Retrospective comparative analysis of risk factors and outcomes in patients with carbapenem resistant Acinetobacter baumannii bloodstream infections: cefoperazone-sulbactam associated with resistance and tigecycline increased the mortality

Figures & data

Figure 1 Flowchart of the case selection process.

Abbreviations: A. baumannii, Acinetobacter baumannii; BSI, bloodstream infection; CLSI, Clinical and Laboratory Standards Institute; CRAB, carbapenem-resistant A. baumannii.

Table 1 Risk factors for carbapenem resistance in Acinetobacter baumannii bloodstream infections

Risk factor, n (%)	Non-CRAB	CRAB (n=242)	Univariate analysis	Multivariate logistic regression analysis
	(n=51)		P-value	OR (95% CI)	P-value
Age >60 years	20 (39.2)	124 (51.2)	0.199	-	-
Male	37 (72.5)	164 (67.8)	0.54	-	-
ICU stay prior to BSI	3 (5.9)	163 (67.4)	0.000	6.884 (1.215-39.015)	0.029
Hospital stay >30 days prior to BSI	2 (3.9)	74 (30.6)	0.000	2.904 (0.298-28.317)	0.359
Readmission within 90 days	42 (82.4)	199 (82.2)	0.984	-	-
APACHE II score >15 at admission	5 (9.8)	115 (47.5)	0.000	3.812 (0.875-16.605)	0.075
Surgical operation	17 (33.3)	101 (41.7)	0.266	-	-
Invasive procedure within 30 days prior to BSI
Tracheotomy	2 (3.9)	47 (19.4)	0.007	1.909 (0.211-17.258)	0.565
Mechanical ventilation	10 (19.6)	202 (83.5)	0.000	1.236 (0.217-7.045)	0.811
Central venous catheterization	11 (21.6)	204 (84.3)	0.000	3.374 (0.621-18.348)	0.159
Pulmonary artery catheterization	6 (11.8)	158 (65.3)	0.000	1.745 (0.310-9.822)	0.528
Urinary catheterization	13 (25.5)	211 (87.2)	0.000	2.611 (0.420-16.238)	0.303
Gastric tube indwelling	10 (19.6)	189 (78.1)	0.000	0.917 (0.167-5.049)	0.921
Chest drainage	6 (11.8)	47 (19.4)	0.197	-	-
Abdominal drainage	7 (13.7)	77 (31.8)	0.009	1.672 (0.357-7.819)	0.514
Hemodialysis	2 (3.9)	65 (26.9)	0.000	1.335 (0.099-17.943)	0.828
Sputum aspiration	6(11.8)	108(44.6)	0.000	1.729 (0.304-9.816)	0.537
More than four procedures	7 (13.7)	203 (83.9)	0.000	0.764 (0.072-8.123)	0.823
Drug use in the 30 days prior to BSI
Methylprednisolone	5 (9.8)	116 (47.9)	0.000	4.279 (0.854-21.446)	0.077
Tacrolimus	3 (5.9)	33 (13.6)	0.125	-	-
Antifungal	2 (3.9)	76 (31.4)	0.000	1.618 (0.170-15.385)	0.675
Fluoroquinolone antibiotics	4 (7.8)	51 (21.1)	0.028	2.920 (0.459-18.574)	0.256
Cephalosporin antibiotics	9 (17.6)	43 (17.8)	0.984	-	-
Tigecycline	1 (2.0)	34 (14.0)	0.016	3.408 (0.230-50.534)	0.373
Cefoperazone-sulbactam	3 (5.9)	62 (25.6)	0.000	8.136 (1.230-53.800)	0.030
Carbapenem antibiotic	4 (7.8)	165 (68.2)	0.000	10.432 (2.079-52.358)	0.004
Piperacillin-tazobactam	4 (7.8)	79 (32.6)	0.000	1.253 (0.238-6.595)	0.790
Underlying disease
Hypertension	14 (27.5)	94 (38.8)	0.125	-	-
Hepatitis/cirrhosis	12 (23.5)	58 (24.0)	0.947	-	-
Diabetes	3 (5.9)	50 (20.7)	0.013	2.585 (0.277-24.127)	0.405
Renal insufficiency	4 (7.8)	48 (19.8)	0.145	-	-
Cardiac	5 (9.8)	31 (12.8)	0.552	-	-
Respiratory	3 (5.9)	23 (9.5)	0.408	-	-
Tumor	2 (3.9)	15 (6.2)	0.527	-	-
Cerebrovascular diseases	2 (3.9)	10 (4.1)	0.945	-	-
>1 kind of underlying disease	9 (17.6)	86 (35.5)	0.013	1.410 (0.371-5.364)	0.614
Comorbid conditions
Pulmonary infection	7 (13.7)	83 (34.3)	0.004	1.468 (0.335-6.429)	0.611
Septic shock	2 (3.9)	63 (26.0)	0.001	4.480 (0.313-64.140)	0.269
MOF	2 (3.9)	33 (13.6)	0.052	-	-
Abdominal cavity infection	4 (7.8)	14 (5.9)	0.578	-	-
Stroke	1 (2.0)	12 (3.3)	0.345	-	-
Gastrointestinal bleeding	2 (3.9)	8 (3.3)	0.826	-	-
>1 complication	5 (9.8)	77 (31.8)	0.001	1.393 (0.177-10.966)	0.753

