Open AccessTransfer of R Factors from Escherichia Coli to Salmonellas in the Rumen of Sheep
Author(s) -
M. G. Smith
Publication year - 1977
Publication title -
journal of medical microbiology/journal of medical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 117
eISSN - 1473-5644
pISSN - 0022-2615
DOI - 10.1099/00222615-10-1-29
Subject(s) - rumen , biology , microbiology and biotechnology , escherichia coli , salmonella , feces , starvation , inoculation , in vivo , bacteria , enterobacteriaceae , transfer factor , food science , immunology , biochemistry , fermentation , genetics , gene , endocrinology
Adult sheep were given into the rumen c. 10(8) cells each of donor strains of E. coli containing an R factor and prospective salmonella-recipient organisms and were maintained on a diet of lucerne chaff; the animals excreted the organisms, remained healthy, and no transfer of the R factor was detected. When the animals were starved for 48 h before inoculation, the ruminal environment was altered so that, on resumption of feeding, small numbers (c. 10(2)-10(4) cells--less than one cell per ml of rumen fluid) of the introduced organisms were able to multiply and reach sufficient numbers for the transfer of R factors to occur within the rumen. One animal, given 7-8 X 10(3) cells of recipient S. lomita after starvation for 48 h, became a carrier of this organism. A second animal, given 4-4 X 10(2) cells of S. typhimurium after starvation for 48 h, developed acute, fatal salmonellosis 5 days later; at the time of death, large numbers of salmonella organisms (c. 10(9) cells per g) were present in the faeces; these included many (c. 10(6) cells per g) that had received the R factor by transfer in vivo. These results indicate that short periods of starvation may enhance the transfer of R factors and possibly other plasmids between suitable micro-organisms in vivo, and may increase the susceptibility of animals to pathogenic micro-organisms.