Cryptobia iubilans infection in juvenile discus

Four commercial producers of discus (Symphysodon aequifasciatus) were found to have fish infested with the flagellate Cryptobia iubilans. Affected fish had granulomatous gastritis, and many also had granulomatous disease of other organs. The parasite had to be differentiated from the related flagellates Spironucleus spp, which induce different lesions. Transmission electron microscopy was found to be useful in detecting and identifying the parasite. Morbidity and mortality rates in the various fish populations appeared to be linked to a number of variables, including water quality, presence of other parasites and bacteria, diet, species, size, and age of the fish, and optimization of husbandry appeared to be important in alleviating the severity of disease. Metronidazole was not effective for treatment of C iubilans, but bath treatments with dimetridazole (80 mg/L for 24 hours, repeated daily for 3 days) or 2-amino-5-nitrothiazol (10 mg/L for 24 hours, repeated daily for 3 days) may be useful in decreasing the prevalence of infestation.     

Geminivirus DNA replication and cell cycle interactions

The Geminiviridae family includes a large number of viruses that infect plants and have a unique geminate virion particle, a single-stranded genome of approximately 2.6-3.0 kb, and replicate through a rolling-circle mechanism. Since they encode for just a few proteins (4-6 depending on the members that belong to four different genera), a rich variety of interactions has evolved between viral proteins and host factors to develop the virus replicative cycle. Among them, we have been particularly interested so far: (i). in the interference with cell cycle regulatory proteins of the retinoblastoma-related (RBR)/E2F pathway and (ii). in the interaction with host DNA replication factors necessary for the assembly of a functional replication complex at the viral origin of DNA replication during the rolling-circle stage. Yeast two-hybrid assays revealed that wheat dwarf virus RepA protein, but nor Rep protein, interacts with plant RBR protein. Interestingly, deletion of the C-terminal domain of Rep confers the truncated protein the ability to interact with RBR, suggesting that this domain may hinder the LXCXE RBR-binding motif. Secondary structure predictions support such a possibility.     

Efficacy of a combination of 10% imidacloprid/50% permethrin for the prevention of leishmaniasis in kennelled dogs in an endemic area

The efficacy of imidacloprid 10%and permethrin 50% (Advantix; Bayer AG, Germany) in a spot-on formulation was evaluated in the field as a control measure to prevent canine leishmaniasis (CanL) in dogs in an endemic area of southern Italy. In February 2005, out of 845 dogs initially tested for CanL, 631 dogs which tested negative (315 from a kennel in Bari (KB) and 316 from a kennel in Ginosa (KG)) in a serological and a parasitological examination were allocated to one of three groups: Group A-treated with imidacloprid 10% and permethrin 50% once a month; Group B-treated every 2 weeks; and Group C-untreated control animals. All the dogs were examined serologically and parasitologically for CanL prior to the start of the study, in November 2005 (end of the sandfly season) and in March 2006 (end of the study). An initial CanL seroprevalence of 24.7% (209 dogs) was detected in KB and KG. In KB Leishmania infection, inferred by positivity in at least one of the three tests performed at the interim or final follow-up, was found in one animal from Group A and in nine from Group C. No positive animals were detected in Group B, thus giving a final protection efficacy of 88.9% in Group A and 100% in Group B. In KG Leishmania infection was identified in one animal from Groups A and B, respectively, and 11 from Group C (protection efficacy of 90.36% in Group A and 90.73% in Group B). The incidence density rates (IDRs) of infection in both Groups A and B at each kennel were statistically significantly lower than that registered in Group C (KB p<0.05 and KG p<0.01). The results clearly show that a combination of imidacloprid 10% and permethrin 50%, by virtue of its repellent activity against sandflies, is effective under both application regimes in preventing CanL in the field in endemic areas.     

Retrospective comparison of first‐line adjuvant anthracycline vs metronomic‐based chemotherapy protocols in the treatment of stage I and II canine splenic haemangiosarcoma

Splenectomy followed by adjuvant chemotherapy is commonly used to treat canine splenic haemangiosarcoma (HSA), although it is unclear if different treatment protocols may have a similar efficacy. The objective of this retrospective study was to assess outcome in dogs with stage I and II splenic HSA treated with either first‐line adjuvant anthracycline (AC) or metronomic (MC)‐based chemotherapy protocols, by comparing median time to progression (TTP) and median survival time (MST). Medical records of nine institutions were searched for dogs diagnosed with stage I and II splenic HSA that underwent adjuvant treatment with AC‐ or MC‐based protocols following splenectomy. Patients treated with MC following AC were included in an additional group (AMC). Ninety‐three dogs were included: 50 in the AC group, 23 in the AMC group and 20 in the MC group. The overall MST was 200 days (range 47‐3352) and the overall median TTP was 185 days (range 37‐1236). The median TTP of stage I dogs was significantly longer compared to stage II dogs (338 vs 151 days, respectively, P = .028). When adjusting for treatment type, the MST was 154 days for the AC group (range 47‐3352 days), 338 days for the AMC group (range 79‐1623 days) and 225 days for the MC group (range 57‐911 days). The difference in MST and median TTP was not found to be statistically significant between treatment groups. This study suggests that adjuvant MC in canine splenic HSA may result in a similar outcome when compared to other treatment protocols. Further studies are warranted to confirm these findings.     

