Table 2. Chlorhexidine and octenidine minimal inhibitory concentrations (MIC) of ICU-attributable bacterial isolates from clinical samples reported by study group and period.
| Total | Chlorhexidine group | Octenidine group | Routine care group = control | ||||
|---|---|---|---|---|---|---|---|
| Baseline | Intervention | Baseline | Intervention | Baseline | Intervention | ||
| Staphylococcus aureus | |||||||
| n (%) | 155 (100.0%) | 38 (25.0%) | 22 (14.1%) | 24 (15.4%) | 18 (11.5%) | 23 (14.7%) | 30 (19.2%) |
| Chlorhexidine | |||||||
| MIC50 in est. [μg/ml] (IQR) | 5.0 (2.0–5.0) | 5.0 (5.0–5.0) | 2.0 (2.0–4.3) | 5.0 (2.0–5.0) | 2.0 (2.0–5.0) | 5.0 (2.0–5.0) | 5.0 (2.8–10.0) |
| MIC90 in est. [μg/ml] | 5.0 | 5.0 | 4.3 | 5.0 | 5.0 | 5.0 | 10.0 |
| Octenidine | |||||||
| MIC50 in est. [μg/ml] (IQR) | 2.0 (2.0–2.0) | 2.0 (2.0–4.0) | 2.0 (0.8–2.0) | 2.0 (2.0–2.0) | 2.0 (2.0–2.0) | 2.0 (2.0–4.0) | 2.0 (2.0–2.0) |
| MIC90 in est. [μg/ml] | 2.0 | 4.0 | 2.0 | 2.0 | 2.0 | 4.0 | 2.0 |
| Coagulase-negative staphylococci | |||||||
| n (%) | 122 (100.0%) | 31 (25.4%) | 31 (25.4%) | 17 (13.9%) | 11 (9.0%) | 15 (12.3%) | 17 (13.9%) |
| Chlorhexidine | |||||||
| MIC50 in est. [μg/ml] (IQR) | 5.0 (2.0–5.0) | 5.0 (2.0–5.0) | 2.0 (1.0–2.0) | 5.0 (5.0–5.0) | 2.0 (1.0–3.5) | 5.0 (2.0–5.0) | 5.0 (5.0–5.0) |
| MIC90 in est. [μg/ml] | 5.0 | 5.0 | 2.0 | 5.0 | 3.5 | 5.0 | 5.0 |
| Octenidine | |||||||
| MIC50 in est. [μg/ml] (IQR) | 2.0 (2.0–4.0) | 2.0 (2.0–4.0) | 2.0 (0.8–2.0) | 2.0 (2.0–4.0) | 0.8(0.8–2.0) | 4.0 (2.0–4.0) | 2.0 (2.0–2.0) |
| MIC90 in est. [μg/ml] | 4.0 | 4.0 | 2.0 | 4.0 | 2.0 | 4.0 | 2.0 |
| Escherichia coli | |||||||
| n (%) | 227 (100.0%) | 64 (28.2%) | 37 (16.3%) | 41 (18.1%) | 18 (7.9%) | 39 (17.2%) | 28 (11.9%) |
| Chlorhexidine | |||||||
| MIC50 in est. [μg/ml] (IQR) | 5.0 (2.0–5.0) | 5.0 (2.0–5.0) | 2.0 (2.0–5.0) | 5.0 (5.0–5.0) | 2.0 (2.0–5.0) | 5.0 (5.0–5.0) | 5.0 (2.0–10.0) |
| MIC90 in est. [μg/ml] | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 | 10.0 |
| Octenidine | |||||||
| MIC50 in est. [μg/ml] (IQR) | 4.0 (2.0–4.0) | 4.0 (4.0–4.0) | 2.0 (2.0–4.0) | 4.0 (4.0–4.0) | 2.0 (2.0–4.0) | 4.0 (4.0–4.0) | 4.0 (2.0–4.0) |
| MIC90 in est. [μg/ml] | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 |
| Klebsiella spp. | |||||||
| n (%) | 150 (100.0%) | 28 (18.7%) | 28 (18.7%) | 23 (15.3%) | 29 (19.3%) | 20 (13.3%) | 22 (14.7%) |
| Chlorhexidine | |||||||
| MIC50 in est. [μg/ml] (IQR) | 50.0 (20.0–50.0) | 50.0 (20.0–50.0) | 20.0 (20.0–50.0) | 50.0 (50.0–50.0) | 50.0 (20.0–50.0) | 50.0 (42.5–50.0) | 50.0 (20.0–50.0) |
| MIC90 in est. [μg/ml] | 50.0 | 50.0 | 50.0 | 50.0 | 50.0 | 50.0 | 50.0 |
| Octenidine | |||||||
| MIC50 in est. [μg/ml] (IQR) | 4.0 (4.0–8.0) | 4.0 (4.0–12.0) | 4.0 (4.0–4.0) | 8.0 (4.0–10.0) | 4.0 (4.0–4.0) | 4.0 (4.0–13.0) | 4.0 (4.0–4.0) |
| MIC90 in est. [μg/ml] | 8.0 | 12.0 | 4.0 | 10.0 | 4.0 | 13.0 | 4.0 |
| Pseudomonas aeruginosa | |||||||
| n (%) | 136 (100.0%) | 19 (14.0%) | 18 (13.2%) | 17 (12.5%) | 40 (29.4%) | 18 (13.2%) | 24 (17.6%) |
| Chlorhexidine | |||||||
| MIC50 in est. [μg/ml] (IQR) | 50.0 (50.0–50.0) | 50.0 (35.0–50.0) | 50.0 (50.0–50.0) | 50.0 (50.0–50.0) | 50.0 (50.0–50.0) | 50.0 (50.0–50.0) | 50.0 (50.0–50.0) |
| MIC90 in est. [μg/ml] | 50.0 | 50.0 | 50.0 | 50.0 | 50.0 | 50.0 | 50.0 |
| Octenidine | |||||||
| MIC50 in est. [μg/ml] (IQR) | 12.0 (8.0–24.0) | 8.0 (8.0–20.0) | 8.0 (8.0–16.0) | 16.0 (8.0–16.0) | 12.0 (8.0–16.0) | 24.0 (8.0–32.0) | 16.0 (8.0–24.0) |
| MIC90 in est. [μg/ml] | 24.0 | 20.0 | 16.0 | 16.0 | 16.0 | 32.0 | 24.0 |
Median MIC (MIC50) with inter quartile ranges (IQR) and MIC90 are given in estimated concentrations (est. μg/ml) derived from extraction solutions that were harvested from the ready-to-use products. MIC are reported for Staphylococcus aureus, coagulase-negative staphylococci, Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa in total and by study group (chlorhexidine, octenidine, routine care) and period (baseline, prior to the intervention period, intervention, at the end of the intervention period). Percentages of bacterial isolates per study group and period refer to the total number per species.