Experimental enteric infection of gnotobiotic piglets with Chlamydia suis strain S45     

Guscetti F  Schiller I  Sydler T  Heinen E  Pospischil A 《Veterinary microbiology》2009,135(1-2):157-168

Enteric chlamydial infections of pigs with Chlamydia (C.) suis are frequent and often subclinical. The enteric pathogenicity of C. suis strain S45 was investigated in gnotobiotic piglets. Piglets from three litters (n=31) were inoculated with egg-grown chlamydiae at 2-3 days of age (n=17) or used as controls (n=14). They were observed for clinical signs, killed and necropsied sequentially at 2-13 days postinoculation (DPI). Feces were collected daily and investigated with an ELISA for chlamydial antigen. At necropsy, specimens were collected for histopathology and for immunohistochemical, PCR-based, and serological (complement fixation test, ELISA) detection of chlamydiae. Chlamydial replication and associated symptoms and lesions were observed from 2 to 13 DPI and were particularly pronounced within the first week PI. Clinical symptoms consisted of moderate-to-severe diarrhea, slight and transient anorexia, weakness and body weight loss. Immunohistochemistry and ELISA revealed that chlamydial replication was particularly marked at 2-4 DPI and primarily located in the small intestinal villus enterocytes. Further sites of replication included large intestinal enterocytes, the lamina propria and Tunica submucosa, and the mesenteric lymphnodes. Histopathological changes included moderate-to-severe villus atrophy with flattened enterocytes and focal villus tip erosions, and moderate mucosal inflammatory cell infiltrates and lymphangitis in the small intestine. PCR of spleen tissue and blood was mostly negative for chlamydiae, indicating that they did not substantially disseminate into the host up to 13 DPI. All sera were negative for anti-chlamydial antibodies. In conclusion, C. suis strain S45 elicited significant enteric disease and lesions in gnotobiotic piglets indicating its pathogenic potential for swine.  相似文献   

Molecular characterisation of chlamydial isolates from birds     

Sudler C  Hoelzle LE  Schiller I  Hoop RK 《Veterinary microbiology》2004,98(3-4):235-241

Fifty-one chlamydial isolates from birds collected in Switzerland were classified by amplification and restriction analysis of the 16S-23S rRNA intergenic spacer region as Chlamydophila psittaci. The aim was to characterise a broad panel of chlamydial strains from birds and to apply and verify the methods of classification and differentiation described for chlamydial organisms. Two of the six known avian chlamydial serovars (A and B) were found by serotyping with monoclonal antibodies. One isolate was not typable. Digestion of ompA-PCR amplicons by AluI generated four distinct restriction patterns (genotypes A, B, F and G). Genotypes A and B correlated in most cases to serovars A and B, respectively. One serovar A isolate was verified as genotype B instead of A and one serovar B isolate belonged to genotype A. The non-serotypable isolate was of genotype F and one serovar A generated genotype G. OmpA sequences of one strain of each genotype were determined and compared to data bank entries. Amino acid sequences of genotype A and B strains corresponded well, showing more than 98.0% homology. The homologies of genotypes F and G sequences to genotype A strain were 82.0 and 83.0% respectively.  相似文献   

Predation on native fish eggs by invasive round goby revealed by species‐specific gut content DNA analyses     

Elisabeth Lutz  Philipp Emanuel Hirsch  Karen Bussmann  Joschka Wiegleb  Hans‐Peter Jermann  Roxane Muller  Patricia Burkhardt‐Holm  Irene Adrian‐Kalchhauser 《水产资源保护:海洋与淡水生态系统》2020,30(8):1566-1577

1. Conservation of riverine fish often aims to improve access to spawning grounds and restore longitudinal connectivity by removing migration barriers, and involves substantial investments. However, these investments also enable non‐native predators to invade upstream into spawning areas and potentially adversely affect the recruitment of threatened freshwater fish through egg or fry predation.
2. Detecting egg predation is often challenging. Visual inspections of fish gut contents may underestimate predation of soft materials such as eggs and fry, which limits the discovery of predators preying upon these life‐stages. DNA‐based detection assays may offer a more sensitive tool to assess predation of soft materials.
3. A conservation issue was confirmed by developing and applying a species‐specific DNA‐based detection assay: invasive round goby (Neogobius melanostomus) prey on the eggs or fry of the threatened common nase (Chondrostoma nasus) in Switzerland.
4. DNA‐based detection assays were also developed for five other valuable native fish species, including endangered salmonid and cyprinid river spawners. The applicability of the assays was confirmed in a series of laboratory and field feeding experiments involving eggs and fish tissue. In addition, this work provides a guiding framework for conservation managers regarding the use and applicability of different DNA‐based detection approaches for gut content analysis.
5. The results of this study could inform local conservation measures – such as temporary reductions in the density of round goby at spawning sites prior to spawning – and demonstrate how targeted application of species‐specific molecular markers may advance freshwater fish management.

