TABLE 1.

MICs and MBCs for selected domestic drain isolates before and after repeated exposure to a commercial QAC^a

Isolateb	MIC (mg/liter)			MBC (mg/liter)
	Before	P7	P14	Before	P7	P14
Aeromonas hydrophila M 4.3	15.6	15.6	15.6	31.2	41.6 (18)	31.2
Aeromonas jandei M 4.2	15.6	15.6	15.6	52 (18)	31.2	83.3 (36)
Ralstonia sp. strain M 4.13	15.6	31.2	125	125	104.1 (36)	187 (108.2)
Aranicola proteolyticus M 20.1	7.8	31.2	31.2	48.4 (23.8)	83.3 (36)	83.3 (36)
Stenotrophomonas maltophilia M 4.17.	7.8	7.8	7.8	31.2	31.2	31.2
Pseudomonas sp. strain M 4.7	15.6	15.6	31.2	52 (63.1)	88.5 (63.1)	72.9 (47.7)
Eubacterium sp. strain M 4.14	15.6	15.6	31.2	20.8 (9)	31.2	31.2
Chryseobacterium indologenes M 4.29	15.6	15.6	15.6	31.2	26 (9)	31.2 (27)
Achromobacter xylosoxidans M 4.31	3.9	3.9	3.9	3.9	3.9	7.8
Pseudomonas nitroreducens M 4.6	15.6	7.8	7.8	57.2 (59.1)	31.2 (27)	57.2 (59.1)
Enterococcus saccharolyticus M 20.4	31.2	7.8	7.8	25.0	62.5	62.5
Chryseobacterium sp. strain M 4.28	3.9	3.9	15.6	3.9	3.9	41.6 (18)
Bacillus cereus M 4.21	3.9	3.9	3.9	31.2	31.2	62.5
Citrobacter sp. strain M 20.9	7.8	7.8	7.8	10.4 (4.5)	44.2 (31.5)	7.8
Sphingobacterium multivorum M 30.1	3.9	1.9	7.8	3.9	1.9	62.5
Pseudoxanthomonas sp. strain M. 40.1	7.8	3.9	3.9	15.6	3.9	3.9
Microbacterium phyllosphaerae M 4.30	3.9	3.9	3.9	14.3 (14.7)	15.6 (13.5)	7.8

^aData were determined by broth dilution endpoint. Data show means from duplicate experiments. Where data varied between replicates, standard deviations are given in parentheses.

^bM, MBRG.