Table 1.

Indole production in clinical and environmental Vibrio cholerae

V. cholerae strains	Indole (mM) Mean ± SD
C1 (O1)	3.2 ± 0.3
C2 (O1)	3.0 ± 0.1
C3 (non-O1)	3.1 ± 0.1
C4 (non-O1)	2.8 ± 0.2
E1 (non-O1)	2.8 ± 0.2
E2 (non-O1)	3.0 ± 0.2
E3 (O1)	2.9 ± 0.2
E4 (O1)	4.2 ± 0.2a

V. cholerae O1 was cultured in 50 mL of LB broth at 37 °C, 24 h and indole production was determined

C clinical isolates, E environmental isolates

^aSignificant difference (p < 0.05)