EXPERIMENTAL-INFECTION IN MICE WITH YERSINIA ENTEROCOLITICA (STRAIN BIOTYPE-4, SEROGROUP O - 3, PHAGE TYPE-VIII) - GROWTH OF INOCULUM IN ATHYMIC OR CYCLOPHOSPHAMIDE TREATED MICE

  • 1 January 1978
    • journal article
    • research article
    • Vol. B129  (1) , 27-36
Abstract
I.v. infection of Swiss mice with a strain of Y. enterocolitica unable to colonize normal mice by the oral route, induced a systemic infection. Viable bacteria were isolated from homogenates of liver, spleen and lungs, as early as 1 h after the challenge and were detected during 2 wk. The number of viable bacteria isolated from the blood was always very low. Fecal samples permitted the isolation of Y. enterocolitica even after 2 wk, while at this time no more bacteria were isolated from the tissues. The duration of the infection remained unchanged with an inoculum of 103, 104 and 105 viable bacteria. Depending on the size of the inoculum, liver macroscopic abscesses occurred more or less rapidly after the challenge. These abscesses disappeared spontaneously. A single i.v. injection of cyclophosphamide (200 mg/kg) 6 days after the challenge was followed by an important rise of the number of bacteria in all the tissues. Comparative studies of i.v. infected athymic (nude) mice and controls showed a higher number of bacteria in the liver and spleen of the athymic animals.