Fifteen newborn germ-free pigs were inoculated with 2 strains, D-282 and T-15, of Streptococcus suis type II. Some pigs also were preinoculated with Bordetella bronchiseptica, which successfully predisposed them to S suis infection. The 2 streptococcal strains were differentiated by muramidase treatment, which released certain high molecular-weight proteins, termed muramidase-released proteins (MRP), from the cell wall of strain D-282, but not from the cell wall of strain T-15. Only strain D-282 (MRP-positive) induced clinical signs of disease and markedly increased neutrophil numbers in pigs. Streptococci were more frequently isolated from fecal swab specimens obtained from pigs inoculated with strain D-282 (MRP-positive) than from specimens obtained from pigs inoculated with strain T-15 (MRP-negative). Both strains were isolated from nasal swab specimens obtained from all infected pigs. Postmortem examination revealed fibrinopurulent meningitis, polyserositis, and polyarthritis in pigs inoculated with strain D-282; this strain was isolated from the CNS, serosae, visceral organs, heart, and joints. Whereas strains D-282 caused several pathologic changes, strain T-15, isolated from the lungs, caused only pneumonia. Both strains were isolated from the tonsils of all pigs. Virulence differed distinctly between the MRP-positive and the MRP-negative strains.

A bacteriophage for Corynebacterium glutamicum strain LP-6 was isolated from swine waste. It belongs to the Siphoviridae family or Bradley morphologic group B, has a narrow host range, and is sensitive to chloroform and resistant to carbon tetrachloride. The phage is unstable (96% inactivation) in swine waste stored for 4 months at 22 C. The DNA has a molecular weight of approximately 20 Md, cohesive ends, and numerous restriction endonuclease sites. The phage differs from other known C glutamicum phages.

Properties of the attachment of Treponema hyodysenteriae to Henle intestinal epithelial (HIE 407) cells were examined. The frequency of attachment depended on the motility and viability of the spirochetes. Rabbit hyperimmune and swine convalescent antisera inhibited attachment. Treatment of HIE cells with neuraminidase had no effect on attachment; however, treatment of spirochetes with the enzyme decreased adherence significantly (P = 0.01). Attachment was inhibited by N-acetylneuraminic acid, D-glucuronic acid, and fetuin. Adherence was increased following coincubation with N-acetylglucosamine or yeast mannan. Surface antigens of T hyodysenteriae, isolated by chemical extraction, competitively inhibited adherence. Concentrated T hyodysenteriae culture supernatant fractions inhibited adherence, but concentrated phosphate buffered-saline washings of the spirochete and concentrated uninoculated media did not inhibit adherence. Sialic acid was detected in unwashed T hyodysenteriae and spent culture supernatant fractions in higher concentrations than from washed spirochetes and uninoculated media. It was concluded that the binding adhesins on T hyodysenteriae for cultured HIE cells may contain sialic acid residues.

A D-xylose absorption test was conducted on 4 healthy mares deprived of food for 12, 36, 72, and 96 hours before the test, with a 13- to 15-day adjustment period between each test. Maximal plasma concentrations after 72 and 96 hours of food deprivation were approximately 36% lower than those obtained after the 12- and 36-hour periods (P = 0.0001). Absorption curves were flatter and the decrease in plasma concentration was slower after the 72- and 96-hour periods of food deprivation. The rate of D-xylose absorption (P = 0.0108) and the initial rate of urinary excretion (P = 0.0117) were slower at 72 and 96 hours. Gastric emptying appeared to be progressively delayed with food deprivation, as evident by the delay in peak D-xylose excretion in urine (P = 0.0268). Areas under the plasma concentration-time curves and quantitites of D-xylose excreted in urine were similar for all periods of food deprivation, evidence that the same amounts of D-xylose were absorbed, despite changes in the plasma curve. A 15-hour collection period was sufficient to recover all D-xylose excreted in the urine, and during all periods 9.8 +/- 0.6% (mean +/- SEM) of the oral dose was eliminated in the urine.

Factors that influenced the in vitro bactericidal activity of bovine neutrophils against Actinomyces pyogenes were investigated. Neutrophils and serum from 2 clinically normal donor cows were incubated with bacteria for 2 hours. To determine bactericidal activity, colony-forming units were counted after a 48-hour incubation on blood agar plates. Microscopic examination indicated that in the presence of serum, bacteria were cell associated after incubation, whereas when serum was replaced by medium, bacteria were not cell associated. Bactericidal activity of neutrophils was similar whether the sera were heat-treated at 56 C for 30 minutes or were not heated. Heating the serum at 65 C for 30 minutes significantly (P less than 0.001) reduced bactericidal activity. Bactericidal activity decreased (P less than 0.001) as serum concentration (greater than 10%) decreased. More than 80% of the bacteria were killed within the 40 minutes of incubation. The opsonizing capacity of serum varied significantly (P less than 0.01) among 12 cows. Similarly, neutrophil bactericidal activity (by cow) was affected significantly (P less than 0.001). Preincubation of serum with A pyogenes significantly (P less than 0.001) reduced the opsonizing ability of the serum. Culture filtrate of A pyogenes was not chemotactic for neutrophils in vitro.

