2.11. Coliform counts in faecal sam

2.11. Coliform counts in faecal samples
Coliform counts were determined in the faecal samples, which were taken directly from
the rectum of each animal with a sterile cotton swab (Collection swab; EUROTUBO,
Madrid, Spain). Three replicates of faecal samples of each piglet were taken simultaneously.
The cotton swabs were weighed before and after taking the faecal samples to determine
the net weights of the samples. To be consistent, the weight of each faecal sample was
multiplied by nine to determine the amount of sterile PBS to be added to each tube to
yield a 101 dilution. The cotton swabs were shaken vigorously and then vortexed for 2 min.
Ten-fold serial dilutions in sterile PBS were performed up to 1010 and aliquots (0.1 mL)
of 10-fold serial dilutions were pour plated with eosin methylene blue agar (EMB, Levine
Formulation). The plates were inverted and incubated at 37±1 ◦C for 1–2 days. Incubated
plates were observed for the optimum number of CFU, between 30 and 300 colonies per
plate. The results were expressed as the number of colonies counted per gram (wet weight)
of faeces (Tortuero et al., 1995).
All media or supplements (Nutrient broth,MRSagar and Rothe agar, methylene blue agar,
glycerol, yeast extract) were obtained from Cultimed Panreac Qu´ımica S.A., Barcelona,
Spain