Phenotypic and genotypic characteristics of antimicrobial resistant Escherichia coli isolated from symbovine flies, cattle and sympatric insectivorous house martins from a farm in the Czech Republic (2006-2007)

The prevalence of antimicrobial resistant Escherichia coli was tested in symbovine flies and sympatric house martins (Delichon urbica) at a dairy farm. Antimicrobial resistant E. coli was detected in 89% (n = 147) of isolates from flies within a calf barn. Isolates with the same antimicrobial resistance phenotypes, genes, and pulsotypes were found between both fly and calf E. coli isolates, suggesting that the calves were the initial source of the antimicrobial resistant strains in fly isolates. Symbovine flies were considered as important reservoirs of antimicrobial resistant E. coli strains at a dairy farm, due to their intensive contact with cattle feces and manure. House martin fecal samples from the same farm contained 4.5% (n = 393) of antimicrobial resistant E. coli. House martin isolates displayed different macrorestriction profiles than fly isolates and the significance of house martins as a reservoir and vector of antimicrobial resistant E. coli appears low.     

The cannulation of the caudal caval vein through the femoral vein in the pig for endocrine research

The present study was designed to examine the usefulness of cannulation of the caudal caval vein through the femoral vein for the measurement of hormone concentrations in the reproductive tract in the pig. The experiment was performed on sexually pubertal gilts (Polish Large White x Polish Landrace) of a similar age (7-8 months) and body mass (100-110 kg) after two controlled subsequent estrous cycles. Six gilts in the luteal phase (10th day) of the estrous cycle were used in this experiment. The animals were subjected to a surgical procedure which included:--premedication (Combelen, i.m. 1 ml/10 kg of body mass) and than after 20-30 min general anaesthesia (Vetbutal, i.v., dose 30-40 ml) according to body mass and the symptoms observed,--insertion of cannulas (o.d. 2.2 and i.d. 1.8 mm)--one into the jugular vein and the other into the caudal caval vein through the femoral vein. In several gilts the cannulas were inserted into the caudal caval vein to a depth of 14, 18, 20, 23, 25 and 30 cm from the femoral ring. The concentrations of progesterone (P4) and testosterone (T) were analysed in samples of blood plasma from the jugular and caudal caval veins by radioimmunoassay (RIA). The largest differences in hormone concentrations between the jugular and caudal caval veins were ascertained when a cannula was inserted into the caudal caval vein to a depth of 20 cm from the femoral ring. In other cases the differences were less prominent, or no differences were observed (e.g. 14 cm for progesterone and testosterone or 18 cm for testosterone).     

Dexamethasone-induced changes in sympathetic innervation of porcine ovaries and in their steroidogenic activity

The aim of the present study was to determine changes in the density of sympathetic nerves in porcine ovaries with dexamethasone (DXM)-induced cysts and the alterations in steroidogenic activity and amounts of catecholamines in the affected gonads. Cystic ovaries were supplied by numerous sympathetic nerve fibers. The amount of noradrenaline in the cysts (fluid, wall) was significantly higher than in the large follicles of the control group. After DXM injections, the amounts of noradrenaline and adrenaline significantly increased in the walls of small and medium-sized follicles. In the cysts (fluid, wall) the levels of androgens and estrogens were significantly lower, whereas progesterone was higher in the cystic wall. DXM administration led to a significant increase in the estrone content in the fluid of small follicles. Moreover, a decrease in the amounts of progesterone and androgens was found in the follicular fluid and walls of medium-sized follicles. DXM injections resulted in a significant increase in the immunoexpression of P450(scc) and 3beta-HSD in the cysts, a significant increase of P450(scc) in the follicles, and a decrease of 3beta-HSD and P450(arom). The present study shows that the DXM treatment leads to an increase in the density of intraovarian sympathetic nerves, paralleled by the amount of catecholamines, and that it is capable of changing the steroidogenic activity of porcine ovary bearing cysts. Thus, it appears possible that these events may be, at least partly, involved in the pathogenesis of this disorder.     

The effect of intrauterine infusion of inflammation-provoking factors on proinflammatory cytokines and hormones in rat peripheral blood

The aim of the study was to determine, using the rat model, whether uterine infections cause an increase in cytokine concentrations in peripheral blood, and whether this increase is accompanied by changes in the pituitary-ovarian axis function. The levels of tumor necrosis factor-alpha, interleukin-1beta, luteinizing hormone, follicle-stimulating hormone, prolactin, progesterone, testosterone and estradiol-17beta in blood plasma as well as the weight of the uterus were determined after intrauterine infusion of lipopolysaccharide (15 microg), peptidoglycan (1 mg) and Escherichia coli (10(6) cfu) suspension on the day of metaestrus. On days 3, 7 and 10 after treatment the rats were sacrificed to collect the blood samples. Inflammation of uterus and vaginal discharge developed in all rats after treatment. The administration of lipopolysaccharide, peptidoglycan and Escherichia coli induced considerable changes in ovarian cyclic activity, mainly diestrus was observed. Application of all these factors resulted in an increase (P<0.05, P<0.01) of plasma levels of tumor necrosis factor-alpha, interleukin-1beta, mainly on day 3 and 7. In the rats receiving pathological factors, the plasma levels of luteinizing hormone, follicle-stimulating hormone, prolactin and estradiol-17beta decreased (P<0.05, P<0.01) whereas progesterone and testosterone increased (P<0.05). These results indicate that in rats, the developing inflammatory process of the uterus following lipopolysaccharide, peptidoglycan and Escherichia coli infusions is connected with an increase of tumor necrosis factor-alpha, interleukin-1beta concentrations in peripheral blood, and is accompanied by changes in the pituitary-ovarian axis function.     

