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1.  Respiratory disease in calves produced with aerosols of parainfluenza-3 virus and Pasteurella haemolytica. 
In four experiments, 22 calves were exposed to aerosols of parainfluenza-3 virus, followed by Pasteurella haemolytica at intervals of three to 13 days. The purpose of each experiment was to study viral-bacterial interactions in the respiratory tracts. Two experiments, in which the viral aerosols were diluted by the addition of air, produced sporadic temperature elevations while two experiments with undiluted viral aerosols produced consistent temperature elevations. Diluted viral aerosols produced lobular sized lesions in the lungs and hemagglutinating inhibition antibodies in sera, whilst undiluted aerosols produced a synergistic effect in the form of purulent pneumonia in ten of 14 calves when the interval between viral and bacterial aerosols was from three to ten days. Histopathological changes attributable to the virus only were seen in all experiments, and the histopathological changes due to mixed infection of parainfluenza-3 virus and P. haemolytica are described in detail. This is the first report of extensive purulent pneumonia in calves after parainfluenza-3 virus and P. haemolytica exposure. This was achieved using much smaller inocula than in experiments previously reported.
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PMCID: PMC1320327  PMID: 6290015
2.  Aerosol vaccination of calves with pasteurella haemolytica against experimental respiratory disease. 
Three experiments were conducted on calves in which the efficacy of vaccination with live Pasteurella haemolytica in aerosol was tested by challenge with sequential aerosol exposure to bovine herpesvirus 1 and P. haemolytica. Neither single nor multiple aerosol vaccinations protected against the experimental disease. Macroscopically recognizable rhinitis, tonsillitis, tracheitis and pneumonia occurred in both controls and vaccinates. In one experiment as many as three aerosol vaccinations with live P. haemolytica for up to 20 minutes failed to elicit clinical signs in exposed calves. Pasteurella haemolytica was isolated less frequently from tissues of vaccinated calves than from those of nonvaccinated calves. Pasteurella haemolytica was isolated from deep nasal swabs of 4/14 vaccinated calves five and six days after viral exposure. It was concluded that although bovine herpesvirus 1 vaccination has been shown previously to prevent the experimental disease produced by bovine herpesvirus 1-P. haemolytica, live P. haemolytica vaccination by aerosol will not provide the same protection.
PMCID: PMC1320326  PMID: 6290014
3.  Experimental bovine pneumonic pasteurellosis. I. Prevention of the disease. 
Fifteen three- to six-month old Hereford-cross calves were divided into three groups. The first group was inoculated with bovid herpersvirus 1 (Strain 108), the second with a commercial intranasal vaccine against bovid herpesvirus 1 and the third group acted as controls. At least three weeks after vaccination, all calves were weaned, placed in an environmental chamber at 25.0 degrees C (days) and -13.3 degrees C (nights) and challenged with an aerosol of bovid herpesvirus 1 followed four days later by an aerosol of Pasteurella haemolytica. All surviving calves were sacrificed four days after the second aerosol. None of the calves inoculated with bovid herpesvirus 1 virus or the commercial vaccine developed a generalized pneumonia, although there were one or two nodules (4--8 mm diameter) in two of the calves given the commercial vaccine. Four of the five control calves had extensive lobar pneumonia at necropsy, two of the five died from the disease. Details of the clinical, pathological, bacteriological, virological and some of the serological findings are reported.
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PMCID: PMC1319889  PMID: 487247
4.  Experimental Bovine Pneumonic Pasteurellosis II. Genesis and Prevention 
Two experiments were conducted. In the first, 16 crossbred Hereford calves were divided into two equal groups. The first group was vaccinated intranasally with a commercial vaccine against bovid herpesvirus 1 and the second group was unvaccinated. The calves were later exposed to an aerosol of bovid herpesvirus 1 (strain 108) for five minutes. Four calves from each group were subjected to transportation and four calves from each group were kept in an environmental chamber for four days. Four days after viral aerosol all calves were exposed to an aerosol of Pasteurella haemolytica and the same subgroups were again transported or held in the chamber for a further four days.
The calves that did not die from pneumonia were necropsied ten days after the final day of transport. Pulmonary lesions were present in both vaccinated and control animals but were less extensive in the vaccinated calves. Six of eight vaccinated but none of the eight control calves survived.
In the second experiment, eight crossbred Hereford calves were divided into two equal groups. One group was vaccinated with bovid herpesvirus 1 (strain 108) and the other acted as controls. Four weeks later all calves were sequentially exposed to aerosols of bovid herpesvirus 1 (strain 108) and P. haemolytica four days apart. Three of the four controls but none of the vaccinates died from pneumonia. Every lobe of the lungs in all the controls was affected by pneumonia while no pulmonary lesions were found in the vaccinated calves. The differences in efficacy of the modes of vaccination and the possible role of transport stress are discussed.