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Pond management and water quality for drip irrigation in Mediterranean intensive horticultural systems     

Santiago Bonachela  Melchor Juan  J. Jesús Casas  Francisca Fuentes-Rodríguez  Irene Gallego  María Antonia Elorrieta 《Irrigation Science》2013,31(4):769-780

The influence of pond management on water quality for drip-irrigated crops was studied throughout a field survey and a mesocosm experiment. Water sources were pooled into two groups: ground or surface water (GW/SW) and recycled wastewater. Pond covering, which was limited to about a quarter of them, improved water quality by reducing phytoplankton biomass. However, biocide applications and pond dredging were ineffective at improving in-pond water quality. Dredging did not reduce the concentrations of planktonic chlorophyll a or total suspended solids (TSS) in GW/SW fed ponds, whereas biocide applications increased both parameters. Field and experimental data proved that the two predominant taxa of submerged aquatic vegetation (SAV) found in ponds (Potamogeton pectinatus and Chara spp.) improved water quality by increasing water oxygenation and decreasing chlorophyll a and TSS concentrations. Preserving SAV (especially Chara spp.) appears to be an environment-friendly, cost-effective and recommendable alternative strategy for irrigation pond management.  相似文献   

C and N concentrations in different compartments of outgrown oak coppice forests under different site conditions in Central Italy     

Giovanni Di Matteo  Irene Tunno  Pierfrancesco Nardi  Paolo De Angelis  Giada Bertini  Gianfranco Fabbio 《Annals of Forest Science》2014,71(8):885-895

Context

Harvesting of Mediterranean oak coppice forests has been progressively suspended on a share of cover over the last decades. Positive growth trend in outgrown coppices no longer harvested on short rotations now drives natural forest restoration on wide areas, and it represents a potential carbon sink in view of global warming.

Aims

Our goals were to estimate carbon (C) and nitrogen (N) content per compartment in two deciduous oak outgrown coppice forests, aged differently and growing under unequal site quality, to verify whether C concentration across compartments is in agreement with the conventional conversion rate of 0.5.

Methods

Ecosystem C and N pools were assessed by multiplying the whole coppice mass (combining specific allometric functions, root-to-shoot ratio, and soil sampling) by respective C and N concentrations.

Results

The results point out that the largest percentage of N was stored in 15-cm topsoil (84.06 and 73.34 % at the younger and older site, respectively), whereas the proportion of organic ecosystem C pool was more variable, as a consequence of the amount and allocation of phytomass. We found that, in most cases, C concentration was less than the conventional conversion rate of 0.5, especially in deadwood, O layer, and root compartments.

Conclusion

The findings provide further knowledge of C and N storage into these new built-up forest types and the evidence that a detailed analysis may get higher accuracy in the pools estimate, producing a more reliable outlook on dynamics and climate change mitigation ability of these systems.  相似文献   

The Effect of Nixtamalization Extrusion Process and Tortillas Making on the Stability of Anthocyanins from Blue Corn through the Kinetic and Thermodynamic Parameters     

Menchaca-Armenta  Mariela  Frutos  María José  Ramírez-Wong  Benjamín  Quintero-Ramos  Armando  Torres-Chávez  Patricia Isabel  Valero-Cases  Estefanía  Muelas-Domingo  Raquel  Ledesma-Osuna  Ana Irene  Campas-Baypoli  Olga Nydia 《Plant foods for human nutrition (Dordrecht, Netherlands)》2021,76(3):334-339

Plant Foods for Human Nutrition - The blue corn-based products are considered functional foods due to their high concentration of anthocyanins. The aim of this study was to estimate the kinetic and...  相似文献   

Molecular assay for the identification of Setaria tundra     

Favia G  Cancrini G  Ferroglio E  Casiraghi M  Ricci I  Rossi L 《Veterinary parasitology》2003,117(1-2):139-145