Effect of dietary corn oil supplementation on equine gastric fluid acid, sodium, and prostaglandin E2 content before and during pentagastrin infusion

The effect of corn oil (approximately 60% [wt/vol] linoleic acid) dietary supplementation on various components of equine gastric secretion was studied by use of a repeated-measures experimental design. Four healthy adult ponies were surgically fitted with gastric cannulas. The ponies were then fed a free-choice hay diet for 5 weeks, which was followed by 5 weeks of the same diet supplemented with 45 mL of corn oil daily. Gastric contents were analyzed under basal and pentagastrin-stimulated conditions once weekly during the latter 2 weeks on each diet. Gastric contents were collected at 30-minute intervals, and volume, hydrogen ion concentration, sodium content, and prostaglandin E2 (PGE2) content were measured. Data were analyzed by a linear fixed-effect modeling procedure. During the diet supplemented with corn oil, the ponies had, under basal and pentagastrin-stimulated conditions, significantly decreased acid output and significantly increased PGE2 and sodium outputs compared to those measured before corn oil supplementation. We conclude that corn oil supplementation may be an effective and inexpensive way to increase the protective properties of equine glandular gastric mucosa. This could be particularly helpful in reducing the chances of ulceration associated with nonsteroidal anti-inflammatory drug (NSAID) administration.     

Effect of ovariohysterectomy on canine postsurgical leukocyte function

The effect of surgery on phagocytic activity of blood leukocytes and mitogen-induced blastogenesis of lymphocytes was studied in fourteen dogs. Simple ovariohysterectomy with anaesthesia induced by ketamine and xylazine or by ketamine, xylazine and halothane caused a short nonsignificant depression of phagocytic activity that persisted for four hours after surgery. Ingestion capacity of leukocytes decreased significantly immediately after surgery. Mitogen-induced blastogenesis of lymphocytes was depressed significantly in the first 48 hours and despite partial recovery this parameter did not reach the value of the control groups until the end of observation (7 days). A more conspicuous decrease of blastogenic response of blood lymphocytes to mitogens was found after the use of ketamine and xylazine in a dose maintaining anaesthesia. Anaesthesia with ketamine and xylazine in the lower dose and maintained with halothane resulted in a later improvement of the blastogenic response of lymphocytes.     

Effect of Planting Date and Thermal Energy Intensity on Rate of Phosphorus and Potassium Accumulation by Maize (Zea mays L.)1

The effect of planting date and thermal energy intensity (TEI) on the rate of phosphorus (P) and potassium (K) accumulation by maize from a Hamerly clay loam soil (Aerie Calciaquoll) was examined with and without supplemental irrigation. Soil- and air-TEI expressed as growing degree days per day (GDD d^?1) were determined from hourly temperature measurements taken within each plot. Net K accumulation occurred during the vegetative growth stage, reached maximal rates of about 62.2 to 91.4 mg plant^?1 day^?1, and attained maximal accumulations ranging from about 1.15 to 2.3 g plant^?1. Accumulation of P occurred during vegetative and reproductive growth stages, reached maximal rates of about 4.6 to 10.3 mg and 6.5 to 12.1 mg plant^?1 day^?1, respectively and maximal accumulations of 0.175 to 0.27 g and 0.11 to 0.26 g plant^?1, respectively. During vegetative growth, K and nitrogen (N) accumulation characteristics were closely correlated with about 2 moles of N accumulated per mole of K. Maximal accumulation of K (and N) consistently preceded that of P by about 5.2 to 8.3 days and that of the plant dry weight by about 15.9 to 20.5 days during the vegetative growth stage. Time required to reach maximal accumulation during the reproductive growth stage, t_r followed the order N < P < dry weight for early plantings and followed the order N < P < dry weight for delayed plantings. Time coefficients for K and P accumulation were correlated closely with soil-TEI, but models of each coefficient relied on unique combinations of TEI. Time coefficients for dry matter accumulation were apparently unrelated to soil- or air-TEI.     

Identification of MCP/CD46 analogue on bovine erythrocytes using the new monoclonal antibody IVA-520

MCP/CD46 is a widely distributed C3b/C4b binding regulatory glycoprotein of the complement system that has been identified on all human peripheral blood cells except erythrocytes. In this paper, we describe the identification of bovine CD46 on all blood cells, including erythrocytes, with the newly prepared monoclonal antibody IVA-520. This antibody cross-reacts with human and pig cells. Furthermore, the molecule identified by IVA-520 functionally behaves as the MCP molecule, showing cofactor activity for the factor I-mediated cleavage of bovine C3 complement factor.