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

Abstract

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.

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

“…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.…”

“…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).…”

Pharmacokinetics of Tylvalosin Alone or in Combination with Vitamin E in Broiler Chickens

“…(firstly tested dose 2 h before starting TVN administration) then tylvalosin 25 mg kgG 1 b.wt., had been given later (Forrester et al, 2011), as a single oral dose (intra-crop route). Blood samples (1 mL each) were collected from wing vein just Asian J.…”

“…Single dose study: Twelve apparently healthy broiler chickens were divided into 2 groups, the first group administered tylvalosin 25 mg kgG 1 b.wt., (Forrester et al, 2011), as a single oral dose and the second group were given vit E (2 mg kgG 1 b.wt.) (firstly tested dose 2 h before starting TVN administration) then tylvalosin 25 mg kgG 1 b.wt., had been given later (Forrester et al, 2011), as a single oral dose (intra-crop route).…”

“…Adv., 10 (10): 556-566, 2015 Acetylisovaleryltylosin tartrate (aivlosin) is an antimicrobial of the macrolide group with antibacterial activity against Gram positive, some Gram negative organisms and mycoplasma and this drug used extensively in Latin America for treating mycoplasmosis, there are few publications describing its pharmacokinetics (Cerda et al, 2010). Tylvalosin antibiotic commonly used in poultry farms for the treatment of respiratory infections specially treatment of mycoplasmosis at the recommended dose 25 mg kgG 1 for 3 days (Forrester et al, 2011) so studying its pharmacokinetics after oral administration in broiler chickens very important after single and repeated dosing alone or pre-treated with vit E.…”