Table 7.

Disc-diffusion inhibition zones of Y. pestis at various time points.

Inhibition Zone	Inhibition Zone Diameter (mm)
Incubation Duration (h)	CIP	TET	GEN	CHL	TRS
18	35–40	28	27–28	31–36	40–42
20	36–40	29–30	28–30	30–35	40–42
22	39–41	30	28–29	31–36	40–42
24	39–42	30–32	28–30	30–35	39–42

CIP—ciprofloxacin; TET—tetracycline; GEN—gentamicin; CHL—chloramphenicol; TRS—trimethoprim–sulfamethoxazole; the diameters were determined by at least three independent assays.