Notes: Data are expressed as numbers (%) unless otherwise stated. CVC: catheter placed in the internal jugular vein or subclavian vein or groin femoral vein. Pulmonary artery catheterization: catheter placed in the pulmonary artery; it is used to detect heart failure or sepsis, monitor therapy, and evaluate the effects of drugs. Sputum aspiration: sucking the secretions of the respiratory tract by mouth, nasal cavity, and artificial airway (tracheostomy) to keep the airway open and prevent complications such as inhalation pneumonia, atelectasis, and asphyxia. “–”P<0.05 in the univariate analysis were entered into a multivariate analysis; P≥0.05 in the univariate analysis were not entered into a multivariate analysis.

Abbreviations: APACHE II, Acute Physiology and Chronic Health Evaluation II; BSI, bloodstream infection; CRAB, carbapenem-resistant Acinetobacter baumannii; CVC, central venous catheter; ICU, intensive care unit; MOF, multiple organ failure.

Table 2 Risk factors for 28-day mortality in patients with A. baumannii-BSI

Risk factor, n (%)	Survivors (n=150)	Nonsurvivors (n=86)	Univariate analysis,P-value	Multivariate logistic regression analysis
				OR (95% CI)	P-value
Age >60 years	68 (45.3)	54 (62.8)	0.010	1.329 (0.569-3.106)	0.511
Male	108 (72.0)	53 (61.6)	0.100	-	-
Carbapenem resistance	102 (68.0)	84 (97.7)	0.000	4.966 (0.569-41.365)	0.138
WIICU stay after BSI	59 (39.3)	72 (83.7)	0.000	2.676 (1.045-6.851)	0.040
Appropriate antibiotic treatment	112 (74.7)	40 (46.5)	0.000	0.254 (0.088-0.734)	0.011
Readmission within 90 days	113 (75.3)	77 (89.5)	0.008	4.167 (1.158-14.993)	0.029
APACHE II score >19 at diagnosis	22 (14.7)	53 (61.6)	0.000	2.998 (1.269-7.085)	0.012
Drug use after BSI
Methylprednisolone	48 (32.0)	48 (55.8)	0.000	2.277 (0.960-5.402)	0.062
Tacrolimus	19 (12.7)	4 (4.7)	0.046	0.258 (0.057-1.169)	0.079
Fluoroquinolone	27 (18.0)	12 (14.0)	0.295	-	-
Cefoperazone-sulbactam	67 (44.7)	43 (50.0)	0.429	-	-
Carbapenem	72 (48.0)	50 (58.1)	0.013	1.942 (0.748-5.038)	0.173
Tigecycline	46 (30.7)	53 (61.6)	0.000	3.750 (1.216-11.564)	0.021
APACHE II <15	16 (10.7)	3 (3.5)	0.148	-	-
APACHE II >16 and <25	26 (17.3)	38 (44.2)	0.031	-	-
APACHE II >26	4 (2.7)	12 (14.0)	0.858	-	-
>2 types of antibiotic	56 (37.3)	44 (51.2)	0.039	1.387 (0.507-3.795)	0.524
Underlying disease
Hypertension	55 (36.7)	35 (40.7)	0.539	-	-
Hepatitis/cirrhosis	33 (22.0)	18 (20.9)	0.670	-	-
Diabetes	21 (14.0)	16 (18.6)	0.349	-	-
Renal insufficiency	28 (18.7)	14 (16.3)	0.644	-	-
Coronary	23 (15.3)	11 (12.8)	0.592	-	-
Respiratory	20 (13.3)	13 (15.1)	0.704	-	-
Tumor	10 (6.7)	5 (5.8)	0.796	-	-
Cerebrovascular	7 (4.7)	2 (2.3)	0.366	-	-
>1 underlying disease	53 (35.3)	26 (30.2)	0.424	-	-
Comorbid conditions
Pulmonary infection	39 (26.0)	29 (33.7)	0.208	-	-
Septic shock	7 (4.7)	33 (38.4)	0.000	4.151 (1.156-14.901)	0.029
Respiratory failure	11 (7.3)	15 (17.4)	0.017	1.473 (0.387-5.611)	0.570
MOF	2 (1.3)	16 (18.6)	0.000	9.705 (1.520-61.970)	0.016
Abdominal cavity infection	9 (6.0)	7 (8.1)	0.529	-	-
Stroke	3 (2.0)	7 (8.1)	0.024	5.083 (0.757-34.139)	0.094
Gastrointestinal bleeding	2 (1.3)	7 (8.1)	0.009	3.793 (0.456-31.561)	0.217
>1 complication	14 (9.3)	38 (44.2)	0.000	1.642 (0.465-5.794)	0.441

