Genome Mining for Antimicrobial Compounds in Wild Marine Animals-Associated Enterococci

New ecosystems are being actively mined for new bioactive compounds. Because of the large amount of unexplored biodiversity, bacteria from marine environments are especially promising. Further, host-associated microbes are of special interest because of their low toxicity and compatibility with host health. Here, we identified and characterized biosynthetic gene clusters encoding antimicrobial compounds in host-associated enterococci recovered from fecal samples of wild marine animals remote from human-affected ecosystems. Putative biosynthetic gene clusters in the genomes of 22 Enterococcus strains of marine origin were predicted using antiSMASH5 and Bagel4 bioinformatic software. At least one gene cluster encoding a putative bioactive compound precursor was identified in each genome. Collectively, 73 putative antimicrobial compounds were identified, including 61 bacteriocins (83.56%), 10 terpenes (13.70%), and 2 (2.74%) related to putative nonribosomal peptides (NRPs). Two of the species studied, Enterococcus avium and Enterococcus mundtti, are rare causes of human disease and were found to lack any known pathogenic determinants but yet possessed bacteriocin biosynthetic genes, suggesting possible additional utility as probiotics. Wild marine animal-associated enterococci from human-remote ecosystems provide a potentially rich source for new antimicrobial compounds of therapeutic and industrial value and potential probiotic application.     

Inheritance of long juvenile period under short day conditions for the BR80-6778 soybean (Glycine max (L.) Merrill) line

The long juvenile period characteristic (LJP), which delays flowering under short day conditions, has been identified in soybean cultivars (Glycine max L. Merrill). This characteristic may be especially important as it increases the range of adaptation of soybean in low latitudes and gives greater flexibility for sowing periods within the same latitude. The inheritance of the long juvenile period was studied in the BR80-6778 soybean line to provide knowledge to support the development of cultivars adapted to short day conditions. Cultivars with classic flowering, Paraná, Bossier, Bragg and Davis, which flower early under short day conditions, were also used as parents in single crosses. They were crossed among themselves and with the genotypes with LJP, BR80-6778 and MG/BR 22 (Garimpo). The study was carried out under short day conditions (early sowings) in greenhouses and in the field at Embrapa National Soybean Research Center, Londrina, PR. Flowering was assessed daily. The results indicated that the BR89-6778 line shares a pair of alleles with the Paraná cultivar, and when associated with the cc allele retards flowering under short day conditions. The following genotype constitutions were attributed to the cultivars: Paraná (aaBBCC), Bossier (AabbCC), and BR80-6778 (aaBBcc). The combination of the genes aabb and aabbcc has a pronounced effect on the manifestation of the trait. This revised version was published online in July 2006 with corrections to the Cover Date.     

Chemistry and ecotoxicity of heat-treated pine wood extractives

Pine (Pinus pinaster) wood was heat-treated in an autoclave for 2?C12?h at 190?C210°C. Hemicelluloses were the first compounds affected by the treatment. In general, the sugar decrease was higher for arabinose and galactose followed by xylose and mannose. Lignin started to degrade for small mass losses but at a slower rate than hemicelluloses, and cellulose only degraded significantly for severe treatments. Almost all of the original extractives disappeared, and new compounds arose such as anhydrosugars and phenolic compounds. The compounds that might leach from heat-treated wood were mainly those identified in the water and ethanol extracts, all of which were not harmful at the existing concentrations, thereby reinforcing the wood heat treatment as an environmental benign process.     

