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In pullorum disease, the expression of nervous signs has been rarely reported in the field situations until now. During the three years from 1995, the nervous signs were found in four chicken farms situated in Kyung-gi province. Most of the chicks were infected mainly between two and three weeks age and mortality per day was found range from 2.7% to 3% in the epidemiological investigation of infected flocks. All submitted flocks had expressed a typical nervous signs including the torticolis. A total of nine Salmonella strains from all tested flocks were isolated and identified finally as a Salmonella bioserovar pullorum ( S. pullorum) by biochemical and serological method. Among the three antigenic forms, six (66.7%) strains were typed as an intermediate type (XII2 = XII3), whereas three (33.3%) were typed standard type (XII3 > XII2) by both serological and chemical analysis methods. All S. pullorumstrains were resistant to novobiocin, streptomycin, and cephalrothine, respectively and also revealed identical large (85 kbp; SSP) and small plasmid patterns. The genetic relatedness was examined among the SP strains and also between field and live vaccine strain (9R) of S. gallianrum(SG) using the RAPD method. The present method could discriminate among the S. pullorum strains according to their antigenic types and even among the same farm strains. These results suggested that the present method could be used rapid, simple and efficient tools for molecular epidemiological typing study for the specific Salmonella serotypes at the common clinical laboratories.
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