In vitro and in vivo susceptibility of the honeybee bacterial pathogen Paenibacillus larvae subsp. larvae to the antibiotic tylosin

The minimal inhibitory concentrations (MICs) of tylosin were determined to 67 strains of Paenibacillus larvae subsp. larvae, the causal agent of American Foulbrood (AFB) disease, from different geographical origins. MIC values obtained ranged from 0.0078 to 0.5 microg/ml. These very low values imply that no resistance to tylosin was found in any isolate of the Foulbrood pathogen. The measurement of diseased larvae with AFB-clinical symptoms in three different field studies demonstrated that tylosin treatment could be effective in vivo. No negative effects in colonies were noted at any dosage rates or forms of application. These studies demonstrate that tylosin, as tartrate, can be used to treat AFB in honeybee colonies.     

Effect of artificial chilling on the depth of endodormancy and vegetative and flower budbreak of peach and nectarine cultivars using excised shoots

Stem cuttings were obtained from 12 peach and nectarine cultivars during leaf fall, placed in plastic bags at 3.0 ± 0.1 °C to simulate 0–800 h of chilling and forced to budbreak at 20.0 ± 1.0 °C for a period of 6 weeks. Some cultivars showed high blooming and leafing without exposure to chilling; chilling enhances leafing and blooming but the percentage increment was higher in leaf buds. In general, maximum budbreak was reached with less chilling accumulation (<100–200 h) in flower buds compared with leaf buds; excessive chilling caused a reduction of the percentage budbreak in flower but not in leaf buds. Additionally, chilling modified the proportion of blooming that occurred before leafing. In non-chilled shoots, blooming occurred earlier than leafing, except in cv. ‘San Pedro 16–33’ but the proportion of blooming before leafing decreased significantly with chilling in most cases. By studying the mean time to budbreak, we conclude that the flower bud generally has a lower intensity of rest; the intensity of rest declines at a slower rate in flower than in leaf buds with chilling; flower buds had greater heat requirements than leaf buds when the chilling requirement had been covered, so that each peach cultivar had a point of critical chilling accumulation below which blooming tended to occur earlier, and above which leafing tends to occur first. Flower and leaf buds had different depths of endodormancy but similar chilling requirements in the majority of peach and nectarine cultivars studied. Finally, different varieties with similar chilling requirements showed different responses to chilling. Therefore, the cutting test measuring the response of vegetative and floral buds provides considerable information on the characterisation of the variety, compared with the sole and traditional data of chilling requirements.     

Development and application of an enzyme-linked immunosorbent assay to detect antibodies against prevalent Salmonella serovars in swine in southern Brazil.

The implementation of Salmonella control programs in the pork production chain demands rapid and cost-effective methods to assess the prevalence of infection in pig herds. The objective of the present study was to develop an in-house enzyme-linked immunosorbent assay (ELISA) based on S. Typhimurium lipopolysaccharides (LPS) to measure the prevalence of infection caused by Salmonella in swine herds. Coating antigen was produced by phenol extraction of S. Typhimurium culture. After standardization of ELISA test conditions, the assay was validated by testing serum samples on different animal categories: pigs orally inoculated with S. Typhimurium and sentinel animals in contact with them, naturally infected animals, colostrum-deprived piglets, and bacterin-immunized pigs. Seroconversion was observed in inoculated pigs (7 days postinfection [DPI]) and in the sentinels (21 DPI). Nonspecific reactions were not detected in the sera of colostrum-deprived animals. Serum samples from animals immunized with Salmonella Agona, Salmonella Derby, Salmonella Panama, and Salmonella Bredeney bacterins showed marked cross-reaction with the LPS from the serovar Typhimurium. Moreover, positive results obtained with the in-house ELISA were associated with Salmonella isolation in 75 infected pig herds. Comparisons with 2 commercial kits showed a linear correlation coefficient of 0.847 between the in-house ELISA and kit A and 0.922 with kit B but a low agreement in the qualitative results. In conclusion, the newly developed in-house ELISA based on S. Typhimurium LPS can be a useful tool to determine the intensity of Salmonella sp. infection in swine herds.     

New gastropod vectors and tetrodotoxin potential expansion in temperate waters of the Atlantic Ocean

Tetrodotoxin is a potent low weight marine toxin found in warm waters, especially of the Indian and Pacific Oceans. Intoxications are usually linked to the consumption of the puffer fish, although TTX was already detected in several different edible taxa. Benthic organisms such as mollusks and echinoderms, with different feeding habits, were collected monthly along the Portuguese coast from the summer of 2009 until the end of 2010. The extraction and analysis techniques were optimized and TTX and some analogues were detected for the first time in two intertidal gastropod species-Gibbula umbilicalis and Monodonta lineata by LC-MS/MS and UPLC-MS/MS. Although the levels are low, these findings suggest that monitoring of TTX and analogues in North Atlantic species should be implemented so as to detect potentially new toxin vectors and seasonal and/or geographical patterns.     

Cetacean occurrence,habitat preferences and potential for cetacean–fishery interactions in Iberian Atlantic waters: results from cooperative research involving local stakeholders

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Industrial Pollution of Environmental Compartments in the Sinos River Valley, RS, Brazil: Geochemical–Biogeochemical Characterization and Remote Sensing

Two environmental relief compartments from Sinos Valley, Rio Grande do Sul State, Brazil, interpreted in the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images, are contaminated, in different ways, by two industrial landfills. One of the landfills is located in a fluvial plain with thin superficial sediments made of expansive clays. In this landfill, metals like Cr, Co, Ni, Cu, Pb, Zn, and Ba, have concentrated more than that of other landfill, which is located on a low hill in a sedimentary arenitic terrain. The metals have also accumulated in plant tissues in the investigated areas. Plants have accumulated more Mn, Zn, Ba, and Cu.     

Reduction of skeletal anomalies in meagre (Argyrosomus regius,Asso, 1801) through early introduction of inert diet

The consolidation of meagre (Argyrosomus regius) in aquaculture requires an understanding and optimization of larval rearing and nutritional conditions. The aim of this study was to analyse the effects of an early introduction of inert diets during larval rearing, on growth performance, digestive enzymes activity and development of skeletal anomalies. This study evaluated the effects of three different timings for the introduction of inert diet during larval rearing: a control group (CTRL) where inert diet was initiated at 14 days after hatching (DAH) and two treatment groups that had an earlier introduction of inert diet at 8 DAH (T1) and 11 DAH (T2). Meagre larvae exhibited similar pancreatic and intestinal enzymatic activities among the different dietary treatments. No differences in the overall prevalence of anomalies were observed between treatments at 25 or 50 DAH, however, a significant reduction was observed in all groups with the transition from larval to juvenile stage. The precocious introduction of inert diet shifted the distribution of vertebral anomalies to a more anterior vertebral column region. Altogether, this study shows that earlier introduction of inert diets in meagre hatcheries can be beneficial for meagre production in aquaculture.