Diacetoxyscirpenol (DAS) was given IV to pigs (0, 0.5, and 1.0 mg/kg of body weight), cattle (0 and 0.5 mg/kg), and dogs (0 and 0.5 mg/kg). Blood was collected and hemograms were done at 0.5-hour intervals for 8 hours. The animals were euthanatized at 8 hours after treatment, and bone marrow samples were taken and examined by light microscopy. Moderate to severe necrosis of bone marrow hematopoietic elements was found in animals given DAS. The sequential increase in the type and number of abnormal cells in the blood suggested a successive destruction of the hematopoietic elements. A marked left shift in the neutrophil population was found in animals given DAS. Metarubricytes and large platelets were found in the blood of animals given DAS. Lymphocytes were replaced with immature cells. Pathologic changes were most severe in the pigs given a dosage of 1.0 mg of DAS/kg. The order of species sensitivity to DAS was pigs greater than dogs much greater than cattle.

Concurrent bacteriologic culture of feces and agar gel immunodiffusion (AGID) testing was performed on all cows and bred heifers over 14 months old in 10 dairy herds during a 32-month period to determine the effectiveness of the AGID test for the detection of subclinical paratuberculosis. Herds were sampled 5 times and, when possible, culled animals were tested again at slaughter. During 5 herd-wide samplings, Mycobacterium paratuberculosis was isolated from 139 fecal specimens obtained from 109 cattle. Results of the AGID test were simultaneously positive 40 of 139 times (28.8%). Thirty-six of the 109 cattle (33.0%) determined to be infected had a positive AGID test result at some point during the 5 herd-wide samplings. When results of tests performed at time of slaughter were included, 117 cattle were identified as infected by culture methods; 55 of these (47.0%) were AGID test-positive at some point during the study. The upper limit of the maximal false-positive rate for the AGID test was 2.1%. On the basis of colony counts from cultures, subclinically infected cows shedding higher numbers of M paratuberculosis in the feces were more likely to have positive AGID test results (P less than 0.0001). In known infected cattle, neither the culture nor AGID test results were consistently positive on repeated testing. Of 48 official calfhood paratuberculosis vaccinates tested as adults, 3 had positive AGID test results and in 1 of these, M paratuberculosis was also isolated from the feces, indicating that the rate of false-positive AGID test results in calfhood vaccinates is low.

Fecal samples from 131 cattle clinically suspect for paratuberculosis were cultured bacteriologically, using the traditional sedimentation processing method and a processing method that included a centrifugation step. Of 16 samples that were contaminated, 6 were culture-positive on at least 1 medium and by 1 processing method. Ten of 131 (7.6%) fecal samples processed by both methods were lost because of contamination. The number of culture-positive samples (using both processing methods) were 65 of 121 (53.7%) on media without miconazole and 60 of 121 (49.6%) on media with miconazole. Seven of the 121 (5.8%) samples were culture-positive, using centrifugation, after 16 weeks' incubation at 37 C. Thirteen of 60 (21.7%) isolates were obtained only with centrifugation, and 10 of these had low colony counts, suggesting that a centrifugation step may have concentrated microorganisms that would have gone undetected without centrifugation. Six of 60 (10%) isolates positive for M paratuberculosis on the sedimentation method were negative on the centrifugation method. Contamination rates were significantly (P less than 0.001) increased when centrifugation was used. The miconazole significantly (P less 0.001) decreased contamination rates when centrifugation was used.

Three serologically indistinguishable viruses from the avian adenovirus type-II splenomegaly virus of chickens, marble spleen disease virus of pheasants, and hemorrhagic enteritis virus of turkeys, were analyzed by restriction endonuclease fingerprinting. The DNA from these viruses were examined with 6 restriction endonucleases (Bgl II, EcoRI, HindIII, Hha I, Xho I, and BamHI). Markedly different DNA cleavage patterns were found in these virus isolates with all the 5 enzymes, except with BamHI, suggesting genetic differences between isolates of adenovirus type II. Restriction endonuclease analyses were found to provide a method for distinguishing genetically different, and yet serologically similar, strains of avian adenovirus type II.

Colostral volume and IgG and IgM concentrations were determined in 6 multiparous mares at foaling and then every 2 hours from 16 to 20 hours after parturition. Serum IgG and IgM concentrations at foaling also were determined in each mare. The rate of mammary secretion was 292 +/- 26 ml/h (range, 202 to 389 ml/h), and the colostral volume was 5.1 +/- 0.5 L (range, 3.2 to 7.0 L). The colostral IgG and IgM contents were 440 +/- 106 g (range, 199 to 855 g) and 3.1 +/- 0.9 g (range, 0.7 g to 7.1 g), respectively. There was no significant correlation between serum and initial colostral IgG and IgM concentration or between serum and total colostral IgG or IgM values. The colostral IgG and IgM concentrations at foaling correlated well with the total colostral IgG and IgM contents, respectively. The initial 250 ml of colostrum contained 10 +/- 1.4% (range, 6.0 to 13.9%) and 6 +/- 1.0% (range, 2.4 to 8.5%) of the total IgG and IgM contents, respectively, and the initial 500 ml of colostrum contained 20 +/- 2.7% (range 12.0 to 27.1%) and 14 +/- 1.2% (8.2 to 17%) of the total colostral IgG and IgM contents, respectively.