Table 1. Biofilm bacterial counts on different parts of the milking machines of farm 1 (F1) and farm 2 (F2) and on stainless steel coupons placed into the milking machine of farm 1 for different time intervals.
| log10 cfu/cm2 mean (SD) |
Milking equipment retainer (R) plastic |
Filter tube (FT) stainless steel |
Beginning of the pressure pipe (BP) stainless steel |
End of the pressure pipe (EP) plastic |
Outlet of the bulk tank (OB) stainless steel |
Coupon (C) stainless steel |
||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Farm 1 (F1) (n = 9) |
Farm 2 (F2) (n = 2) |
F1 (n = 3) |
F2 (n = 1) |
F1 (n = 2) |
F2 (n = 1) |
F1 (n = 3) |
F2 (n = 1) |
F1 (n = 3) |
F2 (n = 1) |
F1, 48 h (n = 3) |
F1, 72 h (n = 1) |
|
| Total microbial count (TSA) | 6.3 (1.1) | 4.4 (1.9) | 2.8 (0.9) | 2.6 | 2.7 (2.4) | < 0.8 | 4.2 (0.5) | 1.8 | 3.8 (2.1) | 5.5 | 0.4 (0.4) | 1.1 |
| Enterobacterales (VRBD) | 5.1 (1.1) | 2.1 (2.1) | < 0.7 | < 0.7 | 0.9 (0.2) | < 0.8 | < 0.7 | 0.8 | 2.3 (1.5) | 3.8 | < dl | < dl |
| Pseudomonas spp. (CFC) | 2.8 (1.5) | < 0.6 | < 0.7 | < 0.7 | < 0.7 | < 0.8 | < 0.7 | < 0.8 | 1.6 (1.5) | 2.4 | < dl | < dl |
| Staphylococcus spp. (BP) | 3.0 (0.7) | < 0.6 | 1.2 (0.5) | < 0.7 | < 0.7 | < 0.8 | 2.3 (1.4) | < 0.8 | 1.3 (0.8) | < 0.5 | < dl | < dl |
| Lactic acid bacteria (MRS) | 0.9 (0.5) | nd | 1.7 (1.0) | nd | 1.9 (1.7) | nd | 3.3 (0.6) | nd | 1.8 (1.6) | nd | < dl | < dl |
Bacterial counts are given as mean log10 cfu/cm2 calculated from the indicated number of parallels (n) achieved by pooling of the samples. The standard deviation is given in brackets. nd: not determined; < dl: lower than the detection limit of 1 cfu/18.8 cm2; TSA: trypticase soy agar; VRBD: violet red bile glucose agar; CFC: cetrimide agar; BP: baird parker agar; MRS: de Man, Rogosa, and Sharpe agar.