Outbreak of Pasteurella pneumotropica in a closed colony of STOCK-Cd28(tm1Mak) mice.

Fifteen mice with Pasteurella pneumotropica orbital abscesses were noted in mice that were homozygous for a targeted Cd28 gene mutation. Only one mouse heterozygous for the Cd28 mutation was affected. According to phenotypic reactions and 16S rDNA sequencing, the isolates were most similar to biotype Heyl. This article provides evidence for an immunologic basis of susceptibility to P. pneumotropica infection. Fifteen mice with Pasteurella pneumotropica orbital abscesses were noted in mice that were homozygous for a targeted Cd28 gene mutation. Only one mouse heterozygous for the Cd28 mutation was affected. According to phenotypic reactions and 16S rDNA sequencing, the isolates were most similar to biotype Heyl. This article provides evidence for an immunologic basis of susceptibility to P. pneumotropica infection.