The response of animals to Pasteurella multocida vaccination as measured by PMPT and ELISA

Inglés. The passive mouse protection test (PMPT) is often used during investigations of Haemorrhagic septicaemia (HS). Although this test has been shown to give a good indication of the immunity of individual animals, it is none-the-less expensive, time-consuming and difficult to standardize. Several experiments were conducted during which the PMPT was compared to ELISA as an alternative methods for investigating the response of cattle to vaccination with Pasteurella multocida. A group of cattle were vaccinated with one or two doses of a commercial HS vaccine and the ELISA antibody response was compared with the protective response observed in the PMPT. The PMPT utilised the virulent Katha strain of P. multocida as the challenge strain and the ELISA used a lipopolysaccharide extracted from formalin-killed bacteria of the same strain as the antigen. The use of one or two doses of vaccine as a booster dose made no significant difference in the subsequent antibody response. The correlation (R2=0.740, n718) between PMPT and ELISA was significant (p0.01). A group of cattle and buffalo were also vaccinated with various strains of P. multocida isolated from cattle or bison. All strains produced positive PMPT protective responses and the animals were resistant to challenge with a known HS-causing strain of P. multocida (strain M1404). The ELISA titres of most of the animal were, however, low at the time of challenge and were not a reliable indicator of resistance to infection. The results indicate that both the PMPT and the HS-antibody ELISA are not specific to HS-causing strains of P. multocida but may only indicate previous exposure to Pasteurella antigen

desconocido. Uji proteksi pasif pada mencit (PMPT) sudah sering digunakan dalam penyidikan penyakit Septicaemia Epizootica (SE). Meskipun uji ini telah mampu memperlihatkan petunjuk yang baik dari kekebalan individu hewan, uji ini ternyata cukup mahal, memerlukan waktu yang lama dan sukar distandardisasi. Beberapa percobaan dilakukan untuk membandingkan PMPT dan ELISA yang merupakan uji alternatif untuk menyelidiki respon sapi terhadap vaksinasi dengan Pasteurella multocida. Sekelompok sapi telah divaksinasi dengan satu atau dua dosis vaksin SE komersial dan respon antibodinya diukur dengan ELISA dan PMPT. Hasil kedua pengujian kemudian dibandingkan. PMPT dilakukan dengan menggunakan galur Katha ganas dari P. multocida sebagai galur tantang. ELISA menggunakan ekstrak lipopolysakarida dari bakteri galur sama yang dibunuh dengan formalin sebagai antigen. Penggunaan satu atau dua dosis vaksin sebagai booster ternyata tidak memberikan respon antibodi yang berbeda nyata. Korelasi (r2 = 0,740; n = 718) antara PMPT dan ELISA adalah nyata (p0,01)