Multidrug-Resistant and Extensively Drug-Resistant Enterobacteriaceae: Prevalence, Treatments, and Outcomes – A Retrospective Cohort Study

Figures & data

Table 1 Demographics and Baseline Characteristics Based on Resistance Type

Characteristics	Overall (n=138)	Alive (n=22/138)	Dead (n=116/138)	p-value*
Gender				0.004
Male	64 (46.4%)	4 (18.2%)	60 (51.7%)
Female	74 (53.6%)	18 (81.8%)	56 (48.3%)
Age				0.93
Mean ± SD	60.1 ± 17.7	59.7 ± 21.4	60.1 ± 17.1
Median [min, max]	63.5 [14.0, 94.0]	69.5 [15.0, 87.0]	63.0 [14.0, 94.0]
History of DM	75 (54.3%)	12 (54.5%)	63 (54.3%)	0.98
History of cancer	27 (19.6%)	5 (22.7%)	22 (19.0%)	0.68
Bacteria				0.26
E. coli	71 (51.4%)	12 (54.5%)	59 (50.9%)
K. pneumoniae	45 (32.6%)	9 (40.9%)	36 (31.0%)
Enterobacter species	22 (15.9%)	1 (4.5%)	21 (18.1%)
MDR/XDR strains				0.78
MDR	130 (94.2%)	21 (95.5%)	109 (94.0%)
XDR	8 (5.8%)	1 (4.5%)	7 (6.0%)
Resistance type				0.48
ESBL	71 (51.4%)	13 (59.1%)	58 (50.0%)
CPE	14 (10.1%)	3 (13.6%)	11 (9.5%)
Other	53 (38.4%)	6 (27.3%)	47 (40.5%)
Source				0.56
Urine	34 (24.6%)	7 (31.8%)	27 (23.3%)
Wound	16 (11.6%)	4 (18.2%)	12 (10.3%)
Blood	15 (10.9%)	0 (0%)	15 (12.9%)
Sputum	14 (10.1%)	4 (18.2%)	10 (8.6%)
Tracheal aspirate	12 (8.7%)	2 (9.1%)	10 (8.6%)
Central line	12 (8.7%)	3 (13.6%)	9 (7.8%)
Urinary catheter	8 (5.8%)	1 (4.5%)	7 (6.0%)
Peritoneal fluid	7 (5.1%)	1 (4.5%)	6 (5.2%)
Tissue	7 (5.1%)	0 (0%)	7 (6.0%)
Others	13 (9.3)	0 (0%)	13 (11.2%)
Ventilation	85 (61.6%)	11 (50.0%)	74 (63.8%)	0.22
ESRD	26 (18.8%)	4 (18.2%)	22 (19.0%)	0.93
Prior 4 weeks antibiotic use	99 (71.7%)	12 (54.5%)	87 (75.0%)	0.05
Prior 90 days antibiotic use	110 (79.7%)	18 (81.8%)	92 (79.3%)	0.79
Prior 4 weeks antibiotic use	99 (71.7%)	12 (54.5%)	87 (75.0%)	0.05
Inotropes	75 (54.3%)	8 (36.4%)	67 (57.8%)	0.06
ICU length of stay ≥ 72 hours before culture	63 (45.7%)	11 (50.0%)	52 (44.8%)	0.66

Notes: *Chi-square test was used to compare categorical data and independent sample t-test to compare continuous data. Data presented as mean ± standard deviation for continuous variables, or number and (percentages) for categorical variables.

Abbreviations: CPE, carbapenem-producing Enterobacteriaceae; DM, diabetes mellitus; ESBL, extended-spectrum β-lactamase; ESRD, end-stage renal disease; ICU, intensive care unit; MDR, multidrug-resistant; SD, standard deviation; XDR, extensively drug-resistant.

Figure 1 Number of antibiotic therapy and their appropriateness in MDR Enterobacteriaceae isolates.

Abbreviation: MDR, multidrug-resistant.

Figure 2 Number of antibiotic therapy and their appropriateness in XDR Enterobacteriaceae isolates.

Abbreviation: XDR, extensively drug-resistant.

Table 2 Clinical Outcomes of Study Subjects Divided by MDR/XDR Status

Outcome	Overall (n=138)	MDR Group (n=130)	XDR Group (n=8)	p-value*
ICU LOS in days mean ± SD	27.1 ± 32.7	25.8 ± 31.9	48.0 ± 39.4	0.06
Culture negative, n (%)	56 (40.6%)	52 (40.0%)	4 (50.0%)	0.58
Hospital mortality, n (%)	116 (84.1%)	109 (83.8%)	7 (87.5%)	0.78

Notes: *Chi-square test was used to compare categorical data and independent sample t-test to compare continuous data. Data presented as mean ± standard deviation for continuous variables, or number and (percentages) for categorical variables.

Abbreviations: ICU, intensive care unit; LOS, length of stay; MDR, multidrug-resistant; SD, standard deviation; XDR, extensively drug-resistant.

