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- Author or Editor: Charles W. Purdy x
- Microbiology x
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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.
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)
Summary
The effectiveness of Pasteurella haemolytica biovar A, serovar 1 (Ph1) subunit vaccines was tested in goats, using challenge exposure by transthoracic injection. Twenty-two weanling male Spanish goats were randomly allotted to 4 groups. Six goats were given 2 transthoracic injections into the lung 18 days apart with live Ph1 impregnated in agar beads (positive controls). Six goats were not given injections (negative controls). Five goats were given 2 transthoracic injections into the lung 18 days apart with 4.6 mg of cytotoxin in agar beads. The remaining 5 goats were given 2 im injections, 18 days apart, into the thigh with 4.6 mg of cytotoxin emulsified in incomplete Freunds’ adjuvant. Twenty-four days after the second injection, all goats were challenge-exposed to live Ph1 by transthoracic injection into the lung, and 4 days later, all goats were euthanatized and necropsied. Serum neutralizing anticytotoxin titer was measured throughout the experiment. Mean volume of consolidated lung tissue was 0.38 cm3 for the positive control group, 32 cm3 for the negative control group; 19 cm3 for the cytotoxin-lung group; and 88 cm3 for the cytotoxin-adjuvant-im group. Only the positive control group was protected from Ph1 challenge exposure. The Ph1 cytotoxin subunit vaccine alone appeared to be ineffective, and the anticytotoxin titer was not correlated with protection.
In a separate trial, 32 weanling male Spanish goats were randomly allotted to 5 groups. Each was given 2 transthoracic injections into the lung 22 days apart. Six goats were given Ph1 cytotoxin impregnated into agar beads; 6 were given Ph1 lipopolysaccharide impregnated in agar beads; 6 were given Ph1 capsule impregnated in agar beads. Six goats were given agar beads only (negative controls), and 6 were given live Ph1 impregnated into agar beads (positive controls). Twenty days after the second injection, all goats were challenge-exposed to live Ph1 by transthoracic injection into the lung, and 4 days later, all goats were euthanatized and necropsied. Mean volume of consolidated lung tissue was 0.14 cm3 for the positive control group, 7.59 cm3 for the negative control group, 11.21 cm3 for the cytotoxin group, 10.19 cm3 for the lipopolysaccharide group, and 1.6 cm3 for the capsule group. Again, only injection of live Ph1 (positive controls) induced solid protection; however, the capsule subunit vaccine induced partial protection against challenge exposure in this trial. Lipopolysaccharide and cytotoxin subunit vaccines were ineffective in protecting goats against challenge exposure with live Ph1.
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
Objectives
To follow incidence of Pasteurella haemolytica (PH) in the upper respiratory tract of healthy calves at the farm and through the marketing process, and to determine the effect of vaccination on PH colonization of the upper respiratory tract and on the incidence of respiratory tract disease (RTD).
Animals
2- to 5-month-old calves (n = 104) from 4 farms.
Procedure
Calves were vaccinated with a killed PH serotype-1 product. Nasal secretion and tonsil wash specimens were cultured for PH, and serum antibody was measured by indirect hemagglutination. Calves with RTD were treated with tilmicosin phosphate.
Results
At the feedyard, 73 calves had RTD. The incidence of RTD was significantly related to the farm of origin, and was inversely related to the PH serum titer at the farm, but was not influenced by vaccination. Isolations of PH serotype 1 however, were reduced by vaccination. The major serotypes of PH encountered were 1 and 6.
Conclusion
Vaccination can reduce the frequency of colonization of the uoper respiratory tract by PH. (Am J Vet Res 1936;57:1317-1320)
