Excretion of Mycobacterium bovis by experimentally infected cattle.

摘要: Three groups, each of five calves, four to seven months old, were inoculated intranasally with different numbers Mycobacterium bovis. Infection was established readily in the calves which received an inoculum containing either 10(6) or 10(4) colony forming units (cfu). After every infection there a lag period during organisms could not be isolated from specimens nasal mucus. All animals excreted M bovis and time commencement, quantity duration excretion appeared related inoculation dose. Excretion continued for many weeks, two became intermittent over months. given inocula 92 cfu failed develop disease no immunological responses detected; however, secretions one these 100 days after inoculation.