Abstract
Septicemia caused by Y. pseudotuberculosis in a female patient, aged 61, is reported. The patient suffered from amyloidosis with extensive infiltration of liver, spleen and kidneys. While under treatment with corticosteroids and azathioprine, Y. pseudotuberculasis, serotype IA, was isolated from each of 6 blood cultures. The infection responded favorably to treatment with ampicillin. The development of Y. pseudotuberculosis septicemia owing to impairment of the defense mechanisms by the underyling disease and the treatment given is discussed.