THE INVIVO DIVISION AND DEATH RATES OF SALMONELLA-TYPHIMURIUM IN THE SPLEENS OF NATURALLY RESISTANT AND SUSCEPTIBLE MICE MEASURED BY THE SUPERINFECTING PHAGE TECHNIQUE OF MEYNELL

  • 1 January 1980
    • journal article
    • research article
    • Vol. 41  (4) , 973-979
Abstract
S. typhimurium appears to divide faster in the spleen of naturally susceptible BALB/c than in resistant (B10 .times. A/J)F1 mice. S. typhimurium M526 is an LT2 derivative lysogenic for a non-excluding P22 mutant which allows superinfection with a 2nd, non-replicating, P22 phage so that the proportion of superinfected organisms halves at each divison. The true in vivo division and death rates can be calculated from successive determinations of the superinfected organism proportion and the viable count. The division time was 2.86 h in BALB/c and 5.02 h in (B10 .times. A/J)F1; the death rate was low and actually greater in the susceptible BALB/c strain. Apparently the gene controlling in vivo salmonella net growth rate, which is very important in natural salmonella infection resistance, acts very early by regulating the division rate, perhaps inside macrophages. The acutal mechanism remains unknown.