Antimicrobial susceptibilities and population structure of Staphylococcus epidermidis associated with ovine mastitis

Intramammary infections are a serious problem for dairy sheep farms, and Staphylococcus epidermidis is one of the main etiological agents of ovine mastitis. In this work, 131 S. epidermidis isolates, collected from 2201 dairy Sarda sheep belonging to 14 flocks with high somatic cell count scores, were studied. The flocks were located in diverse geographical areas of Sardinia, Italy. The aim of study was to assess the susceptibility of isolates to 13 antimicrobial agents, many of which are frequently used in mastitis therapy. Oxacillin was used for detecting methicillin-resistant S. epidermidis (MRSE) by disk diffusion test. Thirty-eight percent of the isolates (n = 50) were resistant to penicillin, 7.6% (n = 10) were resistant to tetracycline, and 2.3% (n = 3) were resistant to both penicillin and tetracycline (PTRSE). Two isolates were resistant to five antimicrobials including methicillin. Analysis of staphylococcal cassette chromosome mec (SCCmec) elements showed that both MRSE isolates harbored SCCmec type IVa. Based on pulsed-field gel electrophoresis (PFGE) typing by SmaI macrorestriction, S. epidermidis isolates were grouped into four clusters at 75% similarity level. The two multi-drug resistant MRSE isolates displayed distinct PFGE patters. This study indicates that S. epidermidis isolates from sheep milk samples may accumulate resistance markers for different antimicrobial agents. Furthermore, the occurrence of PTRSE and MRSE suggests to adopt adequate hygienic measures when handling animals with intramammary infections, in order to prevent spreading PTRSE and MRSE strains to humans through direct contact and/or consumption of contaminated food.     

Molecular characterization of Corynebacterium pseudotuberculosis isolates using ERIC-PCR

Caseous lymphadenitis is an infectious sheep and goats disease caused by Corynebacterium pseudotuberculosis and characterized by abscesses in superficial and visceral lymph nodes. C. pseudotuberculosis strains isolated from these hosts have been shown to be very difficult to type by the existing methods. The aim of this study is evaluating the potential of the Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) as a tool for molecular typing of C. pseudotuberculosis strains isolated in sheep. One hundred and twenty seven isolates of C. pseudotuberculosis were isolated from lesions suspected to have had caseous lymphadenitis collected from sheep at the slaughterhouse. Animals were from 24 flocks in 13 municipalities of the Minas Gerais State, Brazil. Species identification of the isolates was performed by routine biochemical tests and mPCR. Fingerprint was performed by RAPD using ERIC-1R, ERIC-2 and ERIC-1R+ERIC-2 primers. Seventeen different genotypes were generated by ERIC 1-PCR, 21 genotypes by ERIC 2-PCR and 21 genotypes by ERIC 1+2-PCR. Hunter-Gaston Discrimination Index (HGDI) found for ERIC 1, ERIC 2, ERIC 1+2 PCR were 0.69, 0.87, and 0.84, respectively. For most herds evaluated observed at most three different genotypes among isolates from animals of these property, in all ERIC-PCR assays. However a few flocks observed between four and nine genotypes per flock. The W Kendall value found for correlation among the three techniques of ERIC-PCR was 0.91 (P<5.0 x 10(-6)). The results show that ERIC-PCR has good discriminatory power and advantages over other DNA-based typing methods, making it a useful tool to discriminate C. pseudotuberculosis isolates.     

Farmed Gilthead Sea Bream (Sparus aurata) by-Products Valorization: Viscera Oil ω-3 Enrichment by Short-Path Distillation and In Vitro Bioactivity Evaluation

This study shows a pilot scale protocol aimed to obtain an omega 3-enriched oil after the processing of farmed gilthead sea bream viscera (SBV); this was oil was tested in vitro for bioactivity, attesting to the possibility to turn waste into profit The quality of the oil, in terms of requirements for animal and human consumption, was assessed by determining some chemical parameters, such as peroxide value (PV), thiobarbituric acid reactive substances (TBARS), ρ-anisidine (ρ-AV) content, total oxidation value (TOTOX), and phospholipids and free fatty acid (%), both in crude viscera oil (CVO) and refined viscera oil (RVO). Among the extraction conditions, the higher CVO yields were obtained at 60 °C for 10 min (57.89%) and at 80 °C for 10 min (67.5%), and the resulting oxidation levels were low when utilizing both extraction conditions. RVO, obtained from CVO extracted at 60 °C, showed the highest quality on the basis of the assessed parameters. The ethyl esters of the total fatty acid (TFA) contents extracted from RVO were enriched in the ω-3 polyunsaturated fatty acid fraction (PUFAE) up to almost 56% via short path distillation (SPD). Antioxidant activities and adipogenic properties were tested in vitro. PUFAE protected 3T3 L1 cells from oxidative stress and exerted an anti-adipogenic effect in Dicentrarchus labrax pre-adipocytes, attesting to the beneficial properties for both farmed fish and human health. These results could stimulate the adoption of solutions aimed to recover and utilize aquaculture by-products at a higher scale, turning “waste into profit” and indicating a strategy to reach more sustainable business models in aquaculture resource utilization according to the principles of the circular economy.     

