ひな白痢の非特異反応鶏に対する加熱抗原の野外応用試験成績

Abstract

Recently, observation was made on some chickens which belonged to a group of birds showing normal rates of laying eggs with regular hatchability and manifesting no abnormal clinical signs, and which gave positive rapid agglutination reactions, although no organisms of Salmonella pullorum had been isolated from them. Then, investigation was carried out on them to clarify the presence of any antigen in them. It was the final purposes of the present study to eliminate such nonspecific reaction and make a more accurate diagnosis.1. Antigen was prepared from the 9-25 strain of Sal. pullorum. The organisms of this strain were suspended in buffer saline solution containing 0.5 per cent of phenol and 0.1 per cent of malachite green, so that a turbidity of ×100 of MacFarland tube 2 might be produced. Then they were heated at 80°C for 15 to 30 minutes.2. In the field, the heated antigen of Sal. pullorum was compared with the commercial antigen in rapid agglutination tests on 119 diseased chickens from which Sal. pullorum had been isolated, and 187 chickens showing nonspecific reactions. As a result, the heated antigen gave rise to reactions not so different from those given by the commercial antigen when the sera of the diseased chickens were examined.3. Of 2, 640 birds collected from 31 poultry farms and showing nonspecific reactions, 892 (34%) gave positive agglutination tests with the commercial antigen. On the other hand, 39 (1.7%) showed positive agglutination tests with the heated antigen. None of them, however, reacted within 30 seconds. In this procedure, the positive rate of nonspecific reaction against the heated antigen was quite different from that against the commercial antigen among the chickens which had manifested nonspecific reactions.