The region involved in export of the capsule polysaccharides to the cell surface of Haemophilus paragallinarum was cloned and the genetic organisation determined. Degenerate primers designed from sequence alignment of the capsule transport genes of Haemophilus influenzae, Pasteurella multocida and Actinobacillus pleuropneumoniae were used to amplify a 2.6 kb fragment containing a segment of the...

The full sequence of plasmid p250, isolated from Haemophilus paragallinarum strain HP250, has been obtained. The plasmid contains seven ORFs: a putative integrase, a putative replication protein (repB) and five ORFs similar to those from the haemocin (bacteriocin) hmcDCBAI operon from Haemophilus influenzae. Of 19 other non-plasmid-containing H. paragallinarum strains screened (11 serovar refer...

A NAD-dependent isolate 46 (C-3) of Haemophilus paragallinarum, which was previously demonstrated to be of high virulence, was transformed to NAD independence using a plasmid isolated from a naturally occurring NAD-independent isolate of H. paragallinarum. The transformation was performed by two different methods and the identity of all of the isolates, before and after transformation was confi...

Atypical Haemophilus paragallinarum have been isolated from both laying hens and broilers suffering from typical symptoms of infectious coryza in South Africa. Re-inoculation of these bacteria into SPF chickens resulted in similar pathology. The bacteria could be successfully re-isolated from the experimentally infected chickens. Four of the isolates from layers and 3 of those from broilers wer...