Fig. 9.

Glycine increases the susceptibility of clinical bacteria to killing by serum. a Percent survival of multidrug-resistant E. coli, P. aeruginosa, K. pneumoniae, and MRSA in the presence of 100 mM glycine, 100 µL serum, or both, or 100 µL HI serum plus 100 mM glycine. Differences were found at p < 0.01 between the group with glycine + serum and the three other groups in all samples (n = 3). b, c BALB/c mice were infected with the indicated bacteria by i.p. injection (see methods) and treated with glycine as described (see text). Bacterial load was measured in blood, kidney, spleen, and liver (b) and with time in the blood (c) (n = 6). d Glycine concentrations in the spleen, liver, and kidney were measured at 48 h after the i.p. injection of the indicated glycine concentration (n = 10). e, f Rag1^−/− (e) and BALB/c (f) mice were infected with the indicated bacteria by i.p. injection (see methods) and treated with glycine as described (see text). Bacterial load was measured in blood, kidney, liver, and spleen (n = 6). g Glycine-enabled killing of the indicated bacteria by 100 μL other sources of serum with or without 100 mM glycine for the indicated length of time (n = 3). h Percent survival of mice infected the indicated bacterial pathogens and then treatment by saline (control), ampicillin (320 mg kg⁻¹), glycine (800 mg kg⁻¹) or both as described (see text for details) (n = 6). Results are displayed as mean ± SEM, and significant differences are identified (*p < 0.05, **p < 0.01) as determined by two-tailed Student’s t test. See also Supplementary Figs. 19–20