Zentralblatt fur Veterinarmedizin. Reihe B. Journal of veterinary medicine. Series B最新文献

The effect of dry-cow therapy was evaluated on the basis of the culling rate, occurrence of clinical mastitis, mean of cow milk somatic cell counts (CMSCC), and milk yield, in a trial including 608 cows. The cows were randomly divided into four groups: control group A (92 cows), group B treated with placebo (base ointment of Benestermycin (Leo) without antibiotics) (105 cows), one intramammary dose per infected quarter, group C treated with Benestermycin (Leo), one intramammary dose being infused in each infected quarter (196 cows); and group D treated with Leocillin with dihydrostreptomycin (Leo); one intramammary dose being used every second day, on four occasions per infected quarter (215 cows). The study included infected cows. If less than three of the quarters of the udder were diagnosed as having mastitis at first sampling, only infected quarters were treated. Otherwise, all quarters were treated. Multivariable analysis showed no significant effect of therapy on culling rate. The control groups (A + B) had a greater increase of cows having at least one case of clinical mastitis compared to the therapy groups (C + D), (from 0.26 to 0.57 in controls comparing to 0.38 to 0.43 in therapy groups). The difference between control and therapy groups during lactation was close to significant both before and after in the lactation after therapy (P < 0.10). The multivariable analysis showed a significant benefit of dry-cow therapy of 0.409 In unit in geometric mean CMSCC (corresponding to 125,000/ml), 200,000/ml in weighted CMSCC and 189 kg milk yield per lactation. According to these results selective dry-cow therapy for cows included in this study is recommended.

The streptococcal cultures used in the present study were isolated from dogs, bovines and humans and could be classified into Lancefield's serological group G. Most of the group G streptococci grew in fluid media as granular sediment with clear supernatant and formed compact colonies in soft agar. The majority of the group G streptococci from dogs and bovines displayed CAMP-like synergistic haemolytic activities on sheep blood agar, fermented lactose and salicin and produced the enzyme alpha-D-galactosidase. The group G streptococci from humans mainly fermented trehalose and produced the enzyme beta-D-glucuronidase. In addition, some of the group G streptococci reacted with type antigen X and R and two cultures with M6 specific antiserum. A positive opacity factor reaction could be observed with few group G streptococci isolated from dogs and bovines, but not with those from humans. In binding studies with 125I-labelled plasma proteins most of the cultures interacted with 125I-immunoglobulin G and 125I-albumin. Binding of 125I-IgG was more pronounced among group G streptococci isolated from humans. The determination of antibiotic susceptibility revealed that most of the group G streptococci were susceptible to bacitracin, cefoxitin, clindamycin, erythromycin, gentamicin, penicillin and sulfamethoxazole-trimethoprim. Some of the cultures were resistant to minocycline, neomycin and tetracycline. All this data clearly distinguished group G streptococci isolated from animals and humans and could additionally be used for individual characterization of this microorganism. This might be useful in epidemiological aspects and contribute to understanding infections caused by these bacteria.

The IgG seroreaction of Salmonella-infected cattle herds against a fimbrial antigen (SEF14) was compared with that against lipopolysaccharide (LPS) antigens. Sera from 23 dairy herds (n = 205) from an island with no occurrence of salmonellosis, four herds (n = 303) with recent outbreaks of S. dublin and four herds (n = 168) with recent outbreaks of S. typhimurium, were tested in a SEF14-ELISA, S. dublin LPS (0:1, 9, 12) ELISA and S. typhimurium LPS (0:1, 4, 5, 12) ELISA. At a cut-off OD of 0.5, only one of the animals tested from the salmonellosis-free island showed significant seroreaction against the SEF14 antigen, which was confirmed in a Western-blot analysis. Three out of the four S. dublin-infected herds had several seroreactors in the SEF14-ELISA, whereas all the four herds were positive in the 0:1, 9, 12-ELISA. All but two samples (both from the same herd) in the four S. typhimurium-infected herds, positive in the 0:1, 4, 5, 12-ELISA, had OD values below 0.5 in the SEF14-ELISA. The results indicate that cattle can produce detectable specific antibodies against fimbrial antigens which may be used for screening of S. dublin-infected herds, particularly in areas with low prevalence of salmonellosis, increasing the predictive value of serology.

The microbiological characteristics of otic exudates from 26 dogs with chronic otitis externa was studied with special reference to the implication of yeasts in the aetiology of the disease. A high frequency of yeasts and Staphylococcus aureus were isolated, alone or in association. In reference to the yeasts, there was a clear predominance of the genus Candida (48% of the total yeasts). Malassezia (Pytirosporum) represented only 3% of the isolates. It can be concluded that yeasts have an important role in the pathogenicity of this disease. For the microbiological diagnosis of otitis externa, we recommend the simultaneous use of Columbia/5% Sheep Blood Agar and Sabouraud-Dextrose without antibiotic addition, the use of 37 degrees C as the incubation temperature and direct microscopic observation of the sample before culture.