PMCID: PMC1319890  PMID: 487248
5.  Pneumonia in Calves Produced with Aerosols of Bovine Herpesvirus 1 and Pasteurella haemolytica 
In each of 11 experiments, four calves were exposed first to an aerosol of bovine herpesvirus 1 (BHV1, virus of infectious bovine rhinotracheitis) and second to an aerosol of Pasteurella haemolytica. The interval between aerosols was three to five days. In two other experiments, calves were exposed only to a bacterial aerosol. Climate was controlled for all experiments from the day of viral exposure and for eight of the experiments it was also controlled for four to six days before the first aerosol. The concentration of infectious doses of virus in the aerosols and the number of bacteria in the aerosols of each calf were determined. Macroscopically recognizable rhinitis, tonsillitis, laryngitis, tracheitis and pneumonia of lobar distribution in 42 lobes from 11 calves were seen in five experiments in which bacterial aerosol followed the viral aerosol by at least four days. One calf died with marked respiratory disease in each of four experiments within four days of exposure to the bacterial aerosol. Production of pneumonia was dependent on an interval between aerosols of at least four days but not on the condition of controlled climate on the environmental chamber either before or after the viral aerosol nor on the period of habituation allowed calves of some experiments.
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PMCID: PMC1277638  PMID: 210912
7.  The recovery of a Mycoplasma from Citellus richardsonii richardsonii (ground squirrel). 
Swabs from the upper respiratory tract, external genitalia and the eyes and portions of the lungs, spleen, kidney, liver and uteri of two ground squirrels were cultured for mycoplasma. The upper respiratory tracts of both animals were positive for mycoplasma as were the lungs, liver and spleen of one of the animals. Preliminary serological studies, growth inhibition test against 38 known antisera, growth precipitation against 15 antisera and fluorescent antibody technique with eight conjugates have, with the exception of a minor precipitin reaction against Mycoplasma bovirhinis, all been negative. The isolates are believed to be representative of either one or more new mycoplasma species.
PMCID: PMC1277725  PMID: 861842
8.  Recovery of Pasteurella hemolytica from aerosols at differing temperature and humidity. 
A Pasteurella hemolytica suspension with fetal calf serum was aerosolized in a standard system with ambient temperature of 30 or 2 degrees C and relative humidity conditions of 90 or 60%. The number of organisms sprayed in five minutes and the number recovered from one third of the aerosol during these five minutes was determined. Recoveries were influenced by temperature difference between aerosol and collecting fluid. Recoveries ranged between 0.059--0.94%.
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PMCID: PMC1277722  PMID: 861840
9.  Mycoplasma agalactiae subsp. bovis in pneumonia and arthritis of the bovine. 
The pneumonic lungs of 42 cattle from 26 feedlots were examined for the presence of mycoplasma, pathogenic bacteria and viruses. Four animals representative of two lots failed to yield mycoplasma. One of these yielded the virus of infectious bovine rhinotracheitis and Pasteurella hemolytica, the other yielded only P. P. multocida. Nine animals in eight lots yielded Mycoplasma sp.: five of these were M. bovirhinis, two were M. arginini and two were untypable. All of these animals yielded one or more of P. hemolytica, P. multiocida, infectious bovine rhinotracheitis virus or bovine virus diarrhea virus. Twenty-five of 29 animals in 16 lots yieled M. agalactiae subsp. bovis from lung tissues. The same organism was recovered from the arthritic joints of 12 of these animals. Eight of the 25 animals yielded no other pathogen and all of these had not received any treatment. Nine of the 25 M. agalactiae subsp. bovis positive animals also yielded one or more of P. hemolytica, P. multocida, Corynebacterium pyogenes or infectious bovine rhinotracheitis virus. Bacteriological and virological studies were not completed for the remaining eight of the 25 positive animals. In five lots of cattle which had not received medication for pneumonia and for arthritis only M. agalactiae subsp. bovis was recovered. Twenty-five grossly normal lungs obtained from normal cattle at the time of slaughter were cultured and all were negative. The possible role of M. agalactiae subsp. bovis in pneumonia and arthritis was discussed.
