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Seroepidemiologic survey for adenovirus infection in lambs.
1993
Lehmkuhl H.D. | Cutlip R.C. | Brogden K.A.
A serologic survey was conducted to determine the prevalence and seroconversion rates for ovine adenovirus (OAV) serotypes 1-4 and bovine adenovirus (BAV) serotypes 2, 3, and 7 in sheep in Iowa and in surrounding states. For 2 consecutive years, paired serum samples were obtained from 1- to 2-month-old lambs as they entered a ram test station and, again, 2 months later. Sera were tested for adenovirus antibodies by use of a microtitration serum virus-neutralization test. At the time of entry, high prevalence of antibody (titer greater than or equal to 2) was detected to all tested adenoviruses except BAV-3. All adenoviruses were active in the ram test station both years, as indicated by greater than or equal to fourfold increase in adenovirus antibody titer (seroconversion) in some of the lambs. The prevalence and seroconversion rate for OAV-1 was 94.0 and 7.2%, respectively; for OAV-2, 98.6 and 15.1%; for OAV-3, 86.5 and 11.0%; for OAV-4, 98.4 and 13.2%; for BAV-2, 97.6 and 22.4%; for BAV-3, 11.4 and 3.8%; and for BAV-7, 81.6 and 4.5%. The results indicate that adenovirus infections were widespread in the sheep population and that the prevalence of active infection based on seroconversion rates was approximately 45%.
Show more [+] Less [-]Total and differential leukocyte counts, N-acetyl-beta-D-glucosaminidase activity, and serum albumin content in foremilk and residual milk during endotoxin-induced mastitis in cows
1993
Foremilk, residual milk, and blood samples were studied for 10 days during acute mastitis episodes induced by endotoxin infused via the teat canal. Quarter milk and blood samples were collected frequently for 3 days after the infusion and thereafter once or twice daily. Leukocyte concentration in milk and blood was determined by flow cytometry. Within 2 hours after infusion of the endotoxin, clinical mastitis was observed. Total leukocyte concentration and proportion of neutrophils increased significantly (P < 0.05) by postinfusion hour (PIH) 2 in foremilk and by PIH 4 in residual milk. From PIH 2, serum albumin content and N-acetyl-beta-D-glucosaminidase activity were significantly increased in both fractions. Neutrophils were the predominant leukocyte population in both fractions until PIH 59. From PIH 72, lymphocytes were the predominant cell population until PIH 175 in foremilk and until PIH 223 in residual milk. Serum albumin content and N-acetyl-beta-D-glucosaminidase activity in residual milk was significantly lower than in foremilk from PIH 4 to 24 and from PIH 24 to 59, respectively. Regarding total and differential leukocyte counts, values for the 2 fractions followed the same pattern throughout the course of inflammation, probably owing to frequent sample collection. Total and differential cell counts tended to differ between the fractions during some periods, although differences were not statistically significant. When samples were taken less frequently, the total leukocyte concentration in residual milk was higher than that in foremilk. Although sample collections were frequent, clustering of immature neutrophils was not observed in the cytofluorogram of blood leukocytes in this study. Residual milk seems to be the fraction that best reflects the condition in the quarter at the particular time when the milk sample is taken. Results also indicate that residual milk reflects the condition of the secretory tissue, as well as the lower regions of the gland.
Show more [+] Less [-]Enzyme-linked immunosorbent assay for serologic detection of Salmonella dublin carriers on a large dairy
1993
Cows and calves from a 1,600-cow drylot dairy were screened for IgG antibodies to Salmonella dublin lipopolysaccharide (LPS), using an indirect ELISA. The ELISA was performed on milk samples from lactating cows and on sera from nonlactating cows and calves. Fecal samples were collected from calves and nonlactating cows for culture of Salmonella spp. All seropositive cattle were retested by culture and ELISA 5 times at monthly intervals or until antibody concentration decreased. None of the cattle remained culture-positive and seronegative. Prior to and during the sample collection period, approximately 30% of calves < 8 weeks old died of S dublin infection. Vaccination of cows with a killed S dublin/S typhimurium vaccine at cessation of lactation was a routine management practice. The ELISA-determined Igg response to vaccination had decreased by 50 days after vaccination. Eight cows and 5 calves that maintained a high serologic response to S dublin were purchased and moved to a research facility for 6 months of intensive monitoring. Lactating cows were milked twice daily, and culture of milk and feces for Salmonella spp was performed 5 times/wk. Serum IgG antibodies to S dublin LPS were measured weekly, using ELISA. At the end of 6 months, all 13 cattle were necropsied and tissues were obtained for culture of Salmonella spp. All 8 cows and 5 calves maintained persistently high ELISA titer for the 6 months of testing, and shed S dublin in the milk and/or feces during the same period. On this basis, they were termed S dublin carriers. Salmonella dublin was isolated from mammary tissue of 2 calves at necropsy, indicating that bacteremia may be a mode of mammary infection by S dublin. Results of the study indicated serologic testing can be used successfully on a large dairy to identify S dublin carrier cattle. Using initial milk screening, 42 of 1,268 lactating cows were identified as suspect, requiring repeated serologic testing. One nonlactating cow, 7 of the 42 suspect lactating cows, and 5 of the 222 calves maintained an Igg response, and were found to be S dublin carriers. Carrier cows shed S dublin in 3.35% of fecal samples and 2.51% of milk samples, and carrier calves shed S dublin in 17.26% of fecal samples.
