Table 1.
Clinical and microbiological characteristics of bloodstream infections due to AmpC-producing Enterobacteriaceae in the Calgary Zone
| Enterobacter spp. 1 | Serratia spp. 2 | Citrobacter spp. 3 | Providencia & Morganella spp. 4 | E. coli 5 | Other 6 | |
|---|---|---|---|---|---|---|
| No. of episodes | 255 | 73 | 51 | 39 | 30 | 10 |
| Source of infection (no. episodes) | ||||||
| Biliary | 46 | 2 | 6 | 2 | 3 | 4 |
| Bowel | 18 | 5 | 4 | 4 | 2 | 0 |
| Urinary | 43 | 10 | 13 | 15 | 5 | 2 |
| Pneumonia | 14 | 13 | 2 | 0 | 1 | 0 |
| CVS source | 0 | 1 | 0 | 0 | 0 | 0 |
| SST source | 7 | 4 | 0 | 0 | 0 | 0 |
| BJ source | 1 | 0 | 2 | 4 | 0 | 0 |
| CNS source | 1 | 0 | 0 | 0 | 0 | 0 |
| Unknown | 125 | 38 | 24 | 14 | 19 | 4 |
| Comorbid conditions | ||||||
| Myocardial infarction | 15 (5.9%) | 4 (5.5%) | 4 (7.8%) | 4 (10%) | 2 (6.7%) | 0 (0%) |
| CHF | 32 (13%) | 18 (25%) | 5 (9.8%) | 6 (15%) | 2 (6.7%) | 1 (10%) |
| PVD | 6 (2.4%) | 7 (9.6%) | 1 (2.0%) | 4 (10%) | 2 (6.7%) | 1 (10%) |
| CVD | 8 (3.1%) | 5 (6.8%) | 1 (2.0%) | 2 (5.1%) | 0 (0%) | 1 (10%) |
| Dementia | 2 (<1%) | 0 (0%) | 2 (3.9%) | 3 (8.5%) | 1 (3.3%) | 0 (0%) |
| CPD | 20 (7.8%) | 13 (18%) | 2 (3.9%) | 5 (13%) | 8 (27%) | 3 (30%) |
| Rheumatic disease | 2 (<1%) | 0 (0%) | 1 (2.0%) | 3 (8.5%) | 0 (0%) | 0 (0%) |
| Peptic ulcer disease | 9 (3.5%) | 4 (5.5%) | 1 (2.0%) | 2 (5.1%) | 0 (0%) | 1 (10%) |
| Hemiplegia/Paraplegia | 6 (2.4%) | 4 (5.5%) | 2 (3.9%) | 3 (8.5%) | 1 (3.3%) | 0 (0%) |
| Renal disease | 31 (12%) | 17 (23%) | 7 (14%) | 9 (23%) | 2 (6.7%) | 0 (0%) |
| Mild liver disease | 10 (3.9%) | 1 (1.4%) | 1 (2.0%) | 0 (0%) | 0 (0%) | 0 (0%) |
| Moderate severe liver disease | 12 (4.7%) | 4 (5.5%) | 1 (2.0%) | 2 (5.1%) | 2 (6.7%) | 1 (10%) |
| Malignancy | 53 (21%) | 8 (11%) | 15 (29%) | 2 (5.1%) | 1 (3.3%) | 2 (20%) |
| Metastatic solid cancer | 27 (11%) | 3 (4.1%) | 2 (3.9%) | 1 (2.6%) | 5 (17%) | 1 (10%) |
| DM w/o complication | 25(9.8%) | 7 (9.6%) | 2 (3.9%) | 4 (10%) | 3 (10%) | 0 (0%) |
| DM w/ complications | 14 (5.5%) | 6 (8.2%) | 3 (5.9%) | 6 (15%) | 1 (3.3%) | 0 (0%) |
| Median Charlson (IQR) | 3 (1–5) | 4 (2–6) | 3 (2–4) | 4 (3–7) | 4 (1–5) | 4 (4–6) |
| Median age (IQR) | 58.0 (39 – 72.3) | 65.6 (52.1 – 74.2) | 59.1 (36.6 – 75.3) | 72.9 (62.9 – 79.6) | 58.6 (41.1 – 77.3) | 71.2 (64.4 – 81.6) |
| Male sex (%) | 62% | 60% | 75% | 74% | 33% | 50% |
| Surveillance definition | ||||||
| Nosocomial | 138 (24, 17% ) | 45 (14, 31%) | 22 (1, 4.5%) | 13 (2, 15%) | 11 (0, 0%) | 3 (0, 0%) |
