Swine influenza A viruses (swIAVs) can play a crucial role in the generation of new human pandemic viruses. In this study, in-depth passive surveillance comprising nearly 2,500 European swine holdings and more than 18,000 individual samples identified a year-round presence of up to four major swIAV lineages on more than 50% of farms surveilled. Phylogenetic analyses show that intensive reassortment with human pandemic A(H1N1)/2009 (H1pdm) virus produced an expanding and novel repertoire of at least 31 distinct swIAV genotypes and 12 distinct hemagglutinin/neuraminidase combinations with largely unknown consequences for virulence and host tropism. Several viral isolates were resistant to the human antiviral MxA protein, a prerequisite for zoonotic transmission and stable introduction into human populations. A pronounced antigenic variation was noted in swIAV, and several H1pdm lineages antigenically distinct from current seasonal human H1pdm co-circulate in swine. Thus, European swine populations represent reservoirs for emerging IAV strains with zoonotic and, possibly, pre-pandemic potential. ll Resource

The emergence of the human 2009 pandemic H1N1 (H1N1pdm) virus from swine populations refocused public and scientific attention on swine as an important source of influenza A viruses bearing zoonotic potential. Widespread and year-round circulation of at least four stable lineages of porcine influenza viruses between 2009 and 2012 in a region of Germany with a high-density swine population is documented here. European avian influenza virus-derived H1N1 (H1N1av) viruses dominated the epidemiology, followed by human-derived subtypes H1N2 and H3N2. H1N1pdm viruses and, in particular, recently emerging reassortants between H1N1pdm and porcine HxN2 viruses (H1pdmN2) were detected in about 8% of cases. Further reassortants between these main lineages were diagnosed sporadically. Ongoing diversification both at the phylogenetic and at the antigenic level was evident for the H1N1av lineage and for some of its reassortants. The H1avN2 reassortant R1931/11 displayed conspicuously distinct genetic and antigenic features and was easily transmitted from pig to pig in an experimental infection. Continuing diverging evolution was also observed in the H1pdmN2 lineage. These viruses carry seven genome segments of the H1N1pdm virus, including a hemagglutinin gene that encodes a markedly antigenically altered protein. The zoonotic potential of this lineage remains to be determined. The results highlight the relevance of surveillance and control of porcine influenza virus infections. This is important for the health status of swine herds. In addition, a more exhaustive tracing of the formation, transmission, and spread of new reassortant influenza A viruses with unknown zoonotic potential is urgently required.

Torque teno virus: Determination of viral genomic loads by genogroup-specific multiplex rt-PCR, detection of frequent multiple infections with genogroups 1 or 2, and establishment of viral full-length sequences. Veterinary Microbiology, Elsevier, 2009, 143 (2-4) This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.Page 1

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Porcine reproductive and respiratory syndrome (PRRS) is one of the economically most important diseases of swine. Viraemia and the prolonged persistence of the virus are among the most critical factors. Virus replication and severity of disease vary with virus isolates, and there is rising evidence for a genetic component of the host susceptibility. Dissecting the genetic basis of resistance/susceptibility to PRRS virus (PRRSV) might lead to improved knowledge on the molecular mechanisms of PRRS and the establishment of genetic markers for future disease control. The aim of this study was to establish a porcine model with emphasized genetic differences in PRRSV susceptibility. Seven 'Wiesenauer Miniature' pigs (MI), a local German breed and eight commercial Pietrain (PI) pigs were challenged with 10(5) TCID(50) of an attenuated PRRSV strain (Ingelvac PRRSV MLV). Clinical status, viraemia and seroconversion of the pigs were compared. No clinical signs were observed during the experiment. Viraemia peaked on day 6 p.i., with 100% of viraemic pigs in PI and on day 12 p.i with 87% of viraemic MI. Viraemia lasted for up to 35 days in MI and for at least 72 days in PI. This surprising result was confirmed by a second study with another four MI. MI and PI showed maximum virus titres of 10(2.5) TCID(50)/ml of serum and 10(4.5) TCID(50)/ml, respectively, indicating a virus replication in MI of approximately 3.3% that of PI over the complete period. MI were more efficient in antibody production. With such pronounced breed differences, the model is of high relevance for the genetic dissection of PRRS pathogenesis and susceptibility.