The Activities of Antimicrobials Against Stenotrophomonas maltophilia Isolates and Evaluation of Clinical Outcomes Among Treatment Regimens in Patients with Stenotrophomonas maltophilia Infections: A Retrospective Multicenter Cohort Study

Figures & data

Table 1 Characteristics of Patients with S. maltophilia Infection (n = 208)

Characteristics	Values
Male, number (%)	125 (60)
Age (years), median (interquartile range; IQR)	69 (26)
Body weight (kg), median (IQR)	60 (20)
BMI (kg/m^2), median (IQR)	18.7 (3)
Serum creatinine (mg/dL), median (IQR)	1.2 (1.6)
Creatinine clearance (mL/min), median (IQR)	45.3 (62.2)
Serum albumin (g/dL), median (IQR)	2.61 (0.79)
Charlson comorbidity score (CCI), median (IQR)	5 (3)
Chronic respiratory diseases, median (IQR)	24 (11.5)
APACHE II score, median, (IQR)	19 (9)
SOFA score, median (IQR)	6 (5)
Septic shock, number (%)	108 (51.9)
Intensive care unit, number (%)	87 (41.8)
Haemodialysis, number (%)	33 (15.9)
Central venous catheters, number (%)	127 (61.1)
Mechanical ventilation, number (%)	149 (71.6)
Immunocompromised status, number (%)	39 (18.8)
Primary of infections
Pneumonia, number (%)	127 (61.1)
Bloodstream infections, number (%)	69 (33.2)
Intraabdominal infections, number (%)	4 (1.9)
Urinary tract infections, number (%)	4 (1.9)
Skin and soft tissue infections, number (%)	3 (1.4)
Lung abscess, number (%)	1 (0.5)
Microbials
Mono-microbial infections (S. maltophilia only), number (%)	96 (46.2)
Treatment
Documented antibiotic treatment regimens, number (%)	169 (81.2)
TMP-SMX-based regimen, number (%)	53 (25.5)
Dose (mg/kg/day), median (IQR)	10.3 (5.10)
Levofloxacin-based regimen, number (%)	104 (50)
Dose (mg/kg/day), median (IQR)	11.5 (5.38)
Monotherapy regimen or susceptible to S. maltophilia, number (%)	159 (94.1)
TMP-SMX	44 (27.7)
Levofloxacin	98 (61.6)
Ceftazidime	14 (8.8)
Tigecycline	3 (1.9)
Combination therapy regimen for S. maltophilia, number (%)	10 (6)
TMP-SMX + levofloxacin	5 (50)
TMP-SMX + ceftazidime	2 (20)
TMP-SMX + tigecycline	1 (10)
TMP-SMX + minocycline	1 (10)
Levofloxacin + tigecycline	1 (10)
Empirical antimicrobial therapy, number (%)	185 (88.9)
Beta-lactams/beta-lactamase inhibitors	32 (17.3)
3rd generation cephalosporins	22 (11.9)
Carbapenems	76 (41.1)
Colistin	5 (2.7)
Fosfomycin	2 (1.1)
Tigecycline	1 (0.5)
Vancomycin	1 (0.5)
Colistin combination regimens	37 (20)
Tigecycline combination regimens	3 (1.6)
Inappropriate treatment regimen for S. maltophilia, number (%)	39 (18.8)
Beta-lactams/beta-lactamase inhibitors	10 (25.6)
3rd generation cephalosporins	2 (5.1)
Carbapenems	21 (53.8)
Colistin	3 (7.7)
Fosfomycin	1 (2.6)
Colistin combination regimens	2 (5.1)

Abbreviations: APACHE II, The Acute Physiology and Chronic Health Evaluation; SOFA, Sequential Organ failure Assessment; TMP-SMX, trimethoprim-sulfamethoxazole.

Table 2 The Treatment Outcomes of S. maltophilia Infections (n = 208)

Treatment Outcomes	Number (%)
Treatment failure	138 (66.3)
30-day mortality	102 (49)
Microbiological outcomes
Microbiological cured (n=63)*	63 (100)

Note: *Microbiological cure reported among patients with bloodstream infections who repeat hemoculture.

