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- Author or Editor: Charles W. Purdy x
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Summary
A comparison of immune variables following lung sensitization with live Pasteurella haemolytica serotype 1 (Ph1)-impregnated agar beads was done in 2 separate trials. The Phi immune variables studied were blood bactericidal activity, serum bacteriolysis, total classical complement, and indirect hemagglutination antibody. Each trial had 16 male weanling goats: 6 controls and 10 principals. In trial 1, each goat was surgically catheterized through the trachea, then the material was deposited in a bronchus. The controls received only agar beads and the principals received agar beads impregnated with live Phi. These goats were studied for 32 days, euthanatized, and necropsied. In trial 2, the controls were each transthoracically injected with agar beads into the left lung and the principals were similarly injected with agar beads impregnated with live Phi. These goats were studied for 35 days, then challenge exposed transthoracically by injection of Phi in saline solution (1.2 × 107 cfu/ml) into the right lung. Four days later, they were euthanatized and necropsied. The volume of lung consolidated tissue was an excellent measure of Phi immunity. Principal goats generated solid protective immunity to subsequent challenge exposure because minimal or no lung consolidation was observed, whereas large volumes of lung consolidation were seen in the controls.
The principal goats in trial 1 gave a weak serum indirect hemagglutination Phi antibody response, which was attributed to the bronchial method of depositing the Phi. The corresponding response of the control group remained negative. The Phi agar beads (1 × 106 cfu in 0.5 ml) protected the bacteria from immediate phagocytosis and lysis as indicated by the induced pneumonic deaths of 2 principals 5 days later. Also, live Phi were isolated on day 32 during necropsy of respiratory tracts of 3 principals. At necropsy, no Phi isolates were found in the controls. Bacteriolytic activity was not induced against Phi in either control or principal groups in this trial.
In trial 2, the indirect hemagglutination Phi antibody response of the controls remained unchanged throughout the study, but antibody titers of the principals increased to a geometric mean of 1:250 seven days after lung injection (1 × 105 cfu in 0.5 ml). Serum bacteriolytic titers on day 0 indicated that both principals and controls could be subgrouped to high or low subgroups on the basis of their bacteriolytic activity. The bacteriolytic activities of the controls remained unchanged during the experiment, and neither control subgroup was protected from Phi challenge exposure. Bacteriolytic activities of the high and low principal subgroups responded differently to Phi agar bead lung injection, but both principal subgroups were protected from lung challenge exposure. The low principal subgroup generated high titers of indirect hemagglutination Phi antibody, whereas, the high principal subgroup generated lower antibody titers. Total complement, serum bacteriolytic, and blood bactericidal profiles were similar in the principal group with high bacteriolytic activity. The immune factors that protected 2 principal subgroups did not appear to be associated with Phi serum bacteriolysis.
SUMMARY
An epidemiologic study of Pasteurella haemolytica serovar 1 (Ph1) in market-stressed feeder calves from 7 farms in eastern Tennessee was conducted. The nasal mucus of each calf was cultured sequentially at the farm of origin (day 0), at an auction market (day 133), and at a feedyard in Texas (days 141, 148, 155, and 169). Of the 103 calves tested, 77 were culture-positive, including 1 on day 0, 1 on day 133, 20 on day 141, 57 on day 148, 50 on day 155, and 14 on day 169. From the 143 Ph1 isolates, 20 enzyme profiles were determined by use of a commercial enzyme system that detects 19 enzymatic reactions; 4 antimicrobial susceptibility profiles were obtained, using the disk-diffusion method, which evaluated susceptibility to 11 antibacterial drugs. All isolates were positive for acid phosphatase and alkaline phosphatase, but were negative for α-galactosidase, α-mannosidase, β-glucosidase, β-glucuronidase, cystine aminopeptidase, N-acetyl-β-glucosaminidase, and trypsin. Other positive enzyme reactions included: leucine aminopeptidase, 140 Ph1 isolates; phosphohydrolase, 90 isolates; α-fucosidase, 63 isolates; esterase (C4), 59 isolates; valine aminopeptidase, 30 isolates; esterase lipase (C8), 24 isolates; β-galactosidase, 2 isolates; and α-glucosidase, chymotrypsin and lipase (C14), 1 isolate each. Thirty-four Ph1 profiles were identified, using combined enzyme and antimicrobial susceptibility profiles. The data indicate that the strains isolated during the feedyard period may have been determined more by farm of origin (P ≤ 0.001) than by habitation with calves from other farms while in the feedyard. The combined enzyme and antimicrobial susceptibility profile method is a rapid and simple epidemiologic technique for tracking Ph1 strains in market-stressed feeder calves.
