Status of listeric agglutinins in a sheep flock affected with Listeria ivanovii

Abstract

Status of listeric agglutinins was assessed in a flock of sheep with history of abortion due to Listeria ivanovii. A trypsinized agglutination antigen was prepared from Listeria ivanovii and used for the detection of agglutinating antibodies in standard tube agglutination test (SAT). The serum samples were tested in duplicate-one as a whole serum and second after treatment with 2-mercaptoethanol (2ME) to detect 2ME sensitive IgM and 2ME resistant IgG agglutinins. All the 254 sheep contained listeric agglutinins' in whole serum, but following treatment of sera with 2ME, half of them showed negative reaction in SAT. Sixty sheep showing titres up to 1 :80 with whole serum contained 2ME sensitive IgM only, whereas 94 sheep having titres 1 :320 or above contained 2ME resistant IgG besides IgM. Of the remaining 100 sheep with titre of 1: 160, 2ME resistant 190 agglutinins were seen in 33 animals only. All the aborted sheep contained 2ME , resistant IgG and 2ME sensitive IgM.