. 2018 Dec 21;13(12):e0209389. doi: 10.1371/journal.pone.0209389

Table 2. Minimum inhibitory concentration (MIC) of compounds O06, C17, and N08 against panel of drug resistant Gram-negative and Gram-positive bacteria.

Addition of the efflux inhibitor phenylalanine-arginine β-naphthylamide (PAβN) improves the MIC for Gram negative organisms. Cm: chloramphenicol. Lev: levofloxacin.

PAβN (40μg/mL)	Compound (μg/mL)
	O06		C17		N08		Cm		Lev
	-	+	-	+	-	+	-	+	-	+
Multi-drug resistant bacterial strains
A. baumanii	48	24	>96	24	>96	1.5	---	---	---	---
P. aeruginosa PAO1	>96	24	>96	48	>96	12	---	---	0.25	0.015
CR-K. pneumoniae (ATCC BAA-1705)	96	96	96	48	>96	6	1250	39	---	---
MRSA	48	N/A^a	24	N/A^a	<0.75	N/A^a	---	---	---	---
Susceptible bacterial strains
K. pneumoniae Kp233^b	96	---	48	---	>96	---	<9	---	0.031	---
E. coli urine isolate Ec235^c	96	---	96	---	>96	---	<9	---	0.015	---
E. coli urine isolate Ec236^c	96	---	96	---	>96	---	<9	---	0.015	---
Group A streptococcus	48	N/A^a	96	N/A^a	>96	N/A^a	---	---	---	---

^a Combination of compound with PAβN was not tested in Gram-positive organisms because they do not express resistance-nodulation-division (RND) class of multidrug efflux pumps targeted by PAβN

^b A carbapenem-susceptible clinical strain of K. pneumoniae

^c Antibiotic-sensitive clinical isolates of uropathogenic E. coli