Notes: Data are expressed as number (%) unless otherwise stated. “–”P<0.05 in the univariate analysis were entered into a multivariate analysis; P≥0.05 in the univariate analysis were not entered into a multivariate analysis.

Abbreviations: A. baumannii, Acinetobacter baumannii; APACHE II, Acute Physiology and Chronic Health Evaluation II; BSI, bloodstream infection; ICU, intensive care unit; MOF, multiple organ failure;.

Figure 2 Kaplan–Meier survival estimates among patients with A. baumannii-BSI.

Notes: (A) Treatment with or without tigecycline. (B) Tigecycline dose effect.
Abbreviations: A. baumannii, Acinetobacter baumannii; BSI, bloodstream infection.

Table S1 Patients age distribution

Patient’s age (years)	Non-CRAB, n (%)	CRAB, n (%)
0-18	1 (2.0)	2 (0.8)
18-60	30 (58.8)	116 (47.9)
61-75	13 (25.5)	86 (35.5)
>75	7 (13.7)	38 (15.7)
Total	51	242

Abbreviation: CRAB, carbapenem-resistant Acinetobacter baumannii.

Table S2 Location of diagnosis department

Diagnosis department	Infection cases	Composition ratio (%)
ICU (internal medicine)	70	23.9
ICU (emergency)	45	15.4
ICU (surgical)	41	14.0
ICU (liver transplantation ward)	30	10.2
ICU (negative pressure ward)	7	2.4
Hepatobiliary and pancreatic surgery ward	50	17.1
Infection ward	22	7.5
Nephrology ward	8	2.7
Emergency ward	7	2.4
Neurosurgery ward	5	1.7
Cardiothoracic surgery ward	5	1.7
Hematology ward	3	1.2

Abbreviation: ICU, intensive care unit.

Table S3 Drug susceptibility of A. baumannii

Drug (strain number)	Sensitive	Intermediary	Resistance
Ampicillin-sulbactam (293)	55 (18.8)	15 (5.1)	223 (76.1)
Cefoperazone-sulbactam (174)	50 (28.7)	25 (14.4)	99 (56.9)
Piperacillin-tazobactam (222)	36 (16.2)	2 (0.9)	184 (82.9)
Cefepime (293)	50 (17.1)	0	243 (82.9)
Ceftazidime (293)	53 (18.1)	10 (3.4)	230 (78.5)
Imipenem (293)	51 (17.4)	0	242 (82.6)
Ciprofloxacin (293)	53 (18.1)	0	240 (81.9)
Levofloxacin (293)	67 (22.9)	124 (42.3)	102 (34.8)
Amikacin (192)	130 (67.7)	7 (3.7)	55 (28.6)
Gentamicin (293)	92 (31.4)	14 (4.8)	187 (63.8)
Tobramycin (293)	106 (36.2)	3 (1.0)	184 (62.8)
Tigecycline (161)	120 (74.5)	25 (15.5)	16 (10.0)

Abbreviation: A. baumannii, Acinetobacter baumannii.