Table 3 Factor Associated with Treatment Failure and 30-Day in Hospital Mortality of S. maltophilia Infections

Variables	Treatment Failure				30-Day Mortality
	Univariate Analysis		Multivariate Analysis		Univariate Analysis		Multivariate Analysis
	OR (95% CI)	P value	OR (95% CI)	P value	OR (95% CI)	P value	OR (95% CI)	P value
Age ≥69 years (n=106)	2.33 (1.29–4.22)	0.005*			2.27 (1.30–3.96)	0.004*
Hypoalbuminemia (<2.5 g/dL) (n=75)	2.03 (1.08–3.83)	0.027*			1.94 (1.09–3.45)	0.023*
CCI (>5) (n=88)	2.20 (1.20–4.06)	0.011*			1.66 (0.96–2.90)	0.071*
APACHE II (≥ 15) (n=154)	6.23 (3.19–12.29)	<0.001*	3.37 (1.46–7.76)	0.004*	5.06 (2.47–10.36)	<0.001*	3.27 (1.45–7.39)	0.004*
Mechanical ventilation (n=149)	2.82 (1.51–5.27)	<0.001*			2.00 (1.08–3.72)	0.026*
Septic shock (n=108)	2.72 (1.50–4.93)	<0.001*			3.43 (1.94–6.08)	<0.001*	2.53 (1.36–4.69)	0.003*
Immunocompromised status (n=39)	1.18 (0.56–2.49)	0.672			1.18 (0.59–2.37)	0.641
Primary infections
Respiratory tract infections (n=128)	2.26 (1.25–4.08)	0.006*			1.34 (0.77–2.35)	0.303
Bacteraemia (n=69)	2.09 (1.14–3.82)	0.015*			1.21 (0.68–2.15)	0.523
Microbial
Polymicrobial infections (n=112)	3.07 (1.69–5.59)	<0.001*	3.20 (1.35–7.55)	0.008*	1.42 (0.82–2.46)	0.207
Antibiotic regimen
TMP-SMX-based regimen (n=53)	0.21 (0.11–0.41)	<0.001*	0.29 (0.11–0.76)	0.012*	0.53 (0.28–0.99)	0.047*	0.68 (0.34–1.38)	0.283
Levofloxacin-based regimen (n=104)	2.41 (1.33–4.37)	0.003*			1.21 (0.70–2.09)	0.488
Ceftazidime (n=14)	1.93 (0.52–7.17)	0.316			1.02 (0.35–3.02)	0.970
Between antibiotic regimen
Levofloxacin-based VS TMP-SMX-based	2.79 (1.37–5.68)	0.005*			1.75 (0.89–3.46)	0.106
Ceftazidime VS TMP-SMX-based	3.27 (0.82–13.09)	0.093			1.65 (0.50–5.40)	0.408
Levofloxacin-based VS ceftazidime	0.86 (0.22–3.34)	0.829			1.08 (0.35–3.30)	0.892
Ceftazidime VS TMP-SMX-based or levofloxacin- based	1.74 (0.47–6.54)	0.409			1.14 (0.38–3.41)	0.814
Monotherapy VS combination therapy	2.30 (2.47–11.18)	0.303			1.77 (0.48–6.50)	0.392
Appropriate VS inappropriate antibiotic agent	0.63 (0.28–1.37)	0.243			0.55 (0.27–1.12)	0.099
Dosing regimen
TMP-SMX dosage < 10 mkd VS ≥ 10 mkd	0.86 (0.28–2.58)	0.782			1.02 (0.33–3.11)	0.974
Levofloxacin dosage < 10 mkd VS ≥ 10 mkd	1.23 (0.45–3.29)	0.691			2.07 (0.84–5.13)	0.116

Notes: Mann–Whitney U-test, logistic regression analysis. *Defined as statistically significant test result (p< 0.05).

Abbreviations: CCI, Charlson comorbidity score; APACHE II, The Acute Physiology and Chronic Health Evaluation; mkd, mg/kg/day; TMP-SMX, trimethoprim-sulfamethoxazole; OR, odds ratio; CI, confidence interval.

Figure 1 Kaplan–Meier survival curve for treatment failure following the TMP-SMX and levofloxacin-based regimens.