Stenotrophomonas maltophilia Infections: Clinical Characteristics and Factors Associated with Mortality of Hospitalized Patients

Figures & data

Table 1 Baseline Characteristics, Clinical Data, and Treatment Outcomes of Hospitalized Patients Who Had S. maltophilia Infections

Characteristics	Total n = 100
Median age (range), years	66 (19–90)
Male, n (%)	47 (47)
Underlying disease, n (%)
Diabetes mellitus	31 (31)
Hypertension	51 (51)
Cardiac disease	22 (22)
Chronic pulmonary disease	12 (12)
Chronic kidney disease	21 (21)
Chronic liver disease	13 (13)
Cerebrovascular disease	17 (17)
Malignancies	45 (45)
Organ transplant recipient	2 (2)
Autoimmune diseases	6 (6)
Receiving immunosuppressive therapy	20 (20)
Cause of hospitalization, n (%)
Infections not related to S. maltophilia^a
Respiratory tract infection	14 (14)
Urinary tract infection	8 (8)
Hepatobiliary tract infection	7 (7)
Bacteremia	6 (6)
Intra-abdominal infection	4 (4)
Others	6 (6)
Scheduled chemotherapy	6 (6)
Surgery	16 (16)
Diagnostic intervention	14 (14)
Others	19 (19)
Critically ill patient, n (%)	46 (46)
Median ICU LOS (range), days	10 (1–207)
Median APACHE II score (range)	18 (2–32)
Median SOFA score (range)	8 (1–19)
Type of S. maltophilia infection, n (%)
Community acquired infection	0
Hospital acquired infection^b	100 (100)
Type of in-patient unit during the infection, n (%)
Medicine ward	36 (36)
Surgery ward	7 (7)
ICU	35 (35)
Others	22 (22)
Median duration before the infection (range), days	19 (1–207)
Median SOFA score at the infection (range)	6 (1–19)
S. maltophilia infection with bacteremia, n (%)	43 (43)
Primary focus of infection, n (%)
Primary bacteremia	11 (11)
CRBSI	14 (14)
Pneumonia	53 (53)
Intra-abdominal infection	6 (6)
Hepatobiliary tract infection	8 (8)
Urinary tract infection	7 (7)
Ocular infection	1 (1)
Antimicrobial treatment, n (%)
Empirical antimicrobial treatment
Appropriate	16 (16)
Inappropriate	84 (84)
Definite antimicrobial treatment
Appropriate	72 (72)
Inappropriate	28 (28)
Median duration of definite antimicrobial treatment (range), days	14 (2–60)
Treatment outcomes at discharge, n (%)
Survived	46 (46)
Deceased	54 (54)

Notes: ^aPre-existing infection prior to the onset of S. maltophilia infection. ^bTwo cases acquired S. maltophilia infection after the hospital discharge. One patient had bacteremia post endoscopic retrograde cholangiopancreatography, another patient had urinary tract infection post-percutaneous nephrostomy.

Abbreviations: APACHE II, acute physiology and chronic health evaluation; CRBSI, catheter-related bloodstream infection; ICU, intensive care unit; LOS, length of stay; SOFA, sequential organ failure assessment.

Table 2 Clinical Characteristics at the Onset of the S. maltophilia Infections

Characteristics	Total n = 100
Antimicrobial agent used in the preceding 2 weeks, n (%)	91 (91)
Carbapenems	62 (56)
Piperacillin-tazobactam	18 (16)
Cephalosporins	11 (10)
Serum albumin level <3 g/dL, n (%)	88 (88)
Urinary catheterization, n (%)	71 (71)
On mechanical ventilator, n (%)	58 (58)
Surgery during the preceding month, n (%)	43 (43)
Intravascular catheterization, n (%)	40 (40)
Multi-organ dysfunction, n (%)	37 (37)
Central venous catheter, n (%)	37 (37)
Concurrent immunosuppressive treatment, n (%)	33 (33)
Hemodialysis, n (%)	22 (22)
Previous S. maltophilia colonization, n (%)	19 (19)
Chemotherapy during the preceding month, n (%)	13 (13)

Table 3 The Number of Organisms Co-Isolated with S. maltophilia in the Index Culture Specimen for Diagnosis of S. maltophilia Infections from 65 Patients

Type of Organism	Total
Gram-negative bacteria, n
Enterobacteriaceae	25
Acinetobacter baumannii	19
Pseudomonas aeruginosa	12
Others	8
Gram-positive bacteria, n
Staphylococci	12
Enterococci	10
Others	1
Candida spp., n	13

Table 4 Percentage of Antimicrobial Susceptibility Testing Profile of 100 S. maltophilia Isolates from the Study Subjects

Agent^a	S	I	R
Minocycline	100	–	–
Levofloxacin	94	–	6
Trimethoprim-sulfamethoxazole	91	-	9

Note: ^aTesting by disk diffusion method according to the Clinical and Laboratory Standards Institute (CLSI).

Abbreviations: I, intermediate; R, resistant; S, susceptible.

Table 5 Factors Associated with All-Cause in-Hospital Mortality of Patients Who Had S. maltophilia Infection

Variables	Univariate		Multivariate
	OR (95% CI)	P-value	OR (95% CI)	P-value
Pre-existing respiratory infection	6.28 (1.33–29.78)	0.021
Critical illness	3.33 (1.45–7.62)	0.005
Multi-organ dysfunction	2.44 (1.05–5.70)	0.039
On mechanical ventilator	4.44 (1.90–10.39)	0.001	4.43 (1.86–10.59)	0.001
Concurrent immunosuppressive therapy	2.67 (1.10–6.47)	0.029	2.26 (1.04–6.82)	0.042
Intravascular catheterization	4.43 (1.79–10.92)	0.001
Urinary catheterization	4.83 (1.87–12.47)	0.001
Serum albumin level <3 g/dL	4.13 (1.05–16.33)	0.043
Polymicrobial organism isolated	1.17 (0.51–2.67)	0.705