Table S4 APACHE II score of nontigecycline group and tigecycline group in A. baumannii-BSI patients

Antimicrobial	A. baumannii-BSI	28-day mortality,	P-value	Mean APACHE II	P-value
regimen	patients	n (%)		score at infection
Nontigecycline therapy	137	33 (24.1)	<0.05	16.16	<0.05
Tigecycline therapy	99	53 (53.5)		19.32

Abbreviations: A. baumannii, Acinetobacter baumannii; APACHE II, Acute Physiology and Chronic Health Evaluation II.

Table S5 Risk factors for 28-day mortality in patients with CRAB BSI

Risk factor, n (%)	Surviva (n=102)	Nonsurvival (n=84)	Univariate analysis P-value	Multivariate logistic regression analysis
				OR (95% CI)	P-value
Age >60 years	47 (46.1)	49 (58.3)	0.096
Male	73 (71.6)	51 (60.7)	0.118
ICU stay after BSI	59 (57.8)	70 (83.3)	0.000	2.649 (1.065-6.590)	0.036
Appropriate treatment	66 (64.7)	38 (45.2)	0.008	0.439 (0.151-1.271)	0.129
Readmission within 90 days	74 (72.5)	75 (89.3)	0.004	3.379 (0.971-11.756)	0.056
APACHE II score >19 at diagnosis	22 (21.6)	52 (61.9)	0.000	3.738 (1.623-8.609)	0.002
Drug use after BSI
Methylprednisolone	41 (40.2)	47 (56.0)	0.032	2.167 (0.911-5.154)	0.080
Tacrolimus	15 (14.7)	4 (4.8)	0.046	0.386 (0.086-1.744)	0.216
Fluoroquinolone antibiotics	22 (21.6)	10 (11.9)	0.082
Cefoperazone-sulbactam	54 (52.9)	43 (51.2)	0.812
Carbapenem antibiotics	62 (60.8)	48 (57.1)	0.615
Piperacillin-tazobactam	35 (34.3)	19 (22.6)	0.080
Tigecycline	46 (45.1)	52 (61.9)	0.022	2.129 (0.766-5.919)	0.148
>2 types of antibiotics	51 (50.0)	43 (51.2)	0.872
Underlying disease
Hypertension	41 (40.2)	35 (41.7)	0.839
Hepatitis/cirrhosis	22 (21.6)	17 (20.2)	0.824
Diabetes	18 (17.6)	16 (19.0)	0.806
Renal insufficiency	23 (22.5)	14 (16.7)	0.317
Cardiac	19 (18.6)	10 (11.9)	0.208
Respiratory	17 (16.7)	12 (14.3)	0.656
Tumor	6 (5.9)	5 (6.0)	0.984
Cerebrovascular	5 (4.9)	2 (2.4)	0.369
>1 underlying disease	42 (43.1)	26 (31.0)	0.150
Complication during hospital stay
Pulmonary infection	33 (32.4)	28 (33.3)	0.887
Septic shock	7 (6.9)	32 (38.1)	0.000	3.907 (1.141-13.374)	0.030
Respiratory failure	11 (10.8)	14 (16.7)	0.242
MOF	1 (1.0)	16 (19.5)	0.000	22.751 (2.334-221.761)	0.007
Abdominal cavity infection	5 (4.9)	7 (8.3)	0.343
Stroke	3 (2.9)	6 (7.1)	0.184
Gastrointestinal bleeding	1 (1.0)	6 (7.1)	0.028	3.126 (0.270-36.208)	0.362
>1 complication	12 (11.8)	36 (42.9)	0.000	1.521 (0.535-4.320)	0.431

Note: Data are expressed as numbers (%) unless otherwise stated.

Abbreviations: APACHE II, Acute Physiology and Chronic Health Evaluation II; BSI, bloodstream infection; CRAB, carbapenem-resistant Acinetobacter baumannii; ICU, intensive care unit; MOF, multiple organ failure.