In vitro studies of Lactobacillus delbrueckii subsp. lactis in Atlantic salmon (Salmo salar L.) foregut: tissue responses and evidence of protection against Aeromonas salmonicida subsp. salmonicida epithelial damage     

Salinas I  Myklebust R  Esteban MA  Olsen RE  Meseguer J  Ringø E 《Veterinary microbiology》2008,128(1-2):167-177

Probiotic bacteria increase the host health status and protect mucosal tissue against pathogen-caused damage in mammalian models. Using an in vitro (intestinal sac) method this study aimed to address (a) the in vitro ability of Lactobacillus delbrueckii subsp. lactis to remain in the gastrointestinal tract of Atlantic salmon (Salmo salar L.) and (b) its ability to prevent cellular damage caused by successive incubation with Aeromonas salmonicida subsp. salmonicida the causative agent of furunculosis. Short in vitro incubation of salmon foregut with (TRITC)-labelled L. delbrueckii subsp. lactis showed that the probiont was able to colonize the enterocyte surface as studied by confocal microscopy. Furthermore, foregut incubated with the probiotic bacteria only, resulted in a healthy intestinal barrier whereas exposure to A. salmonicida disrupted its integrity. However, pre-treatment of salmon intestine with L. delbrueckii subsp. lactis prevented Aeromonas damaging effects. These results are promising in the context of the use of non-autochthonous probiotic bacteria as prophylactic agents against fish bacterial infections in the gastrointestinal tract.  相似文献   

A non-haemagglutinating isolate of mink enteritis virus     

Esteban Rivera  Bo Sundquist 《Veterinary microbiology》1984,9(4):345-353

A virus was isolated from mink showing clinical and pathological signs of mink enteritis. This virus was identified as mink enteritis virus (MEV) from results of serological tests, determination of its density in CsCl (1.415 g cm^?3), and morphology, including size (20 nm in diameter). The isolate was designated MEV-S. In contrast to other known MEV strains, the MEV-S isolate has no haemagglutinating (HA) activity with swine red blood cells (RBCs) at 4°C and pH 6.8.Neither was there any HA at other pH values and temperatures, or when worse, bovine and rhesus monkey RBC's were used.  相似文献   

Gastrointestinal emptying in the final days of incubation of the chick embryo   总被引：1，自引：1，他引：0  

S Esteban  M Moreno  J M Rayó  J A Tur 《British poultry science》1991,32(2):279-284

1. The gastrointestinal (GI) emptying of the chick embryo was studied in days 19 and 20 of incubation using radioactive (14C-PEG-4000) and coloured (Evans Blue dye) tracer markers. 2. Following administration by oral cannula, the percentages of tracer marker recovered in the yolk sac and the GI tract showed the existence of a GI motor pattern in both 19 d and 20 d chick embryos and suggested that the fluids drunk by the chick embryo during the final days of incubation could have reached the yolk sac from the GI tract via the vitelline diverticulum.  相似文献   

Effect of Pre- and Post-Partum Feed Supplementation on the Productive and Reproductive Performance of Grazing Primiparous Brahman Cows     

Soto R  Rubio I  Galina CS  Castillo E  Rojas S 《Tropical animal health and production》2001,33(3):253-264

This experiment studied the combined effect of pre- and post-calving feed supplementation on the productive and reproductive performance of primiparous Brahman cows. The animals were 4 years old (420 kg live weight) and pregnant, and grazed rotationally on Stargrass (Cynodon nlemfuensis) pastures. Supplementation was given before and after (T1, n = 15), only before (T2, n = 15) or only after (T3, n = 16) calving, and there was an unsupplemented control (T4, n = 16). The supplement (1.5 kg/animal per day, 13.4 MJ digestible energy/kg dry matter and 20% crude protein) was given for 45 days before and/or after calving. Changes in body weight and body condition score and the productive behaviour of the calves were similar (p>0.05) among treatments. The concentration of urea in the plasma was low in the control group (T4) before and after calving. The animals in all the groups had a poor reproductive performance. The percentage of cows in oestrus was higher (p<0.05) in T1 (73.3%) than in T3 (37.5%). The interval from calving to conception (148.7±53.7 days) and the pregnancy rate (48.5%) were similar (p>0.05) among the treatments. The level of supplementation offered before and/or after calving did not improve the pregnancy rate.  相似文献   

