Table 3. Characteristics of patients carrying plasmid-mediated AmpC beta-lactamase- and ESBL-producing Enterobacteriaceae (each 39 patients); univariate logistic regression analysis to define risk factors for plasmid-mediated AmpC beta-lactamase producers.
| Characteristic | pAmpC (n = 39) | ESBL (n = 39) | p-value | OR (95% CI) |
|---|---|---|---|---|
| Demographics: | ||||
| Age, years (median) | 59 (21–87) | 60 (20–88) | * | * |
| Male, n (%) | 15 (38) | 15 (38) | 1.000 | 1.00 (0.40–2.49) |
| Nationality, n (%): | 0.994 | |||
| Swiss | 23 (59) | 24 (62) | 0.90 (0.36–2.22) | |
| South European | 9 (23) | 8 (21) | 1.16 (0.40–3.41) | |
| North European | 2 (5) | 2 (5) | 1.00 (0.13–7.48) | |
| Other | 5 (13) | 5 (13) | 1.00 (0.27–3.77) | |
| Admission from, n (%): | 0.314 | |||
| Home | 32 (82) | 33 (85) | 0.83 (0.25–2.74) | |
| Nursing home | 4 (10) | 1 (3) | 4.34 (0.46–40.74) | |
| Another hospital | 3 (8) | 5 (13) | 0.57 (0.13–2.56) | |
| Period before detection of MRE, n (%): | ||||
| Hospitalization within ≤ 30 days | 18 (46) | 10 (26) | 0.059 | 2.49 (0.96–6.46) |
| Antibiotic exposure within ≤ 30 days ‡ | 20 (63) | 12 (36) | 0.035 | 2.37 (0.94–5.98) |
| Antibiotic exposure at the time of MRE detection | 16 (41) | 15 (38) | 0.817 | 1.11 (0.45–2.76) |
| Co-morbidities, n (%): | ||||
| Any | 28 (72) | 32 (82) | 0.282 | 0.56 (0.19–1.63) |
| Cardiovascular | 20 (51) | 19 (49) | 0.821 | 1.10 (0.46–2.69) |
| Immunosuppression § | 12 (31) | 6 (15) | 0.107 | 2.44 (0.81–7.37) |
| Chronic renal failure (eGFR <60ml/min.) | 9 (23) | 12 (31) | 0.472 | 0.67 (0.25–1.85) |
| Abdominal | 7 (18) | 6 (15) | 0.761 | 1.20 (0.39–3.97) |
| Diabetes mellitus | 7 (18) | 7 (18) | 1.000 | 1.00 (0.32–3.18) |
| Pulmonary (mainly COPD) | 5 (13) | 7 (18) | 0.530 | 0.67 (0.19–2.33) |
| Neoplasia | 3 (8) | 8 (21) | 0.104 | 0.32 (0.08–1.32) |
| McCabe Score, n (%) †: | 0.245 | |||
| 1 | 22 (56) | 24 (62) | 0.80 (0.33–2.00) | |
| 2 | 16 (41) | 11 (28) | 1.77 (0.69–4.56) | |
| 3 | 1 (3) | 4 (10) | 0.23 (0.02–2.16) | |
| Time when MRE was detected, n (%): | ||||
| Treating department: | * | * | ||
| Internal medicine | 17 (44) | 19 (49) | ||
| Surgery | 12 (31) | 13 (33) | ||
| Gynaecology/obstetrics | 6 (15) | 4 (10) | ||
| Intensive care unit | 4 (10) | 3 (8) | ||
| Outpatient treatment | 15 (38) | 8 (21) | 0.082 | 2.42 (0.88–6.65) |
| Devices at detection: | ||||
| No device | 21 (54) | 23 (59) | 0.650 | 0.81 (0.33–1.99) |
| Nasogastric tube | 9 (23) | 0 | 0.002 | Undefined |
| Urinary catheter | 6 (15) | 12 (31) | 0.107 | 0.41 (0.14–1.23) |
| Central venous catheter | 1 (3) | 1 (3) | 1.000 | 1.00 (0.06–16.57) |
| Multiple devices (≥2) | 2 (5) | 3 (8) | 0.644 | 0.65 (0.10–4.11) |
| Source of MRE isolate, n (%): | ||||
| Urinary tract | 27 (69) | 30 (77) | 0.444 | 0.67 (0.25–1.85) |
| Abdomino-rectal | 6 (15) | 5 (13) | 0.745 | 1.24 (0.35–4.45) |
| Pulmonary | 2 (5) | 2 (5) | 1.000 | 1.00 (0.13–7.48) |
| Bone | 2 (5) | 1 (3) | 1.000 | 2.05 (0.18–23.63) |
| Primary sepsis | 1 (3) | 1 (3) | 1.000 | 1.00 (0.06–16.57) |
| Superficial wound swab | 1 (3) | 0 | 1.000 | Undefined |
| Acquisition of MRE isolates, n (%): | ||||
| Community-acquired | 18 (46) | 17 (44) | 0.820 | 1.10 (0.45–2.70) |
| Nosocomial | 13 (33) | 15 (38) | 0.637 | 0.80 (0.32–2.02) |
| Healthcare-associated | 8 (21) | 4 (10) | 0.347 | 2.26 (0.62–8.23) |
| Undeterminable | 0 | 3 (8) | 0.240 | Undefined |
| Clinical significance of MRE isolate, n (%): | ||||
| Infection | 29 (74) | 20 (51) | 0.035 | 2.75 (1.06–7.15) |
| Urinary tract | 21 (72) | 16 (80) | 0.797 | 1.68 (0.68–4.11) |
| Intraabdominal | 3 (10) | 1 (5) | 0.914 | 3.17 (0.31–31.85) |
| Osteomyelitis | 2 (7) | 1 (5) | 1.000 | 2.05 (0.18–23.63) |
| Pneumonia | 1 (3) | 1 (5) | 1.000 | 1.00 (0.06–16.57) |
| Primary sepsis | 1 (3) | 1 (5) | 1.000 | 1.00 (0.06–16.57) |
| Wound infection | 1 (3) | 0 | 1.000 | Undefined |
| Colonization | 10 (26) | 19 (49) | 0.035 | 0.36 (0.14–0.94) |
| Median duration of hospitalization, days (range) | 7 (1–82) | 9 (1–105) | 0.337 | 0.73 (0.24–2.20) |
Abbreviations: pAmpC, plasmid-mediated AmpC beta-lactamase; ESBL, Extended-Spectrum beta-Lactamase; OR, odds ratio; CI, confidence interval; MRE, multidrug-resistant Enterobacteriaceae; eGFR, estimated glomerular filtration rate; COPD, chronic obstructive pulmonary disease
* Matching variables
‡ Patients with known exposure status to antibiotic treatment: 32 in the pAmpC and 33 in the ESBL group
§ >10 mg prednisone equivalent daily for >3 months
† McCabe Score: 1 = non-fatal disease (supposed survival >5 years for >50% of patients with the disease), 2 = ultimately fatal disease (supposed survival 1–5 years for >50% of patients with the disease), 3 = rapidly fatal disease (supposed death within 1 year for >50% of patients with the disease)