Show more [+] Less [-]Leukocyte mobilization to skin lesions in dogs
1993
Wisselink, M.A. | Koeman, J.P. | Willemse, T.
A suction blister technique was used in 10 healthy dogs to remove the epidermis from the dermis in a standardized way. Collection chambers were attached to these skin windows and filled with autologous serum to attract exudative neutrophils. The chambers were emptied by fine-needle aspiration at 4-hour intervals and were refilled with serum for 24 hours after the Int aspiration. The collected cells were counted, differentiated, and stained, using the trypan blue dye-exclusion method to determine cell viability. Multiple skin biopsy specimens obtained during the procedure were examined histologically. The chamber fluid collected after 24 hours was cultured for bacteria. Increasing numbers of viable neutrophils were collected during the 24-hour period from the induced skin windows. In all but 1 dog, sufficient viable neutrophils could be collected to perform further functional tests in vitro. Our conclusion is that this technique might be useful to study chemotaxis in vivo and to perform functional tests on exudative neutrophils.
Show more [+] Less [-]Consequences of dose-dependent immunosuppression by progesterone on parasitic worm burdens in lambs
1993
Fleming, M.W. | Gamble, H.R.
Eighteen female lambs with prior exposure to Haemonchus contortus infections were ovariectomized and assigned to 1 of 3 replacement regimens: 0, 25, or 250 mg of progesterone/d delivered IM. After 3 weeks of hormonal treatment, all lambs were inoculated with 100,000 infective larvae of H. contortus. After 8 weeks of hormonal treatment, a blastogenic assay was performed on blood lymphocyte populations, and the abomasum from each lamb was obtained for larval and adult worm recoveries of H. contortus. Lambs of the 25 mg of progesterone group had significantly (P < 0.05) reduced blastogenic response to concanavalin A and greater adult and larval populations, compared with controls. Lambs of the 250 mg of progesterone group had worm burdens and lymphocyte blastogenesis values intermediate between those of the other treatment groups.
Show more [+] Less [-]Serum interleukin-6 concentrations in endotoxin-infused neonatal foals
1993
Robinson, J.A. | Allen, G.K. | Green, E.M. | Garner, H.E. | Loch, W.E. | Walsh, D.M.
Serum interleukin-6 (IL-6) concentration was measured in 11 colostrum-fed (CF) and 8 colostrum. deprived (CD) 2- to 3-day-old foals after foals were infused with lipopolysaccharide LPS; Escherichia coli O55:B5 endotoxin, 0.5 micrograms/kg of body weight in sterile saline [0.9% NaCl] solution. Four CF and 2 CD foals were given saline solution alone. Serum IL-6 concentration was estimated by use of an in vitro proliferative bioassay, using the IL-6 dependent B.13.29 clone 9 cells. Interleukin-6 concentration increased in all LPS-infused foals, and geometric mean serum IL-6 concentration was significantly higher in CF than CD foals 30 and 90 minutes after infusion. Both LPS-infused. groups had multiple spikes of mean IL-6 concentration that peaked at 120 minutes in CF foals and 150 minutes in CD foals. Results indicated that IL-6 is produced in neonatal foals in response to LPS infusion. Furthermore, colostrum deprivation resulted in longer times to peak mean serum IL-6 concentration and tended to reduce serum IL-6 concentration in neonatal foals.
Show more [+] Less [-]Serum tumor necrosis factor alpha concentrations and clinical abnormalities in colostrum-fed and colostrum-deprived neonatal foals given endotoxin
1993
Allen, G.K. | Green, E.M. | Robinson, J.A. | Garner, H.E. | Loch, W.E. | Walsh, D.M.
We examined the effect of infusion of lipopolysaccharide (LPS) on serum tumor necrosis factor alpha (TNF alpha) concentration and clinical attitude in 2- to 3-day-old colostrum-fed (CF) and colostrum-deprived (CD) foals. Eleven CF and 8 CD neonatal foals were given a bolus IV infusion of Escherichia coli 055:B5 lipopolysaccharide (0.5 microgram/kg of body weight) in sterile saline (0.9% NaCl) solution. Four CF and 2 CD foals were given saline solution alone. Serum IgG concentration and serum anti-LPS IGG(T) antibody titer were determined for each foal prior to infusion. A depression index was used to score clinical abnormalities. Serum TNF alpha concentration was estimated by use of an in vitro cytotoxicity bioassay that used WEHI 164 clone 13 cells as targets. The cytotoxic serum factor was identified as TNF alpha by immunoprecipitation with caprine antisera raised against the 15 NH2-terminal amino acids of human TNF alpha. Tumor necrosis factor alpha was not detected in any preinfusion serum samples nor in any samples from foals given saline solution alone. Serum TNF alpha concentration increased in all LPS-infused foals and peaked between 60 and 90 minutes after infusion. Serum TNF alpha concentrations, expressed as mean percentage of peak serum TNF alpha concentration, persisted longer in CD foals given LPS than in CF foals given LPS. All LPS-infused foals displayed clinical signs of endotoxemia, but mean depression index scores of the CF and CD foals given LPS were not significantly different at any time. Serum TNF alpha concentrations were correlated with depression index scores in both LPS-infused groups. Mean rectal temperature increased by 1 hour and remained high for 4 hours after infusion in CF foals given LPS. Mean rectal temperature in CD foals given LPS was significantly less than that for CF foals given LPS 1 and 2 hours after infusion and was higher than mean rectal temperature prior to infusion 3 and 4 hours after infusion. Neither preinfusion total serum IgG concentration nor serum anti-LPS IgG(T) antibody titer correlated with peak serum TNF alpha concentration in the 19 LPS-infused foals.