PMCID: PMC1277697  PMID: 832194
10.  The indirect hemagglutination test for the detection of antibodies in cattle naturally infected mycoplasmas. 
Stable mycoplasma antigens for the indirect hemagglutination test (IHA) were prepared employing glutaraldehyde treated sheep erythrocytes sensitized with Mycoplasma agalactiae subsp. bovis and Mycoplasma bovigenitalium antigens. Employing these antigens mycoplasma antibodies were detected in sera from cattle which had mastitic symptoms due to natural infection with either M. agalactiae subsp. bovis or M. bovigenitalium. A total of 200 cows from four herds were examined at varying intervals for the presence of M. agalactiae subsp. bovis and for the detection of antibody using growth inhibition and IHA tests. Mycoplasmas were isolated from 37 animals. Growth inhibiting antibody was detected from 56 of the 200 animals. In the IHA tests, antibody titer greater than or equal to 1:80 were detected in 148 animals, 76 of these having antibody titers greater than or equal to 1:160, while sera of 116 normal control animals had no growth inhibiting antibody and none had IHA antibody titers greater than 1:40. M. bovigenitalium was isolated from the milk of three of 26 animals in a fifth herd during an outbreak of mastitis. Growth inhibiting antibodies were demonstrated in the sera of ten of the 26 animals. However, the IHA test detected antibody titers of greater than or equal to 1:160 in 13 animals and of 1:80 in one of the 26 animals. To determine the specificity of the IHA tests, M. agalactiae subsp. bovis and M. bovigenitalium antigens were reacted with rabbit hyperimmune typing sera produced against 12 species of bovine mycoplasmatales. Homologous antisera showed IHA antibody titers of 1:1280 and 1:2560 against M. agalactiae subsp. bovis and M. bovigenitalium respectively, whereas heterologous antisera showed IHA antibody titers of less than or equal to 1:20. Also eight type-specific bovine antisera were reacted with M agalactiae subsp. bovis and M. bovigenitalium antigens in homologous and heterologous tests. Homoogous reactions showed IHA antibody titers greater than or equal to 1:320, whereas heterologous reactions showed IHA titers of less than or equal to 1:20. This IHA test promises to be useful for the detection of bovine mycoplasma antibodies in sera from cattle infected with M. agalactiae subsp. bovis or M. bovigenitalium. Thes test is sensitive, reproducible and specific and the technique is relatively simple and rapid. The antigens were stable for at least seven months.
PMCID: PMC1277514  PMID: 1000374
11.  Mycoplasma species recovered from the reproductive tracts of western Canadian cows. 
Samples of cervico-vaginal mucus from 633 animals from 110 herds were cultured and yielded the following mycoplasmas: T-strain--88: Mycoplasma bovigenitalium--79, Mycoplasma spp. (Leach Group 7)--7, Acholeplasma laidlawii--4, Mycoplasma bovirhinis--2 and one not typable. Uterine exudates and endometrial scrapings from 80 infertile cows in two herds were examined. Four animals were positive, M. bovigenitalium was isolated three times, A. laidlawii and Mycoplasma arginini once each. Sixty-five normal uterine contents from pregnant cows were examined, one yielded M. bovigenigalium and the same organism was recovered from the fetal kidney. T-strain mycoplasma, M. bovigenitalium and other Mycoplasma spp. appear to be a part of the normal flora of the cervico-vaginal region of clinically normal one and two year old bred heifers in Alberta and Saskatchewan. Although M. arginini was not recovered from the cervico-vaginal region, a single recovery was made from the uterus of an infertile cow.
PMCID: PMC1277433  PMID: 1125831
14.  Mycoplasma and Associated Bacteria Isolated from Ovine Pink-eye 
A mycoplasma was recovered from the untreated conjunctival membranes of nine sheep affected by Pink-eye. It was neither isolated from the conjunctiva of treated animals which were affected nor from the conjunctiva of normal animals either in contact or not in contact with affected animals.
Bacteria found on normal conjunctival membranes were Neisseria ovis, Escherichia coli, Staphylococcus epidermididis, Streptococcus and Bacillus spp.
Bacteria found in clinical cases of Pink-eye were N. ovis, E. coli, a Streptococcus and Pseudomonas spp.
PMCID: PMC1319533  PMID: 4251781
17.  A Mycoplasma Isolated from Cattle with Infectious Bovine Keratoconjunctivitis 
A mycoplasma has been recovered from the eyes of calves in two naturally-occurring outbreaks of infectious bovine keratoconjunctivitis; also from a third group of calves accidentally exposed to an animal which had ocular exudates from one of the outbreaks instilled into its eyes.
The severity of the ocular lesions in infectious bovine keratoconjunctivis outbreaks may be related to a mixed infection with the mycoplasma and Moraxella bovis.
Preliminary typing studies indicate the mycoplasma is not serologically related to any known bovine mycoplasma.
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PMCID: PMC1319444  PMID: 4243033
21.  LETTERS TO THE EDITOR 
The Canadian Veterinary Journal  1974;15(10):300-301.
PMCID: PMC1696683  PMID: 17421991

Results 1-21 (21)