Prevention of cervical lymphadenitis in guinea pigs by vaccination

Cervical lymphadenitis, caused by beta hemolytic Streptococcus of Lancefield's group C, was experimentally produced in guinea pigs. Experimental transmission of cervical lymphadenitis was successful when a scratch in the oral mucous membrane was inoculated with a strain of the causative organism which had been isolated during an epizootic of cervical lymphadenitis. Animals without a mouth lesion did not develop the disease when inoculated in the same manner. Another strain, obtained from the American Type Culture Collection (ATCC-12960) was also used. This latter strain was found to have a low degree of pathogenicity for guinea pigs, and it was used for immunization experiments. Seventy-nine percent of animals inoculated orally with strain 12960 withstood later challenge with the virulent strain, whereas only 5% of the controls withstood the same challenge.