Mycoplasmas and respiratory disease in pheasants and partridges

Bradbury, Janet M.; Yavari, Christine A.; Dare, C. M.

doi:10.1080/03079450120066395

Cited by 41 publications

(54 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Respiratory disease in pheasants remains predominantly associated with M. gallisepticum, aMPV, coronaviruses and syngamosis (Bradbury et al, 2001b;Cavanagh et al, 2002;Welchman et al, 2002;Forrester et al, 2011). In the birds described in the present case series, there was evidence of infection with all of these agents with the possible exception of aMPV, which was only demonstrated serologically in one bird.…”

Section: Discussionmentioning

confidence: 71%

“…Several infectious agents have been implicated in the aetiology, either singly or in combination with other agents or other factors. Mycoplasma gallisepticum has been identified as one of the most important infectious agents in respiratory disease, as a primary cause of infectious sinusitis and conjunctivitis (Keymer, 1961;Bradbury et al, 2001b;Forrester et al, 2011), but is not usually implicated in disease of the lungs and air sacs in pheasants Bencina et al, 2003). Other infectious agents including avian metapneumovirus (aMPV) and coronaviruses related to infectious bronchitis virus of chickens have also been associated with both upper and lower respiratory tract disease in pheasants, either in their own right or concurrently with other infectious agents such as M. gallisepticum and Pasteurella multocida Welchman et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

et al. 2013

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionmentioning

confidence: 71%

Section: Introductionmentioning

confidence: 99%

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

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Recent investigations of field outbreaks of upper respiratory disease in UK pheasants and partridges have indicated that Mycoplasma gallisepticum is frequently involved (Bradbury et al, 2001;Welchman et al, 2002). M. gallisepticum causes an economically important respiratory disease in chickens and turkeys, resulting in mild to severe disease signs and has been implicated as a primary pathogen for Chukar and red-legged partridges (Jordan, 1996;McMartin et al, 1996;Ganapathy & Bradbury, 1998).…”

Section: Introductionmentioning

confidence: 98%

Mycoplasma gallisepticumin pheasants and the efficacy of tylvalosin to treat the disease

et al. 2011

Self Cite

View full text Add to dashboard Cite

Infectious sinusitis, a common condition seen in adult pheasants, is primarily caused by Mycoplasma gallisepticum. The aims of the present study were to investigate the pathogenicity of M. gallisepticum in 14-day-old pheasants and evaluate the macrolide antibiotic tylvalosin (TVN) as a treatment for infectious sinusitis. The minimum inhibitory concentration of TVN for five isolates of M. gallisepticum taken from pheasants confirmed their susceptibility to TVN (range: 0.002 to 0.008 µg/ml). One of the isolates (G87/02) was inoculated intranasally into 72 pheasants (two groups of 36) at 14 days of age. Eight days later, when 18/72 (25%) of the pheasants showed clinical signs, one group was treated with 25 mg TVN/kg bodyweight daily in drinking water for three consecutive days. An uninfected, unmedicated control group (n=12) was also included. In contrast to the uninfected control group, a range of clinical signs typical of infectious sinusitis with varying severity was observed in challenged birds and M. gallisepticum was re-isolated from the infraorbital sinus and the eye/conjunctiva at necropsy, 22 days post challenge. In comparison with untreated birds, medication with TVN significantly reduced clinical signs and the re-isolation/detection of M. gallisepticum (P≤0.0021). The daily liveweight gain of treated birds was significantly increased in comparison with untreated birds (P=0.0002), and similar to daily liveweight gains observed in the uninfected control group. In conclusion, TVN at 25 mg/kg bodyweight daily for three consecutive days in drinking water was efficacious in the treatment of M. gallisepticum infection induced by challenging 14-day-old pheasants.

show abstract

“…In the UK we have examined pheasants and partridges involved in incidents of respiratory disease for both M. gallisepticum and M. synoviae by culture and PCR and have found the former in approximately one-third of pheasant incidents and two-thirds of partridge incidents (Bradbury et al, 2001a). M. synoviae did not appear to be involved in respiratory disease although it has been isolated very occasionally from clinically normal pheasants (Bradbury et al, 2001b).…”

Section: Transmission To New Hostsmentioning

confidence: 97%

Poultry mycoplasmas: sophisticated pathogens in simple guise

Bradbury¹

2005

British Poultry Science

View full text Add to dashboard Cite

Mycoplasmas are a genus within the class Mollicutes (trivial name mollicutes), which are the smallest known prokaryotes capable of self-replication. They have a very small genome, and have evolved to this 'minimalist' status by losing non-essential genes, including those involved in cell wall synthesis. The mollicutes exploit their limited genetic material to the maximum and many are successful pathogens in man, animals, birds and plants. Most of those of veterinary importance are in the genus Mycoplasma and include 4 poultry pathogens of economic importance: Mycoplasma gallisepticum, Mycoplasma synoviae, Mycoplasma meleagridis and Mycoplasma iowae. The pathogenetic mechanisms of mycoplasmas are not fully understood, but they are successful pathogens because they can enter the host and multiply, evade the defence mechanisms, cause damage and escape to infect new hosts. M. gallisepticum is one of several motile species and possesses a terminal tip structure that mediates adherence to its target tissues. For some species, including M. gallisepticum, some of the organisms may become intracellular. Some Mycoplasma species, including the pathogenic poultry species, have a remarkable ability to vary their major surface antigens, a mechanism that is thought to help them to persist in their host by evading the immune response. The molecular and cellular events that lead to the development of lesions and clinical disease are still obscure. Some lesions appear to be the result of indirect damage from the host's inflammatory and cellular responses. Despite short survival times in the environment, mycoplasmas are able to transmit successfully to new hosts. In poultry flocks there is both horizontal and vertical transmission, the former being encouraged by intensive husbandry and stress factors. Establishing the pathways of transmission and the possible role of other birds, such as game and wild birds, as intermediate vectors between poultry flocks is now greatly aided by the availability of modern molecular methods for strain typing.

show abstract

Mycoplasmas and respiratory disease in pheasants and partridges

Cited by 41 publications

References 14 publications

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

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

Mycoplasma gallisepticumin pheasants and the efficacy of tylvalosin to treat the disease

Poultry mycoplasmas: sophisticated pathogens in simple guise

Contact Info

Product

Resources

About