Total serum immunoglobulin M levels are affected by immunomodulators in seabream (Sparus aurata L.)   总被引：3，自引：0，他引：3  

Cuesta A  Meseguer J  Esteban MA 《Veterinary immunology and immunopathology》2004,101(3-4):203-210

Immunoglobulin M (IgM) is a major component of the teleost humoral immune system. Despite the significance of IgM levels as an immune parameter, there are relatively few studies on changes induced in its total levels in serum. This study examines the effects of several immunomodulators (vitamin A, chitin, yeast cells or levamisole, which act as immunostimulants, and crowding, hypoxia or anaesthetics, which act as stressors) upon the total serum IgM levels of non-immunized gilthead seabream (Sparus aurata L.). Total serum IgM levels of fish fed with the assayed immunostimulant-supplemented diets were statistically higher than those in fish fed a non-supplemented diet, especially in the case of levamisole. On the other hand, serum IgM levels of fish subjected to different stressors were not affected by crowding, hypoxia or certain anaesthetics. However, benzocaine and a narcotic dose of 2-phenoxyethanol provoked a great reduction, while quinaldine sulphate increased IgM levels to a significant degree. These results show how the seric IgM levels can be differently affected by some immunomodulators and the important role they may play in the regulation of total circulating IgM levels in seabream. The possibility of using total serum IgM for assessing immunostimulation, disease diagnosis and stress symptoms during fish farming is discussed.  相似文献   

Hysterothylacium winteri sp. n. (Nematoda: Anisakidae), a parasite of Chilean rock cod, Eleginops maclovinus (Perciformes: Eleginopidae), from South Chile     

Torres P  Soto MS 《Folia parasitologica》2004,51(1):55-60

Hysterothylacium winteri sp. n. (Nematoda: Anisakidae) was collected from the intestine of a marine-estuarine fish, Eleginops maclovinus (Valenciennes) (Perciformes: Eleginopsidae), from Abtao in the Gulf of Ancud, Chile. Sixteen (51.6%) out of 31 fish were infected; the intensity was 1-10 (mean 4) worms/host. The new species belongs to the group of congeners possessing one double pair of postanal papillae. By possessing a lateral pair of phasmids situated near the tip of tail, H. winteri most closely resembles Hysterothylacium habena. The new species can be distinguished by the lip flanges forming broadly rounded points and the equal, short spicules (320-400 microm long) representing 0.9-1.7% of body length.  相似文献   

Mortality in relation to growth rate and soil resistance varies by species for underplanted Nothofagus seedlings in scarified shelterwoods     

Daniel P. Soto  Pablo J. Donoso  Klaus J. Puettmann 《New Forests》2014,45(5):655-669

This study evaluated early mortality patterns of planted Nothofagus dombeyi (Mirb.) Blume (evergreen, shade intolerant) and Nothofagus alpina (P. et E.) Oerst. (deciduous, mid-tolerant to shade) seedlings established in scarified gaps in a Nothofagus old-growth forest in the Chilean Andes that was subjected to a shelterwood cut. Soils were scarified with heavy machinery that removed up to 40 cm of the upper horizons (e.g. it completely removed the litter layer and organic horizon, and in some cases partially the A horizon) to eliminate bamboo (Chusquea culeou E. Desv) shoots and rhizomes from the scarified areas. Two years after planting, seedlings were growing free of understory competition and mortality patterns were assessed using logistic regression models with the following predictor variables: (1) basal diameter growth in the prior year, and (2) soil strength measured as resistance to penetration. The probability of mortality of both species was highly predictable based on recent basal diameter growth. N. dombeyi seedlings appeared to be less affected by mortality, as reflected in lower sensitivity of mortality at lower growth rates compared to N. alpina. High values of resistance to penetration (>2,000 kPa) induced a higher probability of mortality in N. alpina (up to 40 % at 3,500 kPa). In contrast, N. dombeyi mortality was not significantly influenced by soil strength, which illustrates the more stress-resistant and pioneer character of this species. This study showed that recent growth rates can be used as a predictor of future mortality, but these relationships need to be calibrated for each species. In addition, our results suggest that species characteristics that relate to resource limitations, such as shade tolerance, are not adequate to understand effects of other stressors, such as soil disturbance, on mortality patterns.  相似文献   