SUMMARY
A method of inducing Pasteurella haemolytica serotype 1 (Ph1) lung infection in goats, using low numbers of bacteria and without impairing host immunity, was developed. Two trials were conducted. Results of trial 1, using 10 principals (Ph1 agar beads) and 6 controls (agar beads alone), indicated that Ph1 organisms imbedded in agar beads could survive host lung defenses for 32 days. Results of trial 2 indicated that lung immunity in the inoculated goats (principals) was high and they were more protected than controls against a transthoracic challenge of Ph1 (1.18 × 107 colony-forming units) injected into a lung of each goat on posttreatment day 35. When comparing challenge-exposed principals with controls, the controls developed rectal temperatures above normal for a longer time, duration of anorexia was longer, and signs of depression were seen. The controls developed large areas of consolidated lung tissue, more Ph1 isolates were recovered from nasal turbinates and lung tissue, and higher Ph1 concentrations were found in the lungs. The serum Ph1 indirect hemagglutination antibody titers in the principals of both trials increased, compared with titers in controls. Principal goats in ferial 2 had higher Ph1 indirect hemagglutination antibody titers after injection of Phi-impregnated agar beads and less severe lung lesions after challenge exposure than did controls. The small pneumonic consolidated lesions in the principals, compared with extensive lesions in controls after Ph1 challenge exposure, indicated a high degree of immunity after exposure to Ph1 organisms imbedded in agar beads.
Abstract
Objective—To compare Salmonella isolates cultured from feedyard and nonfeedyard (control) playas (ie, temporary shallow lakes) of the Southern High Plains.
Sample Population—Water and muck (sediment) samples were obtained from 7 feedyard playas and 3 nonfeedyard playas in the winter and summer.
Procedure—Each water and muck sample was enriched with sulfur-brilliant-green broth and incubated in a shaker at 37°C for 24 hours. A sample (100 mL) of the incubated bacterial-enriched broth was then mixed with 100 mL of fresh sulfur-brilliant-green enrichment broth and incubated in a shaker at 37°C for 24 hours. After the second incubation, a swab sample was streaked on differential media. Suspect Salmonella isolates were further identified by use of biochemical tests, and Salmonella isolates were confirmed and serovar determinations made.
Results—Salmonella isolates were not recovered from the 3 control playas. Seven Salmonella enterica serovars were isolated from 5 of 7 feedyard playas in the summer, and 13 S enterica serovars were isolated from 7 of 7 feedyard playas in the winter. In the summer, 296 isolates were cultured, and 47 were Salmonella organisms. In the winter, 288 isolates were cultured, and 171 were Salmonella organisms.
Conclusions and Clinical Relevance—Results indicated that feedyard playas are frequently contaminated with many Salmonella serovars. These pathogens should be considered whenever feedyard managers contemplate the use of water from these playas. Water from feedyard playas should not be used to cool cattle in the summer or for dust abatement. ( Am J Vet Res 2004;65:40–44)
SUMMARY
Classical hemolytic complement (C) of calves was analyzed during a protocol designed to imitate the usual market handling of feeder calves from the southeastern United States. Serum C concentrations of the calves (n = 100 × 4 years) were evaluated on their farm of origin, on arrival at an auction market, on arrival at a feedyard, and during their first 4 weeks in the feedyard. Complement concentrations (measured in ch 50 units) were typically lowest at the farm of origin and highest when the calves entered the auction market 28 to 133 days later. Serum C concentrations decreased after the calves encountered the severe stresses of being in the auction market for 7 days, 24-hour truck transport (1,932 km) to the feedyard, and the first 7 days in the feedyard. The C concentrations recovered after 21 to 28 days in the feedyard. Steers had significantly (P ≤ 0.05) lower C concentrations than did heifers in 3 of 4 years at the farm of origin, and in 2 of 4 years at the auction market. Morbid calves had significantly (P ≤ 0.05) lower C values than did healthy calves on day 7 in the feedyard in 3 of 4 years. There were significant differences in C concentrations of calves from different farms of origin in each of the 4 years. There was no significant difference in C concentrations of calves that were vaccinated vs those not vaccinated with Pasteurella haemolytica.
