Light and electron microscopic studies of calf kidneys after exposure to subtoxic lead levels]

Eight calves were fed from the fourth to the twentieth week of age a milk powder diet containing 40 mg lead acetate per kg dry substance. This is twice the lead concentration legally permitted. In average, each animal has daily taken up 0.834 mg lead per kg body weight. Eight calves were used as controls. The animals gained the usual fattening weights and did not show clinical symptoms. Beginning with week 14, increased levels of blood urea were encountered in the animals which received lead in their diet. Morphologically, severe renal lesions were found in these calves. The kidneys were increased in weight, pale and of firm consistency. Histologically, fibrosis and periglomerular interstitial non-purulent nephritis were found. Light- and electronmicroscopically, numerous intranuclear inclusion-bodies typical for lead poisoning were demonstrated in epithelial cells of proximal tubules. The results show, that daily uptake of less than 1 mg lead per kg body weight must be considered as a toxic dose for calves, and not 5-7 mg as stated in literature.     

Comparison of dot blot hybridization, polymerase chain reaction, and virus isolation for detection of bovine herpesvirus-1 (BHV-1) in artificially infected bovine semen.

Bovine semen samples spiked with bovine herpesvirus 1 (BHV-1) were used to compare dot blot hybridization, polymerase chain reaction (PCR), and virus isolation for detection of BHV-1 in bovine semen. The PCR amplification used primers targeting the BHV-1 thymidine kinase gene and a nucleic acid releasing cocktail (GeneReleaser); the PCR product was used as the DNA probe in dot blot hybridization; virus isolation was done in primary bovine fetal testis (BFT) cell cultures. Semen diluted 1:20 in tissue culture medium had the least cytotoxicity and inhibition of viral cytopathic effects in BFT cells, allowing detection of 1 TCID50/100 microL of BHV-1 suspension by virus isolation. The presence of foreign DNA such as bovine sperm DNA or salmon sperm DNA increased the sensitivity of dot blot hybridization in detecting BHV-1, allowing detection of 20,000 TCID50/100 microL of neat semen. The inhibition of PCR amplification of BHV-1 DNA in bovine semen was eliminated by diluting the samples 1:20 in tissue culture medium. The best PCR amplification was obtained when semen was diluted 1:20 and when a reaction buffer of pH 9.0, with 1.0 mM MgCl2 was used. Under these conditions, the PCR followed by ethidium bromide staining of agarose gels could detect 1 TCID20/100 microL of sample, whereas PCR followed by Southern blot hybridization could detect 0.01 TCID50/100 microL of sample.(ABSTRACT TRUNCATED AT 250 WORDS)     

Enzootic abortion in a goat herd, caused by mixed infection with Coxiella burnetii and Chlamydia psittaci. Case report]

We report on an outbreak of enzootic abortion in a herd of goats with high losses caused by mixed infection with Coxiella burnetii and Chlamydia psittaci. Both agents could be detected by microscopic investigation of smears from afterbirths by Giménez staining and by a capture enzyme-linked immunofluorescence assay (Capture ELIFA). Additionally, Coxiella burnetii was isolated from the same tissues in BGM cell cultures. Serological investigations with CF, indirect ELIFA, and IF tests revealed high antibody titers against both agents in most animals. Coxiella antigen was still detected 91 days later in milk samples of two infected goats by Capture ELIFA.     

Laboratory diagnosis and disease occurrence in the current African swine fever eradication program in Spain, 1989–1991

The purpose of this study was to determine the rate of decline and geographical distribution by municipality of clinical and subclinical African swine fever (ASF) in the affected areas of Spain. A second aim was to evaluate the performance of diagnostic tests in the Spanish ASF eradication program. Clinical outbreaks were confirmed using both the direct and indirect immunofluorescence test (and if both were negative, by the hemabsorption test). The serological status of swine was determined by an enzyme-linked immunosorbent assay (ELISA) and suspect serum samples were confirmed by the immunoblot assay.

The number of clinical outbreaks (herds) of ASF for 1989, 1990 and 1991 was 170, 347 and 207, respectively. The numbers of municipalities within each affected province experiencing acute outbreaks for the same time periods were 49, 69 and 48, respectively. Serologically diagnosed animals positive for ASF were 1.1% of animals tested in 1989, 0.5% in 1990 and 0.8% in 1991. The corresponding positive predictive values of the standard ELISA test used were 99.0, 97.9 and 98.8, respectively. Similarly, the number of municipalities within each affected province experiencing serologically positive subclinically infected animals was 269, 178 and 147 for each of the years 1989, 1990 and 1991, respectively.     

Differential effects of heparin on NO and tumor necrosis factor-alpha production in bovine blood mononuclear cells stimulated with Salmonella typhimurium lipopolisaccharide.