The influence of detergents on the development of ciliate communities in activated sludge     

Genoveva Esteban  Carmen Tellez 《Water, air, and soil pollution》1992,61(1-2):185-190

The present study was conducted in a full-scale activated-sludge plant to evaluate the influence of detergent concentration on the development of ciliated protozoa during the biological treatment of wastewater. Density and diversity of ciliates were determined in relation to detergents entering the aeration tanks. Results suggest that a threshold of detergent concentration in wastewater entering the aeration tanks for an efficient biological process is 10 mg L^?1. Values higher than this, yield a significant decrease in ciliate populations.  相似文献   

Spectrophotometric and adsorptive stripping square wave voltammetric determination of iron in olive oils,as complex with 5,5-dimethylcyclohexane-1,2,3-trione 1,2-dioxime 3-thiosemicarbazone (DCDT)     

Galeano Díaz T  Guiberteau A  López Soto MD  Ortiz JM 《Journal of agricultural and food chemistry》2003,51(13):3743-3747

Two methods for the determination of iron in olive oil by spectrophotometry and by adsorptive stripping square wave voltammetry (Ad-SSWV) have been developed. These two methods are based on the formation of a 5,5-dimethylcyclohexane-1,2,3-trione 1,2-dioxime 3-thiosemicarbazone (DCDT)-iron(II) complex in strongly acid media. In both, iron is extracted from the olive oil by using HCl. Spectrophotometric determination of iron with DCDT is based on the feature that the DCDT-Fe complex shows an absorbance maximum at 550 nm. A calibration graph has been constructed from 0 to 4000 ng mL(-)(1), and the detection limit was 115 ng mL(-)(1) (57 ng g(-)(1) in olive oil). On the other hand, the voltammetric determination of the metal is based on the appearance of a peak due to an adsorptive reductive process of the complex that it is observed when the Ad-SSWV technique is used. A calibration graph has been constructed from 0 to 30 ng mL(-)(1), and the detection limit was 0.55 ng mL(-)(1) (13.75 ng g(-)(1) in olive oil according to the proposed procedure).  相似文献   

Survey of persistent organochlorine contaminants (PCBs, PCDD/Fs, and PAHs), heavy metals (Cu, Cd, Zn, Pb, and Hg), and arsenic in food samples from Huelva (Spain): levels and health implications     

Bordajandi LR  Gómez G  Abad E  Rivera J  Del Mar Fernández-Bastón M  Blasco J  González MJ 《Journal of agricultural and food chemistry》2004,52(4):992-1001

Concentrations of PCBs, PCDDs, and PCDFs, heavy metals (Cu, Cd, Zn, Pb, and Hg), and arsenic have been determined in a great variety of food samples purchased in different markets across the city of Huelva, located in southwestern Spain and under strong industrial activity. All samples analyzed presented concentrations below the maximum allowed by the European Community regarding PCDD/Fs, with the exception of samples within the meat group. An estimation of the daily intake resulted in 1.15 pg of WHO(PCDD/Fs)-TEQ/kg of body weight/day for a 70 kg person and 2.63 pg of WHO-TEQ/kg of body weight/day when PCBs were included, therefore accounting for a similar or even higher percentage than PCDD/Fs and showing the importance of their inclusion in monitoring studies. Meat and meat products, together with vegetable oils and dairy products, were the major food groups contributing to the estimated daily intake. For heavy metals and arsenic, the concentrations found were under the value proposed by European regulations, and estimated daily intakes were well below those proposed by the WHO for all metals investigated. PAHs have been analyzed in food samples from marine origin, values ranging from 8.22 to 71.4 ng/g of fresh weight. Pyrene was the most abundant compound, accounting for >80% in the samples investigated. The most carcinogenic PAHs, such as benzo[a]pyrene and dibenz[a,h]anthracene, were in all cases below the limits of detection. Therefore, the samples analyzed in this survey can be considered as safe with regard to the levels obtained and the in-force legislation.  相似文献