Table 3.

Summary of other T3SS inhibitors and their reported inhibitory activities. Specific bacterial effector(s) antagonized by the inhibitors is noted in parentheses.

Representative compounds	Regulation	Secretion/Translocation	T3SS IC50	Infection	Other Pathways	Ref
1		S. typhimurium (SipA, SopE) P. aeruginosa (ExoU)				44
2	exoT transcription	Y. pestis (YopE-βla) P. aeruginosa (ExoS)	12.5 μM for ExoS 22 μM for YopE	Inhibits P. aeruginosa ExoU-dependent CHO cytotoxicity Inhibits C. trachomatis growth in Hep-2 cells	No effect on type II-mediated elastase secretion	45
3	No effect on needle assembly	Y. pseudo-tuberculosis YopE-βla translocation P. aeruginosa		Reduces Hcp-2 ccll-rounding by P. aeruginosa	Increases Yop leakage C20 reduces adherence of Hcp-2 cells	46
4	yopE transcription No effect on OmpA level in EPEC	Y pestis (effectors) YopE-βla translocation EPEC (Tir)	10–15 μM for Yops	Reduces HcLa cells toxicity by Y. pestis		47
5		S. typhimurium (SipB) P. aeruginosa (ExoU)	20–80 μM for SipB >100 μM for ExoU			48
6 Pseudolipasin A		No effect on P. aeruginosa secretion		Protects CHO cells cytotoxicity from the P. aeruginosa effector ExoU Prevents P. aeruginosa-rnediated killing.of Dictyostelium discoideum Inhibits ExoU-mediated killing of Saccharomyces cerevisiae		49
7		Y. pseudotuberculosis		Y. pseudotuberculosis cytotoxicity		50
8		Y. pestis (YopE)	20 μM	Protects Y. pestis cytotoxicity	ATPase activity of BsaS protein from Burkholderia mallei	51
9 Caminoside A	No effect on typc-V effector EspC	EPEC (EspB)	20 μM			52, 53
10 Guadinomines		EPEC	20 nM in hemolysis assay	Prevents hemolysis of erythrocytes		54, 55, 56
11 Aurodox	No effect on expression of GroEL	EPEC (EspA, EspB, EspD)	1.5 μg/ml in hemolysis assay	Prevents hemolysis of erythrocytes Protects Citrobactor rodentium infection		57