Abstract
Objective—To investigate the effects of sterile fine dust aerosol inhalation on antibody responses and lung tissue changes induced by Mucor ramosissimus or Trichoderma viride spores following intratracheal inoculation in goats.
Animals—36 weanling Boer-Spanish goats.
Procedures—6 goats were allocated to each of 2 M ramosissimus–inoculated groups, 2 T viride–inoculated groups, and 2 control (tent or pen) groups. One of each pair of sporetreated groups and the tent control group were exposed 7 times to sterilized fine feedyard dust (mean ± SD particle diameter, < 7.72 ± 0.69 μm) for 4 hours in a specially constructed tent. Goats in the 4 fungal treatment groups were inoculated intratracheally 5 times with a fungal spore preparation (30 mL), whereas tent control goats were intratracheally inoculated with physiologic saline (0.9% NaCl) solution (30 mL). Pen control goats were not inoculated or exposed to dust. Goats received an IV challenge with equine RBCs to assess antibody responses to foreign antigens. Postmortem examinations were performed at study completion (day 68) to evaluate lung tissue lesions.
Results—5 of 7 deaths occurred between days 18 and 45 and were attributed to fine dust exposures prior to fungal treatments. Fine dust inhalation induced similar lung lesions and precipitating antibodies among spore-treated goats. Following spore inoculations, dust-exposed goats had significantly more spores per gram of consolidated lung tissue than did their nonexposed counterparts.
Conclusions and Clinical Relevance—Fine dust inhalation appeared to decrease the ability of goats to successfully clear fungal spores from the lungs following intratracheal inoculation.
Abstract
Objective—To compare the virulence of spores of 7 fungi by tracheal inoculation of goats following exposure of goats to an aerosol of sterilized feedyard dust.
Animals—54 weanling Boer-Spanish goats.
Procedure—A prospective randomized controlled study was conducted. There were 7 fungal treatment groups, a tent control group, and a pen control group (n = 6 goats/group). Goats in the 7 treatment and tent control groups were exposed to autoclaved aerosolized feedyard dust for 4 hours in a specially constructed tent. Goats in the 7 treatment groups were then inoculated intratracheally with 30 mL of a fungal spore preparation, whereas tent control goats were intratracheally inoculated with 30 mL of physiologic saline (0.9% NaCl) solution. These treatments were repeated each week for 6 weeks.
Results—Severity of pathologic changes differed significantly among the 7 fungal treatment groups as determined on the basis of gross atelectatic and consolidated lung lesions and histologic lesions of the lungs. Descending order for severity of lesions was Mucor ramosissimus, Trichoderma viride, Chaetomium globosum, Stachybotrys chartarum, Aspergillus fumigatus, Penicillium chrysogenum, and Monotospora lanuginosa. Trichoderma viride spores were the most invasive and were isolated from the bronchial lymph nodes and thoracic fluid of all 6 goats administered this organism. Spores were observedhistologically in lung tissues harvested 72 hours after inoculation from all treatment groups.
Conclusions and Clinical Relevance—4 of 7 fungal spore types induced significantly larger lung lesions, compared with those induced by the other 3 spore types or those evident in control goats. (Am J Vet Res 2005;66:615–622)
Abstract
Objective—To determine effects of repeated aerosol exposures to fly ash dust on respiratory tracts of tent-confined goats.
Animals—12 weanling Boer-Spanish crossbred goats.
Procedure—Goats were randomly assigned to 2 groups: fly ash treatment group (principal goats, n = 6) or control group (control goats, 6). Aerosolized fly ash dust was provided during a 4-hour period for each of 6 applications given over 3 months and one 2-hour application prior to necropsy. Fly ash particle diameters ranged from 0.1 to 130 µm and averaged 17.8 µm, with 1.5% of fly ash particles in the 0.1- to 5-µm-diameter range. A mean ± SD of 748 ± 152 g/treatment was delivered inside a tent containing principal goats; control goats were placed inside a similar tent for 4-hour treatments without dust. Following treatment, rectal temperatures were taken at 0, 4, 6, 8, 24, and 72 hours; Hcts were recorded at 0, 24, and 72 hours.
