Table 2.
Microbiological features of SSI with or without Pseudomonas aeruginosa
| Microorganisms |
P. aeruginosa SSI (n = 62) |
Other SSI (n = 607) |
P-value | OR (95% CI) |
|---|---|---|---|---|
| Polymicrobial infection, n (%) | 42 (67.7) | 203 (33.4) | < 0.001 | 4.2 (2.39–7.30) |
| Gram-negative bacteria, n (%) | 28 (45.2) | 262 (43.2) | 0.7 | 1.1 (0.64–1.83) |
| - E. coli | 17 (27.4) | 212 (34.9) | 0.2 | 0.7 (0.39–1.26) |
| • E. coli MDRa | 4 (6.5) | 24 (4) | 0.3 | 1.6 (0.56–4.99) |
| - K. pneumoniae | 3 (4.8) | 27 (4.4) | 0.8 | 1.1 (0.32–3.70) |
| • K. pneumoniae MDRa | 1 (1.6) | 8 (1.3) | 0.8 | 1.2 (0.51–9.97) |
| Gram-positive bacteria, n (%) | 10 (16.1) | 177 (29.2) | 0.02 | 0.4 (0.23–0.94) |
| - Enterococcus spp | 6 (9.7) | 111 (18.3) | 0.08 | 0.4 (0.20–1.13) |
| • E. faecalis | 4 (6.5) | 54 (8.9) | 0.5 | 0.7 (0.24–2.02) |
| • E. faecium | 2 (3.2) | 56 (9.2) | 0.1 | 0.3 (0.07–1.37) |
| - S. aureus | 3 (4.8) | 26 (4.3) | 0.8 | 1.1 (0.33–3.86) |
| - Coagulase negative staphylococci | 1 (1.6) | 12 (2) | 0.8 | 0.8 (0.1–6-35) |
| Fungus, n (%) | 1 (1.6) | 19 (3.1) | 0.5 | 0.5 (0.06–3.85) |
| - C. albicans | 1 (1.6) | 15 (2.5) | 0.6 | 0.6 (0.08–4.98) |
| Anaerobes, n (%) | 1 (1.6) | 33 (5.4) | 0.2 | 0.3 (0.03–2.12) |
| - B. fragilis | 0 (0) | 16 (2.6) | 0.1 | 0.9 (0.88–0.92) |
| - C. perfringens | 0 (0) | 3 (0.5) | 0.6 | 0.9 (0.88–0.92) |
P. aeruginosa: Pseudomonas aeruginosa, SSI: surgical site infection, MDR: multidrug-resistant, E. Coli: Escherichia coli, K. pneumoniae: Klebsiella pneumoniae, A. baumannii: Acinetobacter baumannii, E. faecalis: Enterococcus faecalis, E. faecium: Enterococcus faecium, S. aureus: Staphylococcus aureus, C. albicans: Candida albicans, B. fragilis: Bacteroides fragilis, C. perfringens: Clostridium perfringens
aE. coli MDR and K. pneumoniae MDR are included in the box above referring to the organism group