Table 3.

Antibiotics administered to participants before A. baumannii infection

	Colistin-sensitive group (n=57)	Colistin-resistant group (n=20)	P
Antibiotics last 3 months	4 (7)	3 (15)	.367
Antibiotics during hospitalization prior to infection	57 (100)	20 (100)	–
Use of carbapenems	17 (30)	12 (60)	.003
Duration of carbapenem use (days)	0 (0, 2)	4 (0, 8)	.012
Use of antipseudomonal penicillins	17 (30)	12 (60)	.030
Duration of antipseudomonal penicillin use (days)	0 (0, 2)	3 (0, 7)	.023
Use of quinolones	12 (21)	11 (55)	.009
Duration of quinolone use (days)	0 (0, 0)	3 (0, 12)	.002
Use of cephalosporin 3d generation	24 (42)	5 (25)	.194
Duration of cephalosporin 3d generation use (days)	0 (0, 4)	0 (0, 1)	.114
Use of cephalosporin fourth generation	4 (7)	7 (35)	.005
Duration of cephalosporin fourth generation use (days)	0 (0, 0)	0 (0, 4)	.003
Use of colistin	12 (21)	8 (40)	.138
Duration of colistin use (days)	0 (0)	0 (0, 4)	.087
Use of tygecycline	0 (0)	8 (40)	<.001
Duration of tygecycline use (days)	0 (0, 0)	0 (0, 7)	<.001
Use of aminoglycosides	1 (2)	4 (20)	.015
Duration of aminoglycoside use (days)	0 (0, 0)	0 (0, 0)	.005

Data are presented as median (25 %, 75 % quartiles) or n (%); P, comparison between the two groups. Appropriate antibiotic therapy referred to the administration at least one of the in vitro active antimicrobials against the study isolates for at least 48 h. Results by univariate analysis.