%0 Journal Article %A Ozeki, By H. %A Stocker, B. A. D. %A Smith, Sylvia M. %T Transmission of Colicinogeny between Strains of Salmonella typhimurium Grown Together %D 1962 %J Microbiology, %V 28 %N 4 %P 671-687 %@ 1465-2080 %R https://doi.org/10.1099/00221287-28-4-671 %I Microbiology Society, %X SUMMARY: Ability to produce colicines I, E1, E2, K or B was transferred to Salmonella typhimurium strain LT2 by growth in broth with suitable colicinogenic strains of Escherichia coli or Shigella sonnei. When LT2 (colI), i.e. carrying the colicine I factor, or LT2 (colB) were grown overnight in broth with LT2 col − (non-colicinogenic), c. 50 % of the latter became colicinogenic; LT2 (colE2) and LT2 (colK) did not transmit; LT2 (colE1) transmitted to only c. 0.1 % of the acceptor population. But LT2 carrying either colI or colB in addition to colE2, colK or colE1, transmitted both factors. When overnight broth cultures of LT2 (colI) and LT2 col − were mixed and incubated c. 40 % of the latter acquired colI by 20 hr. (when the viable count had doubled); but only c. 0.02 % acquired colI in 3 hr. The low initial transfer results from the fact that in a stock culture of LT2 (colI) only c. 1/5000 bacteria are ‘competent donors’, able to transmit colI. The later large increase in the proportion of colicinogenic bacteria probably results from ‘epidemic spread’ of the colI factor amongst the acceptor population, initiated by the few acceptor bacteria which originally receive it. It is supposed that most bacteria which have just acquired colI become competent donors. In a doubly colicinogenic strain most competent donors transmit both colicine factors. Aeration by shaking during incubation interfered with transmission of colicinogeny, probably by abolishing the prolonged phase of slow growth of unaerated cultures. Growth in the presence of acriflavine did not ‘cure’ LT2 (colI) or LT2 (colI) (colE2) of colicinogeny, nor of ability to transmit. LT2 (colE1) and LT2 (colE2) supported the epidemic spread of colI or colB about as well as did LT2 col −; but in LT2 (colK) the spread of colI was greatly reduced and that of colB somewhat reduced. The prior presence in an acceptor strain of one of the readily transmissible factors, colI or colB, did not interfere with the epidemic spread of the other. But LT2 (colI) did not become a competent donor on accepting colE2 and, by inference, colI from LT2 (colI) (colE2). %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-28-4-671