TABLE 2.

Inhibition of S. mutans GS5 bacteriocin production by other oral streptococci in agar plate assays^a

Bacterial mixturesb	Diameter of inhibition zone (mm)c
	Without CSP	With CSP
GS5 + NG8	38.5 ± 2.5	39.0 ± 3.0
GS5 + Challis	5.5 ± 2.5	38.5 ± 2.5
GS5 + 10558	20.5 ± 3.5	38.5 ± 2.5
GS5 + 10556	22.5 ± 1.0	38.5 ± 2.5
GS5 + 10712	14.0 ± 5.0	39.0 ± 3.0
GS5 + KS32AR	22.0 ± 6.0	38.5 ± 2.5

^aS. mutans GS5 cells in the presence or absence of other oral streptococcal cells were inoculated into THB agar plates with or without the addition of exogenous synthetic CSP (3 μg in 3 μl) for stab cultures. After 24 h of incubation at 37°C under anaerobic conditions, the plates were overlaid with indicator RP66 cells (10⁶ CFU) in 3 ml of THB with 1% low-melting-point agarose. After 24 more hours of incubation at 37°C under anaerobic conditions, the diameters of the clearance zones surrounding the inoculated bacteria were measured.

^bMixtures of S. mutans GS5 and NG8, S. gordonii Challis and 10558, S. sanguis 10556, S. mitis 10712, and S. oralis KS32AR were used.

^cValues are means ± standard deviations from two experiments.