Table 2.
Concentrations of microbiological contaminants in DUWL samples: Type A vs. Type B.
| Microbiological Parameters | Statistical Parameters | Type A | Type B | Type A vs. Type B: p-value (One-Sided) |
|---|---|---|---|---|
| HPCs at 36 °C | % of positive samples (CDC 2003) |
38.1% | 0 | 0.002 |
| % of positive samples (D.lgs 31/2001) |
69.1% | 56.3% | ||
| Median, IQR | 1.95, 0.63 Log cfu/mL | 1.33, 0.41 Log cfu/mL | ||
| Range of the mean concentration (min-max) | 1.44–2.99 Log cfu/mL | 0.89–1.41 Log cfu/mL | ||
| Reference value: 500 cfu/mL (2.69 Log cfu/mL) Source of the reference value: CDC 2003 [26] Reference value: 20 cfu/mL (1.3 Log cfu/mL) Source of the reference value: Italian D.lgs 31/2001 [30,31] | ||||
| P. aeruginosa | % of positive samples | 77.4% | 25.0% | 0.004 |
| Median, IQR | 1.86, 0.73 Log cfu/100 mL | 0.31, 1.04 Log cfu/100 mL | ||
| Range of the mean concentration (min-max) | 0.92–2.58 Log cfu/100 mL | 0.00–1.17 Log cfu/100 mL | ||
| Reference value: 0 cfu/100 Ml Source of the reference value: Italian D.lgs 31/2001 [30,31] | ||||
| Legionella spp. | % of positive samples | 91.7% | 37.5% | 0.05 |
| Median, IQR | 2.50, 0.08 Log cfu/L | 2.29, 0.56 Log cfu/L | ||
| Range of the mean concentration (min-max) | 2.42–2.74 Log cfu/L | 1.80–2.52 Log cfu/L | ||
| Reference value: 100 cfu/L (2 Log cfu/L) Source of the reference values: Italian Guidelines 2015 [34] Emilia Romagna Guidelines, 2017 [35]. | ||||