الكاتب: Multiple References

Haemophilus somnus produces various types of infection in cattle, such as thromboembolic meningoencephalitis (TEME) after an acute septicemia (2, 10, 18), respiratory infection (23), abortion (4, 27), vulvitis (21), weak calf syndrome (28), and arthritis (26). TEME is a major cause of deaths in feedlot cattle, according to a survey carried out in Canada (15), and has been recognized since 1976 in Japan. H. somnus is a gram-negative, fermentative small rod whose taxonomic position is still unclear (3) and which is found in the respiratory tracts (5, 6) and genital tracts (11, 12) of cattle. As mentioned by Stephens et al. (24), H. somnus may be part of the normal bovine flora, in which case it could be regarded as a poorly invasive opportunist. Whereas the mechanism of H. somnus invasion is still unclear, some factors, including season (5, 7, 19), respiratory infections with virus or mycoplasma (1, 20), and shipment (16, 17), may induce TEME after septicemia.