Immunogenicity and protection against Haemophilus parasuis infection after vaccination with recombinant virulence associated trimeric autotransporters (VtaA).

Haemophilus parasuis is the etiological agent of Glässer's disease in swine, characterized by fibrinous polyserositis, polyarthritis and meningitis. The lack of a vaccine against a broad spectrum of strains has limited the control of the disease. Recently, virulence associated trimeric autotransporters (VtaA) were described as antigenic proteins of H.

Identification of potentially virulent strains of Haemophilus parasuis using a multiplex PCR for virulence-associated autotransporters (vtaA).

Haemophilus parasuis is the aetiological agent of Glässer's disease and is also a commensal of the upper respiratory tract of pigs. Trimeric autotransporter (vtaA) genes have been identified in H. parasuis and divided into three groups on the basis of the translocator domain sequence.

Comparison of muscle fluid and serum for detection of antibodies against hepatitis E virus in slaughter pigs.

Muscle fluid was investigated as an alternative to serum for detecting anti-hepatitis E virus (HEV) antibodies in slaughter pigs. Samples of serum and diaphragmatic muscle juice from 67 pigs were analysed by anti-HEV IgG ELISA. Compared to the serum ELISA, the ELISA on diaphragmatic muscle fluid had a sensitivity of 93%, a specificity of 91.

Longitudinal study of hepatitis E virus infection in Spanish farrow-to-finish swine herds.

Hepatitis E is a zoonotic disease and is highly prevalent in European swine livestock. There is a need to compare the infection dynamics of hepatitis E virus (HEV) between herds with the same production system and determine the percentage of animals that could arrive infected at slaughter age. Therefore, a longitudinal study was performed in six Spanish farrow-to-finish affected farms.

Experimental infection with H1N1 European swine influenza virus protects pigs from an infection with the 2009 pandemic H1N1 human influenza virus.

The recent pandemic caused by human influenza virus A(H1N1) 2009 contains ancestral gene segments from North American and Eurasian swine lineages as well as from avian and human influenza lineages. The emergence of this A(H1N1) 2009 poses a potential global threat for human health and the fact that it can infect other species, like pigs, favours a possible encounter with other influenza viruses circulating in swine herds. In Europe, H1N1, H1N2 and H3N2 subtypes of swine influenza virus currently have a high prevalence in commercial farms.

Virulence-associated trimeric autotransporters of Haemophilus parasuis are antigenic proteins expressed in vivo.

Glässer's disease is a re-emerging swine disease characterized by a severe septicaemia. Vaccination has been widely used to control the disease, although there is a lack of extended cross-protection. Trimeric autotransporters, a family of surface exposed proteins implicated in host-pathogen interactions, are good vaccine candidates.

Pigs orally inoculated with swine hepatitis E virus are able to infect contact sentinels.

The purpose of the present study was to explore the most likely natural route of infection of swine hepatitis E virus (HEV) by oral inoculation of pigs and to investigate the potential infection by direct contact exposure. A preliminary experiment was performed to assess the infectiousness of the bile used as source of virus. Once confirmed, 16 pigs were inoculated via oral drop with an HEV positive bile suspension containing 2x10(5) genome equivalents per pig.

Anti-HEV antibodies in domestic animal species and rodents from Spain using a genotype 3-based ELISA.

A truncated ORF2 capsid HEV antigen derived from a genotype 3 strain was developed in insect cells and insect larvae, and compared with the Sar55 antigen and a commercial ELISA. The antigen expressed in insect cells showed a better correlation with Sar55 (kappa value (k)=0.84) than the insect larvae antigen (k=0.

Trimeric autotransporters of Haemophilus parasuis: generation of an extensive passenger domain repertoire specific for pathogenic strains.

Haemophilus parasuis is the agent responsible for causing Glässer's disease, but little is known about the pathogenic determinants of this major pig disease. Here we describe, for the pathogenic strain Nagasaki, the molecular characterization of 13 trimeric autotransporters as assessed by the presence of YadA C-terminal translocator domains which were classified into three groups. All passenger domains possess motifs and repeats characteristic of adhesins, hemagglutinins, and invasins with various centrally located copies of collagen-like repeats.

Retrospective serological study on hepatitis E infection in pigs from 1985 to 1997 in Spain.

The objective of the present work was to ascertain the date in which hepatitis E virus (HEV) was introduced in the Spanish pig population. For this, a serological retrospective study was carried out using archived sera. A total of 2871 serum samples gathered between 1985 and 1997 and collected in 208 farms of Spain were tested for anti-HEV IgG by an in-house ELISA.

Genetic characterization of the complete coding regions of genotype 3 hepatitis E virus isolated from Spanish swine herds.

The complete coding regions of five hepatitis E virus isolates of swine origin from two different pig farms and the complete genome sequence of two of these strains were obtained and compared to other full length or partial HEV sequences. Based on the nucleotide sequence, the examined Spanish isolates were 87.1-99.

Hepatitis E virus infection dynamics and organic distribution in naturally infected pigs in a farrow-to-finish farm.

The objective of the present study was to determine the pattern of Hepatitis E virus (HEV) infection in a naturally infected, farrow-to-finish herd. For that purpose, a prospective study was conducted in randomly selected 19 sows and 45 piglets. Blood samples were collected from sows at 1 week post-farrowing and from piglets at 1, 3, 6, 9, 12, 15, 18 and 22 weeks of age.

Epidemiological study of hepatitis E virus infection in European wild boars (Sus scrofa) in Spain.

Evidence of hepatitis E virus (HEV) infection in Spanish domestic pig has been reported and hence it was advisable to search for this zoonotic pathogen in wild boar populations. A total of 150 wild boar serum samples from eight geographic areas from South-Central Spain were used to investigate HEV infection in European wild boar (Sus scrofa) by means of serology and PCR and its distribution by age, region and management system. Anti-HEV IgG, IgM and IgA were determined by an in-house ELISA.

Detection of hepatitis E virus in liver, mesenteric lymph node, serum, bile and faeces of naturally infected pigs affected by different pathological conditions.

The objective of the present study was to detect hepatitis E virus (HEV) in different samples from naturally infected pigs and to characterise genetically the detected strains. Serum, bile, liver, lymph nodes and faeces of 69 animals from 1 week to 4 months of age with different pathological conditions were collected. Reverse transcriptase-polymerase chain reaction (RT-PCR) to detect HEV and histopathology of tissues was conducted.

Hepatitis E virus epidemiology in industrialized countries.

To determine the prevalence of Hepatitis E virus (HEV) in industrialized nations, we analyzed the excretion of HEV strains by the populations of Spain, France, Greece, Sweden, and the United States. Twenty of 46 (43.5%) urban sewage samples collected in Barcelona from 1994 to 2002 tested positive for HEV.

Genetic analysis of hepatitis A virus strains recovered from the environment and from patients with acute hepatitis.

The molecular epidemiology of hepatitis A virus (HAV) was studied by analysing HAV strains recovered from environmental water samples over a 7 year period and strains recovered from patients with acute hepatitis over a 5 year period. A total of 54 samples of raw domestic sewage and 66 samples of river water were collected. HAV particles were concentrated and detected by nested RT-PCR.