Inheritance of resistance to Soybean mosaic virus in FT-10 soybean

The occurrence of a new isolate from the G5 strain of Soybean mosaic virus (SMV), which broke the resistance of soybean cultivar FT-10, was first reported in Brazil in 1995. Cultivar Davis is an ancestor of ‘FT-10’ and the likely source of resistance to the virus. Diallel crosses among resistant cultivars Epps (PI 96983), Ogden and FT-10, and susceptible cultivar Hill were made to investigate the inheritance of SMV resistance in FT-10. The experiments for genetic studies were performed undergreen house conditions. Plants of the F₂ population and F₃ families from each cross and the parents were inoculated with SMV G1 and G5 strains. Plants were classified as: symptom less (R), susceptible with typical symptoms of mosaic (S), and systemic necrosis (N). Plants showing necrosis or no symptoms were classified as resistant. Each F₃ family was classified as resistant (homozygous),susceptible (homozygous), or segregating (heterozygous). The results of both F₂ and F₃ were analyzed by Chi-square tests. The results suggested that FT-10 carries an allele at the Rsv ₁ locus for resistance to SMV. However, the allele is different from those in Epps and Ogden. The symbol Rsv ₁ ^d is a tentatively named for the newly detected allele in FT-10. This allele probably originated from Davis cultivar. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of a Fish Oil Rich in Docosahexaenoic Acid on Cardiometabolic Risk Factors and Oxidative Stress in Healthy Rats

Omega-3 polyunsaturated fatty acids are associated with a lower risk of cardiometabolic diseases. However, docosahexaenoic acid (DHA) is easily oxidized, leading to cellular damage. The present study examined the effects of an increased concentration of DHA in fish oil (80% of total fatty acids) on cardiometabolic risk factors and oxidative stress compared to coconut oil, soybean oil, and fish oil containing eicosapentaenoic acid (EPA) and DHA in a balanced ratio. Forty healthy male Sprague–Dawley rats were supplemented with corresponding oil for 10 weeks. Supplementation with the fish oil containing 80% DHA decreased plasma fat, plasma total cholesterol and muscle fat compared to the coconut oil and the soybean oil. Increasing concentrations of DHA induced incorporation of DHA and EPA in cell membranes and tissues along with a decrease in ω-6 arachidonic acid. The increase in DHA promoted lipid peroxidation, protein carbonylation and antioxidant response. Taken together, the increased concentration of DHA in fish oil reduced fat accumulation compared to the coconut oil and the soybean oil. This benefit was accompanied by high lipid peroxidation and subsequent protein carbonylation in plasma and in liver. In our healthy framework, the slightly higher carbonylation found after receiving fish oil containing 80% DHA might be a protecting mechanism, which fit with the general improvement of antioxidant defense observed in those rats.     

Multidrug and multispecies resistance in sheep flocks from São Paulo state, Brazil

The economic importance of sheep production is increasing worldwide simultaneously with the emergence of parasitic resistance. This study aimed to survey the current situation of management practices and parasite resistance in sheep flocks in S?o Paulo state, Brazil. A questionnaire was given to 35 sheep farmers to obtain information related to flock management practices. Of these flocks, 30 were submitted to the fecal egg count reduction test (FECRT) with at least one of the five following anthelmintics: albendazole, closantel, ivermectin, levamisole, and moxidectin, for comparison against an untreated control group. In the survey, the median number animals per flock was 301, mainly of the Santa Ines breed (in 75.8% of the flocks) and crossbred animals (in 54.5% of the flocks). The predominant farming system was semi-intensive (82.9%), using rotational grazing (80%). Selective treatment was based on FAMACHA grade (47.1%) and in clinical signs (41.2%). The most often applied anthelmintics were macrocyclic lactones (42.9-54.2% in the last three applications). Considering the anthelmintics employed in this study, 10.7% of the farms' flocks were resistant to three, 35.7% to four, and 53.6% to all five anthelmintics. The main helminth genera observed before and after treatments were Haemonchus sp. (75.8%) and Trichostrongylus sp. (19.1%), but all observed genera (Cooperia sp., Oesophagostomum sp., and Strongyloides sp.) were detected by the FECRT. Considering efficacy values less than or equal to 90% in the FECRT as resistant, 100% of flocks were resistant to albendazole and ivermectin, 96.6% to moxidectin, 92.9% to closantel, and 53.6% to levamisole. It is thus possible to conclude that multidrug resistance is widespread in sheep flocks in S?o Paulo state, Brazil, and this involves all prevalent helminth genera.