ethanolic Moringa leaf extracts.

OBJECTIVE To evaluate the antibacterial effect of aqueous and ethanolic moringa leaf extracts (Moringa oleifera) on the growth of gram-positive and negative bacteria. METHODS Paper disks were soaked with 100, 200, 300 and 400 μL of extract at 20 g/180 mL and 10 g/190 mL. All extracts were tested against Escherichia coli (ATCC25922), Staphylococcus aureus (ATCC25923), Vibrio parahaemolyticus, Enterococcus faecalis (ATCC29212), Pseudomonas aeruginosa (ATCC27853), Salmonella enteritidis (IH) and Aeromonas caviae. The susceptibility tests were performed using the modified disk diffusion method. RESULTS The strains E. coli, P. aeruginosa and S. enteritidis (IH) were resistant to all treatments. In general, disks with 400 μL extract were the most efficient against S. aureus, V. parahaemolyticus, E. faecalis and A. caviae. CONCLUSIONS The study indicates a promising potential for aqueous and ethanolic Moringa leaf extracts as alternative treatment of infections caused by the tested strains.

Susceptibilidade "in vitro" a antimicrobianos de estirpes de Vibrio spp isoladas de camarões (Litopenaeus vannamei) e de água de criação destes animais provenientes de uma fazenda de camarões no Ceará Nota prévia

Foram feitos ensaios de susceptibilidade a antibioticos em 48 cepas de Vibrio isoladas do cultivo do Litopenaeus vannamei no Ceara. Para os testes de difusao foram utilizados 11 antibioticos. A especie que apresentou maior percentagem de resistencia aos antimicrobianos foi V. cholerae, onde 33,33% das 12 cepas testadas mostraram-se resistentes a sulfazotrim, 25% a ampicilina e 33,33% a ceftriaxona.

HGA-2, a novel galactoside-binding lectin from the sea cucumber Holothuria grisea binds to bacterial cells.

A novel lectin, HGA-2, was isolated from the sea cucumber Holothuria grisea. The protein was isolated by a single chromatographic step using a column of Guar Gum as affinity. HGA-2 showed an apparent molecular mass of 17 kDa and 34 kDa under reducing and nonreducing conditions, respectively. The hemagglutinating activity was specific for rabbit erythrocytes, showing no activity for human blood A, B and O. Its hemagglutinating activity was inhibited by carbohydrates containing galactose, with higher affinity for GalNAc and glycoprotein porcine stomach mucin (PSM). HGA-2 was stable at pH 6-10, significantly declining at pH 5 and a temperature of 40°C, with its activity being abolished at 100 °C. The HGA-2 protein was found to be Ca(2+)-dependent; it was highly toxic against Artemia nauplii and able to recognize and agglutinate cells of Escherichia coli. Amino acid sequences of tryptic peptides of HGA-2 strongly suggest that HGA-2 is a member of the C-type lectin family.

Quantification and distribution of vibrio species in water from an estuary in Ceará-Brazil impacted by shrimp farming

. The pH value was the environmental factor most strongly associated with the abundance of vibrios. Sixty-two vibrio strains were isolated belonging to 15 species (6 of which observed in June-September and 8 in October). The most frequently isolated species were V. parahaemolyticus and V. cholerae .

Antioxidant, hemolytic, antimicrobial, and cytotoxic activities of the tropical Atlantic marine zoanthid Palythoa caribaeorum

Marine invertebrates are capable of synthesizing bioactive compounds, which may be beneficial to human health. The aim of this study was to evaluate the antioxidant, hemolytic, antimicrobial and cytotoxic activities of crude extract (70% EtOH), and dichloromethane (DCM), ethyl acetate (EtOAc), and aqueous (Aq) fractions of the marine zoanthid Palythoa caribaeorum. The phenolic compound contents of the crude extract, DCM, EtOAc and Aq fractions were 12.33, 18.17, 10.53, and 3.18 mg GAE per gram, respectively. DPPH radical scavenging activity showed slight variation. IC50 of crude extract, DCM, EtOAc and Aq fractions were 11.13, 11.25, 11.74, and 11.28 µg mL(-1), respectively. Among the sample, ferrous ion chelating was the highest in crude extract (IC50 302.90 µg mL(-1)), followed by EtOAc, Aq, and DCM fractions with 457.77, 547.91, and 641.82 µg mL(-1), respectively. Ferric-reducing antioxidant power showed optical density at about 0.5. The samples tested exhibited low hemolytic activity under 10% up to a concentration of 50 μg mL(-1). No antimicrobial activity was observed against any of the tested bacterial strains. For the cytotoxic activity, LC50 of DCM, crude extract, EtOAc, and Aq were 52.10, 83.06, 86.34, and 117.45 μg mL(-1), showing high toxicity.

THERMOTOLERANT COLIFORM DIE-OFF IN WATER TREATED WITH MORINGA OLEIFERA SEEDS

The objective of this study was to test the ability of moringa seeds (Moringa oleifera) to eliminate thermotolerant coliforms (TTC) in water samples from a contaminated river in Northeastern Brazil (Rio Acarau, Sobral). The treatment was administered in two concentrations: 5 g (T1) and 10 g (T2) homogenized seeds/1000 mL water. Twenty water samples were shaken continuously for 60 min and aliquots were drawn at 10, 20, 30 and 60 min to determine the most probable number of TC. The greatest die-off (99.9%) was observed for T1 at 20 min. Our findings show that moringa seeds are an effective means of eliminating coliforms and may be employed in bacterial decontamination of water bodies.