Table 2: Proportion of resistant and MBL-producing strains by presence of FQ or AG resistance in imipenem-resistant Pseudomonas aeruginosa.

Resistance to FQs Resistance to AGs
All strains
(n = 169) 		Yes
(n = 66) 		No
(n = 103) 		P Yes
(n = 12) 		No
(n= 157) 		P
Resistance to antibiotics
Piperacillin1) 36 (21.3) 21 (31.8) 15 (14.6) 0.003 4 (33.3) 32 (20.4) 0.347
Ceftazidime1) 53 (31.4) 33 (50.0) 20 (19.4) <0.001 8 (66.7) 45 (28.7) 0.022
Cefepim 38 (22.5) 28 (42.4) 10 (9.7) <0.001 7 (58.3) 31 (19.7) 0.006
Aztreonam 91 (53.8) 45 (68.2) 46 (44.7) 0.004 9 (75.0) 82 (52.2) 0.146
Ciprofloxacin1) 49 (29.0) - - - 8 (66.7) 41 (26.1) 0.011
Levofloxacin 60 (35.5) - - - 6 (50.0) 54 (34.4) 0.350
Gentamicin1) 12 (7.1) 8 (12.1) 4 (3.9) 0.042 - - -
Amikacin1) 4 (2.4) 3 (4.5) 1 (1.0) 0.274 - - -
MBL production 14 (8.3) 11 (16.7) 3 (2.9) 0.003 4 (33.3) 10 (6.4) 0.010

Values are expressed as the number (%).
FQs, fluoroquinolones; AGs, aminoglycosides; MBL, metallo-β-lactamase 1)Minimum inhibitory concentrations (MICs) for piperacillin, ceftazidime, ciprofloxacin, gentamicin and amikacin were not measured in eleven, one, one, one, and thirteen strains, respectively.