FIG 7.

Prophylactic treatment with deoxycholic acid inhibits pneumococcal colonization in a mouse model of colonization. (A) Experimental design. Three groups of mice (n = 8 each) were utilized; groups 1 and 2 drank regular water throughout, whereas group 3 was prophylactically (pro) treated by adding DoC (0.2 μg/ml) to their drinking water at day 0. At day 6, all three groups were infected with S. pneumoniae EF3030. Then, 24 h postinoculation, mice in groups 1 and 2 were treated via intranasal (nasal) inoculation with PBS (Ctrl) or DoC (10 μg each nostril) two times a day for 4 days. All mice were sacrificed at day 10, and the nasopharynx, trachea, lungs, and blood were collected. (B) Mice in all three groups were weighed at days 0 and 10. (C) Nasopharyngeal specimens were homogenized, diluted, and plated onto BAP with gentamicin (25 μg/ml) to obtain bacterial density (CFU/ml). (D and E) DNA was extracted from nasopharyngeal homogenates and used in species-specific lytA-based qPCRs (D) or reactions targeting the mouse β-actin gene (E). In panels C and D, NS indicates P > 0.249, and ** indicates P < 0.003 compared with control mice.