Seroprevalence of hepatitis E virus in dogs in Switzerland

Hepatitis E virus (HEV) is the causative agent of an acute and in most cases self‐limiting hepatitis. Of the four major HEV genotypes that infect humans, genotype 3 and 4 are zoonotic and have been identified in humans but predominantly in pigs and wild boar, which are considered the main reservoirs. However, the known host range of zoonotic HEV may be increasing to comprise additional species, including companion animals. Several studies have identified contact with dogs as a risk factor for HEV infection in humans, yet information on the occurrence of HEV in Swiss dogs is lacking. To examine a possible risk of exposure, this study was designed to assess the seroprevalence of HEV in 84 Swiss dogs. Serum and plasma samples collected from four veterinary clinics were screened for HEV‐specific antibodies by HEV‐antibody ELISA test kit. In addition, information of 22 dogs regarding the country of origin, the type of dog feed and any history of hunting was recorded. Samples from seropositive animals were also screened for the presence of HEV RNA by quantitative real‐time RT‐PCR (qRT‐PCR). Overall, 38% (32 of 84) of the dogs tested seropositive for anti‐HEV, indicating exposure to HEV. Among the 22 dogs for which information was available, HEV‐specific antibodies were detected in three of five dogs that were born abroad, in one of two dogs that were fed a raw meat‐based diet, and in one hunting dog. No viral RNA could be detected in any of the serum and plasma samples; thus, the genotype of the strains remained undetermined. This study provides further evidence for canine exposure and susceptibility to HEV and highlights the need to further assess the risks of HEV transmission to humans with contact to dogs.     

Composition and antifungal activity of the essential oil of Seseli annuum wild-growing in Serbia

The essential oil from the aerial parts of Seseli annuum, wild-growing in Serbia, was obtained by hydrodistillation and analyzed using GC and GC/MS. A total of 43 components were identified representing 96.5% of S. annuum oil. The most abundant compounds were germacrene D (29.8%), sabinene (10.3%), beta-ocimene Z (9.8%) and limonene (8.6%). The essential oil showed antifungal activity against fifteen fungi with MICs between 12.5 to 50 microl/ml.     

Selection of rhizobacteria able to produce metabolites active against Meloidogyne exigua

This work aimed to select potentially useful rhizobacteria for the control of Meloidogyne exigua, a widely disseminated root-knot nematode found in Brazilian coffee fields. Initially, crude metabolites produced in liquid medium by 69 isolated rhizobacteria strains (previously obtained from several plants collected in the south of Minas Gerais State, Brazil) were tested in vitro for lethality towards M. exigua second stage juveniles (J₂). Substances produced by strains of Bacillus cereus, B. megaterium, B. pumilus, B. thuringiensis, Enterobacter asburiae, E. cloacae and Paenibacillus macerans caused high mortality in J₂. Subsequently, the ten most active crude metabolites were selected and assessed for nematicidal activity in a biotest with M. exigua-inoculated coffee plants. Although strains of B. cereus, B. pumilus and P. macerans caused a significant reduction in the number of root galls and/or nematode eggs per plant 90 days after treatment, the best results were obtained with the application of B. megaterium strain 54-06.     

Growth periodicity in trees of Coffea arabica L. in relation to nitrogen supply and nitrate reductase activity

Vegetative growth of branches and leaf area gain in field-grown Arabica coffee trees in Viçosa, southeastern Brazil, exhibited active and quiescent phases. Nitrogen supplementation during the cool season did not prevent growth decline, nor did it alter the overall pattern of the tree growth; however, it enabled the plants to grow faster following the quiescent growth phase. Growth was related poorly to both nitrate content and nitrate reductase activity in leaves. In roots, N-fertilization in addition to accounting for greater content of nitrate, amino acids and ammonium was also associated with the maintenance of the nitrate reductase activity, but nitrate reduction was apparently nil in leaves during most of the cool season.     

Influence of Habitat and Land Use on the Assemblages of Ephemeroptera,Plecoptera, and Trichoptera in Neotropical Streams

Insects of the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT) are often used to assess the conditions of aquatic environments, but few studies have examined the differences in these communities between riffles and pools. Our objective was to test whether riffles shelter greater richness and abundance of EPT, as well as to assess the sensitivity of these insects for detecting impacts from different land uses in streams in southeastern Brazil. Samples were collected in the dry season of 2012 with a Surber sampler in riffles and pools of nine streams (forest, pasture, and urban areas). Principal component analysis distinguished the streams according to different land uses as a function of percentage of plant cover and water oxygenation level and showed partial distinction between riffles and pools as a function of current speed and percentage of ultrafine sand. Detrended correspondence analysis indicated the distinction in EPT composition between riffles and pools, except in urban streams. The results of this study confirm the expected differences in the EPT fauna structure between riffles and pools, especially in forest and pasture environments. The individual metrics of riffle and pool assemblages showed significantly different responses to land use. Therefore, we suggest individual sampling of riffles and pools, since the metrics of these assemblages’ insects can differ between these habitats and influence the results of assessments in low-order streams.     

Phaeobacter grown in biofilters: a new strategy for the control of Vibrionaceae in aquaculture

Growth, biofilm formation, antagonism and residence time in green seawater tanks maintained under fish rearing conditions of Phaeobacter 27‐4 were studied in commercial biofilters made from plastic, sintered glass and ceramic. Phaeobacter reached 10⁸–10⁹ CFU cm^?3 and formed rosettes in all materials, but a multilayer biofilm was only observed in the ceramic biofilters. In sterile seawater, plastic and ceramic biofilters reduced Vibrio anguillarum and V. splendidus concentration in one‐two Log after 24–48 h, showing 10²–10³ CFU mL^?1. Sintered glass biofilters only inactivated V. anguillarum. In Marine Broth, sintered glass and ceramic biofilters inhibited V. anguillarum growth in two‐three Log, showing 10⁴–10⁵ CFU mL^?1 after 24 h. Plastic biofilters reduced V. anguillarum concentration in one Log after 48 h. V. splendidus growth was only inhibited by sintered glass and ceramic biofilters in one‐two Log, showing 10⁷ CFU mL^?1 after 24 h. Phaeobacter also diminished biofilters colonization by the pathogens, both in seawater and in MB. Phaeobacter residence time in green seawater tanks maintained under fish rearing conditions was longer with sintered glass and ceramic biofilters. The latest showed the lowest detachment and, after 11 days, Phaeobacter (10⁶ bacteria·cm^?3) covered more than 80% of biofilters total culturable bacteria. DGGE profiles showed that Phaeobacter biofilters stabilizes the green seawater bacterial microbiota.     

The common carp <Emphasis Type="Italic">Cyprinus carpio</Emphasis> in Croatia (Danube and Adriatic basins): a historical review

This review provides the first historical account of the ecology and biology of common carp Cyprinus carpio in the Danube and Adriatic basins of Croatia, and emphasises the species’ economic relevance and management implications. As a semi-native species that is native to the Danube but translocated across the Adriatic Basin, carp plays an important role for aquaculture, recreational and artisanal fisheries. However, original strains have now disappeared, and because of genetic pollution in inland waters there is an increasing demand for restoring populations of the now rare and threatened wild carp, making conservation measures a priority. Translocations of carp across water bodies of the Adriatic Basin mostly for food supply did not prove successful in the long term, as the resulting ecological impacts may have been higher than the expected economic advantages. Measures for the prevention of further (uncontrolled) carp re-stocking are therefore necessary and this will require closer collaboration between scientists and environmental managers.