We report the molecular characterization of the amplification products obtained by specific PCR experiments aimed to identify the 5S ribosomal spacer of Setaria tundra specimens isolated from roe deer (Capreolus capreolus) in north Italy, which represent the first record of the parasite in this country. Three different fragments of approximately 400, 800, and 1200 bp (base pairs) are produced. Sequence analyses showed that all three fragments share a very high level of similarity to 5S spacer sequences of some Setaria species and other filariae present in genebank. Based on these sequences, we were able to design species-specific PCR primers for the precise identification of S. tundra.  相似文献   

Genetic diversity of recent bovine viral diarrhoea viruses from the southeast of Austria (Styria)     

Vilcek S  Greiser-Wilke I  Durkovic B  Obritzhauser W  Deutz A  Köfer J 《Veterinary microbiology》2003,91(2-3):285-291

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Cytologic findings, and feline herpesvirus DNA and Chlamydophila felis antigen detection rates in normal cats and cats with conjunctival and corneal lesions     

Volopich S  Benetka V  Schwendenwein I  Möstl K  Sommerfeld-Stur I  Nell B 《Veterinary ophthalmology》2005,8(1):25-32

Samples were collected from 36 cats with feline herpesvirus (FHV-1)-related ocular disease (conjunctivitis, epithelial or stromal keratitis, or corneal sequestration), and 17 cats without ocular changes. Corneoconjunctival swabs, scrapings and biopsies were tested in various combinations for presence of FHV-1 DNA using single round (sr) polymerase chain reaction (PCR) and nested PCR (nPCR). Additional swabs from the inferior conjunctival fornix were tested by enzyme-linked immunosorbent assay for Chlamydophila felis antigen. Cytologic evaluation was carried out on conjunctival (cats with conjunctivitis) and corneal (cats with keratitis) cytobrush preparations. FHV-1 DNA was detected by PCR in 14 (39%) cats with ocular disease and 1 (6%) of the control group. Agreement between srPCR and nPCR results was significant (P < 0.01). FHV-1 DNA was detected in 3/7 cats with conjunctivitis, 5/6 cats with epithelial keratitis, 3/11 cats with stromal keratitis, and 3/12 cats with corneal sequestration. There was a significant association (P = 0.0027) between viral presence and epithelial keratitis. However, no significant association was found between viral presence and conjunctivitis (P = 0.059), stromal keratitis (P = 0.15), or corneal sequestration (P = 0.18). With respect to FHV-1 DNA detection, intersample agreement was significant (P < 0.03). No sampling technique seemed more likely than another to harvest detectable viral DNA, except for cats with corneal sequestrum in which viral DNA was not detected using corneoconjunctival swabs. FHV-1 DNA was detected in 6/9 samples with intranuclear inclusion bodies and in 6/7 cats with eosinophils on cytologic examination. All samples tested negative for C. felis antigen.  相似文献   

Comparison of immunohistochemistry and two rapid tests for detection of abnormal prion protein in different brain regions of sheep with typical scrapie.     

Rosa Bolea  Eva Monleón  Irene Schiller  Alexander J Raeber  Cristina Acín  Marta Monzón  Inmaculada Martín-Burriel  Thomas Struckmeyer  Bruno Oesch  Juan José Badiola 《Journal of veterinary diagnostic investigation》2005,17(5):467-469

One of the "gold standard" techniques for postmortem confirmation of scrapie diagnosis in sheep and goats is immunohistochemical examination of brain tissue. Active surveillance for scrapie is mainly performed by rapid diagnostic tests on the basis of postmortem immunochemical detection of prion protein (PrP) in the obex tissue. The aim of this study was to determine the performance of 2 rapid tests, Prionics-Check LIA (a chemiluminescence sandwich enzyme-linked immunosorbent assay) and Prionics-Check Western blot for scrapie diagnosis when applied to brain areas other than the obex, in comparison with the recognized immunohistochemistry. Prion protein was detected in the obex, cervical spinal cord, and thalamus from all the scrapie-positive sheep by the 3 tests. Western blot and LIA were negative in other areas of the brain, although weak immunohistochemical staining was detected. The results show that the 2 rapid tests studied may detect PrP in brain areas other than the obex, although with a lower sensitivity than immunohistochemistry when there is minimal PrP deposition.  相似文献