Intracorneal challenge of mouse strains DBA/1 and DBA/2 with Pseudomonas aeruginosa demonstrated that these strains were naturally resistant; they spontaneously recovered within four weeks postinfection. On the other hand, mouse strains BALB/c and C57BL/6 were susceptible to corneal infections and exhibited permanent eye damage. Resistance was dominant over susceptibility since the F1 generation obtained by crossing the DBA/1 or the DBA/2 strains (resistant) with the BALB/c strain (susceptible) were all resistant. Natural resistance to intracorneal challenge with P. aeruginosa is controlled by two or more autosomal dominant genes, at least one of which is located outside of the major histocompatibility (H-2) complex. F1 hybrids of the susceptible BALB/c and C57BL/6 background exhibited resistance to intracorneal infection. On the basis of these complementation studies, plus data from the F2 generation obtained by crossing the F1 progeny obtained from the mating of BALB/c with C57BL/6, it is concluded that each susceptible strain bears one autosomal resistance gene and that a dominant gene is required at each of the two loci involved for resistance to be expressed.
Animals Female