Table 2.

Susceptibility of PA14 and PA14Δhfq toward different classes of antibiotics in SCFM medium.

Classes/Subclass	Antibiotic	Mode of action	MIC	PA14	PA14Δhfq	PA14	PA14Δhfq
SCFM				High inoculuma		Low inoculumb
β-LACTAM ANTIBIOTICS
Cephems/Cephalosporins IV	Cefepime	Cell wall	mg/L	2/3	1.5/1.5	0.75/0.75	0.5/0.5
Penems/Carbapenems	Imipenem	Cell wall	mg/L	1/1	0.5/0.5	0.5/1	0.25/0.25
NON-β-LACTAM ANTIBIOTICS
Aminoglycosides	Gentamicin	Protein synthesis	mg/L	8/8	2/2	4/4	2/1
Fluoroquinolones	Ciprofloxacin	DNA metabolism	mg/L	0.25/0.25	0.12/0.12	0.12/0.06	0.06/0.06
Fosfomycins	Fosfomycin	Cell wall	mg/L	>1024/>1024	12/6	384/384	1/2
Lipopeptides/Polymixins	Colistin	Cell membrane	mg/L	12/12	4/4	2/3	1.5/1.5
Tetracyclines	Tetracycline	Protein synthesis	mg/L	32/32	8/16	64/64	16/16

/, Results of two independent experiments; >, more resistant than the highest concentration tested.

^aHigh inoculum, corresponds to 4 × 10⁹ CFU/mL.

^bLow inoculum, corresponds to 2 × 10⁶ CFU/mL.