Characterization of Fungal Biodiversity In Compost and Vermicompost

The ability of fungi to break down complex carbon sources makes them of vital importance in both the generation and application of compost. This paper illustrates the diversity and functions of the mycoflora of both a green compost (made solely thermophilically from plant debris) and a vermicompost (made mesophilically by the action of earthworms on plant and animal wastes). The soil dilution plate technique was applied on 3 media (PDA, CMC, PDA plus cycloheximide) and at 3 incubation temperatures (24°C, 37°C and 45°C) to isolate and identify fungal entities. Enzymatic activities (amylase, cellulase, chitinase, esterase, ligninase, pectinase, phosphatase, plastic degradation and xylanase) of most species from both composts were evaluated with a semiquantitative method on 15 substrates. There were substantial qualiquantitative differences in the species composition of the two composts. A total of 193 entities were isolated: 54 from green compost only, 77 from vermicompost only, 62 from both. This taxonomic diversity was reflected in the metabolic potential. Amilase, cellulase, protease and esterase activities were significantly higher in the green compost. Lignin and plastic polymer degradation were significantly higher in the vermicompost. Structural and functional characterization of this kind is of assistance in determining both the most appropriate application of composts and their hygienic quality.     

Basidiomycetes from Compost and their Dye Degradation and Enzyme Activities

The degree of decolorization of Poly R-478, a highly recalcitrant anthraquinone dye, by three basidiomycetes belonging to Polyporales isolated from compost was investigated together with the enzymes involved. Decolorization tests in two liquid cultures, one with a simple mycelium inoculum, the other with an inoculum of mycelium grown on straw, resulted in 70% and 87% decolorization respectively in 7 days. However, the efficiency did not increase significantly in the presence of the lignocellulose substrate. The three strains produced laccase and/or manganese peroxidase activity during the decolorization, whereas lignin peroxidase activity was not observed. Previous growth on straw enhanced the synthesis of ligninolytic enzymes, though there was no correlation between enzyme activity and decolorization. The three fungi can be proposed as promising candidates for the treatment of colored industrial effluents and probably for soils contaminated by complex polymers, such as polycyclic aromatic hydrocarbons.     

Aurantoside J: a new tetramic acid glycoside from Theonella swinhoei. Insights into the antifungal potential of aurantosides

The chemical investigation of an Indonesian specimen of Theonella swinhoei afforded four aurantosides, one of which, aurantoside J (5), is a new compound. The structure of this metabolite, exhibiting the unprecedented N-α-glycosidic linkage between the pentose and the tetramate units, has been determined through detailed spectroscopic analysis. The four obtained aurantosides have been tested against five fungal strains (four Candida and one Fusarium) responsible of invasive infections in immuno-compromised patients. The non-cytotoxic aurantoside I (4) was the single compound to show an excellent potency against all the tested strains, thus providing valuable insights about the antifungal potential of this class of compounds and the structure-activity relationships.     

2,3,7,8-Tetrachlorodibenzo-p-dioxin influences bovine herpesvirus 1 replication through upregulation of SIRT3 and cytoskeletal reorganization

Infection of kidney cells (MDBK) with Bovine Herpesvirus 1 (BoHV-1) is affected by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), which accelerates BoHV-1-induced apoptosis and increases virus replication. Herein, to elucidate the mechanism through TCDD modifies BoHV-1 infection, we analyzed the modulation of a members of Sirtuin proteins family in MDBK cells. We found that mitochondrial SIRT3 was upregulated during infection. This change was accompanied by cytoskeletal rearrangements and cell extensions. All these trends were drastically modified by TCDD. We hypothesize that, taken together, these results might further clarify the processes responsible for the action of TCDD on the BoHV-1 replication, resulting in enhanced virus production.     

Effects of light intensity on growth,feeding activity and development in common sole (Solea solea L.) larvae in relation to sensory organ ontogeny

The effects of four light intensities (1000 lx, 500 lx, 50 lx, 3 lx) on growth, survival and feeding activity in common sole (Solea solea L.) larvae were studied from 4 to 51 days post hatching (dph). During the pelagic larval stage (4–12 dph), larvae reared at 3 lx showed a lower growth. From 19 onwards, the larvae reared under 3 lx displayed a significant (P ≤ 0.05) higher SGR than the other treatments and a higher final weight compared to 1000 lx and 500 lx. Survival rate was higher under intermediate light intensities (500 and 50 lx). Larvae reared at 3 lx displayed a significant delay in the degree of metamorphosis compared to the other treatments, while at 33 dph metamorphosis was completed under all treatments. Histological examination revealed the importance of vision and light in the first feeding of this species, while after metamorphosis, the full development of other sensory organs indicated that feeding activity is also mediated by chemosensory perception. Results indicate that high light intensity seems to be more suitable during the pelagic larvae, while the opposite would ensure better growth from the onset of metamorphosis to the benthic phase.