| HCAI | 70 (6, 8.6%) | 12 (1, 8.3%) | 16 (0, 0%) | 17 (3, 18%) | 10 (1, 10%) | 4 (0, 0%) |
| Community acquired | 47 (3, 6.4%) | 16 (3, 19%) | 13 (0, 0%) | 9 (1, 11%) | 9 (0, 0%) | 3 (1, 33%) |
| p-value | 0.08 | 0.248 | 1.000 | 1.000 | 0.633 | 0.600 |
| Per year of infection | ||||||
| 2000 | 20 (7.8%) | 6 (8.2%) | 2 (3.9%) | 7 (18%) | 0 (0%) | 1 (10%) |
| 2001 | 26 (10%) | 13 (18%) | 3 (5.9%) | 0 (0%) | 4 (13%) | 3 (30%) |
| 2002 | 24 (9.4%) | 5 (6.9%) | 5 (9.8%) | 1 (2.6%) | 4 (13%) | 1 (10%) |
| 2003 | 33 (13%) | 3 (4.1%) | 3 (5.9%) | 9 (23%) | 5 (17%) | 2 (20%) |
| 2004 | 31 (12%) | 9 (12%) | 8 (16%) | 3 (7.7%) | 2 (6.7%) | 2 (20% |
| 2005 | 20 (7.8%) | 14 (19%) | 8 (16%) | 8 (21%) | 2 (6.7%) | 1 (10%) |
| 2006 | 24 (9.4%) | 6 (8.2%) | 5 (9.8%) | 5 (13%) | 7 (23%) | 0 (0%) |
| 2007 | 31 (12%) | 7 (9.6%) | 10 (20%) | 2 (5.1%) | 2 (6.7%) | 0 (0%) |
| 2008 | 46 (18%) | 10 (14%) | 7 (14%) | 4 (10%) | 4 (13%) | 0 (0%) |
| Susceptibility testing (percentage susceptible) | ||||||
| Ciprofloxacin | 248/255 (98%) | 71/73 (97%) | 47/50 (94%) | 36/38 (95%) | 24/30 (80%) | 10/10 (100%) |
| Gentamicin | 251/255 (99%) | 72/73 (99%) | 45/50 (90%) | 34/38 (90%) | 23/30 (77%) | 10/10 (100%) |
| Piperacillin-tazobactam | 203/255 (80%) | 69/73 (95%) | 46/50 (92%) | 38/38 (100%) | 29/30 (97%) | 7/10 (70%) |
| TMP/SMX | 242/255 (95%) | 73/73 (100%) | 39/50 (78%) | 31/38 (82%) | 19/30 (63%) | 10/10 (100%) |
| Tobramycin | 251/255 (99%) | 64/73 (88%) | 45/50 (90%) | 33/38 (87%) | 26/30 (87%) | 10/10 (100%) |
| Imipenem | 255/255 (100%) | 73/73 (100%) | 50/50 (100%) | 38/38 (100%) | 30/30 (100%) | 10/10 (100%) |
1Includes 34 E. aerogenes, 1 E. asburiae, 2 E. cancerogenus, 210 E. cloacae, 6 E. sakazakii and 2 E. spp bacteremia episodes.
2Includes 3 S. liquefaciens, 67 S. marcescens, 1 S. odorfera and 2 S. spp. bacteremia episodes.
3Includes 17 C. braakii, 30 C. freundii, 2 C. spp. and 2 C. youngae bacteremia episodes.
4Includes 27 M. Morganii, 3 P. rettgeri and 9 P. stuartii bacteremia episodes.
5Includes 30 E. coli bacteremia episodes.
6Includes 7 H. alveii, 2 Salmonella spp. and 1 K. pneumoniae bacteremia episodes.
CVS = Cardiovascular, SST = Skin and Soft Tissue, BJ = Bone and Joint, CNS = Central Nervous System, CHF = Congestive Heart Failure, PVD = Peripheral Vascular Disease, CVD = Cerebrovascular Disease, CPD = Chronic Pulmonary Disease, TMP/SMX = Trimethoprim/Sulfamethoxazole.