Fish and seafood traceability based on AFLP markers: Elaboration of a species database

Several sociological, health and conservation arguments request a correct labelling of seafood products. Nowadays, molecular genetics is a useful tool for food chain traceability, particularly in regards to species identification. Among the variety of PCR-based molecular markers, AFLPs (Amplified Fragment Length Polymorphisms) have recently been used to investigate genomes of different complexities. This paper assesses the potential use of the AFLP technology to determine fish and seafood species in processed commercial products and domestic stocks. In particular a species database of fish, molluscs and crustaceans has been created with the aim to identify species of origin of seafood products by previously defined AFLP patterns. Different EcoRI and TaqI primer combinations were selected from 20 screened combinations in relation to the total number of detected fragments and polymorphic ones. Most informative combinations were E32/T32, E32/T33, E33/T33, E33/T37, E33/T38, E40/T33, E40/T37, E42/T32, E42/T37. The comparison of informative markers between unknown frozen or fresh products and reference samples has enabled the accurate identification of 32 different species. The taxonomic characterization has been performed either at the species or at the population level depending on the number of available individuals. AFLP variation at the population level is particularly helpful for the stock traceability of domestic strains. Size homoplasy was also investigated in one species to assess the rate of non-homologous comigrating fragments and to detect additional polymorphic markers to be used in stock identification. Results of Band Sharing Index (BSI) and percentage of polymorphic fragments are presented and are discussed in relation to the wide applicability of AFLPs both for fish and seafood safety and authenticity testing in such fields as food traceability and restocking management. The database, available upon request at nonnis@biol.unipr.it, will be continuously updated.     

Environmental influences on the recruitment dynamics of juvenile European eels,Anguilla anguilla,in a small estuary of the Tyrrhenian Sea,Sardinia, Italy

1. The European eel, Anguilla anguilla, is a catadromous and migratory species of commercial importance. Its complex life cycle results in its exposure to many risk factors, which have resulted in stock declines across all life stages since the 1970s.
2. The temporal recruitment dynamics of juvenile eels (glass eels and elvers) were investigated in a small Mediterranean estuary (Sardinia, Italy). The composition of the population and the monthly and seasonal variations in the abundances of juvenile eels was assessed over 78 sampling events (from February 2017 to February 2018). Furthermore, the effects of abiotic variables on the abundances of glass eels and elvers were investigated using generalized additive models (GAMs).
3. Glass eels had the greatest abundance during the winter months, whereas elvers had the greatest abundance during spring. Modelling revealed that the abundance of glass eels was mostly explained by the combined effects of water temperature (12.3–14.5 °C), tidal coefficient (40–110 cm), moon phase, season, and river mouth condition, whereas the abundance of elvers was associated with water temperature (14–21 °C), dissolved oxygen content (>7 mg/L), and season. These results suggest that the annual recruitment of juvenile eels occurs throughout the year, with clear seasonal migration dynamics.
4. The use of multiple statistical approaches allowed us to identify the importance of several environmental variables in regulating the recruitment dynamics, providing useful information for conserving eel stocks through the restoration of the natural flow regime and the connectivity between freshwater habitats and the sea.

     

GIS-models work well, but are not enough: Habitat preferences of Lanius collurio at multiple levels and conservation implications

Species conservation largely depends on knowledge of habitat needs of target species. GIS-models are increasingly used to assess habitat preferences and distribution of target species, but their accuracy is constrained by availability of digital data layers. We developed a two-steps approach aiming at showing pros and cons of landscape (GIS)- and site-level habitat models, identifying key habitat factors for conservation of a threatened bird species, the red-backed shrike Lanius collurio. A spatially explicit GIS-model was generated using landscape variables, and a second model at site level was developed using fine-scale variables measured on the ground. The GIS-based model was then extrapolated to the entire region to obtain a map of distribution of suitable habitats. Positive associations between shrike occurrence and both hedgerow length and partial shrub cover were detected at both scales. Shrikes were also positively associated with grassland cover at landscape level and with partial cover of untilled herbaceous vegetation at the finer scale, and negatively affected by lucerne cover. The GIS-model led to an affordable map of predicted habitat suitability which should help conservationists to focus on different local priorities, but was unable to identify effects of untilled and lucerne cover. Site-level model gave fine details for habitat management, but its application elsewhere requires ground-measurements of factors. Combining the multiscale models could indicate more urgent actions at large scales (e.g. maintaining suitable habitats, or improving connectivity among isolated patches) and draw a detailed figure of the most suitable habitat for the species. Shrike occurrence was associated with a higher number of shrub and tree species: the indicator value of the species should ensure general benefits for biodiversity from dedicated management.     

Molecular characteristics of humic acids extracted from compost at increasing maturity stages

The molecular composition of humic acids (HA) extracted from compost at increasing maturity stages was determined by off-line TMAH-thermochemolysis-GC-MS, in combination with solid-state nuclear magnetic resonance (NMR) and infrared (IR) spectroscopies. While spectroscopy measurements followed the bulk changes, thermochemolysis provided a detailed molecular variation of HA composition. Both thermochemolysis and spectroscopy indicated that polysaccharides, alkyl, cyclic, and aromatic compounds were the predominant components of HA, the stable fraction of compost. NMR dipolar dephasing (DD) experiments confirmed that HA extracts contained lignin in lower amount than its oxidized degradation products. The progressive compost maturity was reflected in HA extracts by a decrease of carbohydrate content and a selective preservation of hydrophobic alkyl molecules, such as medium- and long-chain fatty acids, aliphatic alcohols, linear hydrocarbons, and plant polyester derivatives, like long-chain alkyl dicarboxylic acids, and ω-hydroxyacids. Spectroscopy results showed a concomitant entrapment in HA of biolabile compounds, such as peptidic moieties. The wide range of identified lipid components and plant biomarkers may represent useful tools to trace origin, quality, and transformation of amended compost in soil ecosystems.