Spontaneous and evolutionary changes in the antibiotic resistance of Burkholderia cenocepacia observed by global gene expression analysis

Table 2 Number of B. cenocepacia genes with a >2-fold change in expression

*B. cenocepacia* strain and growth condition	Number of genes significantly altered in expression (>2 fold):
Exposure of J2315 to sub-MIC antimicrobials:	Up-regulated	Down-regulated	Total
J2315 wt + 50 mg/L AMK	17	2	19
J2315 wt + 2 mg/L MEM	53	6	59
J2315 wt + 10/50 mg/L TMP/SMX	39	17	56
J2315 wt + 0.05 mM CPZ	13	5	18
J2315 wt + 0.05 mM CPZ + 50 mg/L AMK	19	16	35
J2315 resistant mutants:
J2315-A	26	28	54^a
J2315-A + 50 mg/L AMK	32	50	82^a
J2315-A + 250 mg/L AMK	37	38	75^a
J2315-M	39	59	98^a
J2315-M + 2 mg/L MEM	67	24	83^a
J2315-M + 8 mg/L MEM	39	74	113^a
J2315-T	41	39	80^a
J2315-T + 10/50 mg/L TMP/SMX	44	38	82^a
J2315-T + 60/300 mg/L TMP/SMX	52	53	105^a
ST28 outbreak isolates:
BCC1616	89	166	255
BCC1617	83	115	198

^a The number of genes differentially expressed were significantly different (p < 0.001; one-way analysis of variance with square root transformation) in the resistant mutants compared to the corresponding condition of J2315 exposed to each respective antibiotic.

ISSN: 1471-2164