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Streptococcus suis has been well-recognized as a zoonotic pathogen worldwide, and the diversity and unpredictable adaptive potential of sporadic human strains represent a great risk to the public health. In this study, S. suis LSM178, isolated from a patient in contact with pigs and raw pork, was assessed as a hyper-virulent strain and interpreted for the virulence based on its genetic information. The strain was more invasive for Caco-2 cells than two other S. suis strains, SC19 and P1/7. Sequence analysis designated LSM178 with serotype 2 and a novel sequence type 1005. Phylogenetic analysis showed that LSM178 clustered with highly virulent strains including all human strains and epidemic strains. Compared with other strains, these S. suis have the most and the same virulent factors and a type I-89 K pathogenicity island. Further, groups of genes were identified to distinguish these highly virulent strains from other generally virulent strains, emphasizing the key roles of genes modeling transcription, cell barrier, replication, recombination and repair on virulence regulation. Additionally, LSM178 contains a novel prophage conducive potentially to pathogenicity. [ABSTRACT FROM AUTHOR]

During the surveillance of avian influenza viruses in the Dongxi Lake wetland of Hubei in 2015-2016, an H11N9 avian influenza virus was isolated from a bean goose ( Anser fabalis). Phylogenetic analysis showed that the HA gene of this isolate belongs to the North American lineage; however, the NA and the internal genes of the isolate were generated from the Eurasian lineage. This strain had reduced pathogenicity in mice and was capable of replication in the mouse lung without prior adaptation. This is the first report detecting H11N9 subtype influenza virus from migratory birds in central China. These findings highlight the transmission of avian influenza virus along the East Asian-Australian flyway and the need for continuing surveillance in central China. [ABSTRACT FROM AUTHOR]

Actinobacillus pleuropneumoniae is an important swine respiratory pathogen causing great economic losses worldwide. Identification of conserved surface antigenic proteins is helpful for developing effective vaccines. In this study, a genome-wide strategy combined with bioinformatic and experimental approaches, was applied to discover and characterize surface-associated immunogenic proteins of A. pleuropneumoniae. Thirty nine genes encoding outer membrane proteins (OMPs) and lipoproteins were identified by comparative genomics and gene expression profiling as being-highly conserved and stably transcribed in the different serotypes of A. pleuropneumoniae reference strains. Twelve of these conserved proteins were successfully expressed in Escherichia coli and their immunogenicity was estimated by homologous challenge in the mouse model, and then three of these proteins (APJL_0126, HbpA and OmpW) were further tested in the natural host (swine) by homologous and heterologous challenges. The results showed that these proteins could induce high titers of antibodies, but vaccination with each protein individually elicited low protective immunity against A. pleuropneumoniae. This study gives novel insights into immunogenicity of the conserved OMPs and lipoproteins of A. pleuropneumoniae. Although none of the surface proteins characterized in this study could individually induce effective protective immunity against A. pleuropneumoniae, they are potential candidates for subunit vaccines in combination with Apx toxins. [ABSTRACT FROM AUTHOR]