Table 3 Characteristics Associated with Hospital Mortality in Study Subjects (N=138)

	Unadjusted Analysis OR (95% CI)
Male gender	4.82 (1.68–17.47)
Age (years)	1.00 (0.97–1.03)
History of DM	0.99 (0.39–2.48)
History of cancer	0.80 (0.28–2.62)
XDR strain	1.35 (0.22–25.90)
Bacteria
K. pneumoniae	Reference
E. coli	1.22 (0.46–3.20)
Enterobacter species	5.23 (0.90–100.28)
Resistance type
ESBL	0.57 (0.19–1.56)
CPE	0.46 (0.11–2.48)
Other	Reference
Ventilation	1.76 (0.70–4.46)
ESRD	1.05 (0.35–3.92)
Prior 90 days antibiotic use	0.85 (0.23–2.54)
Prior 4 weeks antibiotic use	2.5 (0.96–6.41)
Inotropes	2.39 (0.95–6.41)
ICU length stay ≥ 72hrs until culture	0.81 (0.32–2.04)
Appropriateness of therapy	1.58 (0.63–3.98)

Abbreviations: CI, confidence interval; CPE, carbapenem-producing Enterobacteriaceae; DM, diabetes mellitus; ESBL, extended-spectrum β-lactamase; ESRD, end-stage renal disease; ICU, intensive care unit; OR, odds ratio, SD, standard deviation; XDR, extensively drug-resistant.

Table 4 Characteristics Associated with Negative Cultures in Study Subjects (N=138)

	Unadjusted Analysis OR (95% CI)
Male gender	0.62 (0.31–1.22)
Age (years)	1.00 (0.98–1.02)
History of DM	0.74 (0.37–1.47)
History of cancer	1.47 (0.62–3.44)
XDR Strain	1.5 (0.34–6.60)
Bacteria
K. pneumoniae	Reference
E. coli	0.98 (0.46–2.11)
Enterobacter species	1.25 (0.44–3.52)
Resistance type
ESBL	0.67 (0.32–1.39)
CPE	2.35 (0.71–8.54)
Other	Reference
Ventilation	0.30 (0.14–0.60)
ESRD	1.05 (0.35–3.92)
Prior 90 days antibiotics use	0.43 (0.18–0.99)
Prior 4 weeks antibiotics use	0.54 (0.25–1.15)
Inotropes	0.60 (0.29–1.16)
ICU length stay ≥ 72hrs until culture	1.19 (0.60–2.36)
Appropriateness of therapy	0.67 (0.33–1.33)

Abbreviations: CI, confidence interval; CPE, carbapenem-producing Enterobacteriaceae; DM, diabetes mellitus; ESBL, extended-spectrum β-lactamase; ESRD, end-stage renal disease; ICU, intensive care unit; OR, odds ratio, SD, standard deviation; XDR, extensive drug-resistant.

Table 5 Characteristics Associated with LOS in Study Subjects (N=138)

	Unadjusted Analysis Coefficient (95% CI)	Adjusted Analysis Coefficient (95% CI)
Male gender	−3.33 (−14.42–7.76)	–
Age (years)	−0.16 (−0.47–0.18)	–
History of DM	7.83 (−3.21–18.87)	–
History of cancer	−10.40 (−24.21–3.42)	–
XDR Strain	22.21 (−1.12–45.54)*	2.03 (−19.28–23.33)
Bacteria
K. pneumoniae	Reference	Reference
E. coli	−14.69 (−26.86- [−2.51])*	−4.64 (−15.80–6.51)
Enterobacter species	−0.18 (−16.75–16.39)	− 3.62 (−18.36–11.12)
Resistance type
ESBL	−2.44 (−14.24–9.36)	–
CPE	3.69 (−16.43–23.81)	–
Other	Reference	–
Ventilation	17.34 (6.31–28.38)*	11.49 (1.02–21.97)**
ESRD	6.45 (−7.86–20.76)	–
Prior 90 days antibiotics use	11.51 (−2.09–25.11)*	−1.33 (−13.67–11.01)
Prior 4 weeks antibiotics use	3.53 (−8.74–15.79)	–
Inotropes	−12.24 (−23.16- [−1.32])	−11.72 (−21.54- [−1.89])**
ICU length stay ≥ 72hrs until culture	33.10 (23.50–42.71)*	28.65 (17.85–39.46)**
Appropriateness of therapy	−7.71 (−18.90–3.49)	–

Notes: *Variables with p-values below 0.1 were included in the adjusted model. **p-value <0.05.

Abbreviations: CI, confidence interval; CPE, carbapenem-producing Enterobacteriaceae; DM, diabetes mellitus; ESBL, extended-spectrum β-lactamase; ESRD, end-stage renal disease; ICU, intensive care unit; OR, odds ratio, SD, standard deviation; XDR, extensively drug-resistant.