role of domestic animals in the epidemiology of plague. III. Experimental infection of swine

Swine were shown to be clinically refractory to experimental plague. Yersinia pestis, formerly known as Pasteurella pestis, was not isolated from blood or from buccal-cavity cultures 4 hr or more after oral challenge. In spite of the lack of clinical evidence of infection, all of the swine developed high titers of indirect-hemagglutination (IR) antibody specific for Fraction I antigen of Y. pestis within nine days of exposure. Peak titers of IR antibody occurred by day 28 and remained essentially unchanged for a period of 200 days. Swine did not produce complement-fixing antibody against the Fraction I antigen of Y. pestis.