title: Distribution pattern of bovine viral diarrhoea virus strains in intensive cattle herds in Italy.
abstract: The genetic variation of bovine viral diarrhoea virus (BVDV) was studied by comparative nucleotide sequence analysis of 26 Italian field strains collected during the period 1995-2000 in 18 cattle herds. A fragment within the 5'-untranslated region (UTR) was sequenced directly from gel-purified products obtained by reverse transcription polymerase chain reaction. BVDV-1b (n=14), -1c (n=1), -1d (n=1) and BVDV-2 (n=2) strains have been isolated. Most herds were infected by BVDV-1b. Pairwise similarity and cluster analysis of the remaining BVDV-1 isolates (n=8) did not provide a clear-cut assignation to defined BVDV-1 groups. This is the first time that a BVDV-2 isolation was reported in Italy. Among BVDV-2 reference strains, Italian BVDV-2 isolates showed the highest sequence similarity with the CD87 strain. Both BVDV-2 strains were isolated in two healthy animals from different herds. The 5'-UTR sequence of one of the two BVDV-2 strains was identical to a German BVDV field strain. Complete nucleotide homology was found only among BVDV strains isolated from the same herd, showing a herd-specific clustering. Moreover, 99.6% homology was observed between strains from herds linked by livestock trade. Despite the small number of BVDV isolates analysed, it revealed a high level of genetic diversity among Italian field BVDV strains.
authors.affiliation: Department of Animal Pathology, Hygiene and Public Health, Faculty of Veterinary Medicine, University of Milan, Via Celoria 10, 20133, Milano, Italy. camilla.luzzago@unimi.it
authors.forename: C
authors.initials: C
authors.lastname: Luzzago
authors.forename: C
authors.initials: C
authors.lastname: Bandi
authors.forename: V
authors.initials: V
authors.lastname: Bronzo
authors.forename: G
authors.initials: G
authors.lastname: Ruffo
authors.forename: A
authors.initials: A
authors.lastname: Zecconi
mesh_terms: D020121:5' Untranslated Regions / Q000737:chemistry / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000453:epidemiology* / Q000821:virology; D002417:Cattle; D016000:Cluster Analysis; D018076:DNA, Complementary / Q000737:chemistry; D030241:Diarrhea Virus 1, Bovine Viral / Q000145:classification / Q000235:genetics; D030242:Diarrhea Virus 2, Bovine Viral / Q000145:classification / Q000235:genetics; D001908:Diarrhea Viruses, Bovine Viral / Q000145:classification* / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype; D007558:Italy / Q000453:epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012689:Sequence Homology, Nucleic Acid
chemical_list: D020121:5' Untranslated Regions; D018076:DNA, Complementary