Extended Data Fig. 5: Determination of reservoirs of tissue-associated persisters after intravenous infection, and subsequent plasmid transfer.
From: Salmonella persisters promote the spread of antibiotic resistance plasmids in the gut
a, An equal mix of five SL1344 P2cat tag strains (SmR and CmR) were intravenously infected into mice (103 CFU). Treatments were as described in Fig. 2b (grey circles, 3 intraperitoneal doses of ceftriaxone; n = 8 singly housed mice from 2 independent experiments) or mice were left untreated (black circles; n = 8 singly housed mice from 2 independent experiments). Mice were euthanized on day 5 of the experiment (after the final dose of ceftriaxone was given). The tissue-associated populations in organs were enumerated by selective plating. Detection limit by selective plating is shown as a dotted line. Lines indicate median. b, c, Faecal bacterial population sizes of mice in Fig. 2d, e (comparison of wild-type and SPI-2-negative donors in the intravenous model). Faecal loads of donors (blue, SmR and CmR), recipients (green, KanR) and transconjugants (red, CmR and KanR) were determined by selective plating on MacConkey agar. Black dotted line indicates the detection limits for donors and transconjugants. Green dotted line indicates the detection limit for recipients. The detection limit is higher for recipients once transconjugants reach a density of >108 CFU per gram of faeces. Before this happens, recipients can be found below the detection limit; the black dotted line should then be considered as the detection limit. Blue lines connect medians of donor populations; red lines connect medians of transconjugant populations. b, Mice infected with wild-type S. Typhimurium donors (solid circles). c, Mice infected with SPI-2-deficient S. Typhimurium donors (open circles).
