The hepatitis E virus (HEV) is a leading causative agent of acute hepatitis in humans. Zoonotic HEV strains have been isolated from several animal species, including pigs. New HEV variants have been recently isolated from camels in the Middle East. In the present study, fecal samples from fallow deer, formosan deer, alpaca, and guanaco were analyzed for the detection of HEV. One HEV strain was detected from guanaco, a species of camelids. The nucleotide sequence of guanaco HEV was identical to those of deer HEV-3 strains, which implied the cross-species transmission of HEV-3 from deer to guanaco.

Human hepatitis B virus (HBV) infection remains a serious public health problem worldwide, as it is one of the main risk factors for hepatocellular carcinoma (HCC). Cross-species transmission of HBV has been reported in non-human primates, and pigs may also be infected with HBV or an HBV-like agent. The purpose of this study was to demonstrate the presence of HBV antigens and anti-HBV antibodies in pig sera, providing further support for the existence of HBV or an HBV-like agent in pig populations. The HBV surface antigen (HBsAg) and HBV e antigen (HBeAg) in pig serum samples were detected using HBsAg and HBeAg ELISA Kits, respectively. Antibodies to HBsAg and the Hepatitis B core antigen (HBcAg) in serum samples were also detected using anti-HBsAg and anti-HBcAg antibody ELISA Kits, respectively. HBsAg and HBeAg were detected in 7 of 442 (1.6%) and 7 of 184 (3.8%) pig serum samples, respectively. Furthermore, antibodies specific to HBsAg and HBcAg were identified in 45 of 442 (10.2%) and 39 of 434 (9.0%) pig serum samples, respectively. However, neither HBV DNA nor antibodies to HBeAg were detected in 409 and 298 pig serum samples, respectively. HBV antigens and anti-HBV antibodies were both present in a considerable number of pig serum samples, suggesting that pigs could be infected with a variant HBV or an HBV-like agent. Further studies will be necessary to confirm cross-species infection of pigs with HBV.

Salmonella species is one of the major bacterial agents that causes gastrointestinal disease in pigs. Natural antimicrobials derived from plants may be alternative therapeutics that could replace currently used antibiotics in the control of infectious disease. In this study, we assessed the antibacterial activity of Oenothera biennis L. extract against Salmonella Typhimurium both in vitro and in vivo. O. biennis L. extract had a strong inhibitory effect on S. Typhimurium in vitro, reducing bacterial growth by 87%. For the in vivo experiment, 16 post-weaned pigs were divided into 4 groups consisting of 4 pigs each: an uninfected, untreated negative control group; an untreated positive control group that was infected with S. Typhimurium; and two groups that were infected with S. Typhimurium and treated with either 0.1% or 0.5% O. biennis L. extract. Pigs were followed for 21 days after infection, and their body weight, daily gains, feed conversion ratio (FCR), and feed efficiency (FE) were monitored. The pigs treated with O. biennis L. extract had significantly higher daily gains than the positive control group (p<0.05). The O. biennis L. extract-treated pigs also exhibited better weight gain and FE, as well as a lower FCR and less severe diarrhea, than the positive controls but these results were not statistically significant. Our study demonstrates that O. biennis L. extract has antibacterial effects against S. Typhimurium, both in vitro and in vivo, and that these antibacterial effects may produce better growth performance in pigs infected with S. Typhimurium.

Matrix 2 protein ectodomain (M2e) of influenza virus appears to be a promising vaccine candidate because its sequence is highly conserved among virus strains. However, M2e is too meager to induce a strong immune response by itself. Several approaches are being used to increase the antigenicity of M2e. In an effort to enhance the M2e-specific immune response, we generated a TAT-conjugated M2e recombinant protein. Seven-week-old BALB/c mice were divided into three groups and transcutaneously immunized with 100 μg TAT-8×M2e (TAT conjugated with eight copies of M2e) and 8×M2e (eight copies of M2e) proteins on days 1, 15 and 29. The control mice were injected with PBS on the same days. Antibody titers specific for M2e were measured using indirect ELISA. Mice immunized with the TAT-8×M2e and 8×M2e proteins developed almost the same levels of M2e-specific total IgG and IgG1 antibodies. However, a higher level of M2e-specific IgG2a was observed in mice immunized with TAT-8×M2e than in those immunized with 8×M2e. These results suggest that TAT has an adjuvant effect that induces a Th1-type immune response. Therefore, the TAT-M2e vaccine can be applied to animals as a new influenza vaccine for enhancement of Th1-type immune responses.