Demonstration ofOrnithobacterium rhinotrachealein pheasants (Phasianus colchicus) with pneumonia and airsacculitis

Abstract

Outbreaks of respiratory disease were investigated in reared pheasants (Phasianus colchicus) aged approximately 18 to 32 weeks, released into the semi-wild on four shooting estates in southern England. The clinical signs in the affected birds included swelling of the face and eyes, loss of condition, gasping respirations and coughing. The gross pathology findings included sinusitis, airsacculitis, pleural oedema and lung lesions. The histopathological findings in the affected lungs were characterized by a granulomatous pneumonia. Ornithobacterium rhinotracheale (ORT) was isolated from respiratory tract tissues, and 16S rRNA gene sequencing on three isolates revealed two distinct genotypes, one previously associated with some electrophoretic type (ET) 1 strains and the other a novel genotype that clustered among sequences previously associated with ET 3, ET 4, ET 5 and ET 6 isolates. The localization of ORT within the lung tissue was demonstrated by fluorescent in-situ hybridization in the bronchial exudate of three cases, although not within the granulomatous lesions themselves. In each case, ORT was identified as part of a complex of other respiratory agents including avian paramyxovirus type 2, avian coronavirus, Mycoplasma gallisepticum, Mycoplasma synoviae and other Mycoplasma species, Escherichia coli, Pasteurella multocida, other Pasteurellaceae and Syngamus trachea, suggesting synergism with other agents. Exposure to other intercurrent factors, including adverse weather conditions and internal parasitism, may also have exacerbated the severity of disease.

Effect of experimental Ornithobacterium rhinotracheale infection along with live infectious bronchitis vaccination in broiler chickens

“…Frequent isolation of ORT from various organs indicated that the isolates were commonly recovered from lungs, air sac, and trachea. This was in agreement with van Empel and Hafez (1999) and Welchman et al (2013) who recorded that the air sacs and lungs were the organs with highest isolation rate of ORT.…”

“…In pheasants, Welchman et al (2013) identified ORT as a part of a complex of other respiratory agents that included: avian paramyxovirus type 2, avian coronavirus, Mycoplasma species, Escherichia coli, Pasteurella species, and Syngamus trachea, suggesting synergism with these agents. This was the cause of granulomatous pneumonia and fibrinous air sacculitis that lead to severe respiratory distress.…”

Comparative pathomorphological, bacteriological and serological examination of broiler breeders and pheasants experimentally infected withOrnithobacterium rhinotracheale

“…In field conditions, ORT has been isolated in pheasants which exhibited respiratory signs as part of a complex of other respiratory agents including avian paramyxovirus type 2, avian coronavirus, Mycoplasma spp., Escherichia coli, Pasteurella multocida, other Pasteurellaceae and Syngamus trachea suggesting synergism with other agents (Welchman et al, 2013). Although ORT was maximally favoured in relation to the host in our investigations, the intensity of pathomorphological changes in pheasants was lower compared with those described in natural infection by Welchman et al (2013), probably because they have been aggravated by the other agents. The pathomorphological changes in those naturally infected pheasants, unlike in the present experiment, were characterized by caseous sinusitis and caseous airsacculitis.…”

“…ORT was isolated from pheasants (Charlton et al, 1993;Welchman et al, 2002) but its role in respiratory disease of this bird species has not been clarified. Welchman et al (2013) later demonstrated ORT in pheasants with pneumonia and airsacculitis within the lung tissue by fluorescent in situ hybridization as part of a complex of other respiratory agents.…”

Molecular Characterization of the Recently Emerged Poultry Pathogen Ornithobacterium rhinotracheale by Multilocus Sequence Typing

“…ORT is an emerging bacterial pathogen of global concern in poultry production and has already been isolated in the USA, Brazil, France, the Netherlands, Germany, South Africa, Israel, Japan, Taiwan and even more countries [ 7 – 10 ]. A wide variety of birds including economically important poultry species as well as wild birds like pigeons, pheasants, partridges, falcons and rooks [ 1 , 7 , 11 , 12 ] are susceptible to ORT infection or have been found to carry ORT.…”