Results—Rectal temperatures were significantly increased at 4, 6, and 8 hours and decreased at 72 hours, compared with 0 hours. Mean ± SEM Hct values were significantly increased for principal goats (37.47 ± 0.39%), compared with control goats (36.17 ± 0.42%). A significant increase in the mean area of gross atelectatic lung lesions (1,410 mm2) was found in principal goats (n = 6), compared with control goats (440 mm2; 5).
Conclusions and Clinical Relevance—An increase in atelectatic lung lesions was observed in principal goats, compared with control goats; however, overall, fly ash dust effects were nontoxic. ( Am J Vet Res 2005;66:991–995)
Abstract
Objective
To determine the effectiveness of Pasteurella multocida biovar A, serovar 3 (Pm A:3) killed by exposure to UV light and incorporated with a polyacrylate bead carrier as a vaccine.
Animals
18 weanling male Spanish goats.
Procedure
Prospective, randomized controlled study with 3 treatment groups: positive-control (PC), negative-control (NC), and principal Pm A:3 bacterin (PA) groups. Six PC goats each received live Pm A:3 and polyacrylate beads twice, 22 days apart, by transthoracic injection into the left lung. Six NC goats each received only PA beads twice, 22 days apart, by transthoracic injection. Six principal goats each received Pm A:3 vaccine SC twice, 22 days apart. Fourteen days after the second vaccination, all goats were challenge exposed with live Pm A:3 by transthoracic injection into the right lung, and 4 days later they were euthanatized and necropsied.
Results
Mean volume of consolidated lung tissue at the challenge site was 1.75 cm3 for the PC group, 15.18 cm3 for the NC group, and 3.9 cm3 for the PA vaccine group. The NC group had a significantly (P ≤ 0.002) larger mean volume of consolidated lung tissue than did the PC and PA groups after challenge exposure.
Conclusions
The PA bacterin and the PC groups developed protective immunity against live Pm A:3 challenge exposure. An SC administered, UV light-killed, Pm A:3 bacterin induced protective immunity similar to that induced by virulent live Pm A:3 injected into the target organ, the lung. (Am J Vet Res 1997;58:841–847)
Abstract
Objective
To determine the effectiveness of Pasteurella haemolytica biovar A, serovar 1 (Ph A1) killed by UV light and incorporated with an oil adjuvant or carriers.
Animals
40 weanling male Spanish goats.
Procedure
Goats were randomly allotted to 1 of 6 treatment groups: 4 Ph A1 bacterins (agar beads, polyacrylate beads [PA], phosphate-buffered saline solution, Freund's incomplete adjuvant), live Ph A1 with polyacrylate beads (LiPhPA), and polyacrylate beads (UnVac). Each of 4 Ph A1 vaccines was administered SC twice, 21 days apart, to 1 of 4 groups; another group received only PA beads SC, and the last group received live Ph A1 with PA beads by transthoracic injection into the left lung. 14 days after the second vaccination, all goats were challenge exposed with live Ph A1 by transthoracic injection into the right lung, and 4 days later, all goats were euthanatized and necropsied.
Results
Mean volume of consolidated right lung tissue was 1.02 cm3 for the LiPhPA group, 168.1 cm3 for the UnVac group, 2.3 cm3 for the Freund's incomplete adjuvant bacterin group, 5.53 cm3 for the PA bacterin group, 9.01 cm3 for the agar beads bacterin group, and 7.51 cm3 for the phosphate-buffered saline solution bacterin group. Mean volume of consolidated lung tissue was significantly different between the UnVac group and the other 5 groups.
Conclusion
The LiPhPA group and 4 bacterin groups developed protective immunity against live Ph A1 challenge exposure.
Clinical Relevance
An SC administered, UV light- killed Ph A1 bacterin induced protective immunity equal to that induced by virulent live Ph A1 injected into the target organ, the lung. (Am J Vet Res 1996;57:1168-1174)