The effects of short-term restraint stress on leukocyte counts, lymphocyte proliferation and lysis of erythrocytes were studied in six gilts. A catheter was inserted into the jugular vein and two blood samples were collected before the onset of stress. Thereafter a hog snare was applied and blood samples were collected at 0.5, 2, and 3.5 min after the start of snaring. Neither the total WBC number, nor the total number of lymphocytes, or the total number of polymorphonuclear leukocytes changed significantly throughout the study. This was also true for the degree of intravasal lysis of erythrocytes. In whole blood cultures stimulated with pokeweed mitogen, an increase (P < 0.05) in the lymphocyte proliferation was recorded in samples collected 3.5 min after the start of restraint. In the mononuclear cell cultures, no significant changes were found in lymphocyte proliferation of blood collected 3.5 min after the start of restraint. Taken together, the short-term stress during blood sampling may affect the cell-mediated immunity but not the leukocyte count nor lysis of erythrocytes in pigs.

The specific lacrimal fluid IgA levels and the specific serum IgG levels of broiler chicks (meat type hybrids (MT)), brown-egg layer chicks (heavy layer (HL)), and white leghorn chicks (light layer (LL)) were compared after infectious bronchitis virus (IBV) ocular vaccination at 1 day of age. All birds were maintained as a mixed population throughout the experiment of 45 days. The class specific antibody levels were determined at regular intervals by enzyme-linked immunosorbent assays. All birds responded to the vaccination stimulus as shown by a significant increase of antibody levels in both serum and lacrimal fluid. When comparing the IgG response of the chicken lines tested, LL chicks showed higher serum IBV-IgG values at the time of maximal response at days 5 and 9 post-vaccination (pv). This bird group also showed a more homogeneous (lowest coefficient of variation of values) serum IgG response. On day 13 pv and until the last serum sampling day (day 41 pv) all three chicken types showed statistically identical serum IBV-IgG levels. The local IgA response detected in lacrimal fluids showed differences between the chicks at the time of maximal levels (days 5 to 14 pv), the response of LL chicks being the highest. LL chicks maintained higher specific IgA levels than MT and HL chicks almost throughout the experimental period. According to the coefficient of variation of the absorbance values (36%), the IgA response shown by LL chicks was the most homogeneous.

Immunoglobulin G (IgG) binding proteins on the surface of Streptococcus suis could be readily detected by direct cultivation of the bacteria on nitrocellulose membranes and subsequent treatment of the membranes with human IgG. Among the 75 S. suis isolates tested two cultures (S. suis P43, S. suis P143) caused a blue colouration of the membranes indicating IgG binding activities. The IgG binding proteins could be solubilized by heat treatment of the bacteria at an acid pH and also by mutanolysin treatment. Western blot analysis revealed numerous protein bands with IgG binding activities. The IgG binding proteins were also released into the culture supernatant of the bacteria. This could be detected for 51 of the 75 S. suis using a microfiltration assay. In binding studies with 125I-IgG S. suis P43 and S. suis P143 but none of the other S. suis isolates showed a significant binding of the protein. These two cultures additionally bound 125I-albumin, 125I-alpha 2-macroglobulin and 125I-fibrinogen all from humans but not 125I-chicken IgG or 125I-human haptoglobin 2-1. The binding profiles of the two S. suis cultures tested indicate a close relation of these binding proteins with streptococcal protein G.

To determine the prevalence of A. pleuropneumoniae serotypes in Finnish pig populations, 692 blood samples of sows were randomly collected from Finnish slaughterhouses. These were assayed with a direct ELISA for 12 Actinobacillus pleuropneumoniae serotypes. The specificity of the ELISA was tested using rabbit antisera against these serotypes. Cross-reactions were detected between serotypes 6 and 8 and between serotypes 1, 9 and 11, and serotype 5 antiserum reacted with serotype 6 antigen, but the other serotypes did not cross-react. When assaying the blood samples serotype 3 and 2 antibodies were found in 51% and 26% of samples, respectively. Other serotypes were found only in smaller numbers. Most of the samples, 61%, had antibodies towards some serotype of A. pleuropneumoniae. Antibodies towards serotypes 2 and 3 were found in pigs throughout Finland.

Prepartum bacteriologic examination of secretions from 42 dairy heifers 12-14 weeks prepartum revealed a total of 24 Staphylococcus aureus infected quarters, 53 Staphylococcus species infected quarters, and 20 Streptococcus species infected quarters. Prepartum intramammary therapy of primigravid dairy heifers with two commercially available dry cow antibiotics (penicillin-novobiocin or cephapirin) resulted in cure rates of 94%, 97%, and 100% for S. aureus, Staphylococcus species, and Streptococcus species intramammary infections (IMI), respectively. No protective effect was observed for dry cow treatment of uninfected quarters of heifers for any of the antibiotic preparations. No antibiotic was detectable in heifer secretions collected at parturition indicating that antibiotic concentrations may have fallen below protective levels prior to parturition.