Show more [+] Less [-]Antigenic analysis of Chlamydia pecorum and mammalian Chlamydia psittaci by use of monoclonal antibodies to the major outer membrane protein and a 56- to 64-kd protein
1993
Kuroda-Kitagawa, Y. | Suzuki-Muramatsu, C. | Yamaguchi, T. | Fukushi, H. | Hirai, K.
Monoclonal antibodies were prepared against 40- and 56- to 64-kd antigens of Chlamydia pecorum strain Maeda, which was isolated from a cow with pneumonia. Using the monoclonal antibodies, 5 strains of C pecorum, 25 strains of mammalian and 19 strains of avian C psittaci, 1 strain of C pneumoniae, and 3 strains of C trachomatis were analyzed for immunologic reactivity by use of the indirect immunofluorescent test. Monoclonal antibody analysis revealed immunologic relatedness between C pecorum and mammalian strains of C psittaci, which were completely differentiated from the other avian strains. Bovine strains were distinguished from ovine strains. Antigenic diversity mm observed for bovine and ovine strains. Feline- and guinea pig-derived strains were shown to be immunologically different from bovine and ovine strains. Results provide the basis for typing and epidemiologic study of bovine and ovine strains of C pecorum and C psittaci.
Show more [+] Less [-]Prevention of pathophysiologic and immunomodulatory effects of gastrointestinal nematodiasis in calves by use of strategic anthelmintic treatments
1993
Yang, Zhunhe | Gibbs, H.C. | Xiao, L. | Wallace, C.R.
Effects of strategic anthelmintic treatment on pathophysiologic and immunologic changes induced by infection with Ostertagia ostertagi and Cooperia oncophora were studied in 2 groups, of 12 calves each: an infected group, inoculated with 200,000 mixed O ostertagi and C oncophora third-stage larvae (L3) on day 1; and an infected-treated group, similarly inoculated, but treated with ivermectin at 9 and 33 days. All calves were also inoculated at 12 weeks with Brucella abortus vaccine, at 13 weeks with bovine rhinotracheitis vaccine (bovine herpesvirus 1), and at 14 weeks with a soluble O ostertagi L3 extract, then were allowed to graze on a contaminated pasture. Four calves from each group were slaughtered at 7, 11, and 19 weeks of the study. Calves of the infected group had significantly (P < 0.05) lower weight gain than did those in the infected-treated group (60.90 kg vs 75.86 kg). They also had high plasma pepsinogen and serum gastrin values, and low serum albumin concentration from 2 or 4 weeks. Calves in the infected-treated group had steady weight gain and no significant changes in albumin and gastrin values. They also had less severe abomasal lesions and higher carcass yield. Compared with calves of the infected-treated group, those of the infected group had significantly (P < 0.05) lower blood lymphocyte reactivity to phytohemagglutinin at 14 and 16 weeks, to concanavalin A at 10 weeks, to pokeweed mitogen at 14 weeks, and to soluble O ostertagi L3 extract at 2, 4, and 14 weeks. They also had significantly (P < 0.05) lower IgG1 concentration to excretory-secretory antigens of the fourth-stage larvae of O ostertagi at 13, 18, and 19 weeks. In addition, they had significantly (P < 0.05) higher total mean eosinophil count. Antibody responses to B abortus and bovine herpesvirus 1, however, were not different between the 2 groups.
Show more [+] Less [-]Linkage of serum resistance, aerobactin production, and resistance to antimicrobial agents on conjugal plasmids in some strains of Escherichia coli isolated from septic foals
1993
Hirsh, D.C. | Kirkham, C. | Wilson, W.D.
Fifteen isolates of Escherichia coli obtained from the blood and tissues of septic foals had plasmid DNA of size ranging from 2.5 to 93 megadaltons. These isolates grew in normal equine serum (serum resistant), a trait previously documented to be expressed by isolates obtained from blood and tissues of septic foals, but not by isolates obtained from the feces of clinically normal horses. Of these isolates, 3 contained conjugal plasmids that encoded resistance to multiple antimicrobial agents linked to serum resistance and, in 1 isolate, to production of aerobactin as well. Serum resistance and production of aerobactin are related to virulence of septicemic E coli from non-equine sources.
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