The objective of the study was to identify risk factors for reintroduction of Actinobacillus pleuopneumoniae and Mycoplasma hyopneumoniae (enzootic pneumonia) onto pig farms in areas in Switzerland that were involved in an eradication programme from 1996 to 1999 and to assess the role of dealers in relation to these reinfections. The study was based on the comparison of pig farms that were rein...

BACKGROUND Bacterial lung infections are a major cause of economic losses in the pig industry; they are responsible for approximately 50% of the antibiotics used in pigs and, therefore, also present an increasing concern to consumer protection agencies. In response to this changing market we investigated the feasibility of an old approach aimed at the breeding selection of more resistant pigs. ...

Infectious epididymitis is considered a major cause of economic losses for the sheep industry worldwide. This study aimed to investigate clinical and pathological changes associated with experimental infections with A. seminis and H. somni in rams. Twenty rams of age 18 to 24 months were infected by intraepididymal inoculation of A. seminis (n = 10) and H. somni (n = 10). Rams were weekly exami...

We have investigated the use of a natural transformation protocol to introduce mutations into Actinobacillus pleuropneumoniae serotypes 1 and 5b. For both strains tested, we recovered 1 in 10(8) transformants during culture in rich medium, a result that was independent of the growth phase. This low frequency of transformation of A. pleuropneumoniae did not increase when bacteria were grown unde...

We have identified a highly transformable strain of Actinobacillus pleuropneumoniae whose competence is regulated by the competence-activator Sxy as in other Pasteurellaceae. Other strains were poorly transformable or nontransformable. The genomes of two poorly transformable strains contain intact sets of competence genes. Moreover, we show that the low competence of one of these strains is not...

Molecular Infectious Diseases Groupf Department of Paediatrics, Imperial College of Science, Technology and Medicine, S t Mary's Hospital, London Copperand zinc-containing superoxide dismutases ([Cu,Zn]-SODS) are generally considered almost exclusively eukaryotic enzymes, protecting the cytosol and extracellular compartments of higher organisms from damage by oxygen free-radicals. The recent de...

Serotyping of Actinobacillus pleuropneumoniae, the etiologic agent of porcine pleuropneumonia, is important for epidemiological studies and for the development of homologous vaccine cell preparations. The serology is based on the specific chemical structures of capsular polysaccharides (CPSs) and lipopolysaccharide (LPS) antigenic O-polysaccharide moieties (O-PSs), and knowledge of these struct...

The gene (aroA) of Actinobacillus pleuropneumoniae, serotype 2, encoding 5-enolpyruvylshikimate-3-phosphate synthase was cloned by complementation of the aroA mutation in Escherichia coli K-12 strain AB2829, and the nucleotide sequence was determined. A pair of primers from the 5' and 3' termini were selected to be the basis for development of a specific PCR assay. A DNA fragment of 1,025 bp wa...

A case of infective endocarditis in a 59-year-old female caused by Actinobacillus actinomycetemcomitans is reported. The organism was recovered from 9 blood cultures. Despite treatment with penicillin and gentamicin the illness led to destruction of the aortic valve.