TABLE 2.

Characteristics of antibiotic regimens used during KPC-Kp or MDR-AB infection^a

Antibiotic therapyb	KPC-Kp (n = 128)	MDR-AB (n = 92)	Pc
No. of antibiotics used
Only 1 as definitive therapy	7 (5.5)	9 (9.8)	0.2
2 in combination as definitive therapy	41 (32)	28 (30.4)	0.8
3 in combination as definitive therapy	53 (41.4)	38 (41.3)	1.0
4 in combination as definitive therapy	27 (21.1)	10 (10.9)	0.06
5 in combination as definitive therapy	0	1 (1.1)	0.4
Colistin-containing regimen as definitive therapy	67 (52.3)	73 (79.3)	<0.001
Tigecycline-containing regimen as definitive therapy	91 (71.1)	35 (38)	<0.001
Gentamicin-containing regimen as definitive therapy	35 (27.3)	5 (5.4)	<0.001
Rifampin-containing regimen as definitive therapy	16 (12.5)	36 (39.1)	<0.001
Carbapenem-containing regimen as definitive therapy	98 (76.5)	67 (72.8)	0.6
Use of colistin aerosol inhalation therapy	0	13 (14.1)	<0.001
≥2 in vitro-active antibiotics used within 24 h	48 (37.5)	1 (1.1)	<0.001
Definitive therapy with ≥2 antibiotics displaying in vitro activity	61 (47.7)	5 (5.4)	<0.001
Time to initial definitive therapy (mean ± SD) (days)	2.7 ± 0.8	3.1 ± 0.7	0.08

^aData are presented as the number (%), unless otherwise stated. KPC-Kp, Klebsiella pneumoniae carbapenemase-producing K. pneumoniae; MDR-AB, multidrug-resistant Acinetobacter baumannii.

^bDuring the study period, the usual antimicrobial dosages, adopted for the most used antibiotics, were the following: for colistin, a loading dose of 6 to 9 million IU, followed by 3 million IU every 8 h (in the period from 2010 to 2011) or a loading dose of 9 million IU followed by 4.5 million IU every 12 h; for tigecycline, a loading dose of 150 to 200 mg followed by 100 mg every 12 h; for gentamicin, a dosage of 5 mg/kg every 24 h; for rifampin, a dosage of 10 mg/kg/day; for meropenem, a dosage of 2 g every 8 h or 1.5 g every 6 h.

^cP values in bold are statistically significant.