Contagious caprine pleuropneumonia: some observations in a field vaccination trial using inactivated Mycoplasma strain F38.

The efficacy of an inactivated Mycoplasma strain F38-saponin vaccine in natural infection with contagious caprine pleuropneumonia was investigated. A total of 10,000 goats were vaccinated, out of which 400 were regularly monitored for a period of six months post-vaccination. Immunised animals remained free from infection throughout the period of observation. The antibody response was followed using complement fixation and slide agglutination tests. Both tests could detect F38 antibody in the majority of vaccinated goats but the slide agglutination test was found to be more sensitive than complement fixation. The significance of the results is discussed.

Detection of antibody to mycoplasma F38 in goat sera by an enzyme-linked immunosorbent assay.

An indirect enzyme-linked immunosorbent assay (ELISA) was developed to screen goat sera at a single dilution for antibody to mycoplasma F38. Antibody was detected in sera of six convalescent goats following experimental infection. Antibody was also detected in 34 sera three to four weeks after vaccination. No antibody was detected in 164 sera from goats without a history of vaccination or infection with contagious caprine pleuropneumonia. The ELISA was more sensitive than the complement fixation test in detecting antibody in vaccinated goats.

Efficacy of different adjuvants to potentiate the immune response to mycoplasma strain F-38.

A study was carried out to determine the efficacy of different adjuvants in enhancing antibody response to sonicated F-38 antigens. Goats were immunised against CCPP using antigens incorporated in Freund's incomplete adjuvant (IFA), saponin, aluminium hydroxide gel and buffered saline (PBS) respectively. Antibody responses were determined. The goats were challenged four months after immunisation to assess their immune status. Two of eight goats given antigen in PBS, six of 10 goats given antigen in aluminium hydroxide, seven of eight goats given antigen in IFA and all 10 goats given antigen in saponin withstood the challenge. Saponin and IFA were similar in their immune potentiation ability and were superior to aluminium hydroxide. As IFA has been considered unsuitable for use in food animals saponin may prove valuable in vaccination of goats against CCPP caused by mycoplasma strain F-38.

Treatment of contagious caprine pleuropneumonia.

A combination of dihydrostreptomycin sulphate (250 mg/ml) and penicillin G procaine (200,000 iu/ml) was used to treat contagious caprine pleuropneumonia caused by F38 strain of mycoplasma. A single dose of either 20, 30, 40 or 50 mg/kg body weight of the dihydrostreptomycin sulphate led to the recovery of the treated goats. The recovered goats did not transmit CCPP to susceptible goats housed with them for 2 months. The goats which recovered were found to be solidly immune to an in-contact challenge in which all the control goats died of CCPP. The treated and recovered goats were found not to be carriers of the organism.