We investigated the influence of heparin, one of the extracellular matrix (ECM) components, on nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) production by bovine peripheral blood mononuclear cells (PBMC) and monocytes left to adhere for 2 (freshly adherent monocytes) and 48 h (resting monocytes), activated with Salmonella typhimurium lipopolysaccharide (LPS). After 24-h stimulation with LPS, heparin (100 microg/ml) increased (by about 40%) NO production by peripheral blood mononuclear cells and by freshly adherent monocytes. However, it did not change NO synthesis by the resting monocytes. Unlike its influence on NO level, heparin diminished TNF-alpha production by PBMC and monocytes stimulated with LPS. Microscopical examination of PBMC stained with biotin-labeled heparin, showed that both lymphocytes and monocytes were able to bind this glycosaminoglycan. We suggest that heparin, as a component of ECM, modulates the early response of monocytes to exogenous stimuli.     

Determination of sulfamethazine and trimethoprim in liquid feed premixes by HPLC and diode array detection, with an analysis of the uncertainty of the analytical results.

Sulfamethazine (SMZ) and trimethoprim (TMP) are antibacterials used in veterinary practice. This paper describes a method for their determination in veterinary liquid feed premixes that is based on liquid chromatography with diode array detection. Gradient elution with methanol and ammonium acetate achieved excellent separation of the two analytes within 15 min without any interference from the matrix. Absorbance of the column effluent was monitored at 264 nm for SMZ and at 230 nm for TMP. Detailed analyses of the uncertainties of determinations afford estimated expanded uncertainties of, respectively, 0.2 and 0.1 w/v % for typical SMZ and TMP concentrations of 10.7 and 2.1 w/v %, respectively. At the lower end of the calibrated range of the method, the dominant source of uncertainty is the preparation of standards and the construction of the calibration line.     

Laboratory-based surveillance of salmonellosis of humans in Germany--safety of Salmonella typhimurium and Salmonella enteritidis live vaccines]

The Paul Ehrlich Institute, Langen, in Germany has been licensed different live vaccines of S. Typhimurium and S. Enteritidis for use in the veterinary medicine since I the 90s. The Robert Koch Institute has established a lab-based surveillance system for these live vaccine strains for an evaluation of recent public health safety. Since 2000 all strains of S. Typhimurium and S. Enteritidis from humans were investigated in respect to their phage types and other vaccine markers. 3676 S. Typhimurium strains and 4489 S. Enteritidis strains mainly from Salmonellose patients were investigated after phage typing according to their auxotrophic or antibiotic resistance markers. The live vaccine strains of Zoosaloral, TAD Salmonella vacT or TAD Salmonella vacE and Salmovac SE could not be found from infections in humans.     

The effect of eradication of lice on the occurrence of the grain defect light flecks and spots on cattle hides.

The influence of an eradication programme for lice on the prevalence of light flecks and spots on cattle hides was studied in 33 dairy cattle herds during a period of two and a half years. Lice were eradicated from the main group of herds after 9 to 12 months and the quality of the hides before and after treatment was compared. Hides from slaughtered animals were collected during the study period, tanned and examined with special emphasis on the occurrence of the grain damage light flecks and spots. The prevalence of hides without light flecks and spots increased from 24.2% before treatment to 61.6% after treatment. The prevalence of hides free from the damage increased significantly in all examined anatomical regions. The improvement in hide quality was most marked in the shoulders and neck region which corresponded to the major predilection site of cattle lice. The prevalence of hides with light flecks and spots started to decrease in the first period (2-40 days) after eradication. The changes after treatment suggested that most healing process took place over a period of about 4 months. The eradication programme eliminated the seasonal variation in the prevalence of light flecks and spots which was present before treatment.     

Effect of concentrate crude protein level on grass silage intake, milk yield and nutrient utilisation by dairy cows in early lactation.

Twenty-one multiparous dairy cows were fed concentrates containing three levels (119, 154 and 191 g/kg DM) of crude protein (CP) during the first ten weeks of lactation. Part of the grain and molassed sugar beat pulp was substituted with 0% (RSM0), 15% (RSM15) or 30% (RSM30) repeseed meal. Wilted grass silage was fed ad libitum after calving. The average response between RSM0 and RSM15 was +1.66 kg milk/d per percentage unit change in concentrate CP content. No further response occurred between RSM15 and RSM30. The positive effect of RSM inclusion was seen throughout the experimental period and was associated with increased plasma non esterified fatty acids (NEFA) and decreased plasma insulin concentration one week after calving, and higher efficiency of metabolisable energy utilisation for milk production. Digestibility of the diet remained unaffected. Milk and plasma urea tended to increase with RSM30 indicating excessive supply of rumen degradable protein. Because of the limited potential of cows to compensate for a deficit in feed protein supply by mobilising tissue protein, a substantial milk yield response can be achieved with a moderate level of protein supplementation during early lactation.