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Chapter 10 : Rabbit Model of Tuberculosis
The susceptible rabbit families developed hematogenously spread tuberculosis resembling that found in infants and immunocompromised individuals. The resistance to tuberculosis of some of the American rabbit breeds may be more uniform than that of the New Zealand White rabbits on the market today, and among such breeds, new resistant or susceptible strains may be discovered. Two factors influence resistance to the establishment of tuberculosis: (i) the trapping of tubercle bacilli in the lung and (ii) the initial inactivation of these bacilli. The trapping is partly dependent on the ability of the alveolar macrophages to phagocytize the bacilli. The severity of tuberculosis was determined by both the susceptibility of the host and the virulence of the infecting bacilli. Human strains of tubercle bacilli are less virulent for rabbits than the bovine strains. Recovery from infection with them is the rule, even in genetically susceptible rabbits. The use of these strains of bacilli has made possible the development of one of the most precise tests available for native and acquired resistance to tuberculosis. BCG is usually given intradermally, so the response of Lurie’s resistant and susceptible rabbits to this route of infection is described in this chapter. The acquired immunity from BCG vaccination was higher in resistant than susceptible animals. Lurie obtained a hybrid strain of rabbits (F1) by crossing one of his highly resistant strains with one of his highly susceptible strains. The degree of resistance to tuberculosis of this F1 generation was intermediate between that of the two parent strains.