Observation on certain characteristics of fresh and stock cultures of avian Pasteurella multocida
1988
Chowdhury, K.A. | Amin, M.M. | Ali, M.R. | Hossain, W.I.M.A. (Bangladesh Agricultural Univ., Mymensingh (Bangladesh). Dept. of Microbiology and Hygiene)
An investigation was undertaken to record the colonial morphology, antigenic type, serotyping characters and pathogenicity of fresh and stock cultures of the isolates of P. multocida recovered from natural infection in chickens and ducks. Examination of 55 isolates as fresh cultures revealed that 36(65.45%), 14(25.45%) and 5(9.09%) isolates were of mucoid (M), smooth (S) and smooth (SR) variants respectively. When stored for three years, 5(16.66%) out of 30 M-variants retained their antigenic character and the rest changed to S(23.33%), SR(23.33%) or R(36.66%) variants. Serotyping of the isolates as fresh culture and of those stored for three years indicated that most of the M and S variants were typable by both indirect hemagglutination, (IHA) gel-diffusion precipitation or (GDP) tests while SR and R variants responded to GDP tests only. The virulence of the isolates decreased after storage and the M-variants of both fresh and stock cultures were found to be more pathogenic for mice.
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