The forestomachs of 722 cows, over 2 years oid, from 628 farms in the 4 provinces of Galicia (Coruña, Lugo, Ourense and Pontevedra), NW Spain, were colleeted from slaughterhouses. All the rumens and reticula were examined to detect and count the Paramphistomidae. To determine the parasite intraorganic distribution, 31 animals were chosen randomly and the parasites found in the different anatomical areas of the rumen (ruminal atrium, rumenoreticular sulcus, ventral sae, dorsal sac) and in the reticulum were counted and measured. Fifty parasites were coliected from each infected animal. The specific identification was done morphologically and by ITS2 (Internal Transcribed Spacer 2) sequencing. The infection prevalence was 17.3% and the parasite loads varied between 1- 21200 ( Mean = 1293 ± 2780 SD). Significant differences were observed between the infection prevalences in the four provinces, the highest being in Pontevedra (27.6%). Most parasites were located in the rumen (94.3%), with the percentages found in the atrium (58.2%) and in the rumenoreticular sulcus (26.5%) significantly higher than those found in the dorsal and ventral sacs. Statistically significant differences were also recorded in parasite size. In order to study the genetic variability of Calicophoron daubneyi a 401 bp fragment of the ribosomal RNA internal transcribed spacer 2 (ITS2) was sequenced. Firstly, we analysed the intraindividual variability after sequencing a total of 10 C. daubneyi recovered from two cows. No difference was shown in the ITS2 sequence between the adults taken from different parts of the rumen (ruminal atrium, rumenoreticular sulcus, ventral sac, dorsal sac) and reticulum , in the same eow. Secondly, the interindividual variability was also tested in 21 samples obtained in the four provinces of Galicia (Spain). All sequences were also similar between C. daubneyi adults from different origins.

1 página.-- Trabajo presentado al XII International Congress of Parasitology (Melbourne, Victoria, Australia, 15-20 August, 2010)

Stydy supported by Spanish INIA, Project FAU2006-00021-C03-00

Peer reviewed