title: Novel swine influenza virus subtype H3N1 in Italy.
abstract: To date, three subtypes of swine influenza viruses, H1N1, H1N2, and H3N2 have been isolated in Italy. In 2006, a novel swine influenza virus subtype (H3N1) was isolated from coughing pigs. RT-PCR performed on lung tissues, experimental infection in pigs with the novel isolate, and cloning the virus by plaque assay confirmed this unique H and N combination. The novel isolate was also antigenically and genetically characterized. Genetic and phylogenetic analysis showed that the complete HA gene of the H3N1 strain has the highest nucleotide identity to three Italian H3N2 strains, one isolated in 2001 and two in 2004, whereas the full length NA sequence is closely related to three H1N1 subtype viruses isolated in Italy in 2004. The remaining genes are also closely related to respective genes found in H1N1 and H3N2 SIVs currently circulating in Italy. This suggests that the novel SIV could be a reassortant between the H3N2 and H1N1 SIVs circulating in Italy.
authors.affiliation: Department of Animal Health, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Brescia, Italy. anamaria.morenomartin@bs.izs.it
authors.forename: Ana
authors.initials: A
authors.lastname: Moreno
authors.forename: Ilaria
authors.initials: I
authors.lastname: Barbieri
authors.forename: Enrica
authors.initials: E
authors.lastname: Sozzi
authors.forename: Andrea
authors.initials: A
authors.lastname: Luppi
authors.forename: Davide
authors.initials: D
authors.lastname: Lelli
authors.forename: Guerino
authors.initials: G
authors.lastname: Lombardi
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Zanoni
authors.forename: Paolo
authors.initials: P
authors.lastname: Cordioli
mesh_terms: D000818:Animals; D002460:Cell Line; D004285:Dogs; D009980:Influenza A virus / Q000145:classification* / Q000302:isolation & purification*; D007558:Italy / Q000453:epidemiology; D009976:Orthomyxoviridae Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D010802:Phylogeny; D013047:Specific Pathogen-Free Organisms; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000821:virology*